HK1118387B - Power storage system - Google Patents

Description

Electricity storage system

Technical Field

The present invention relates to an electric storage system that stores dc power and charges and discharges the dc power, and is applicable to, for example, an electric train.

Background

In recent years, it has been known that kinetic energy possessed by a vehicle can be effectively utilized by combining a drive control inverter mounted on an electric train with a power storage system using a power storage device such as a secondary battery or an electric double layer capacitor in a power supply facility installed in a ground substation or the like, storing excess regenerative power generated when the vehicle is braked in the power storage device, and using the stored power when the vehicle is accelerated or the line voltage is lowered (see, for example, patent document 1 and patent document 2)

Patent document 1: japanese laid-open patent publication No. 2003-199354

Patent document 2: japanese patent application laid-open No. 2005-206111

In actual use of the power storage system, it is important and indispensable to use the power storage system stably and safely, how to configure each unit constituting the power storage system, including the arrangement position thereof, how to operate the units in cooperation under what conditions, how to detect an abnormality when the system is abnormal, and how to operate each unit according to the detection result.

However, application development of the power storage system has just started in recent years, and patent documents 1 and 2 describe the outline of the composition and operation of the power storage system, but do not show a specific operation method, an abnormality detection method, and an operation method when an abnormality is detected when the power storage system is started, operated, or stopped.

In view of the above circumstances, an object of the present invention is to provide an electric storage system which can reliably perform start-up, operation, and stop of the electric storage system, which are important and indispensable for practical use, and which can appropriately cope with various abnormalities, and which is most suitable for use in an electric railway system or the like.

Disclosure of Invention

In the power storage system of the present invention, a dc power from a dc power supply is adjusted to a predetermined voltage and current by a DCDC converter unit and stored in a power storage unit, wherein a primary side current detection unit for detecting a current of a main circuit, a primary side voltage detection unit for detecting a voltage of the main circuit, a primary side switching unit for turning on and off the main circuit, and a primary side filter unit for suppressing harmonics of the main circuit are disposed on the dc power supply side (primary side) of the DCDC converter unit, and a secondary side filter unit for suppressing harmonics of the main circuit, a secondary side switching unit for turning on and off the main circuit, a secondary side voltage detection unit for detecting a voltage of the main circuit, and a secondary side current detection unit for detecting a current of the main circuit are disposed on the power storage unit side (secondary side) of the DCDC converter unit, and an operation command from the outside and an operation command from the primary side current detection unit are input, and the secondary side current detection unit, And a system control unit for controlling the system based on signals obtained by the primary side voltage detection unit, the primary side switch unit, the primary side filter unit, the DCDC converter unit, the secondary side filter unit, the secondary side switch unit, the secondary side voltage detection unit, the secondary side current detection unit, and the power storage unit, and controlling the on/off of at least the primary side switch unit, the DCDC converter unit, and the secondary side switch unit.

According to the present invention, it is possible to realize an electric storage system having an optimum system configuration for an electric railway system or the like, capable of reliably performing start-up, operation, and stop, and capable of appropriately dealing with various abnormalities.

Drawings

Fig. 1 is a diagram showing a configuration example of an electric storage system according to embodiment 1 of the present invention.

Fig. 2 is a diagram showing an example of the configuration of the dc power supply 1(1) according to embodiment 1.

Fig. 3 is a diagram showing an example of the composition of the cutting unit 8 according to embodiment 1.

Fig. 4 is a diagram showing an example of the composition of the primary current detection unit 10 according to embodiment 1.

Fig. 5 is a diagram showing an example of the composition of the primary voltage detection unit 20 according to embodiment 1.

Fig. 6 is a diagram showing a configuration example of the primary-side switching unit 30(1) of embodiment 1.

Fig. 7 is a diagram showing an example of the configuration of the switch according to embodiments 1 to 7.

Fig. 8 is a diagram showing a configuration example of the primary-side filter unit 40(1) according to embodiment 1.

Fig. 9 is a diagram showing a configuration example of the DCDC converter 50(1) according to embodiment 1.

Fig. 10 is a diagram showing a configuration example of an inverter circuit 51a according to embodiment 1.

Fig. 11 is a diagram showing a configuration example of the discharge circuit 45(1) of embodiment 1.

Fig. 12 is a diagram showing a configuration example of the secondary filter unit 60(1) according to embodiment 1.

Fig. 13 is a diagram showing a configuration example of the secondary side switch unit 70(1) according to embodiment 1.

Fig. 14 is a diagram showing an example of the configuration of the secondary-side voltage detection unit 80 according to embodiment 1.

Fig. 15 is a diagram showing an example of the configuration of secondary-side current detection unit 90 according to embodiment 1.

Fig. 16 is a diagram showing an example of the composition of the protection device unit 100 according to embodiment 1.

Fig. 17 is a diagram showing an example of the configuration of power storage unit 110 according to embodiment 1.

Fig. 18 is a diagram showing a configuration example of the power storage system according to embodiment 2.

Fig. 19 is a diagram showing a configuration example of the dc power supply 1(2) according to embodiment 2.

Fig. 20 is a diagram showing a configuration example of the primary-side filter unit 40(2) according to embodiment 2.

Fig. 21 is a diagram showing a configuration example of the power storage system according to embodiment 3.

Fig. 22 is a diagram showing a configuration example of the discharge circuit unit 45(2) according to embodiment 3.

Fig. 23 is a diagram showing a configuration example of the power storage system according to embodiment 4.

Fig. 24 is a diagram showing a configuration example of the primary-side switching unit 30(2) according to embodiment 4.

Fig. 25 is a diagram showing a configuration example of the power storage system according to embodiment 5.

Fig. 26 is a diagram showing a configuration example of the secondary-side switching unit 70(2) according to embodiment 5.

Fig. 27 is a diagram showing a configuration example of the power storage system according to embodiment 6.

Fig. 28 is a diagram showing a configuration example of the DCDC converter 50(2) according to embodiment 6.

Fig. 29 is a diagram showing a configuration example of an inverter circuit 51b according to embodiment 6.

Fig. 30 is a diagram showing a configuration example of the discharge circuit unit 45(3) according to embodiment 6.

Fig. 31 is a diagram showing a configuration example of the secondary filter unit 60(2) according to embodiment 6.

Fig. 32 is a diagram showing a configuration example of the power storage system according to embodiment 7.

Description of the reference symbols

1 is a dc power supply, 1a is a dc voltage source, 1b is an overhead wire, 1c is a current collector, 1d is a switch, 1e is a reactor, 1f is a capacitor, 1g is an inverter, 1h is a motor or a load, 1i is a rail, 8 is a cut-off part, 8a is a switch, 10 is a primary side current detection part, 11 is a current detector, 12 is a current detector, 20 is a primary side voltage detection part, 21 is a voltage detector, 30(1) to 30(2) are primary side switch parts, 31a to 31b are switches, 32 is a charging resistor, 31a1 is a main contact, 31a2 is an auxiliary contact, 31a3 is a closed coil, 40(1) to 40(2) are primary side filter parts, 41 is a reactor, 42 is a voltage detector, 43 is a primary side capacitor, 44 is a noise filter, 45(1) to 45(3) is a discharge circuit part, 46a is a primary side diode, 46b is a secondary side diode, 46c1, 46c2 are discharge elements, 46d1, 46d2 are discharge element drive circuits, 46e1, 46e2 are discharge resistors, 50(1) to 50(2) are DCDC converter sections, 51a, 51b are converter circuits, 52a, 52b are converter control sections, 51a1 to 51a4 are switching elements, 51b1 to 51b2 are switching elements, 51a5 are coupling reactors, 60(1) and 60(2) are secondary side filter sections, 61 are reactors, 62 are voltage detectors, 63 are secondary side capacitors, 64 are noise filters, 70(1) to 70(2) are secondary side switch sections, 71a to 71c are switches, 72 are charge resistors, 80 are secondary side voltage detection sections, 81 are voltage detectors, 90 are secondary side current detection sections, 91 are current detection sections, and 100 to protection sections, reference numerals 101a and 101b denote fuses, reference numerals 102a and 102b denote auxiliary contacts, reference numeral 110 denotes a power storage unit, reference numeral 111 denotes a battery, reference numeral 112 denotes a power storage unit monitor, and reference numerals 200(1) to 200(8) denote power storage systems.

Detailed Description

Embodiment mode 1

Fig. 1 is a diagram showing a configuration example of an electric storage system according to embodiment 1 of the present invention.

As shown in fig. 1, the power storage system 200(1) is connected to the dc power supply 1(1) and includes: a disconnecting unit 8 having a current disconnecting means, a primary side current detecting unit 10 located at the rear stage of the disconnecting unit 8 and detecting a current of the primary side main circuit, a primary side voltage detecting unit 20 located at the rear stage of the primary side current detecting unit 10 and detecting a voltage of the primary side main circuit, a primary side switching unit 30(1) located at the rear stage of the primary side voltage detecting unit 20 and switching the primary side main circuit on and off, a primary side filter unit 40(1) located at the rear stage of the primary side switching unit 30(1) and suppressing harmonics of the primary side main circuit, a DCDC converter unit 50(1) located at the rear stage of the primary side filter unit 40(1), a secondary side filter unit 60(1) located at the secondary side of the DCDC converter unit 50 and suppressing harmonics of the secondary side main circuit, a discharge circuit unit 45(1) connecting the positive side, the negative side of the primary side filter unit 40(1) and the positive side of the secondary side filter unit 60(1), and a discharge circuit unit 45(1), A secondary side switch unit 70(1) located after the secondary side filter unit 60(1) and switching on and off the secondary side main circuit, a secondary side voltage detection unit 80 located after the secondary side switch unit 70(1) and detecting a voltage of the secondary side main circuit, a secondary side current detection unit 90 located after the secondary side voltage detection unit 80 and detecting a current of the secondary side main circuit, a protection device unit 100 located after the secondary side current detection unit 90, a power storage unit 100 located after the protection device unit 100, and a system control unit 120(1) controlling these units.

The system control unit 120(1) is configured to output an on command S0 to the disconnecting unit 8, output on commands S1 to S2 to the primary-side switching unit 30(1), output an operation command S3 to the DCDC converter unit 50(1), output an off command S4 to the discharging circuit unit 45(1), and output on commands S5 to S7 to the secondary-side switching unit 70 (1).

The system control unit 120(1) receives the auxiliary contact signal F0 from the disconnecting unit 8, the primary side current I1 and the secondary side differential current I2 from the primary side current detecting unit 10, the primary side voltage V1 from the primary side voltage detecting unit 20, the auxiliary contact signals F1 and F2 from the primary side switching unit 30(1), the primary side capacitor voltage V2 from the primary side filter unit 40(1), the state signal F3 from the DCDC converter unit 50(1), the state signal F4 from the discharging circuit 45(1), the secondary side capacitor voltage V3 from the secondary side filter unit 60(1), the secondary side voltage V4 from the secondary side voltage detecting unit 80, and the secondary side positive side current I3 from the secondary side current detecting unit 90, the secondary side differential current I4 and the secondary side negative current I5 are input with auxiliary contact signals F8 and F9 from the protection device 100, and are input with a state signal F10 from the power storage unit 110.

The system control unit 120(1) receives an operation command C1 from the outside.

The above-described components constitute a control power supply (not shown) supplied from the outside, and are used to drive switches incorporated in the primary-side switch unit or the secondary-side switch unit, to operate the DCDC converter or the discharge circuit, to operate a computer incorporated in the system control unit or the converter unit described below, and the like.

Fig. 2 is a diagram showing an example of the configuration of the dc power supply 1(1) according to embodiment 1 of the present invention.

As shown in fig. 2, the dc power supply 1(1) is a voltage between a current collector 1c and a rail 1i in a circuit including a dc voltage source 1a, an overhead wire 1b, a current collector 1c, and a rail 1 i.

Fig. 3 is a diagram showing an example of the composition of the cutting unit 8 according to embodiment 1 of the present invention.

As shown in fig. 3, this portion is constituted by a switch 8 a.

The switch 8a is a switch (so-called breaker) having a function of automatically interrupting the circuit even if no command is given from the outside when an overcurrent flows.

Fig. 4 is a diagram showing an example of the configuration of the primary-side current detection unit 10 according to embodiment 1 of the present invention, and includes a current detector 11 that detects a primary-side current I1, and a current detector 12 that detects a differential current I2 between the positive side and the negative side.

Both of the current detectors detect the current by converting a magnetic flux generated by the current passing through the current detector into a current value, for example, but the present invention is not limited to this configuration.

When the current detector 12 is normal, since the positive-side current and the negative-side current have the same magnitude and different directions in the circuit that penetrates the positive-side wiring and the negative-side wiring in the directions in which the directions of the currents are reversed, the sum of the magnetic fluxes generated by the positive-side current and the negative-side current is zero, and the current detected by the current detector 12 is zero. However, when a leakage occurs due to deterioration of wiring insulation, a part of the current flows to a device case made of, for example, metal other than the wiring, and therefore, the magnitude of the positive side current and the magnitude of the negative side current are different from each other, and the sum of magnetic fluxes generated by the positive side current and the negative side current passing through the current detector 12 is not zero, and the output I2 of the current detector 12 is not zero.

The system control unit 120(1) is configured to detect the leakage by monitoring the differential current I2 on the primary side.

The reason why the leakage occurs is that the insulation of the wiring becomes poor, and the short circuit or the ground may develop without rapidly repairing the wiring, but the insulation deterioration is detected at the stage of the occurrence of the minute leakage current, and the detected insulation deterioration is input to the system control unit 120(1), and appropriate measures to be described later are taken, whereby the short circuit or the ground can be prevented in advance.

The primary side current I1 and the primary side differential current I2 detected by the current detectors 11 and 12 are output to the system control unit 120 (1).

Further, by disposing the primary-side current detection unit 10 immediately after the cutoff unit 8 (at the front stage of the primary-side current detection unit 20), it is possible to detect a differential current upstream of the circuit as viewed from the dc power supply 1(1), and it is possible to maximize the circuit range in which a leakage current due to the voltage of the dc power supply 1(1) can be detected.

Fig. 5 is a diagram showing an example of the composition of the primary-side voltage detection unit 20 according to embodiment 1 of the present invention. As shown in fig. 5, the primary-side voltage detection unit 20 is composed of a voltage detector that detects a voltage between the positive side and the negative side. The detected primary-side voltage V1 is output to the system control unit 120 (1).

Fig. 6 is a diagram showing a configuration example of primary-side switching unit 30(1) according to embodiment 1 of the present invention.

As shown in fig. 6, the primary-side switching section 30(1) includes: a switch 31a arranged in series with the positive side, a switch 31b arranged in parallel with the switch 31a, and a charging resistor. The on signals S1 and S2 are input to the switches 31a and 31b, respectively, and the auxiliary contact signals F1 and F2 (described below) are input from the switches 31a and 31b to the system control unit 120 (1).

Fig. 7 is a diagram showing an example of the configuration of switches 8a, 31b, 71a to 71c according to embodiment 1 of the present invention. The switches 71a to 71c are explained later.

As shown in fig. 7, the switch includes a main contact 31a1 for opening and closing the main circuit, a close coil 31a3 for driving the main contact 31a1, and an auxiliary contact 31a2 which is mechanically connected to the main contact 31a1, closes in an interlocking manner when the main contact 31a1 is closed, and opens in an interlocking manner when the main contact is opened.

The close coil 31a3 is an electromagnetic coil that is turned on and off in response to on commands S0 to S2 and S5 to S7 input from the system control unit 120(1), and the main contact 31a1 is turned on and off by the presence or absence of the coil driving force.

The auxiliary contact signals F0 to F2 and F5 to F7 indicating the operation of the main contact 31a1 detected by the auxiliary contact 31a2 are output to the system control unit 120 (1).

In the above description, the switches 8a, 31b, and 71a to 71c are mechanical switches, but are not limited to these switches as long as they can confirm the on/off of the circuit and the operation thereof, and may be, for example, semiconductor type contactless switches.

The auxiliary contact 31a2 is configured to close in conjunction with the closing main contact 31a1 and open in conjunction with the opening thereof, but may be configured to open in conjunction with the closing main contact 31a1 and close in conjunction with the opening thereof.

By inputting the signal of the auxiliary contact point linked with the main contact point to the system control unit 120(1), the system control unit can reliably grasp the operation of the switch, establish reliable start, operation, and stop steps, and detect an abnormality of the switch, as will be described later.

Fig. 8 is a diagram showing an example of the configuration of the primary-side filter unit 40(1) according to embodiment 1 of the present invention. As shown in fig. 8, the voltage detector 42 is connected to the reactor 41 at the subsequent stage, and the primary-side capacitor voltage V2 detected by the voltage detector 42 is output to the system control unit 120 (1).

A noise filter 44 is connected to the rear stage of the voltage detector 42, and a primary side capacitor 43 is connected to the rear stage of the noise filter 44.

The noise filter 44 generates high impedance to noise components (common mode noise) flowing in the same direction through the positive-side wiring and the negative-side wiring, and suppresses noise from flowing out to the outside; the wiring can be realized by making the current directions of the positive wiring and the negative wiring mutually reverse and penetrate through the center of a ring-shaped core material made of ferrite or amorphous.

In order to increase the impedance, it is preferable to make the positive-side wiring and the negative-side wiring reverse in the same direction in the core material a plurality of times.

This noise filter 44 is preferably disposed in a preceding stage of the primary side capacitor 43 and in proximity to the primary side capacitor 43.

By providing the noise filter 44 in this way, a power storage system in which noise flows out to the outside with little noise can be obtained.

Further, a circuit (not shown) in which 2 capacitors having good high-frequency characteristics are connected in series is connected in parallel to the primary side capacitor 43, and thus, even if the midpoint of the series is grounded to the case, the outflow of the common mode noise can be suppressed. The use of this structure together with the noise filter 44 can increase the effect of further suppressing the outflow of the common mode noise.

When the voltage detector 42 is connected to the stage subsequent to the noise filter 44, the noise filter 44 acts as an impedance to the common mode noise current of the DCDC converter unit 50(1) (described later) connected in parallel to the stage subsequent to the primary side capacitor 43, and therefore the common mode noise current flows into the system control unit 120(1) through the voltage detector 42 having a relatively small impedance, and may cause the system control unit 120(1) to malfunction. By connecting the voltage detector 42 to the front stage of the noise filter 44, the common mode noise current generated by the DCDC converter 50(1) flows into the system control unit 120(1) through the voltage detector 42, and malfunction can be avoided.

Fig. 9 is a diagram showing a configuration example of the DCDC converter unit 50(1) according to embodiment 1 of the present invention.

As shown in fig. 9, DCDC converter unit 50(1) includes converter current 51a and converter control unit 52a, receives an operation command S3 from system control unit 120(1) to converter control unit 51a, and outputs a state signal F3 from converter control unit 12a to system control unit 120 (1).

Fig. 10 is a diagram showing a configuration example of the inverter circuit 51 a.

As shown in FIG. 10, the circuit includes a bidirectional buck-boost DCDC converter circuit composed of 4 switching elements 51a 1-51 a4 and a coupling reactor 51a 5. The circuit can control power flow bidirectionally, independent of the relationship of the primary side voltage (left terminal in the figure) and the secondary side voltage (right terminal in the figure) of the converter circuit.

Therefore, by setting the voltage of power storage unit 110 to be higher than the voltage of dc power supply 1a, the current of DCDC converter unit 50(1) and the subsequent circuits can be reduced, and the components can be reduced in size, thereby achieving a small-sized and lightweight power storage system.

As shown in fig. 9 and 10, an operation command S3 including command values (target values) of the DCDC converter operation, stop, and control modes, the power flowing between the primary side and the secondary side, the coupling reactor current value ILP (or ILN), the converter primary side current I1P (or I1N), the converter secondary side current I2P (I2N), the primary side capacitor voltage V2, and the secondary side capacitor voltage V3 is input from the system controller 120(1) to the converter controller 52a, and a state signal F3 of the DCDC converter 50(1) is input from the converter controller 52a to the system controller 120 (1).

The status signal F3 is a status signal including the voltage, current, temperature, on/off state of the switching element, and failure state of each unit of the DCDC converter 50 (1). The inverter control unit 52a performs PWM control of the switching elements 51a 1-51 a4 of the inverter circuit 51a in accordance with the operation command S3.

Fig. 11 is a diagram showing an example of the configuration of the discharge circuit section 45(1) according to embodiment 1 of the present invention. As shown in fig. 11, the wiring led from the positive side of the subsequent stage of the primary side filter 40(1) is connected to the primary side diode 46a, the wiring led from the positive side of the preceding stage of the secondary side filter unit 60(1) is connected to the secondary side diode 46a, the cathodes of the two diodes are butted, the positive side of a circuit in which the discharge element 46c and the discharge resistor 46e are connected in series is connected to the butted point, and the negative side is connected to the negative side wiring.

The discharge element driving circuit 46d controls on/off of the discharge element 46 c. The system control unit 120(1) receives a discharge command S4 including an on/off command for the discharge element 46c from the discharge element driving circuit 46d, and receives a state signal F4 including an operating state of the discharge element 46c from the discharge element driving circuit 46d to the system control unit 120 (1).

With the configuration in which the primary-side diode 46a and the secondary-side diode 46b are butted against each other in this way, the electric charges of the primary-side capacitor 43 and the secondary-side capacitor 63 can be discharged to one discharge element 46c, and therefore, a small and lightweight power storage system can be obtained.

Fig. 12 is a diagram showing a configuration example of the secondary-side filter unit 60(1) according to embodiment 1 of the present invention.

As shown in fig. 12, a noise filter 64 is connected to the rear stage of the secondary side capacitor 63, and a voltage detector 62 that detects a secondary side capacitor voltage V3 is connected to the rear stage thereof. The signal V3 detected by the voltage detector 62 is output to the system control unit 120. A reactor 61 is connected to the subsequent stage of the voltage detector 62.

The noise filter 64 is similar in composition to the noise filter 44 described above, and is therefore preferred.

The noise filter 64 is preferably disposed at a stage subsequent to the secondary side capacitor 63 and close to the secondary side capacitor 63.

Further, a circuit (not shown) in which 2 capacitors having good high-frequency characteristics are connected in series is connected in parallel to the secondary side capacitor 63, and thus, even if the midpoint of the series is grounded to the case, the outflow of the common mode noise can be suppressed. The use of this structure together with the noise filter 44 can increase the effect of further suppressing the outflow of the common mode noise.

A reactor 61 is provided for reducing a ripple current generated in the DCDC converter unit 50 (1).

When the voltage detector 62 is connected to the stage subsequent to the noise filter 64, the noise filter 64 acts as an impedance to the common mode noise current of the DCDC converter unit 50(1) (described later) connected in parallel to the stage subsequent to the primary side capacitor 63, and therefore the common mode noise current flows into the system control unit 120(1) through the voltage detector 62 having a relatively small impedance, and may cause the system control unit 120(1) to malfunction. By connecting the voltage detector 62 to the front stage of the noise filter 64, the common mode noise current generated by the DCDC converter 50(1) flows into the system control unit 120(1) through the voltage detector 62, and malfunction can be avoided.

Fig. 13 is a diagram showing a configuration example of the secondary-side switching unit 70(1) according to embodiment 1 of the present invention.

As shown in fig. 13, the primary-side switching unit 70(1) includes a switch 71a arranged in series with the positive side, a series circuit including a switch 71b and a charging resistor 72 connected in parallel with the switch, and a switch 71c arranged in series with the negative side.

The system controller 120(1) receives the on signals S5 to S7 from the switches 71a to 71c, respectively, and the switches 71a to 71c receive the auxiliary contact signals F5 to F7 indicating the operation thereof, respectively, to the system controller 120 (1).

The internal configuration of the switches 71a to 71c is the same as that shown in fig. 7, and therefore, the description thereof is omitted.

The switches 71a to 71c are mechanical switches, but are not limited thereto as long as they can confirm the on/off of the circuit and the operation thereof, and may be, for example, semiconductor type contactless switches.

Fig. 14 is a diagram showing an example of the composition of the secondary-side voltage detection unit 80 according to embodiment 1 of the present invention. As shown in fig. 14, the secondary-side voltage detection unit 80 includes a voltage detection unit 81 that detects the secondary-side voltage V4. The detected signal V4 is outputted to the system control unit 120 (1).

Fig. 15 is a diagram showing an example of the composition of secondary-side current detection unit 90 according to embodiment 1 of the present invention. As shown in fig. 15, the current detector includes a current detection unit 91 that detects a positive secondary side current I3, a current detector 92 that detects a positive and negative differential current I4, and a current detector 93 that detects a negative secondary side current I5.

Any current detector operates by converting magnetic flux generated by a current passing through the current detector into a current value.

The current detector 92 is used to detect leakage current due to insulation degradation of a circuit, and the details thereof are the same as those of the current detector 12 described above, and therefore, the description will be given.

Further, by disposing secondary-side current detection unit 90 immediately before protection device unit 100 (at the rear stage of secondary-side voltage detection unit 80), the differential current closest to power storage unit 110 can be detected, the differential current can be detected on the upstream side of the circuit viewed from power storage unit 110, and the range of the circuit capable of detecting the leakage current generated by the voltage of power storage unit 110 can be maximized.

The secondary side positive side current I3, the secondary side differential current I4, and the secondary side negative side current I5 detected by the current detectors 91-93 are outputted to the system control unit 120 (1).

The same effect can be obtained by omitting the current detector 92, inputting only the signals I3, I5 of the current detectors 91, 92 to the system control unit 120(1), calculating the difference between the two signals, and evaluating the difference.

Fig. 16 is a diagram showing an example of the composition of the protective device unit 100 according to embodiment 1 of the present invention.

As shown in fig. 16, a positive side fuse 101a and a negative side fuse 101b are included, and have a function of opening a circuit as soon as an overcurrent flows. Each of the auxiliary contacts 102a and 102b is provided to close a contact when a fuse is blown and detect the blowing.

Auxiliary contact signals F8 and F9 indicating the states of the auxiliary contacts 102a and 102b are outputted to the system control unit 120 (1).

Further, the fuses 101a and 101b may be opened at the time of blowing to detect the blowing. The auxiliary contact can be replaced by a detection circuit composed of an electronic circuit even if the auxiliary contact is not a mechanical contact.

The switch may be a switch (so-called breaker) that automatically interrupts an electric circuit even if no command is given from the outside when an overcurrent flows.

By providing the fuse on the negative side in addition to the positive side, for example, even when a connection point between the negative-side wiring of the preceding stage of the fuse 101b and each cell 111 in the power storage unit 110 is short-circuited, the circuit can be cut off, and a power storage system having a further excellent protection function can be obtained.

Fig. 17 is a diagram showing an example of the configuration of power storage unit 110 according to embodiment 1 of the present invention. As shown in fig. 17, a plurality of batteries 11 including electric double layer capacitors or secondary batteries are connected in series and parallel, and necessary voltage and capacitance are obtained between terminals of the electric storage unit.

The information on the voltage, current, amount of stored power, temperature, pressure, etc. of the battery 111 or the power storage unit 110 is collected by the power storage unit monitor 112 and output to the system control unit 120(1) as a state signal F10. Next, the operation procedure from the start, the normal operation, and the stop of the power storage system 200(1) having the configuration shown in embodiment 1 will be described.

Further, as a starting method of the present power storage system, a case where the operation is performed after the first-side capacitor 43 or the second-side capacitor 63 is charged and started from the dc power supply 1a (hereinafter, this starting method is referred to as a first-side start) and a case where the operation is performed after the first-side capacitor 43 or the second-side capacitor 63 is charged and started using the energy stored in the power storage unit 110 (hereinafter, this method is referred to as a second-side start) are considered.

Next, the operation procedure at the time of the primary side startup will be described first, and the operation procedure at the time of the secondary side startup will be described next.

At the time of primary side start-up

(step 1A-1)

When the control power source of the system control unit 120(1) is turned on and an operation command C1 including a drive command is input from the outside, an on command S0 of the switch 8a is output, the coil 31a3 of the switch 8a is excited, and the main contact 31a1 is turned on.

In a stage in which the on command S0 is turned on, the auxiliary contact 31a2 of the switch 8a is reliably closed, and the auxiliary contact signal F0 is turned on for a certain time, the system control unit 120(1) recognizes that the switch 8a can be normally turned on.

(step 2A-1)

When recognizing that the state in which the primary-side voltage V1 detected by the voltage detector 21 is equal to or higher than the set value continues for a certain time after the switch 8a is normally turned on, the system control unit 120(1) outputs an on command S2 to excite the coil 31a3 of the switch 31b, thereby turning on the main contact 31a 1. Thus, the primary capacitor 43 is charged through the charging resistance.

The system control unit 120(1) determines that charging of the primary side capacitor 43 is completed after a predetermined time or after a difference between the primary side voltage V1 and the primary side capacitor voltage V2 is equal to or less than a set value and a predetermined time elapses after the switch 31b is recognized as being normally turned on in a stage in which the on command S2 is turned on and the state in which the auxiliary contact 31a2 of the switch 31b is reliably closed and the auxiliary contact signal F2 is turned on continues for a predetermined time, and outputs the on command S1. Accordingly, the coil 31a3 of the switch 31a is excited, and the main contact is closed.

The system control unit 120(1) recognizes that the switch 31a can be normally turned on when the state in which the auxiliary contact 21a2 of the switch 3a is reliably closed and the auxiliary contact signal F1 is on continues for a certain time.

Step 3A-1)

When the system control unit 120(1) confirms that the switch 31a is normally turned on, it outputs an operation command S3 to the inverter control unit 52 a. At this time, S3 is a signal including a command for operating the DCDC converter 50(1) in the initial charging mode to charge the secondary side capacitor 63, the secondary side capacitor voltage V3, and the secondary side voltage V4. When receiving the operation command S3, the inverter control unit 52a controls the inverter circuit 51a to equalize the secondary-side capacitor voltage V3 and the secondary-side voltage V4, and to charge the secondary-side capacitor 63 by passing the required power from the primary side to the secondary side of the inverter.

At this time, in order to prevent the secondary side capacitor 63 and the like from being destroyed by rapid charging, the inverter control unit 52a is configured to charge the secondary side capacitor 63 while controlling the current of the inverter circuit 51a so that the current flowing from the primary side to the secondary side is limited to a set value.

The system control unit 120(1) determines that the charging of the secondary capacitor 63 is completed when the difference between the secondary capacitor voltage V3 and the secondary voltage V4 is within the set value and a set time has elapsed.

(step 4A-1)

When the system control unit 120(1) determines that the charging of the secondary side capacitor 63 is normally completed, the system control unit turns on the on commands S5 and S7 for turning on the switches 71a and 71 c. Accordingly, the closing coil 31a3 of each of the switches 71a and 71c is driven, and the main contact 31a1 is closed. As a result, the auxiliary contact 31a2, which is interlocked with the main contact 31a1, is closed, and auxiliary contact signals F5 and F7 indicating the states of the auxiliary contacts 31a2 are output to the system controller 120 (1).

The system control unit 120(1) recognizes that the turning on of the switches 71a and 71c is normally completed in a stage where the on commands S5 and S7 are turned on, the auxiliary contact 31a2 of the switches 71a and 71c is reliably closed, and the auxiliary contact signals F5 and F7 are turned on for a certain time.

The switches 71a and 71c may be turned on simultaneously or sequentially. By performing the sequential turn-on, the peak power required for the turn-on can be reduced, and only the switch that is turned on last can be made to be a switch that can be turned on and off by current. The switch capable of switching on and off the current is generally large in size, but the number of the switches used is reduced, so that a small and lightweight power storage system is obtained.

(step 5A-1)

When the system control unit 120(1) determines that the on of the switches 71a and 71c is normally completed, it outputs an operation command S3 to the converter control unit 52a to operate the coupling reactor 51a while maintaining the current ILP (or the negative-side ILN) at zero.

Accordingly, the converter control unit 52a controls the converter circuit 51a so that the current ILP of the coupling reactor 51a5 (or the negative-side ILN) becomes zero.

The converter primary side current I1P (or I1N) may be controlled to be zero, the converter secondary side current I2P (or I2N) may be controlled to be zero, and the primary side current I1 detected by the current detector 11 and the secondary side positive side current I3 detected by the current detector 91 may be controlled to be zero. Further, the current detector 91 may be replaced with the current detector 93, and the secondary side negative side current I5, which is the detection value of the current detector 93, may be operated to be zero.

The system control unit 120(1) determines that the converter control unit 52a is normal when a state in which the detected value of the current to be controlled is equal to or less than the set value continues for a predetermined time.

(step 6A-1)

When system control unit 120(1) determines that converter control unit 52a is normal, operation command S3 including current command I or power command P is input to converter control unit 52 a.

Accordingly, the converter control unit 52a controls the current or the power between the primary side and the secondary side to be equal to the command.

The current to be controlled is any one of the current ILP (or negative-side ILN) of the coupling reactor 51a5, the converter primary-side current I1P (or I1N), and the converter secondary-side current I2P (or I2N).

When an operation command S3 including a voltage command V is input from the system control unit 120(1) to the converter control unit 52a, the converter control unit 52a controls the converter circuit 51a so that the voltage on the side indicated by either the primary-side capacitor voltage V2 or the secondary-side capacitor voltage V3 coincides with the voltage command V.

(step 7A-1)

When an operation command C1 including a stop command is input from the outside, the system control unit 120(1) inputs an operation command S3 to the inverter control unit 52a so that the current of the inverter is gradually reduced to zero.

The inverter control unit 52a controls the inverter circuit 51a so that the current gradually decreases to zero at the end.

The time until the current is reduced to zero can be arbitrarily set.

When the state where the current is equal to or lower than the set value continues for a certain time, system control unit 120(1) inputs operation command S3 to stop DCDC converter 50(1), and converter control unit 52a turns off switching elements 51a1 to 51a4 to output it as state signal F3. The system control unit 120(1) confirms the state signal F3 to confirm that the DCDC converter 50(1) is normally stopped.

The current to be controlled is any one of the current ILP (or the negative-side ILN) of the coupling reactor 51a5, the converter primary-side current I1P (or I1N), and the converter secondary-side current I2P (and I2N).

By reducing the current to zero and then turning off the switching elements 51a1 to 51a4, it is possible to prevent the primary side capacitor voltage V2 or the secondary side capacitor voltage V3 from being abruptly overvoltage or the like.

(step 8A-1)

When the system control unit 120(1) confirms that the DCDC converter 50(1) is normally stopped, the on commands S0, S1, S2, S5 to S7 are turned off to open the switches 8a, 31b, 71a to 71 c.

The system control unit 120(1) confirms the auxiliary contact signals F0 to F2 and F5 to F7 indicating the states of the auxiliary contacts 31a2 of the switches 8a, 31b, and 71a to 71c, respectively, and determines that the switches 8a, 31b, and 71a to 71c are normally opened when confirming that the switches are reliably turned off.

By confirming that the DCDC converter 51(1) is stopped and opening the switches 8a, 31b, and 71a to 71c in this way, the switches 8a, 31b, and 71a to 71c can be opened without current, and thus, the main contacts of the switches 8a, 31b, and 71a to 71c can be prevented from being electrically worn.

(on secondary side start)

(step 1B-1)

When the control power supply of the system control unit 120(1) is turned on and a command C1 including a drive command is input from the outside, the system control unit 120(1) confirms that no abnormality has occurred in the state signal F10 from the power storage unit monitor 112 of the power storage unit 110, and turns on the on commands S6 and S7 of the switches 71b and 71C at a time when the state in which the secondary-side voltage V4 detected by the voltage detector 81 is equal to or higher than the set value continues for a certain time. Accordingly, the closing coils 31a3 of the switches 71b and 71c are driven to close the main contact 31a 1. In this way, the auxiliary contact 31a2 that is interlocked with the main contact 31a1 is closed, and the auxiliary contact signals F6 and F7 indicating the states of the auxiliary contacts 31a2 are output to the system control unit 120 (1).

The system control unit 120(1) recognizes that the turning on of the switches 71b and 71c is normally completed in a stage where the on commands S6 and S7 are turned on, the auxiliary contact 31a2 of the switches 71b and 71c is reliably closed, and the auxiliary contact signals F6 and F7 are turned on for a certain time.

The switches 71b and 71c may be turned on simultaneously or sequentially. By turning on the power source sequentially, the peak power required for turning on the power source can be reduced, and a control power source with a small peak rejection can be used.

The switches 71b and 71c are turned on, and the secondary side capacitor 63 is charged by the charging resistor 72.

The system control unit 120(1) recognizes that the state continues for a certain time period after the normal completion of the on operation of the switches 71b and 71c, or that the charging of the secondary capacitor 63 is completed after a certain time period elapses since the difference between the secondary side voltage V4 and the secondary side capacitor voltage V3 is equal to or less than a set value, and outputs an on command S5. Accordingly, the coil 31a3 of the switch 71a is excited, and the main contact 31a1 is turned on.

The system control unit 120(1) recognizes that the switch 71a is normally turned on when the state in which the auxiliary contact 31a2 of the switch 71a is reliably closed and the auxiliary contact signal F5 is on continues for a certain time.

(step 2B-1)

When the system control unit 120(1) confirms that the switch 71a is normally turned on, the system control unit outputs an operation command S3 to the inverter control unit 52 a. At this time, S3 is a signal including a command for operating the DCDC converter 50(1) in the initial charging mode to charge the primary side capacitor 43, the primary side capacitor voltage V2, and the primary side voltage V1. When receiving the operation command S3, the inverter control unit 52a operates the inverter circuit 51a to flow the required power from the secondary side to the primary side, thereby charging the primary side capacitor 43.

In this case, in order to prevent the primary capacitor 43 and the like from being destroyed in rapid charging, the converter control unit 52a is configured to charge the primary capacitor 43 while controlling the current of the converter circuit 51a so that the current flowing from the primary side to the secondary side is limited to a set value.

Inverter control unit 52a controls inverter circuit 51a such that primary-side capacitor voltage V2 becomes equal to primary-side voltage V1, or such that primary-side capacitor voltage V2 becomes equal to a predetermined set value.

The system control unit 120(1) determines that the charging of the primary capacitor 43 is completed when the difference between the primary capacitor voltage V2 and the primary capacitor voltage V1 is within a set value and a set time elapses or the primary capacitor voltage V2 reaches a predetermined set value.

(step 3B-1)

When the system control unit 120(1) determines that charging of the primary side capacitor 43 is completed, the system control unit turns on the on command S1 for turning on the switch 31 a. Accordingly, the switch 31a is driven to turn on the main contact 31a 1. Therefore, the auxiliary contact 31a2, which is interlocked with the main contact 31a1, is closed, and an auxiliary contact signal F1 indicating the state of each auxiliary contact 31a2 is output to the system controller 120 (1).

The system control unit 120(1) confirms that the switch 31a is normally turned on when the on command F1 turns on, the auxiliary contact 31a2 of the switch 31a is reliably closed, and the auxiliary contact signal F1 turns on for a certain time.

(step 4B-1)

The system control unit 120(1) recognizes that the switch 31a is normally turned on, and outputs an on command S0 of the switch 8a to excite the coil 31a3 of the switch 8a and turn on the main contact 31a 1. In a stage in which the on command S0 is turned on, the auxiliary contact 31a2 of the switch 8a is reliably closed, and the condition that the auxiliary contact signal F0 is on continues for a certain time, the system control unit 120(1) recognizes that the switch 8a can be normally turned on.

(step 5B-1)

When the system control unit 120(1) determines that the switch 8a is normally on, it outputs an operation command S3 to the converter control unit 52a to set the current ILP of the coupling reactor 51a5 (or the negative-side ILN) to zero and operate it.

Therefore, the converter control unit 52a controls the converter circuit 51a so that the current ILP of the coupling reactor 51a5 (or the negative-side ILN) becomes zero.

The converter primary side current I1P (or I1N) may be controlled to be zero, the converter secondary side current I2P (or I2N) may be controlled to be zero, and the primary side current I1 detected by the current detector 11 and the secondary side positive side current I3 detected by the current detector 91 may be controlled to be zero.

Further, the secondary side positive side current I3 may be replaced with a secondary side negative side current I5 as a detection value of the current detector 93, and may be made zero.

The system control unit 120(1) determines that the converter control unit 52a is normal when a state in which the detected value of the current to be controlled is equal to or less than the set value continues for a certain period of time.

(step 6B-1)

When system control unit 120(1) determines that converter control unit 52a is normal, operation command S3 including current command I or power command P is input to converter control unit 52 a.

Accordingly, the converter control unit 52a controls the current or the power between the primary side and the secondary side to be equal to the command.

The current to be controlled is any one of the current ILP (or negative-side ILN) of the coupling reactor 51a5, the converter primary-side current I1P (or I1N), and the converter secondary-side current I2P (or I2N).

When an operation command S3 including a voltage command V is input from the system control unit 120(1) to the converter control unit 52a, the converter control unit 52a controls the converter circuit 51a so that the voltage on the side indicated by either the primary-side capacitor voltage V2 or the secondary-side capacitor voltage V3 coincides with the voltage command V.

(step 7B-1)

When an operation command C1 including a stop command is input from the outside, the system control unit 120(1) inputs an operation command S3 to the inverter control unit 52a so that the current of the inverter is gradually reduced to zero.

The inverter control unit 52a controls the inverter circuit 51a so that the current gradually decreases to zero at the end. The time until the current is reduced to zero can be arbitrarily set. When the state where the current is equal to or lower than the set value continues for a certain time, system control unit 120(1) inputs operation command S3 to stop DCDC converter 50(1), and converter control unit 52a turns off switching elements 51a1 to 51a4 to output it as state signal F3. The system control unit 120(1) confirms the state signal F3 to confirm that the DCDC converter 50(1) is normally stopped.

The current to be controlled is any one of the current ILP (or the negative-side ILN) of the coupling reactor 51a5, the converter primary-side current I1P (or I1N), and the converter secondary-side current I2P (and I2N).

By reducing the current to zero and then turning off the switching elements 51a1 to 51a4, it is possible to prevent the primary side capacitor voltage V2 or the secondary side capacitor voltage V3 from being abruptly overvoltage or the like.

(step 8B-1)

When the system control unit 120(1) confirms that the DCDC converter 50(1) is normally stopped, the on commands S0, S1, S2, S5 to S7 are turned off to open the switches 8a, 31b, 71a to 71 c.

The system control unit 120(1) confirms the auxiliary contact signals F0 to F2 and F5 to F7 indicating the states of the auxiliary contacts 31a2 of the switches 8a, 31b, and 71a to 71c, respectively, and determines that the switches 8a, 31b, and 71a to 71c are normally opened when confirming that the switches are reliably turned off.

By confirming that the DCDC converter 51(1) is stopped and opening the switches 8a, 31b, and 71a to 71c in this way, the switches 8a, 31b, and 71a to 71c can be opened without current, and thus, the main contacts of the switches 8a, 31b, and 71a to 71c can be prevented from being electrically worn.

By the above-described operation steps from the start of the operation, the normal operation, and the stop of the operation, a reliably operating power storage system can be obtained.

When the primary side is only used for starting, the switch 71b and the charging resistor 72 of the secondary side switch unit 70(1) are not required, and the operation can be eliminated.

When the secondary side is only used for starting, the switch 31b and the charging resistor 32 of the primary side switch unit 30(1) are not required, and the operation can be eliminated.

Next, a detailed abnormality detection method of the power storage system shown in embodiment 1 and an operation when an abnormality is detected will be described.

In order to safely and stably operate the power storage system, it is necessary to quickly take appropriate measures depending on the type of abnormality when abnormality occurs in each part of the power storage system. Therefore, it is important to detect an abnormality and what measure is taken depending on the type of abnormality, and the following description will be made.

(abnormality detection 1-1) differential Current abnormality detection

When the state in which the primary side differential current I2 and the secondary side differential current I4, which are the outputs of the current detectors 12 and 92, are not equal to or less than the set values continues for a certain time, the system control unit 120(1) determines that a leakage current due to insulation deterioration has occurred in a certain place in the circuit, turns off the on signals S0 to S2 and S5 to S7 of the switches 8a, 31b, and 71a to 71c, turns off the switching elements 51a1 to 51a4 of the DCDC converter 50(1), and inputs a discharge command S4 to the discharge circuit unit 45(1) to discharge the charges of the primary side capacitor 43 and the secondary side capacitor 63.

By operating as described above, it is possible to detect an increase in leakage current, quickly stop the power storage system, and avoid an increase in damage.

The set values may be configured to be composed in multiple stages, and when the differential current is sufficiently small, the set values may be recorded in a system control unit, a device, a recording device (not shown) or an indicator lamp (not shown) provided on a table or the like, without stopping the power storage system, to prompt the inspection.

(abnormality detection 2-1) switch abnormality detection

The system control unit 120(1) determines that the switch 8a is abnormal when the state in which the main contact 31a1 is not closed and the auxiliary contact 31a2 is not closed and the auxiliary contact signal F0 is not conductive continues for a certain time due to a failure or the like of the close coil 31a3 of the switch 8a despite the on command S0 of the switch 8a being turned on, or when the state in which the auxiliary contact 31a2 is conductive and the auxiliary contact signal F0 is also conductive continues for a certain time in the state in which the on command S0 is interrupted.

The switches 8a, 31b, and 71a to 71c are also subjected to abnormality detection in the same manner.

When any of the switches 8a, 31b, and 71a to 71c detects an abnormality, the system control unit 120(1) turns off the on commands S0 to S2 and S5 to S7 of all the switches 8a, 31b, and 71a to 71c, turns off the switching elements 51a1 to 51a4 of the DCDC converter unit 50(1), and inputs a discharge command S4 to the discharge circuit unit 45(1) to discharge the charges of the primary side capacitor 43 and the secondary side capacitor 63.

By operating as described above, a failure of the switch can be detected, and the power storage system can be quickly stopped, thereby preventing the damage from being extended.

(abnormality detection 3-1) detection of abnormality in charging of primary side capacitor (at the time of primary side startup)

When the switch 31b is recognized to be normally turned on in step 2A-1 at the time of the primary side start, and even if a certain time has elapsed, the system control unit 120(1) determines that the charging cannot be completed due to an abnormality such as the ground connection of the primary side capacitor 43, turns off the turn-on commands S0 to S2 of the previously turned-on capacitors 8a, 31a, and 31b, and inputs the discharge command S4 to the discharge circuit unit 45(1) to discharge the charges of the primary side capacitor 43 and the secondary side capacitor 63, when the difference between the primary side voltage V1 and the primary side capacitor voltage V2 is equal to or greater than the set value or when the primary side current I1 is equal to or greater than the set value.

By operating as described above, it is possible to detect an abnormality in the charging circuit of the primary side capacitor 43, to quickly stop the power storage system, and to avoid an increase in damage.

(abnormality detection 4-1) detection of charging abnormality of Secondary side capacitor (at the time of Primary side startup)

When the charging of the secondary side capacitor 63 is not completed within the time set in the above step 3A-1 at the time of the primary side startup or when the state signal F3 indicating the converter failure is received from the converter control unit 52a, the system control unit 120(1) interrupts the on commands S0 to S2 of the switches 8a, 31a, and 31b that were previously turned on when the abnormality occurs in the periphery of the DCDC converter 50(1) or the secondary side capacitor 63, stops the switching elements 51a1 to 51a4 of the DCDC converter 50(1), inputs the discharge command S4 to the discharge circuit unit 45(1), and discharges the charges of the primary side capacitor 43 and the secondary side capacitor 63.

By operating as described above, it is possible to detect an abnormality in the charging circuit of the secondary side capacitor 63, quickly stop the power storage system, and avoid an increase in damage.

(abnormality detection 5-1) detection of charging abnormality of Secondary side capacitor (at the time of Secondary side startup)

Even after a certain time has elapsed after the switches 71B and 71c are normally turned on in step 1B-1 at the time of secondary side startup, the system control unit 120(1) determines that charging cannot be completed due to abnormality of the secondary side capacitor 63 or the like, and turns off the on commands S6 and S7 of the previously turned-on switches 71B and 71c, and inputs the discharge command S4 to the discharge circuit unit 45(1) to discharge the charge of the secondary side capacitor 63, when the difference between the secondary side voltage V4 and the secondary side capacitor voltage V3 is equal to or greater than the set value or when the secondary side positive side current I3 and the secondary side negative side current are equal to or greater than the set value.

By operating as described above, it is possible to detect an abnormality in the charging circuit of the secondary side capacitor 63, quickly stop the power storage system, and avoid an increase in damage.

(abnormality detection 6-1) detection of abnormality in charging of primary side capacitor (at the time of secondary side startup)

When charging of the primary capacitor 43 is not completed within the time set in step 2B-1 at the time of the secondary side startup or when the state signal F3 indicating the converter failure is received from the converter control unit 52a, the system control unit 120(1) interrupts the on commands S6 and S7 of the switches 71B and 71c that were previously turned on when the DCDC converter 50(1) or the periphery of the primary capacitor 43 is abnormal, stops the switching elements 51a1 to 51a4 of the DCDC converter 50(1), and inputs the discharge command S4 to the discharge circuit unit 45(1) to discharge the charges of the primary capacitor 43 and the secondary capacitor 63.

By operating as described above, it is possible to detect an abnormality in the charging circuit of the primary side capacitor 43, to quickly stop the power storage system, and to avoid an increase in damage.

(anomaly detection 7-1) Primary-side capacitor overvoltage detection

When the primary capacitor voltage V2 detected by the voltage detector 42 exceeds a predetermined value, the system control unit 120(1) stops the switching elements 51a1 to 51a4 of the DCDC converter 50(1), turns off the on commands S1, S2, S5 to S7 of the switching elements 31a, 31b, 71a to 71b, and inputs the discharge command S4 to the discharge circuit unit 45(1) to discharge the charges of the primary capacitor 43 and the secondary capacitor 63.

By operating as described above, the overvoltage of the primary side capacitor voltage V2 can be detected, and the power storage system can be stopped quickly, thereby preventing the damage from being increased.

(abnormality detection 8-1) Secondary-side capacitor overvoltage detection

When the secondary side capacitor voltage V3 detected by the voltage detector 42 exceeds a predetermined value, the system control unit 120(1) stops the switching elements 51a1 to 51a4 of the DCDC converter 50(1), turns off the on commands S1, S2, S5 to S7 of the switching elements 31a, 31b, 71a to 71b, and inputs the discharge command S4 to the discharge circuit unit 45(1) to discharge the charges of the primary side capacitor 43 and the secondary side capacitor 63.

By operating as described above, the overvoltage of the secondary side capacitor voltage V3 can be detected, and the power storage system can be stopped quickly, thereby preventing the damage from being increased.

(anomaly detection 9-1) DC converter overcurrent detection

The system control unit 120(1) turns off the switching elements 51a1 to 51a4 of the DCDC converter 50(1) when the currents of the switching elements 51a1 to 51a4 of the converter circuit 51a are equal to or higher than a predetermined value.

The currents of the switching elements 51a1 to 51a4 may be replaced by the current ILP of the coupling reactor 51a5 or the negative side current ILN, and the switching elements 51a1 to 51a4 are turned off when the current is equal to or greater than a predetermined value.

The on commands S1, S2, and S5 to S7 of the switching elements 31a, 31b, and 71a to 71b are not turned off, and the discharge command S4 is not input to the discharge circuit unit 45(1), so that the charges of the primary capacitor 43 and the secondary capacitor 63 are not discharged.

The reason why the capacitor charges are not discharged and only the switching elements 51a1 to 51a4 are blocked is that the overcurrent of the DCDC converter may be a phenomenon that occurs temporarily due to a disturbance of a rapid change in the primary-side capacitor voltage V2 or the secondary-side capacitor voltage V3, and the DCDC converter itself cannot be said to be abnormal immediately, and the DCDC converter is less likely to be damaged.

By operating as described above, the overcurrent of the DCDC converter can be detected, the power storage system can be quickly stopped, and the damage can be prevented from being enlarged.

The time taken for restart due to capacitor recharging can also be reduced.

(abnormality detection 10-1) DCDC converter temperature abnormality detection

The system control unit 120(1) turns off the switching elements 51a1 to 51a4 when the surface temperatures of the switching elements 51a1 to 51a4 of the inverter circuit 51a or the temperatures of the cooling fans (not shown) mounted on the switching elements 51a1 to 51a4 are equal to or higher than a predetermined value.

Further, the on commands S1, S2, and S5 to S7 of the switching elements 31a, 31b, and 71a to 71c are not turned off, and the discharge command S4 is not input to the discharge circuit 45(1), so that the charges in the primary capacitor 43 and the secondary capacitor 63 are not discharged.

The reason why the capacitor is not discharged and only the switching elements 51a1 to 51a4 are turned off is that a temperature rise of the DCDC converter may be caused by a temporary overload, and the DCDC converter itself cannot be said to be abnormal immediately, and the DCDC converter is less likely to be damaged.

Further, it is preferable to provide another set value smaller than the set value, and control to reduce the current of the DCDC converter to suppress a temperature rise at a time point when the set value is exceeded, and to turn off the switching elements 51a1 to 51a4 when the set value is exceeded, so that the operation can be continued as much as possible.

By operating as described above, it is possible to detect a temperature abnormality of the DCDC converter, quickly stop the power storage system, and avoid an increase in damage.

The time taken for restart due to capacitor recharging can also be reduced.

(abnormality detection 11-1) abnormality detection of switching element

When an abnormality (the contents of the abnormality will be described later) in the switching elements 51a1 to 51a4 of the inverter circuit 51a is detected by the detection circuit (not shown) built in the switching elements 51a1 to 51a4, the drive circuit (not shown) of the switching elements 51a1 to 51a4, or the inverter control unit 52a, the system control unit 120(1) stops the switching elements 51a1 to 51a4 of the DCDC converter 50(1) after recognizing the abnormality by the state signal F3, turns on commands S0, S1, S2, S5 to S7 of the switches 8a, 31b, and 71a to 71c off, and inputs the discharge command S4 to the discharge circuit unit 45(1) to discharge the charges of the primary side capacitor 43 and the secondary side capacitor 63.

When an abnormality is detected by a built-in detection circuit (not shown), the switching elements 51a1 to 51a4 may autonomously turn off the switches without a turn-off command from the system control unit 120(1) or the inverter control unit 52 a. Switching elements with such functionality are referred to as smart power modules. Thus, the switch can be quickly turned off without delay after the abnormality is detected, and the protection performance is improved.

The abnormality is a case where the current flowing through the switching elements 51a1 to 51a4 has an excessive sharp rising edge, a case where the internal temperature of the switching elements 51a1 to 51a4 is equal to or higher than a predetermined value, or a case where the voltage of the on/off signal of the switching elements 51a1 to 51a4 is unstable. These phenomena are phenomena that may be associated with the breakage of the switching elements 51a 1-51 a 4.

By operating as described above, it is possible to detect an abnormality of the switching element, quickly stop the power storage system, and avoid an increase in damage.

(anomaly detection 12-1) Primary side overcurrent detection

When the switch 8a is automatically released due to an overcurrent after the step 1A-1 or the step 4B-1 of the switch 8a of the disconnecting unit 8 is turned on, the system control unit 120(1) detects that the auxiliary contact signal S0 is turned off in spite of the on command being turned on, stops the switching elements 51A1 to 51A4 of the DCDC converter 50(1), turns off the on commands S0, S1, S2, and S5 to S7 of the switches 8a, 31B, and 71A to 71c, and inputs the discharge command S4 to the discharge circuit unit 45(1) to discharge the charges of the primary side capacitor 43 and the secondary side capacitor 63.

When the switch 8a is released by itself due to an overcurrent, the possibility of an overcurrent flowing due to a short circuit or the ground is considered, and therefore, by operating as described above, the power storage system can be stopped quickly, and the damage can be prevented from being enlarged.

(anomaly detection 13-1) Secondary-side overcurrent detection

When the fuse 101a or 101b is blown, the system control unit 120(1) detects that the auxiliary contacts F8 and F9 are turned on, stops the switching elements 51a1 to 51a4 of the DCDC converter 50(1), blocks the on commands S0, S1, S2, and S5 to S7 of the switches 8a, 31b, and 71a to 71c, and inputs the discharge command S4 to the discharge circuit unit 45(1) to discharge the electric charges of the primary side capacitor 43 and the secondary side capacitor 63.

The fuses 101a and 101b are blown out in consideration of the possibility of a current flowing through the fuses due to a short circuit or a ground, and therefore, the power storage system can be quickly stopped by the above operation, and the damage can be prevented from being increased.

(abnormality detection 14-1) storage unit abnormality detection

The system control unit 120(1) turns off the switching elements 51a1 to 51a4 when a state signal F10 indicating temperature constant, overcharge, and overdischarge is input from the power storage unit monitor 112.

Thereafter, if F10 indicates a temperature abnormality, the operation of the switching elements 51a 1-51 a4 is started.

When overcharging is indicated, since electric power is discharged from power storage unit 110, DCDC converter 50(1) is operated so that electric power can flow only from the secondary side to the primary side.

On the other hand, when overdischarge is indicated, since power storage unit 110 is charged, DCDC converter 50(1) is operated so that power can flow only from the primary side to the secondary side.

After a certain time has elapsed, if state signal F10 indicates a temperature abnormality, overcharge, or overdischarge, and there is a possibility that power storage unit 110 may have an unrecoverable abnormality, system control unit 120(1) stops switching elements 51a1 to 51a4 of DCDC converter 50(1), turns on commands S0, S1, S2, and S5 to S7 for switches 8a, 31b, and 71a to 71c, and inputs discharge command S4 to discharge circuit unit 45(1) to discharge the electric charges of primary capacitor 43 and secondary capacitor 63.

By operating as described above, it is possible to detect an abnormality in the power storage unit, quickly stop the power storage system, and avoid an increase in damage.

In the above-described abnormality detection, it is preferable that the occurrence of an abnormality be recorded or displayed on an indicator lamp (not shown) or a display monitor (not shown) provided in a system control unit or in an apparatus or on a table or the like.

Among the above-mentioned abnormality detection items, the system control unit 120(1) prohibits the activation of the power storage system while detecting an abnormality because of a high possibility of damage to the following items when restarting, and releases the prohibition of activation only by manually operating a reset key provided in the work table, the system control unit, or the like:

(abnormality detection 1-1) differential current abnormality detection,

(abnormality detection 2-1) switch abnormality detection,

(abnormality detection 3-1) primary side capacitor charging abnormality detection (at the time of primary side startup),

(abnormality detection 4-1) Secondary-side capacitor charging abnormality detection (at Primary-side startup),

(abnormality detection 5-1) Secondary-side capacitor charging abnormality detection (at Secondary-side startup),

(abnormality detection 6-1) primary-side capacitor charging abnormality detection (at the time of secondary-side startup),

(abnormality detection 11-1) detection of abnormality of switching element,

(abnormality detection 12-1) primary side overcurrent detection,

(abnormality detection 13-1) Secondary side overcurrent detection,

(abnormality detection 14-1) power storage unit abnormality detection.

With this configuration, the range of damage to the abnormal portion can be prevented from being widened by the simple restart.

In the above-described abnormality detection items, the system control unit 120(1) automatically restarts the system after a certain time has elapsed after the execution of the stop processing, considering the possibility of a transient phenomenon due to disturbance:

(abnormality detection 7-1) detection of the primary-side capacitor voltage,

(abnormality detection 8-1) detection of Secondary-side capacitor Voltage,

(abnormality detection 9-1) DC/DC converter overcurrent detection,

(abnormality detection 10-1) DCDC converter temperature abnormality detection.

At this time, if it is monitored that there is a reoccurrence of an abnormality and the like abnormality is not detected within a certain time, the operation is continued as it is, and if the like abnormality is detected within a certain time, the power storage system is prohibited from being started up simultaneously with the reoccurrence of the abnormality detection. The prohibition of the activation is released only by manually operating a reset key provided in the table, the system control unit, or the like.

With this configuration, it is possible to prevent the system from being stopped due to a temporary abnormality caused by disturbance, and to avoid the range of damage to the abnormal portion from being widened by a simple restart.

When the control power supply voltage of the system control unit 120(1) is lower than the predetermined value, the following operation is performed.

When the control power supply voltage of the system control unit 120(1) is lower than a predetermined value or is turned off, a discharge command S4 is input to the discharge circuit unit 45(1) to discharge the electric charges of the primary capacitor 43 and the secondary capacitor 63.

The on commands S0 to S2 and S5 to S7 are turned off in order to open the switches 8a, 31b, 71a to 71c at the same time.

The meaning of the above operation is explained.

The switches 51a 1-51 a4 may be damaged when the voltage of the gate signal controlling the on/off operation thereof is reduced. To avoid this damage, the system control unit 120(1) stops the switching operation quickly when the control power supply is turned off, and discharges the charges of the primary side capacitor 43 and the secondary side capacitor 63 without applying a voltage to the switching element.

Since the system control unit 120(1) and the discharge element driving circuit 46d need to maintain the control power supply voltage even after the control power supply is turned off, the system control unit has a power supply backup circuit (not shown) using an electric storage element such as an electrolytic capacitor to maintain the discharge element 46c in an on state for a period before the discharge is completed (usually, about 3 seconds).

With the above configuration, even when the control power supply is suddenly cut off during the operation of the power storage system, the charges of the primary side capacitor 43 and the secondary side capacitor 63 can be reliably discharged, and the switch can be released, so that the switching element and the power storage system can be prevented from being damaged.

By adopting the configuration of embodiment 1 described above, it is possible to obtain an electric storage system that is most suitable for an electric railway system and that has an optimum startup, operation, stop, and abnormality detection method and an operation method when abnormality is detected, which are important and indispensable for practical use of the electric storage system.

In the description of the dc power supply of fig. 2, the dc power supply is obtained from the vehicle side via the current collector and the power storage system is mounted on the vehicle, but it goes without saying that the power storage system may be installed between stations on the ground or in a substation (not shown).

Embodiment mode 2

Fig. 18 is a diagram showing a configuration example of a power storage system according to embodiment 2 of the present invention.

Embodiment 2 is modified based on the composition example of embodiment 1, and therefore, the same components as those of embodiment 1 are denoted by the same reference numerals, and description thereof is omitted, and only different components are described.

As shown in fig. 18, a dc power supply 1(2) is arranged in place of the dc power supply 1(1) and is input to an electric storage system 200 (2).

The power storage system 200(2) is configured to dispose the primary side filter unit 40(2) instead of the primary side filter unit 40 (1).

Fig. 19 is a diagram showing an example of the configuration of the dc power supply 1(2) according to embodiment 2 of the present invention.

As shown in fig. 19, the dc power supply 1(2) is a voltage across the capacitor 1f of a circuit including a drive control device 1j, and the drive control device 1j includes a substation 1a, an overhead wire 1b, a current collector 1c, a rail 1i, a switch 1d having a current interruption function, a reactor 1e, a capacitor 1f, and an inverter 1g that drives a motor or a load 1 h.

Fig. 20 is a diagram showing an example of the configuration of the primary side filter 40(2) according to embodiment 2 of the present invention. The reactor 41 is deleted, the noise filter 44 is connected to the stage subsequent to the voltage detector 42 that detects the primary side capacitor voltage V2, and the primary side capacitor 43 is disposed downstream of the noise filter 44.

The operation steps from the start of the power storage system 200(2) having the configuration shown in embodiment 2, the normal operation to the stop thereof, the abnormality detection method, and the operation for detecting an abnormality have been described in the description of embodiment 1, and therefore the description thereof is omitted here.

By adopting the configuration of embodiment 1 described above, when the power storage system is used in combination with the drive control device 1j, the reactor 1e of the drive control device 1j can be shared, and the reactor 41 in embodiment 1 can be omitted, so that a small and lightweight power storage system can be obtained.

Further, by configuring the switch 1d in which the disconnecting unit 8 is omitted and the drive control device 1j is shared, a further compact and lightweight power storage system can be obtained.

Embodiment 3

Fig. 21 is a diagram showing a configuration example of a power storage system according to embodiment 3 of the present invention.

Embodiment 3 is modified based on the composition example of embodiment 1, and therefore the same components as those of embodiment 1 are denoted by the same reference numerals, and description thereof is omitted, and only different components will be described.

As shown in fig. 21, the power storage system 200(3) is provided with a discharge circuit 45(2) instead of the discharge circuit unit 45(1), and a system control unit 120(3) instead of the system control unit 12 (1).

The system control unit 120(3) is configured to output the primary side discharge command S41 and the secondary side discharge command S42 to the discharge circuit unit 45(2), and to input the state signals F41 and F42 from the discharge circuit unit 45 (2).

Fig. 22 is a diagram showing an example of the configuration of the discharge circuit section 45(2) according to embodiment 3 of the present invention.

As shown in fig. 22, the positive side of the circuit in which the discharge element 46c1 and the discharge resistor 46e1 are connected in series is connected to a wiring led from the positive side of the subsequent stage of the primary filter unit 40(1), and the negative side is connected to the negative side wiring.

The positive side of a circuit in which the discharge element 46c2 and the discharge resistor 46e2 are connected in series is connected to a wiring led from the positive side of the subsequent stage of the secondary side filter unit 60(1), and the negative side is connected to the negative side wiring.

The discharge element 46c1 or 46c2 is on-off controlled by the discharge element drive circuit 46d1 or 46d 2. The discharge element driving circuit 46d1 or 46d2 is configured to receive a primary side discharge command S41 and a secondary side discharge command S42, which include on/off commands for the discharge element 46c1 or 46c2, from the system controller 120(3), and receive a state signal F41 or F42, which includes an operating state of the discharge element 46c1 or 46c2, from the discharge element driving circuit 46d1 or 46d2 to the system controller 120 (3).

The operation steps from the start of the power storage system 200(3) having the configuration shown in embodiment 3, the normal operation, and the stop thereof are explained in the description of embodiment 1 by replacing the system control unit 12(1) with the system control unit 120(3), so that the description is omitted here.

Regarding the abnormality detection method and the operation when an abnormality is detected, the abnormality detection 7-1 and the abnormality detection 8-1 are respectively the abnormality detection 7-3 and the abnormality detection 8-3 described below, which are different from those described in embodiment 1.

(anomaly detection 7-3) Primary-side capacitor overvoltage detection

When the primary-side capacitor voltage V2 detected by the voltage detector 42 exceeds the set value, the system controller 120(3) stops the switching elements 51a1 to 51a4 of the DCDC converter 50(1), turns off the on commands S1, S2, S5 to S7 of the switches 31a, 31b, 71a to 71c, and inputs a primary-side discharge command S41 to the discharge circuit 45(2) to discharge the charge of the primary-side capacitor 43.

By operating as described above, the overvoltage of the primary side capacitor voltage V2 can be detected, and the power storage system can be quickly stopped to avoid the damage from spreading.

In embodiment 3, since the charge discharge of the secondary side capacitor 63 is not performed, an unnecessary discharge operation can be prevented.

(anomaly detection 8-3) Primary-side capacitor overvoltage detection

When the secondary side capacitor voltage V3 detected by the voltage detection unit 42 exceeds the set value, the system control unit 120(3) stops the switching elements 51a1 to 51a4 of the DCDC converter 50(3), turns off the on commands S1, S2, S5 to S7 of the switches 31a, 31b, 71a to 71c, and inputs a secondary side discharge command S42 to the discharge circuit unit 45(2) to discharge the charge of the secondary side capacitor 63.

By operating as described above, the overvoltage of the secondary side capacitor voltage V3 can be detected, and the power storage system can be quickly stopped to avoid the damage from spreading.

In embodiment 3, since the charge discharge of the primary side capacitor 43 is not performed, an unnecessary discharge operation can be prevented.

The other items of abnormality detection will be described in the description of embodiment 1 by replacing the discharge circuit unit 45(1), the discharge command S4, and the discharge element 46c with the discharge circuit 45(2), the primary discharge command S41, the secondary discharge command S42, and the discharge elements 46c1 and 46c2, respectively.

By adopting the configuration of embodiment 3 described above, the primary-side capacitor 43 and the secondary-side capacitor 63 can be discharged as needed, and wasteful discharge operation can be eliminated, so that a power storage system with good efficiency can be obtained.

Embodiment 4

Fig. 23 is a diagram showing a configuration example of a power storage system according to embodiment 4 of the present invention.

Embodiment 4 is modified based on the composition example of embodiment 1, and therefore, the same components as those of embodiment 1 are denoted by the same reference numerals, and description thereof is omitted, and only different components are described.

As shown in fig. 23, the power storage system 200(4) includes a primary-side switch unit 30(2) instead of the primary-side switch unit 30(1), and a system control unit 120(4) instead of the system control unit 120 (1).

Fig. 24 is a diagram showing a configuration example of the primary-side switching unit 30(2) according to embodiment 4 of the present invention.

As shown in fig. 24, the primary-side switching unit 30(2) includes a switch 31a and a switch 31b arranged in series on the positive side, and a charging resistor 32 connected in parallel to the switch 31 b. The on signals S1 and S2 are input to the switches 31a and 31b, respectively, and the auxiliary contact signals F1 and F2 are input from the switches 31a and 31b to the system controller 120 (4).

Next, the operation steps from the start of the power storage system 200(4) to the normal operation to the stop of the power storage system in the configuration of embodiment 4 will be described.

At the start of the primary side:

(step 1A-4)

The explanation is focused on the fact that the system control unit 120(1) is replaced with the system control unit 120(4) in the same manner as the step 1A-1 shown in embodiment 1.

(step 2A-4)

When recognizing that the switch 8a is normally turned on and the state where the primary-side voltage V1 detected by the voltage detector 21 is equal to or higher than the set value continues for a certain time, the system control unit 120(4) outputs an on command S1 to excite the coil 31a3 of the switch 31a and turn on the main contact 31a 1. Thus, the primary side capacitor 43 is charged through the charging resistor 31.

The system control unit 120(4) determines that charging of the primary side capacitor 43 is completed after a predetermined time has elapsed after the switch 31a is recognized to be normally turned on or after a predetermined time has elapsed since the difference between the primary side voltage V1 and the primary side capacitor voltage V2 is equal to or less than a set value, and outputs the on command S2, in a stage in which the on command S1 is turned on and the state in which the auxiliary contact 31a2 of the switch 31a is reliably closed and the auxiliary contact signal F1 is turned on continues for a predetermined time. Accordingly, the coil 31a3 of the switch 31b is excited, and the main contact 31a1 is turned on.

The system control unit 120(4) recognizes that the switch 31b is normally on when the state in which the auxiliary contact 21a2 of the switch 31b is reliably closed and the auxiliary contact signal F2 is on continues for a certain time.

(step 3A-4)

When the system control unit 120(4) confirms that the switch 31b is normally turned on, it outputs an operation command S3 to the inverter control unit 52 a. At this time, S3 is a signal including a command for operating the DCDC converter 50(1) in the initial charging mode to charge the secondary side capacitor 63, the secondary side capacitor voltage V3, and the secondary side voltage V4. When receiving the operation command S3, the inverter control unit 52a controls the inverter circuit 51a to equalize the secondary-side capacitor voltage V3 and the secondary-side voltage V4, and to charge the secondary-side capacitor 63 by flowing the required power from the primary side to the secondary side. At this time, in order to prevent the secondary side capacitor 63 and the like from being destroyed by rapid charging, the converter control unit 52a has a function of charging the secondary side capacitor 63 while controlling the current of the converter circuit 51a and limiting the current flowing from the primary side to the secondary side to a set value.

The system control unit 120(4) determines that the charging of the secondary capacitor 63 is completed when the difference between the secondary capacitor voltage V3 and the secondary voltage V4 is within the set value and a set time has elapsed.

(step 4A-4) to (step 8A-4)

The explanation is focused on the case where the system control unit 120(1) is replaced with the system control unit 120(4) in the same manner as in step 4a1 to step 8A-1 shown in embodiment 1.

When the secondary side is started:

(step 1B-4) - (step 2B-4)

The explanation is focused on the fact that the system control unit 120(1) is replaced with the system control unit 120(4) and is the same as the steps 1B to 1, and the step 2B-1 shown in embodiment 1.

(step 3B-4)

When the system control unit 120(4) determines that charging of the primary side capacitor 43 is completed, the system control unit turns on the on commands S1, S2 for turning on the switches 31a, 31 b. Accordingly, the closing coils 31a3 of the switches 31a and 31a2 are driven to close the main contact 31a 1. Therefore, the auxiliary contact 31a2, which is interlocked with the main contact 31a1, is closed, and auxiliary contact signals F1 and F2 indicating the states of the auxiliary contacts 31a2 are output to the system control unit 120 (4).

The system control unit 120(4) confirms that the turning-on of the switches 31a and 31c is normally completed in a stage where the on commands S1 and S2 are turned on, the auxiliary contact 31a2 of the switch 31a is reliably closed, and the auxiliary contact signals F1 and F2 are turned on for a certain time.

(step 4B-4)

The system control unit 120(4) recognizes that the switches 31a and 31b are normally turned on, and outputs an on command S0 for the switch 8a to excite the coil 31a3 of the switch 8a and turn on the main contact 31a 1.

In a stage in which the on command S0 is turned on, the auxiliary contact 31a2 of the switch 8a is reliably closed, and the condition that the auxiliary contact signal F0 is on continues for a certain time, the system control unit 120(4) recognizes that the switch 8a is normally on.

(step 5B-4 (step 8B-4)

The explanation is focused on the fact that the system control unit 120(1) is replaced with the system control unit 120(4) and is the same as the steps 5B to 1, and the step 8B-1 shown in embodiment 1.

The description of the detection method and the operation when an abnormality is detected will be given in the description of embodiment 1 by replacing the system control unit 120(1) with the system control unit 120 (4).

With the configuration of embodiment 4 described above, since the switches 31a and 31b are arranged in series, even when the switch 31b fails and cannot be opened, the circuit can be opened by the switch 31a, and therefore, a power storage system in which the primary-side circuit can be more reliably opened can be obtained.

Embodiment 5

Fig. 25 is a diagram showing a configuration example of an electricity storage system according to embodiment 5 of the present invention.

Embodiment 5 is modified based on the composition example of embodiment 1, and therefore the same components as those of embodiment 1 are denoted by the same reference numerals, and description thereof is omitted, and only different components will be described.

As shown in fig. 25, the power storage system 200(5) includes a secondary-side switching unit 70(2) instead of the secondary-side switching unit 70(1), and a system control unit 120(5) instead of the system control unit 120 (1).

Fig. 26 is a diagram showing a configuration example of the secondary-side switching unit 70(2) according to embodiment 5 of the present invention.

As shown in fig. 26, the secondary-side switching unit 70(2) includes a switch 71a and a switch 11b arranged in series on the positive side, a charging resistor 72 connected in parallel to the switch 71b, and a switch 71c arranged in series on the negative side.

The pair of switches 71a to 71c are configured such that the system control unit 120(5) receives the on signals S5 to S7, and the switches 71a to 71c receive the auxiliary contact signals F5 to F7, respectively, to the system control unit 120 (5).

The internal configuration of the switches 71a to 71c is the same as that shown in fig. 7, and therefore, the description thereof is omitted.

The switches 71a to 71c are illustrated as mechanical switches, but are not limited thereto as long as the operation can be confirmed by turning on and off the circuit, and may be, for example, semiconductor type contactless switches.

Next, the operation procedure of the power storage system 200(5) having the configuration shown in embodiment 5, which is started from the start-up, and stopped after the structure is normally operated, will be described.

At the start of the primary side:

(Steps 1A-5) to 3A-5)

The explanation is focused on the fact that the system control unit 120(1) is replaced with the system control unit 120(5) and is the same as the steps 1A-1 to 3A-1 shown in embodiment 1.

(step 4A-5)

When the system control unit 120(5) determines that the charging of the secondary side capacitor 63 is completed, the system control unit turns on the on commands S5 to S7 for turning on the switches 71a to 71 c. Accordingly, the closing coil 31a3 of each of the switches 71a to 71c is driven, and the main contact 31a1 is closed. As a result, the auxiliary contact 31a2, which is interlocked with the main contact 31a1, is closed, and auxiliary contact signals F5 to F7, which indicate the states of the auxiliary contacts 31a2, are output to the system controller 120 (5).

The system control unit 120(5) recognizes that the turning on of the switches 71a to 71c is normally completed in a stage where the on commands S5 to S7 are turned on, the auxiliary contact 31a2 of the switches 71a to 71c is reliably closed, and the auxiliary contact signals F5 to F7 are turned on for a certain time.

The switches 71a to 71c may be turned on simultaneously or sequentially. By performing the sequential turn-on, the peak power required for the turn-on can be reduced, and only the switch that is turned on last can be made to be a switch that can be turned on and off by current. The switch capable of switching on and off the current is generally large in size, but the number of the switches used is reduced, so that a small and lightweight power storage system is obtained.

(step 5A-5)

When the system control unit 120(5) determines that the on of the switches 71a to 71c is normally completed, the system control unit 120 outputs an operation command S3 to the converter control unit 52a to operate the coupling reactor 51a while maintaining the current ILP (and the negative-side ILN) at zero.

Accordingly, the converter control unit 52a controls the converter circuit 51a so that the current ILP of the coupling reactor 51a5 (or the negative-side ILN) becomes zero.

The converter primary side current I1P (or I1N) may be controlled to be zero, the converter secondary side current I2P (or I2N) may be controlled to be zero, and the primary side current I1 detected by the current detector 11 and the secondary side positive side current I3 detected by the current detector 91 may be controlled to be zero. Further, the current detector I3 may be replaced with a secondary side negative side current I5 as a detection value of the current detector 93, and set to zero.

The system control unit 120(5) determines that the converter control unit 52a is normal when a state in which the detected value of the current to be controlled is equal to or less than the set value continues for a predetermined time.

(step 6A-5)

The explanation is made in the same way as step 6A-1 shown in embodiment 1 by replacing the system control unit 120(1) with the system control unit 120 (5).

(step 7A-5)

The explanation is focused on the fact that the system control unit 120(1) is replaced with the system control unit 120(5) in the same manner as the step 7A-1 shown in embodiment 1.

(step 8A-5)

The explanation is focused on the fact that the system control unit 120(1) is replaced with the system control unit 120(5) in the same manner as the step 8A-1 shown in embodiment 1.

When the secondary side is started;

(step 1B-5)

When the control power supply of the system control unit 120(5) is turned on and a command C1 including a drive command is input from the outside, the system control unit 120(5) confirms that no abnormality has occurred in the state signal F10 from the power storage unit monitor 112 of the power storage unit 110, and turns on the on commands S5 and S7 of the switches 71a and 71C at a time when the state in which the secondary-side voltage V4 detected by the voltage detector 81 is equal to or higher than the set value continues for a certain time. Accordingly, the closing coils 31a3 of the switches 71a and 71c are driven to close the main contact 31a 1. In this way, the auxiliary contact 31a2 that is interlocked with the main contact 31a1 is closed, and the auxiliary contact signals F5 and F7 indicating the states of the auxiliary contacts 31a2 are output to the system control unit 120 (5).

The system control unit 120(5) recognizes that the turning on of the switches 71a and 71c is normally completed in a stage where the on commands S5 and S7 are turned on, the auxiliary contact 31a2 of the switches 71a and 71c is reliably closed, and the auxiliary contact signals F5 and F7 are turned on for a certain time.

The switches 71a and 71c may be turned on simultaneously or sequentially. By turning on the power source sequentially, the peak power required for turning on the power source can be reduced, and a control power source with a small peak rejection can be used.

The switches 71a and 71c are turned on, and the secondary side capacitor 63 is charged by the charging resistor 72.

The system control unit 120(5) recognizes that the state continues for a certain time period after the normal completion of the on operation of the switches 71a and 71c, or that the charging of the secondary capacitor 63 is completed after a certain time period elapses since the difference between the secondary side voltage V4 and the secondary side capacitor voltage V3 is equal to or less than a set value, and outputs an on command S6. Accordingly, the coil 31a3 of the switch 71b is excited, and the main contact 31a1 is turned on.

The system control unit 120(5) recognizes that the switch 71b is normally turned on when the state in which the auxiliary contact 31a2 of the switch 71b is reliably closed and the auxiliary contact signal F6 is on continues for a certain time.

(step 2B-5)

The explanation is focused on the same as the step 2B-1 shown in embodiment 1, because the system control unit 120(1) is replaced with the system control unit 120(5) and the switch 71a is replaced with the switch 71B.

(step 3B-5) to step 8B-5)

The explanation is focused on the fact that the system control unit 120(1) is replaced with the system control unit 120(5) and is the same as the steps 6B-1 to 8B-1 shown in embodiment 1.

The description of the abnormality detection method is focused on the description of embodiment 1, since the system control unit 120(1) is replaced with the system control unit 120 (5).

With the configuration of embodiment 5 described above, since the switches 71a and 71b are arranged in series, even when the circuit cannot be opened due to a failure of the switch 71b, for example, the circuit can be opened by the switch 71a, and therefore, a power storage system in which the secondary-side circuit can be further reliably opened can be obtained.

Embodiment 6

Fig. 27 is a diagram showing a configuration example of a power storage system according to embodiment 6 of the present invention.

Embodiment 6 is modified based on the composition example of embodiment 1, and therefore the same components as those of embodiment 1 are denoted by the same reference numerals, and description thereof is omitted, and only different components will be described.

As shown in fig. 27, the power storage system 200(6) includes a DCDC converter unit 50(2) instead of the DCDC converter unit 50(1), a discharge circuit unit 43(3) instead of the discharge circuit unit 45(1), a secondary filter unit 60(2) instead of the secondary filter unit 60(1), and a system control unit 120(6) instead of the system control unit 120 (1).

The discharge circuit unit 45(3) is connected to the positive side and the negative side of the subsequent stage of the primary filter unit 40(1), and the secondary filter unit 60(2) does not receive a signal input to the system control unit 120 (6).

Fig. 28 is a diagram showing an example of the configuration of the DCDC converter 50(2) according to embodiment 6 of the present invention.

As shown in fig. 28, DCDC converter 50(2) includes converter circuit 51b and converter control unit 52b, receives an operation command S3 from system control unit 120(6) to converter control unit 52b, and outputs a state signal F3 from converter control unit 52b to system control unit 120 (6).

Fig. 29 is a diagram showing a configuration example of the inverter circuit 51 b.

As shown in FIG. 29, the bidirectional buck converter circuit includes 2 switching elements 51b 1-51 b 2. The present circuit is a circuit capable of bidirectionally controlling a power flow only in a state where a primary side voltage (left side terminal in the figure) of an inverter circuit is always larger than a secondary side voltage (right side terminal in the figure).

Since this circuit requires half the number of switching elements as compared with the converter circuit 51a shown in embodiment 1, the DCDC converter unit can be small and light, and a small and light power storage system can be obtained.

As shown in fig. 28 and 29, an operation command S3 including an operation, a stop, and a control mode of the DCDC converter, power flowing between the primary side and the secondary side, a command value (target value) of the converter primary side current I1P (or I1N), the converter secondary side current I2P (or I2N), and the primary side capacitor voltage V2 is input from the system control unit 120(6) to the converter control unit 52b, and a state signal F3 of the DCDC converter 50(2) is input from the converter control unit 52b to the system control unit 120 (6).

The state signal F3 includes the voltage, current, temperature, on/off state of the switching element, and fault state of each unit of the DCDC converter 50 (2). The inverter control unit 52b performs PWM control of the switching elements 51b1 to 51b2 of the inverter circuit 51b in accordance with the operation control command S3.

Fig. 30 is a diagram showing an example of the configuration of the discharge circuit section 45(3) according to embodiment 6 of the present invention. As shown in fig. 30, the positive side of a circuit in which the discharge element 46c and the discharge resistor 46e are connected in series is connected to a wiring led from the positive side of the subsequent stage of the primary filter unit 40(1), and the negative side is connected to a negative side wiring.

The discharge element 46c is on/off controlled by the discharge element driving circuit 46 d. A discharge command S4 including an on/off command for the discharge element 46c is input to the discharge element driving circuit 46d from the system control unit 120(6), and a state signal F4 including an operating state of the discharge element 46c is input to the system control unit 120(6) from the discharge element driving circuit 46.

Fig. 31 is a diagram showing a configuration example of the secondary-side filter unit 60(2) according to embodiment 6 of the present invention.

As shown in fig. 31, a noise filter 64 is connected, and a reactor 61 is connected at the subsequent stage of the noise filter 64.

This reactor 61 is used for smoothing so that the current of the power storage unit 110 does not include a large ripple component.

The structure of the noise filter 64 is similar to that described in embodiment 1, and therefore is preferred. This noise filter 64 is preferably disposed at the rear stage of the secondary side capacitor 63 and near the secondary side capacitor 63.

Next, the operation procedure of the power storage system 200(6) having the configuration shown in embodiment 6 from the start-up, the normal operation, and then the stop will be described, which is different from embodiment 1.

At the start of the primary side:

(Steps 1A-6), (step 2A-6)

The explanation is focused on the same steps 1A-1 and 2A-1 as in embodiment 1, since the system control unit 120(1) and the DCDC converter unit 50(1) are replaced with the system control unit 120(6) and the DCDC converter unit 50(2), respectively.

(step 3A-6)

This step is not present.

(step 4A-6)

When the system control unit 120(6) determines that the on of the switch 31a is normally completed, the system control unit turns on the on commands S5 and S7 for turning on the switches 71a and 71 c. Accordingly, the closing coil 31a3 of each of the switches 71a and 71c is driven, and the main contact 31a1 is closed. As a result, the auxiliary contact 31a2, which is interlocked with the main contact 31a1, is closed, and auxiliary contact signals F5 and F7 indicating the states of the auxiliary contacts 31a2 are output to the system controller 120 (6).

The system control unit 120(6) recognizes that the turning on of the switches 71a and 71c is normally completed in a stage where the on commands S5 and S7 are turned on, the auxiliary contact 31a2 of the switches 71a and 71c is reliably closed, and the auxiliary contact signals F5 and F7 are turned on for a certain time.

The switches 71a and 71c may be turned on simultaneously or sequentially. By performing the sequential turn-on, the peak power required for the turn-on can be reduced, and only the switch that is turned on last can be made to be a switch that can be turned on and off by current. The switch capable of switching on and off the current is generally large in size, but the number of the switches used is reduced, so that a small and lightweight power storage system is obtained.

(step 5A-6)

When the system control unit 120(6) determines that the on of the switches 71a and 71c is normally completed, it outputs an operation command S3 to the inverter control unit 52a to operate the inverter with the inverter primary-side current I1P (or the negative-side I1N) kept at zero or the inverter secondary-side current I2P (or I2N) kept at zero.

The primary current I1 detected by the current detector 11 and the secondary side positive side current I3 detected by the current detector 91 are also controlled to be zero.

Further, the secondary side positive side current I3 may be replaced with a secondary side negative side current I5 as a detection value of the current detector 93, and the operation may be performed.

The system control unit 120(6) determines that the converter control unit 52b is normal when a state in which the detected value of the current to be controlled is equal to or less than the set value continues for a predetermined time.

(step 6A-6)

When system control unit 120(6) determines that converter control unit 52b is normal, operation command S3 including current command I or power command P is input to converter control unit 52 b.

Accordingly, the converter control unit 52b controls the current or the power between the primary side and the secondary side so as to be equal to the command.

Further, the current of the control target is any one of the converter primary side current I1P (or I1N) and the converter secondary side current I2P (or I2N).

When an operation command S3 including a voltage command V is input from the system control unit 120(6) to the converter control unit 52b, the converter control unit 52b controls the converter circuit 51b so that the voltage V2 of the primary-side capacitor 43 matches the voltage command V.

(step 7A-6)

When an operation command C1 including a stop command is input from the outside, the system control unit 120(6) inputs an operation command S3 to the inverter control unit 52b so that the current of the inverter is gradually reduced to zero.

The inverter control unit 52b controls the inverter circuit 51b so that the current gradually decreases to zero at the end. The time until the current is reduced to zero can be arbitrarily set. When the state where the current is equal to or lower than the set value continues for a certain time, the system control unit 120(6) inputs the operation command S3 to stop the DCDC converter 50(2), and the converter control unit 52b turns off the switching elements 51b1 to 51b4 to output the state signal F3. The system control unit 120(6) confirms the state signal F3 to confirm that the DCDC converter 50(2) is normally stopped.

The current of the control target is any one of the converter primary side current I1P (or I1N) and the converter secondary side current I2P (and I2N).

By reducing the current to zero and then turning off the switching elements 51b1 to 51b4, the primary side capacitor voltage V2 can be prevented from being suddenly overvoltage or the like.

(step 8A-6)

The explanation is focused on the same as the step 8A-1 shown in embodiment 1, except that the system control unit 120(1), the DCDC converter unit 50(1), and the system control unit 120(6) are replaced with the system control unit 120(1), and the DCDC converter unit 50(2), respectively.

When the secondary side is started:

(step 1B-6)

When the control power supply of the system control unit 120(6) is turned on and a command C1 including a drive command is inputted from the outside, the system control unit 120(6) confirms that no abnormality has occurred in the state signal F10 from the power storage unit monitor 112 of the power storage unit 110, and turns on the on commands S6 and S7 of the switches 71b and 71C at a time when the state in which the secondary-side voltage V4 detected by the voltage detector 81 is equal to or higher than the set value continues for a certain time. Accordingly, the closing coils 31a3 of the switches 71b and 71c are driven to close the main contact 31a 1. In this way, the auxiliary contact 31a2 that is interlocked with the main contact 31a1 is closed, and the auxiliary contact signals F6 and F7 indicating the states of the auxiliary contacts 31a2 are output to the system control unit 120 (6).

The system control unit 120(6) recognizes that the turning on of the switches 71b and 71c is normally completed in a stage where the on commands S6 and S7 are turned on, the auxiliary contact 31a2 of the switches 71b and 71c is reliably closed, and the auxiliary contact signals F6 and F7 are turned on for a certain time.

The switches 71b and 71c may be turned on simultaneously or sequentially. By turning on the power source sequentially, the peak power required for turning on the power source can be reduced, and a control power source with a small peak rejection can be used.

The switches 71b and 71c are turned on, and the primary capacitor 43 is charged by the diode portions of the switching elements 51b1 to 51b2 of the charging resistor 72DCDC converter unit 50 (2).

The system control unit 120(6) recognizes that the state continues for a certain time period after the normal completion of the on operation of the switches 71b and 71c, or that the charging of the primary capacitor 43 is completed after a certain time period elapses since the difference between the secondary side voltage V4 and the secondary side capacitor voltage V3 is equal to or less than a set value, and outputs an on command S5. Accordingly, the coil 31a3 of the switch 71a is excited, and the main contact 31a1 is turned on.

The system control unit 120(6) recognizes that the switch 71a is normally turned on when the state in which the auxiliary contact 31a2 of the switch 71a is reliably closed and the auxiliary contact signal F5 is on continues for a certain time.

(step 2B-6)

When the system control unit 120(6) confirms that the switch 71a is normally turned on, it outputs an operation command S3 to the inverter control unit 52 a. At this time, S3 is a signal including a command for operating the DCDC converter 50(2) in the boost charging mode to charge the primary side capacitor 43, the primary side capacitor voltage V2, and the primary side voltage V1. When receiving the operation command S3, the inverter control unit 52b operates the inverter circuit 51b to flow the required power from the secondary side to the primary side, thereby further charging the primary side capacitor 43. In this case, in order to prevent the primary capacitor 43 and the like from being destroyed in rapid charging, the converter control unit 52b is configured to charge the primary capacitor 43 while controlling the current of the converter circuit 51b so that the current flowing from the primary side to the secondary side is limited to a set value.

When the primary-side capacitor voltage V2 and the primary-side capacitor voltage V1 are within the set values or the primary-side capacitor voltage V2 reaches a predetermined set value, the converter control unit 52b performs control so that the current flowing from the secondary side to the primary side decreases and the primary-side capacitor voltage V2 does not increase beyond the set value.

The system control unit 120(6) determines that the charging of the primary capacitor 43 is completed when the difference between the primary capacitor voltage V2 and the primary capacitor voltage V1 is within a set value and a set time elapses or the primary capacitor voltage V2 reaches a predetermined set value.

(step 3B-6), (step 4B-6)

The system control unit 120(1), the DCDC converter unit 50(1) are replaced with the system control unit 120(6), and the DCDC converter unit 50(2) are the same as the steps 3B-1 and 4B-1 shown in the embodiment, respectively, and therefore the description thereof is omitted.

Step 5B-6

When the system control unit 120(6) determines that the switch 8a is normally on, it outputs an operation command S3 to the inverter control unit 52b to operate the inverter with the secondary side current I2P (or I2N) maintained at zero.

Therefore, inverter control unit 52b controls inverter circuit 51b such that inverter secondary side current I2P (or I2N) is zero.

The converter primary side current I1P (or I1N) is also controlled to be zero, and the primary side current I1 detected by the current detector 11, the secondary side positive side current I3 detected by the current detector 91, and the secondary side negative side current I5 detected by the current detector 93 are also controlled to be zero.

The system control unit 120(6) determines that the converter control unit 52b is normal when a state in which the detected value of the current to be controlled is equal to or less than the set value continues for a certain period of time.

(step 6B-6)

When system control unit 120(6) determines that converter control unit 52b is normal, operation command S3 including current command I or power command P is input to converter control unit 52 b.

Accordingly, the converter control unit 52b controls the current or the power between the primary side and the secondary side so as to be equal to the command.

Further, the current of the control target is any one of the converter primary side current I1P (or I1N) and the converter secondary side current I2P (or I2N).

When an operation command S3 including a voltage command V is input from the system control unit 120(6) to the converter control unit 52b, the converter control unit 52b controls the converter circuit 51b so that the primary-side capacitor voltage V2 matches the voltage command V.

(step 7B-6)

When an operation command C1 including a stop command is input from the outside, the system control unit 120(6) inputs an operation command S3 to the inverter control unit 52b so that the current of the inverter is gradually reduced to zero.

The inverter control unit 52b controls the inverter circuit 51b so that the current gradually decreases to zero at the end. The time until the current is reduced to zero can be arbitrarily set. When the state where the current is equal to or lower than the set value continues for a certain time, the system control unit 120(6) inputs the operation command S3 to stop the DCDC converter 50(2), and the converter control unit 52b turns off the switching elements 51b1 to 51b4 to output the state signal F3. The system control unit 120(6) confirms the state signal F3 to confirm that the DCDC converter 50(2) is normally stopped.

The current of the control target is any one of the converter primary side current I1P (or I1N) and the converter secondary side current I2P (and I2N).

By reducing the current to zero and then turning off the switching elements 51b1 to 51b4, the primary side capacitor voltage V2 can be prevented from being suddenly overvoltage or the like.

(step 8B-6)

The explanation is focused on the same as the step 8B-1 shown in the embodiment because the system control unit 120(1), the DCDC converter unit 50(1), and the system control unit 120(6) are replaced with the system control unit 120(1), and the DCDC converter unit 50(2), respectively.

By the above-described operation steps from the start of the operation, after the normal operation, to the stop of the operation, the power storage system which is reliable in operation can be obtained.

In the operation of only the primary-side startup, the switch 71b and the charging resistor 72 of the secondary-side switching unit 70(1) are not required, and can be eliminated.

In the operation that can be started only by the secondary side, the switch 31b and the charging resistor 32 of the primary side switching unit 30(1) are not required, and can be deleted.

Next, a detailed abnormality detection method of the power storage system shown in embodiment 6 and an operation when an abnormality is detected will be described.

In order to safely and stably operate the power storage system, it is necessary to quickly take appropriate measures depending on the type of abnormality when abnormality occurs in each part of the power storage system. Therefore, it is important to detect an abnormality and what measure is taken depending on the type of abnormality, and the following description will be made.

(anomaly detection 1-6) differential Current anomaly detection

When the state in which the primary side differential current I2 and the secondary side differential current I4, which are the outputs of the current detectors 12 and 92, are not equal to or less than the set values continues for a certain time, the system control unit 120(6) determines that a leakage current due to insulation deterioration has occurred in a certain place in the circuit, turns off the on signals S0 to S2 and S5 to S7 of the switches 8a, 31b, and 71a to 71c, turns off the switching elements 51b1 to 51b4 of the DCDC converter 50(2), and inputs a discharge command S4 to the discharge circuit unit 45(3) to discharge the charge of the primary side capacitor 43.

By operating as described above, it is possible to detect an increase in leakage current, quickly stop the power storage system, and avoid an increase in damage.

The set values may be configured to be composed in multiple stages, and when the differential current is sufficiently small, the set values may be recorded in a system control unit, a device, a recording device (not shown) or an indicator lamp (not shown) provided on a table or the like, without stopping the power storage system, to prompt the inspection.

(abnormality detection 2-6) switch abnormality detection

The system control unit 120(6) determines that the switch 8a is abnormal when the state in which the main contact 31a1 is not closed and the auxiliary contact 31a2 is not closed and the auxiliary contact signal F0 is not conductive continues for a certain time due to a failure or the like of the close coil 31a3 of the switch 8a despite the on command S0 of the switch 8a being turned on, or when the state in which the auxiliary contact 31a2 is conductive and the auxiliary contact signal F0 is also conductive continues for a certain time in the state in which the on command S0 is interrupted.

The switches 8a, 31b, and 71a to 71c are also subjected to abnormality detection in the same manner.

When any of the switches 8a, 31b, and 71a to 71c detects an abnormality, the system control unit 120(1) turns off the on commands S0 to S2 and S5 to S7 of all the switches 8a, 31b, and 71a to 71c, turns off the switching elements 51b1 to 51b4 of the DCDC converter 50(2), and inputs a discharge command S4 to the discharge circuit unit 45(3) to discharge the electric charge of the primary side capacitor 43.

By operating as described above, a failure of the switch can be detected, and the power storage system can be quickly stopped, thereby preventing the damage from being extended.

(abnormality detection 3-6) detection of abnormality in charging of primary side capacitor (at the time of primary side startup)

When the switch 31b is recognized to be normally turned on in the above-described step 2A-6 at the time of the primary side start, and even if a certain time has elapsed, the system control unit 120(6) determines that the charging cannot be completed due to an abnormality such as the ground of the primary side capacitor 43 when the difference between the primary side voltage V1 and the primary side capacitor voltage V2 is equal to or larger than the set value or the primary side current I1 is equal to or larger than the set value, turns off the turn-on commands S0 to S2 of the previously turned-on capacitors 8a, 31a, and 31b, and inputs the discharge command S4 to the discharge circuit unit 45(3) to discharge the charge of the primary side capacitor 43.

By operating as described above, it is possible to detect an abnormality in the charging circuit of the primary side capacitor 43, to quickly stop the power storage system, and to avoid an increase in damage.

(abnormality detection 6-6) detection of abnormality in charging of primary-side capacitor (at the time of secondary-side startup)

When the charging of the primary side capacitor 43 is not completed within the time set in the above-described step 2B-5 and step 2B-6 at the time of the secondary side startup or when the state signal F3 indicating the converter failure is received from the converter control unit 52B, the system control unit 120(6) stops the switching elements 51B1 to 51B4 of the DCDC converter 50(2) by blocking the on commands S6 and S7 of the previously turned-on switches 71B and 71c when the abnormality occurs in the periphery of the DCDC converter 50(2) or the primary side capacitor 43, and inputs the discharge command S4 to the discharge circuit unit 45(3) to discharge the charge of the primary side capacitor 43.

By operating as described above, it is possible to detect an abnormality in the charging circuit of the primary side capacitor 43, to quickly stop the power storage system, and to avoid an increase in damage.

(anomaly detection 7-6) Primary-side capacitor overvoltage detection

When the primary capacitor voltage V2 detected by the voltage detector 42 exceeds a predetermined value, the system control unit 120(6) stops the switching elements 51b1 to 51b4 of the DCDC converter 50(2), turns off the on commands S1, S2, S5 to S7 of the switching elements 31a, 31b, 71a to 71b, and inputs the discharge command S4 to the discharge circuit unit 45(3) to discharge the charge of the primary capacitor 43.

By operating as described above, the overvoltage of the primary side capacitor voltage V2 can be detected, and the power storage system can be stopped quickly, thereby preventing the damage from being increased.

(anomaly detection 9-6) DC converter overcurrent detection

The system control unit 120(6) turns off the switching elements 51b1 to 51b4 of the DCDC converter 50(2) when the currents of the switching elements 51b1 to 51b4 of the converter circuit 51b are equal to or higher than a predetermined value.

Further, the currents of the switching elements 51b 1-51 b4 may be replaced by the converter primary side current I1P (or I1N), and when the currents are greater than or equal to a predetermined value, the switching elements 51b 1-51 b4 are turned off.

The on commands S1, S2, and S5 to S7 of the switching elements 31a, 31b, and 71a to 71b are not turned off, and the discharge command S4 is not input to the discharge circuit unit 45(3), so that the charge in the primary side capacitor 43 is not discharged.

The reason why the charge of the capacitor 43 is not discharged and only the switching elements 51b1 to 51b4 are turned off is that the overcurrent of the DCDC converter may be a phenomenon that occurs temporarily due to a disturbance of a rapid change in the primary-side capacitor voltage V2 or the secondary-side capacitor voltage V3, and the DCDC converter itself cannot be immediately abnormal, and the DCDC converter is less likely to be damaged.

By operating as described above, the overcurrent of the DCDC converter can be detected, the power storage system can be quickly stopped, and the damage can be prevented from being enlarged.

The time taken for restart due to capacitor recharging can also be reduced.

(anomaly detection 10-6) DCDC converter temperature anomaly detection

The system control unit 120(6) turns off the switching elements 51b1 to 51b4 when the surface temperatures of the switching elements 51b1 to 51b4 of the inverter circuit 51b or the temperatures of the cooling fans (not shown) mounted on the switching elements 51b1 to 51b4 are equal to or higher than a predetermined value.

Further, the on commands S1, S2, and S5 to S7 of the switching elements 31a, 31b, and 71a to 71c are not turned off, the discharge command S4 is not input to the discharge circuit 45(3), and the charge of the primary side capacitor 43 is not discharged.

The reason why the capacitor is not discharged and only the switching elements 51b1 to 51b4 are turned off is that a temperature rise of the DCDC converter may be caused by a temporary overload, and the DCDC converter itself cannot be said to be abnormal immediately, and the DCDC converter is less likely to be damaged.

Further, it is preferable to provide another set value smaller than the set value, and control the DCDC converter to reduce the current to suppress the temperature rise when the set value is exceeded, and to turn off the switching elements 51b1 to 51b4 when the set value is exceeded, so that the operation can be continued as much as possible.

By operating as described above, it is possible to detect a temperature abnormality of the DCDC converter, quickly stop the power storage system, and avoid an increase in damage.

The time taken for restart due to capacitor recharging can also be reduced.

(abnormality detection 11-6) abnormality detection of switching element

When an abnormality (the content of the abnormality will be described later) in the switching elements 51b1 to 51b4 of the inverter circuit 51b is detected by the detection circuit (not shown) built in the switching elements 51b1 to 51b4 or the drive circuit (not shown) of the switching elements 51b1 to 51b4 or the inverter control unit 52b, the system control unit 120(6) stops the switching elements 51b1 to 51b4 of the DCDC converter 50(2) after recognizing the abnormality by the state signal F3, turns on commands S0, S1, S2, S5 to S7 of the switches 8a, 31b, and 71a to 71c off, and inputs the discharge command S4 to the discharge circuit unit 45(2) to discharge the charge of the primary capacitor 43.

When an abnormality is detected by a built-in detection circuit (not shown), the switching elements 51b1 to 51b4 may autonomously turn off the switches without a turn-off command from the system control unit 120(6) or the inverter control unit 52 b. Switching elements with such functionality are referred to as smart power modules. Thus, the switch can be quickly turned off without delay after the abnormality is detected, and the protection performance is improved.

The above-described abnormality is a case where the current flowing through the switching elements 51b1 to 51b4 has an excessive sharp rising edge, a case where the internal temperature of the switching elements 51b1 to 51b4 is equal to or higher than a certain set value, or a case where the voltage of the on/off signal of the switching elements 51b1 to 51b4 is unstable. These phenomena are phenomena that may be associated with the breakdown of the switching elements 51b 1-51 b 4.

By operating as described above, it is possible to detect an abnormality of the switching element, quickly stop the power storage system, and avoid an increase in damage.

(anomaly detection 12-6) Primary side overcurrent detection

When the switch 8a is automatically released by overcurrent, the system control unit 120(6) turns on the on command and blocks the auxiliary contact signal S0, and when this is detected, stops the switching elements 51b1 to 51b4 of the DCDC converter 50(2), blocks the on commands S0, S1, S2, and S5 to S7 of the switches 8a, 31b, and 71a to 71c, and inputs the discharge command S4 to the discharge circuit unit 45(3) to discharge the charge of the primary side capacitor 43.

When the switch 8a is released by itself due to an overcurrent, the possibility of an overcurrent flowing due to a short circuit or the ground is considered, and therefore, by operating as described above, the power storage system can be stopped quickly, and the damage can be prevented from being enlarged.

(anomaly detection 13-6) Secondary-side overcurrent detection

When the fuse 101a or 101b is blown, the system control unit 120(6) detects that the auxiliary contacts F8 and F9 are turned on, stops the switching elements 51b1 to 51b4 of the DCDC converter 50(2), blocks the on commands S0, S1, S2, and S5 to S7 of the switches 8a, 31b, and 71a to 71c, and inputs the discharge command S4 to the discharge circuit unit 45(3) to discharge the charge of the primary side capacitor 43.

The fuses 101a and 101b are blown out in consideration of the possibility of a current flowing through the fuses due to a short circuit or a ground, and therefore, the power storage system can be quickly stopped by the above operation, and the damage can be prevented from being increased.

(abnormality detection 14-6) storage unit abnormality detection

The system control unit 120(6) turns off the switching elements 51b 1-51 b4 when a state signal F10 indicating temperature constant, overcharge, and overdischarge is input from the power storage unit monitor 112.

Thereafter, if F10 indicates a temperature abnormality, the operation of the switching elements 51b 1-51 b4 is started.

When overcharging is indicated, since electric power is discharged from power storage unit 110, DCDC converter 50(2) is operated so that electric power can flow only from the secondary side to the primary side.

On the other hand, when overdischarge is indicated, since power storage unit 110 is charged, DCDC converter 50(2) is operated so that power can flow only from the primary side to the secondary side.

After a certain time has elapsed, if state signal F10 indicates a temperature abnormality, overcharge, or overdischarge, and there is a possibility that power storage unit 110 may have an unrecoverable abnormality, system control unit 120(6) stops switching elements 51b1 to 51b4 of DCDC converter 50(2), turns on commands S0, S1, S2, and S5 to S7 for switches 8a, 31b, and 71a to 71c, and inputs discharge command S4 to discharge electric charge of primary capacitor 43 to discharge circuit unit 45 (3).

By operating as described above, it is possible to detect an abnormality in the power storage unit, quickly stop the power storage system, and avoid an increase in damage.

In the above-described abnormality detection, it is preferable that the occurrence of an abnormality be recorded or displayed on an indicator lamp (not shown) or a display monitor (not shown) provided in a system control unit or in an apparatus or on a table or the like.

Among the above-mentioned abnormality detection items, the system control unit 120(6) prohibits the activation of the power storage system while detecting an abnormality because of a high possibility of damage to the following items when restarting, and releases the prohibition of activation only by manually operating a reset key provided in the work table, the system control unit, or the like:

(abnormality detection 1-6) differential current abnormality detection,

(abnormality detection 2-6) switch abnormality detection,

(abnormality detection 3-6) primary side capacitor charging abnormality detection (at the time of primary side startup),

(abnormality detection 6-6) primary-side capacitor charging abnormality detection (at the time of secondary-side startup),

(abnormality detection 11-6) detection of abnormality of switching element,

(abnormality detection 12-6) primary-side overcurrent detection,

(abnormality detection 13-6) Secondary side overcurrent detection,

(abnormality detection 14-6) electric storage unit abnormality detection.

In the above-described abnormality detection items, the system control unit 120(6) automatically restarts the system after a certain time has elapsed after the execution of the stop processing, considering the possibility of a transient phenomenon due to disturbance:

(abnormality detection 7-6) detection of the primary-side capacitor voltage,

(abnormality detection 9-6) DC/DC converter overcurrent detection,

(abnormality detection 10-6) DCDC converter temperature abnormality detection.

At this time, if it is monitored that there is a reoccurrence of an abnormality and the like abnormality is not detected within a certain time, the operation is continued as it is, and if the like abnormality is detected within a certain time, the power storage system is prohibited from being started up simultaneously with the reoccurrence of the abnormality detection. The prohibition of the activation is released only by manually operating a reset key provided in the table, the system control unit, or the like.

With this configuration, it is possible to prevent the system from being stopped due to a temporary abnormality caused by disturbance, and to avoid the range of damage to the abnormal portion from being widened by a simple restart.

When the control power supply voltage of the system control unit 120(6) is lower than the predetermined value, the following operation is performed.

When the control power supply voltage of the system control unit 120(6) is lower than a predetermined value or is turned off, a discharge command S4 is input to the discharge circuit unit 45(3) to discharge the charge of the primary side capacitor 43.

The on commands S0 to S2 and S5 to S7 are turned off in order to open the switches 8a, 31b, 71a to 71c at the same time.

The above operation is the same as that described in embodiment 1, and therefore the description thereof is cut.

In the configuration of embodiment 6 described above, since 2 switching elements used in the DCDC converter unit 50(2) can be dealt with, the DCDC converter unit 50(2) can be made small and light in weight, and a small and light power storage system can be obtained.

Embodiment 7

Fig. 32 is a diagram showing a configuration example of a power storage system according to embodiment 7 of the present invention.

Embodiment 7 is modified based on the composition example of embodiment 1, and therefore, the same components as those of embodiment 1 are denoted by the same reference numerals, and description thereof is omitted, and only different components are described.

As shown in fig. 32, the dc power supply 1(2) is arranged in place of the dc power supply 1(1), and is input to the power storage system 200 (7).

The dc power supplies 1(2) and the primary filter units 40(2) have the same compositions as those of fig. 19 and 20 described in embodiment 2, and therefore the description thereof is different.

The operation steps from the start of the power storage system 200(7) having the configuration shown in embodiment 7 to the stop after the normal operation and the abnormality detection method are described in the description of embodiment 6, and therefore the description thereof is preferred.

By adopting the configuration of embodiment 7 described above, when the power storage system is combined with the drive control device 1j, the reactor 1e of the drive control device 1j can be shared, and the reactor 41 in embodiment 6 can be omitted, whereby a small and lightweight power storage system can be obtained.

Further, by configuring the switch 1d in which the disconnecting unit 8 is omitted and the drive control device 1j is shared, a further compact and lightweight power storage system can be obtained.

In the configurations of embodiments 1 to 7 described above, the switch 71c is provided so as to open the negative side of the power storage unit 110, but the positive side may be opened to the minimum, and in this case, the switch 71c may be omitted.

In the configurations of embodiments 1 to 7 described above, the system control unit and the inverter control unit may be integrated, or the control unit may be divided into arbitrary functions in reverse.

In the configurations of embodiments 1 to 7 described above, the power storage system is connected to the dc power supply, but it is needless to say that the output of the converter circuit for rectifying the ac power supply may be connected.

It is needless to say that the configurations of embodiments 1 to 7 described above may be combined with each other as an example of the contents of the present invention, may be combined with another known technique, and may be partially omitted or changed without departing from the scope of the present invention.

Of course, the present invention is not limited to the power storage system for an electric train or the like, and can be applied to various related fields such as an automobile, an elevator, and a power system.

Claims (40)

1. A power storage system in which DC power from a DC power supply is adjusted to a predetermined voltage and current by a DCDC converter unit and stored in a power storage unit,

a primary side current detection unit for detecting a current of a main circuit, a primary side voltage detection unit for detecting a voltage of the main circuit, a primary side switch unit for turning on and off the main circuit, and a primary side filter unit for suppressing harmonics of the main circuit are disposed on a supply source side of the DC power as a primary side of the DCDC converter unit, and the DCDC converter unit

A secondary side filter unit for suppressing harmonics of the main circuit, a secondary side switch unit for switching the main circuit on and off, a secondary side voltage detection unit for detecting a voltage of the main circuit, and a secondary side current detection unit for detecting a current of the main circuit are disposed on the storage unit side, which is a secondary side, of the DCDC converter unit,

and a system control unit that receives status signals obtained from the primary-side current detection unit, the primary-side voltage detection unit, the primary-side switching unit, the primary-side filter unit, the DCDC converter unit, the secondary-side filter unit, the secondary-side switching unit, the secondary-side voltage detection unit, the secondary-side current detection unit, and the power storage unit, and detects an abnormality based on the received status signals, and performs control to stop at least one or more of the primary-side switching unit, the DCDC converter unit, and the secondary-side switching unit individually in response to different contents of the abnormality.

2. The power storage system according to claim 1,

the primary side filter unit includes a reactor connected in series with the main circuit and a primary side capacitor connected between positive and negative of the main circuit, and the secondary side filter unit includes a reactor connected in series with the main circuit and a secondary side capacitor connected between positive and negative of the main circuit, and a discharge circuit unit is provided that discharges the primary side capacitor and the secondary side capacitor separately or simultaneously in accordance with a command from the system control unit.

3. The power storage system according to claim 1 or 2,

the primary-side current detection unit, the primary-side voltage detection unit, the primary-side switching unit, and the primary-side filter unit are arranged in this order, and a cutoff unit having a current cutoff means is provided between the dc power supply and the primary-side current detection unit, and the secondary-side filter unit, the secondary-side switching unit, the secondary-side voltage detection unit, the secondary-side current detection unit, and the power storage unit are arranged in this order, and a protection device unit having a current cutoff means is provided between the secondary-side current detection unit and the power storage unit.

4. The power storage system according to claim 2,

when the power storage system is started, the DCDC converter unit is operated to initially charge the secondary side capacitor incorporated in the secondary side filter by the output thereof, or the primary side capacitor incorporated in the primary side filter is initially charged by the power of the power storage unit.

5. The power storage system according to claim 3,

the cut-off portion is constituted by a switch having an auxiliary contact mechanically connected to the main contact.

6. The power storage system according to claim 1,

the primary side switching unit includes a means for turning on and off the positive electrode side of the main circuit.

7. The power storage system according to claim 6,

the primary side switch unit is constituted by a switch having an auxiliary contact mechanically connected to a main contact.

8. The power storage system according to claim 7,

the primary side switch section has a circuit connecting the switch and a charging resistor.

9. The power storage system according to claim 1,

the primary-side current detection unit includes a means for detecting a difference between currents flowing through the positive-side wiring and the negative-side wiring.

10. The power storage system according to claim 1 or 2,

the primary-side filter section and the secondary-side filter section each have a noise filter.

11. The power storage system according to claim 1,

the DCDC converter unit is composed of a bidirectional buck-boost converter circuit.

12. The power storage system according to claim 1,

the DCDC converter section is composed of a bidirectional buck converter circuit.

13. The power storage system according to claim 1,

the secondary side switching unit includes a means for turning on and off only the positive side or both the positive side and the negative side of the main circuit.

14. The power storage system according to claim 13,

the secondary side switch unit is composed of a switch having an auxiliary contact mechanically connected to the main contact.

15. The power storage system according to claim 14,

the secondary side switch unit has a circuit connecting the switch and a charging resistor.

16. The power storage system according to claim 1,

the secondary-side current detection unit includes a means for detecting a difference between currents flowing through the positive-side wiring and the negative-side wiring.

17. The power storage system according to claim 3,

the protection device unit includes a unit that detects a state of the current interruption unit.

18. The power storage system according to claim 1,

the power storage unit is configured by a plurality of batteries connected in series and parallel, and a state signal from a monitor device that detects the state of the battery is input to the system control unit.

19. The power storage system according to claim 5,

the system control unit is configured to recognize that the cutoff unit is normally turned on by confirming an auxiliary contact signal from the cutoff unit after outputting an on command to the cutoff unit.

20. The power storage system according to claim 7,

the system control unit is configured to confirm an auxiliary contact signal from the primary switch unit after outputting a switch-on command to the primary switch unit, and recognize that the primary switch unit is normally switched on.

21. The power storage system according to claim 2,

the system control unit recognizes that the charging of the primary-side capacitor is completed after a predetermined time has elapsed after a difference between a detection value from the primary-side voltage detection unit and the primary-side capacitor voltage is equal to or less than a predetermined value.

22. The power storage system according to claim 2,

the system control unit recognizes that the secondary-side capacitor is charged after a predetermined time has elapsed after a difference between a detection value from the secondary-side voltage detection unit and the secondary-side capacitor voltage is equal to or less than a predetermined value.

23. The power storage system according to claim 14,

the system control unit confirms an auxiliary contact signal from the secondary switch unit after outputting a switch-on command to the secondary switch unit, and recognizes that the secondary switch unit is normally switched on.

24. The power storage system according to claim 1,

the method includes a step of controlling the current of the DCDC converter unit to be zero after the system control unit confirms that the primary-side switch unit and the secondary-side switch unit are normally turned on, and determining that the converter unit included in the DCDC converter unit is normal when a state in which a current detection value is equal to or less than a set value continues for a predetermined time.

25. The power storage system according to claim 1,

the system control unit gradually decreases the current of the DCDC converter at a predetermined rate when stopping the power storage system, and controls the switching element incorporated in the DCDC converter to be turned off after the current becomes substantially zero.

26. The power storage system according to claim 1,

the system control unit turns off the primary-side switching unit and the secondary-side switching unit after a switching element built in the DCDC converter is turned off.

27. The power storage system according to claim 3,

the system control unit detects an abnormality by using a state signal obtained from the disconnection unit, the primary-side current detection unit, the primary-side voltage detection unit, the primary-side switching unit, the primary-side filter unit, the DCDC converter unit, the secondary-side filter unit, the discharge circuit unit, the secondary-side switching unit, the secondary-side voltage detection unit, the secondary-side current detection unit, the protection device unit, and the power storage unit,

and controlling at least one of the cutoff unit, the primary-side switch unit, the DCDC converter unit, the discharge circuit unit, and the secondary-side switch unit according to the content of the abnormality.

28. The power storage system according to claim 27,

the system control unit is configured to, when the content of the abnormality is that the difference between the currents flowing through the positive-side wiring and the negative-side wiring detected by the primary-side current detection unit is equal to or greater than a set value, or the difference between the currents flowing through the positive-side wiring and the negative-side wiring detected by the secondary-side current detection unit is equal to or greater than a set value,

the discharge circuit unit to which at least the primary-side and secondary-side switching units and the DCDC converter unit are connected is turned on while at least the primary-side and secondary-side switching units and the DCDC converter unit are turned off.

29. The power storage system according to claim 27,

when the content of the abnormality is that any one of the disconnecting unit, the primary-side switching unit, and the secondary-side switching unit is abnormal,

at least the primary-side and secondary-side switching units and the DCDC converter unit are turned off, and the discharge circuit is turned on.

30. The power storage system according to claim 27,

when the content of the abnormality is an abnormality in charging the primary-side capacitor or the secondary-side capacitor,

at least the primary-side and secondary-side switching units and the DCDC converter unit are turned off, and the discharge circuit is turned on.

31. The power storage system according to claim 27,

the system control unit is configured to, when the content of the abnormality is the overvoltage of the primary side capacitor or the secondary side capacitor,

at least the primary-side and secondary-side switching units and the DCDC converter unit are turned off, and the discharge circuit is turned on.

32. The power storage system according to claim 1 or 27,

when the content of the abnormality is the DCDC converter overcurrent,

the DCDC converter unit is blocked.

33. The power storage system according to claim 1 or 27,

when the content of the abnormality is the DCDC converter temperature abnormality,

the DCDC converter unit is blocked.

34. The power storage system according to claim 27,

when the content of the abnormality is an abnormality of a switching element of the DCDC converter,

the primary-side switching unit, the secondary-side switching unit, and the DCDC converter unit are turned off, and the discharge circuit is turned on.

35. The power storage system according to claim 27,

the system control unit turns off at least the primary-side and secondary-side switching units and the DCDC converter unit and turns on the discharge circuit when the content of the abnormality is that the cutoff unit automatically cuts off the circuit without passing through the system control unit.

36. The power storage system according to claim 27,

the system control unit turns on the discharge circuit by turning off at least the primary-side and secondary-side switching units and the DCDC converter unit when the content of the abnormality is that the protection device unit automatically cuts off the circuit without passing through the system control unit.

37. The power storage system according to claim 27,

when the content of the abnormality is that the power storage unit is abnormal, the system control unit turns on the discharge circuit while turning off at least the primary-side switch unit, the secondary-side switch unit, and the DCDC converter unit.

38. The power storage system according to claim 1 or 27,

when the abnormality occurs, the system control unit records the abnormality in the system control unit and notifies an external device of the abnormality.

39. The power storage system according to claim 1 or 27,

the system control unit classifies the abnormality into a plurality of categories according to the contents thereof, and classifies at least the abnormality into an automatic restart after a stop due to detection of the abnormality and a restart without an artificial recovery operation.

40. The power storage system according to any one of claims 1 to 27,

the system control unit is a single control unit that receives an operation command from the outside and all state signals obtained from the primary-side current detection unit, the primary-side voltage detection unit, the primary-side switch unit, the primary-side filter unit, the DCDC converter unit, the secondary-side filter unit, the secondary-side switch unit, the secondary-side voltage detection unit, the secondary-side current detection unit, and the power storage unit.