JP2000262072A - Power regeneration type charge / discharge device - Google Patents

Abstract

(57) [Problem] To provide a power regeneration type charge / discharge device that is small and lightweight, does not require a discharge circuit, and has excellent regeneration efficiency. A power regeneration type charge / discharge device according to the present invention includes an inverter / converter circuit, a battery, and a DC bidirectional converter. DC bidirectional converter 3
Are first and second switch circuits 11, 1 connected in series between the output terminals of the inverter / converter circuit 1.
2, a high-frequency filter 13 connected in parallel to the second switch circuit 12, and first and second switch circuits 11,
A switch control circuit 14 for controlling the on / off of the pulse width of the battery 12 and a current detection circuit 1 for detecting a current flowing through the battery 2
And 5. First and second semiconductor switches
Since the direction of power transmission is switched using the switch circuits 11 and 12, the size and weight can be reduced. Further, since the ON / OFF of the first and second switch circuits 11 and 12 is controlled by the pulse width, the charge / discharge voltage of the battery 2 can be continuously variably controlled over a wide range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for charging a battery using an AC power source and regenerating the discharged power of the battery to the AC power source side to effectively use the power.

[0002]

2. Description of the Related Art There is known a power regenerating type charge / discharge device which regenerates a part of charging power charged in a battery using an AC power supply to an AC power supply side at the time of discharging so as to effectively use power. FIG. 6 is a block diagram showing a schematic configuration of a conventional power regeneration type charge / discharge device of this type. FIG. 6 (a) is a thyristor type power regeneration type charge / discharge device, and FIG. 6 (b) is a power transistor Q12. Is a transistor-type power regeneration type charging / discharging device in which a synchronous rectification circuit is configured using the above.

A thyristor-type power regeneration type charge / discharge device shown in FIG. 6 (a) operates as an AC / DC converter during charging and serves as a DC / AC inverter during discharging, and a battery 52, It has a discharge circuit 53 for forcibly discharging the charging power of the battery 52, and a changeover switch 54 connected between the inverter / converter circuit 51 and the battery 52.

At the time of charging, the battery 52 is charged through a path indicated by a rightward arrow. Specifically, FIG.
The thyristor-type power regeneration type charging / discharging device (a) switches the switch 54 to the position a in FIG. 6A during charging to control the phase angle of the thyristor Q11, and moves the switch 54 to the position b during discharging. To perform an inverter operation using the battery 52 as a power source.

In the case of the apparatus shown in FIG. 6A, the charging voltage of the battery 52 is set to the maximum value of the commercial input AC voltage (2 ^1/2 × effective value).
Since the voltage cannot be raised to the above voltage, the discharge voltage of the battery 52 becomes lower than the commercial input AC voltage,
When regenerating electric power, a transformer for boosting is separately required.

In addition, the inverter / converter circuit 51 shown in FIG. 6A can regenerate only a part of the energy charged in the battery 52, and the remaining energy is generated by the discharge circuit 53 connected in parallel to the battery 52. And the power regeneration efficiency is not very good.

Further, an AC power supply for supplying an AC voltage to the thyristor-type inverter / converter circuit 51 shown in FIG. 6A contains a large number of harmonics, so that a large filter is required.

On the other hand, the transistor type power regeneration type charging / discharging device shown in FIG. 6B can output a DC voltage higher than the input AC voltage, so that the voltage of the battery 52 is higher than the input AC voltage. Can be set to In addition, even if the voltage amplitude of the input AC voltage changes over a wide range, a stable DC voltage can be output, and it is hardly affected by harmonics included in the AC power supply. Further, at the time of discharging, the battery 5
2 is the inverter / converter combined circuit 51a
Until the minimum operating voltage is reached. Further, the changeover switch 54 provided in the thyristor type power regeneration type charging / discharging device is unnecessary, and the transistor type power regeneration type charging / discharging device shown in FIG. 6B is now mainstream.

[0009]

However, FIG.
The conventional transistor-type power regeneration type charging / discharging device shown in (b) also has the following problem. That is, since the conventional transistor-type power regeneration type charging / discharging device has the booster type inverter / converter circuit 51a inside the device, the voltage of the battery 52 must be lower than the input AC voltage by using an insulating transformer or the like. Must be used to perform voltage conversion.

The discharge voltage of the battery 52 is controlled by an inverter /
In order to make the voltage lower than the minimum operating voltage of the converter circuit 51a, a discharge circuit 53 is required as in the device of FIG. The discharge circuit 53 only wastefully consumes power energy as heat, and the regeneration efficiency is not very good.

The present invention has been made in view of the above points, and an object of the present invention is to provide a power regeneration type charge / discharge device which can simplify a circuit configuration, does not require a discharge circuit, and has excellent regeneration efficiency. Is to do.

[0012]

In order to solve the above-mentioned problems, the present invention operates as an AC-DC converter for converting an input AC voltage into a DC voltage when charging a battery, and operates as an AC-DC converter when discharging the battery. A power regeneration type charging / discharging device including a charger / inverter device that acts as a DC-AC inverter during regeneration, and a step-down device that reduces the DC output voltage of the charger / inverter device by pulse width control when charging the battery. A DC bidirectional converter that acts as a type converter and acts as a step-up converter that boosts the discharge voltage of the battery by pulse width control when the battery is discharged, and the charger / inverter device is configured to discharge the battery when the battery is discharged. The voltage boosted by the DC bidirectional converter is regenerated to the AC input side of the charger / inverter device.

According to the first aspect of the present invention, since the battery is charged and discharged by pulse width control, the charge voltage of the battery can be continuously and variably controlled over a wide range, and when the battery is discharged, the discharge power of the battery is utilized. Power can be regenerated on the AC input side of the charger / inverter device.

According to the second aspect of the present invention, since the power transmission direction is switched by turning on and off the first and second switch circuits composed of semiconductor switches and the like, the circuit configuration can be simplified, and the size and weight can be reduced.

According to the third aspect of the present invention, since the first switch circuit is turned on and off by pulse width control, the charge voltage of the battery can be continuously and variably controlled over a wide range by adjusting the pulse width.

According to the fourth aspect of the present invention, the second switch circuit is turned on / off by pulse width control. Therefore, by adjusting the pulse width, a voltage higher than the charging voltage of the battery is supplied to the charger / inverter device. can do.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a power regeneration type charge / discharge device according to the present invention will be specifically described with reference to the drawings.

One of the steps for manufacturing a battery includes an electrode plate forming step. In this step, an electrode plate is formed by applying a voltage in a predetermined direction while continuously changing the polarity of the electrode plate during manufacturing, for which the polarity of the electrode plate has not yet been determined.

Generally, the electric power charged in the battery is discharged using a discharge circuit. However, when the electric power is discharged in the discharge circuit, the electric power is simply wasted. Therefore, the present embodiment will mainly describe an example in which the power charged in the battery in the process of forming the electrode plate is regenerated to the AC power supply side by using a power regeneration type charge / discharge device in order to effectively use the power. .

FIG. 1 is a circuit diagram of an embodiment of a power regeneration type charge / discharge device according to the present invention. The power regeneration type charging / discharging device of FIG. 1 is characterized in that it can be reduced in size and weight and can effectively use power.

The power regeneration type charging / discharging device shown in FIG. 1 includes a well-known inverter / converter circuit (charger / inverter device) 1 and a DC bidirectional converter 3 for charging / discharging a battery 2 in the process of forming an electrode plate. And The inverter / converter circuit 1 functions as an AC-DC converter, that is, a charger when the battery 2 is charged, and functions as a DC-AC inverter when the battery 2 is discharged. The DC bidirectional converter 3 controls the charging voltage of the battery 2 when charging the battery 2, and performs control to regenerate discharge power to the input side of the inverter / converter circuit 1 during discharging.

The inverter / converter circuit 1 has the same configuration as the inverter / converter circuit 51a shown in FIG. 6, and switches S11 to S11 for synchronously rectifying the three-phase AC voltage.
16, a capacitor C1 for smoothing a voltage passed through the switches S11 to S16, a switch control circuit 4 for controlling on / off of the switches S11 to S16, coils L1 to L6 for absorbing noise of the three-phase AC line, and Capacitor C2
C4. Each of the switches S11 to S16 has a transistor Q1 which is turned on / off by a control signal from the switch control circuit 4, and a diode D1 connected in parallel with the transistor Q1 so as to be reverse biased.
These transistors Q1 are, for example, IGBTs or power MOSFETs.
Consists of

The DC bidirectional converter 3, which is the gist of the present invention, is connected in cascade between the terminal of the inverter / converter circuit 1 and the battery 2. The DC bidirectional converter 3 includes first and second switch circuits 11 and 12
A high-frequency filter 13 connected in series with the second switch circuit 12, and first and second switch circuits 11, 1
Switch control circuit 1 that controls the pulse width of ON / OFF of 2
4 and a current detection circuit 15 for detecting a current flowing through the battery 2
And

The first switch circuit 11 is used for IGBT or power
It has a switching element Q2 composed of a MOSFET or the like and a diode D2 connected in parallel to the switching element Q2 so as to be reverse biased. Similarly, the second switch circuit 12 includes a switching element Q3 and a diode D3 connected in parallel.

The high frequency filter 13 has a coil L7 and a capacitor C5. The switching elements Q2 and Q3 and the diodes D2 and D3 in the first and second switch circuits 11 and 12 may be housed in the same IC package or provided separately. There may be either.

The current detection circuit 15 includes a shunt resistor, a Hall element, and the like connected in series to the battery 2. The switch control circuit 14 performs constant current control based on the detection result of the current detection circuit 15 so that the charge / discharge current of the battery 2 becomes constant.

FIG. 2 is a circuit diagram showing the operation of the DC bidirectional converter 3 of FIG. 1 at the time of charging, and FIG. 3 is a circuit diagram showing the operation of the DC bidirectional converter 3 at the time of discharging. The operation of the present invention will be described based on this.

When the battery 2 is charged, the second switch circuit 12 is always off, and the first switch circuit 11 performs an on / off operation under the control of the switch control circuit 14. As a result, while the first switch circuit 11 is on, a current flows from the inverter / converter circuit 1 through the path indicated by the arrow P in FIG. 2, and the battery 2 is charged.

Also, while the first switch circuit 11 is off, an electromotive force is generated to cause a current to flow through the coil L7 in the same direction. A current flows in the direction of arrow Q in FIG.

The charging voltage of the battery 2 changes according to the ON / OFF duty ratio D of the first switch circuit 11.

FIG. 4 shows the output voltage of the inverter / converter circuit 1 (FIGS. 4A and 4D) and the voltage at the node c between the first and second switch circuits 11 and 12 (FIG. 4).
4 (b) and (e), and the charging voltage of the battery 2 (FIG. 4).
It is a figure which shows the relationship with (c), (f)).

For example, when the ON period and the OFF period of the first switch circuit 11 are substantially equal (FIG. 4B), the charging voltage of the battery 2 becomes as shown in FIG. When the ON period of the switch circuit 11 is shorter than the OFF period (FIG. 4E), the charging voltage of the battery 2 becomes as shown in FIG.

As described above, the switch control circuit 14 continuously changes the pulse width of the pulse width control signal for controlling ON / OFF of the first switch circuit 11,
0.0 of the output voltage E1 of the inverter / converter combined circuit 1
The charging voltage of the battery 2 is continuously variably controlled within the range of 2% to 98%. That is, in the present embodiment, when the battery 2 is charged, the output voltage of the inverter / converter combined circuit 1 is continuously and variably controlled from the minimum voltage to the maximum voltage by the same operation as a normal switching regulator, and the battery 2 is charged. Charge.

On the other hand, when the battery 2 is discharged, the first switch circuit 11 is always off and the second switch circuit 12 is turned off.
Performs an on / off operation under the control of the switch control circuit 14. As a result, while the second switch circuit 12 is on, the discharge current from the battery 2 flows through the coil L7 and the transistor Q2 in the second switch circuit 12 through the path indicated by the arrow R in FIG. Stores energy due to the discharge current.

While the second switch circuit 12 is off, a current flows in the direction of arrow S in FIG. 3 through the diode D2 in the first switch circuit 11 due to the energy stored in the coil L7. , The capacitor C1 in the inverter / converter circuit 1 is charged. At this time, by turning on / off the second switch circuit 12, the amount of energy stored in the coil L7 can be adjusted, and the DC bidirectional converter 3 can function as a step-up switching converter.

FIG. 5 is a diagram showing the current waveforms flowing through the nodes a, b and c in FIG. As shown in FIG. 5, when the second switch circuit 12 is turned on, the energy stored in the coil L7 gradually increases, so that the current flowing through the nodes a and b also increases. When the second switch circuit 12 is turned off, the energy stored in the coil L7 is changed to the first switch circuit 11
Is supplied to the capacitor C1 via the diode D2. The current flowing through the node c rapidly rises to the current flowing immediately before turning off, and then gradually decreases. This current charges the capacitor C1 in the inverter / converter circuit 1.

By adjusting the ON period of the second switch circuit 12, the energy stored in the coil L7 in the high frequency filter 13 can be varied, and the charging voltage of the capacitor C1 can be made higher than the charging voltage of the battery 2. Can be.

In a normal step-up switching converter, it is possible to practically step up to about 5 times the supplied DC voltage, so that the voltage across the battery 2 is lower than the rated value.
Until the voltage drops to about 1/4 to 1/5, there is no particular problem.
Can supply power to the inverter / converter combined circuit 1. The well-known inverter / converter circuit 1 of FIG. 1 converts DC energy stored in the capacitor C1 into AC and regenerates it into an AC power supply.

According to the present invention, since the charging and discharging of the battery 2 is controlled by the first and second switch circuits 11 and 12 each formed by a semiconductor switch such as an IGBT, the discharging circuit shown in FIG. 6 is not required. It is possible to reduce the size and reduce the cost of parts. In addition, when the battery 2 is discharged, the power is regenerated to the AC power supply, so that the power can be effectively used and the power consumption can be reduced.

Further, power control in the forward direction (during charging) and in the reverse direction (during discharging) can be performed only by two semiconductor switches (first and second switch circuits 11 and 12), so that the circuit configuration is simplified. In addition, a highly efficient circuit that is small, lightweight, and has little power loss can be obtained.

The switch control circuit 14 only needs to turn on one of the first and second switch circuits 11 and 12, but simultaneously turns on and off these switch circuits 11 and 12 alternately. But it is almost the same. In this case, it was experimentally confirmed that the drive loss can be slightly reduced. This is considered to be due to the fact that the voltage drop due to the on-resistance of the switching elements in the first and second switch circuits 11 and 12 is smaller than the positive voltage drop of the diode.

As described above, according to the present embodiment, the IGBT and the MOSFET
Since the direction of power transmission is switched by turning on and off the first and second switch circuits 11 and 12 composed of the above, the circuit configuration can be simplified, and the size and weight can be reduced. That is, conventionally, in order to transmit power bidirectionally, a bidirectional switch was considered to be necessary.
Since power can be transmitted bidirectionally by using a unidirectional switching element, the circuit configuration can be simplified as compared with the related art, and the cost of parts can be reduced.

The first and second switch circuits 1
Since the ON / OFF states of the batteries 1 and 12 are controlled by the pulse width control, the charging voltage of the battery 2 can be continuously and variably controlled over a wide range. In addition, when the battery 2 is discharged, a voltage higher than the charging voltage of the battery 2 can be supplied to the inverter / converter circuit 1, so that the power can be efficiently regenerated to the input side AC power supply of the inverter / converter circuit 1. Thus, effective use of the discharge power of the battery 2 can be achieved.

In the above-described embodiment, an example in which a three-phase AC power supply is connected to the inverter / converter circuit 1 has been described. However, the present invention can be similarly applied to a case where a single-phase AC power supply is connected.

The circuit configuration of the combined inverter / converter circuit 1 in the present embodiment is not limited to that shown in FIG.

Further, in the above-described embodiment, an example of manufacturing a battery in the process of forming an electrode plate has been described. However, the present invention can be used for purposes other than manufacturing a battery. For example, according to the present invention, regardless of AC input or DC input, regenerative power can be returned to the input-side AC power supply of the inverter / converter combination circuit, and as a result, power receiving equipment can be rationalized and several times that of power receiving equipment. It is possible to operate ground-breaking energy-saving test facilities, such as the operation of test facilities that handle electric power.

[0047]

As described above in detail, according to the present invention, there is provided a DC bidirectional converter which functions as a step-down converter when charging a battery and as a step-up converter when discharging a battery. Thus, the charge / discharge voltage can be variably controlled continuously in a wider voltage range.

Further, when the battery is discharged, the voltage boosted by the DC bidirectional converter is regenerated to the AC power supply on the input side of the battery / inverter device, so that a discharge circuit for forcibly discharging the battery is not required, and the electric power is not required. Can be used effectively.

Further, by switching the power transmission direction by the first and second switch circuits in the DC bidirectional converter, the circuit configuration can be simplified, the size and weight can be reduced, and the power loss can be reduced. Less.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of an embodiment of a power regeneration type charge / discharge device according to the present invention.

FIG. 2 is a circuit diagram showing an operation during charging of the DC bidirectional converter of FIG. 1;

FIG. 3 is a circuit diagram showing an operation at the time of discharging of the DC bidirectional converter.

FIG. 4 is a diagram showing a relationship between an ON period of a first switch circuit and a charging voltage of a battery.

FIG. 5 is a waveform diagram of a current flowing through nodes a, b, and c in FIG. 3;

FIG. 6 is a block diagram showing a schematic configuration of a conventional power regeneration type charge / discharge device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inverter / converter combined circuit 2 Battery 3 DC bidirectional converter 4,14 Switch control circuit 11 First switch circuit 12 Second switch circuit 13 High frequency filter 15 Current detection circuit

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 5G003 AA01 BA01 DA07 DA16 GA01 GB03 GB06 5H007 BB01 BB05 CA01 CB04 CB05 CB23 CC03 CC12 CC23 DA03 DA05 DC02 EA02 5H730 AS17 AS21 BB13 BB14 CC01 CC16 CC17 DD04 FD31 FD21 FD31 XX31 XX XX22 XX33

Claims (4)

[Claims] 1. A charging / inverting device which functions as an AC-DC converter for converting an input AC voltage into a DC voltage when charging a battery, and which functions as a DC-AC inverter when regenerating power when discharging the battery. A power regeneration type charge / discharge device, which acts as a step-down converter that steps down the DC output voltage of the charger / inverter device by pulse width control when charging the battery, and reduces the discharge voltage of the battery when discharging the battery. The battery charger / inverter device includes a DC bidirectional converter that acts as a boost converter that boosts voltage by pulse width control. The charger / inverter device outputs the voltage boosted by the DC bidirectional converter when the battery is discharged. A power regeneration type charging / discharging device characterized by regenerating to an AC input side. 2. The DC bidirectional converter comprises: first and second switch circuits connected in series between two output terminals of the charger / inverter device; and the first and second switch circuits. And a switch control circuit that controls the switching of the first and second switch circuits, wherein the first and second switch circuits are respectively A switching element and a diode connected in parallel to the switching element so as to be reverse-biased, wherein the switch control circuit turns off the second switch circuit when the battery is charged and turns off the first switch. The circuit is turned on / off by pulse width control, and when the battery is discharged, the first switch circuit is turned off and the second switch circuit is turned on by pulse width control. Power regenerative charging and discharging device according to claim 1, characterized in that on and off. 3. The switch control circuit according to claim 1, wherein the first switch is configured to change the charging voltage of the battery continuously from substantially zero volts to near the output voltage of the charger / inverter device when charging the battery. The power regeneration type charging / discharging device according to claim 1 or 2, wherein the circuit is turned on / off by pulse width control. 4. The switch control circuit controls a pulse width of the second switch circuit so that a voltage higher than a charge voltage of the battery is supplied to the charger / inverter device when the battery is discharged. The power regeneration type charge / discharge device according to any one of claims 1 to 3, which is turned on / off by: