JP2001128379A - Charging device and charging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the number of electric double layer capacitors constituting a capacitor block, increase the number of voltage monitor circuits connected in parallel to each of the electric double layer capacitors, and increase the number of circuit constituent elements. Provided is a charging device and a charging method capable of minimizing the size of the device and reducing the cost by minimizing the increase. SOLUTION: A charging current IA is supplied to a capacitor block 20.
Control circuit 10 for supplying power to the capacitors and capacitor stacks CS1 to CSn in which a plurality of capacitors are stacked (stacked)
And a voltage monitor circuit 30 for detecting and monitoring the voltage charged in the capacitor block 20. During the charging operation, the capacitor stacks CS1 to CSn are connected in series to supply the charging current IA. During the voltage monitoring operation, the capacitor stack CS
A capacitor is connected in parallel for each of the layers 1 to CSn, and the charging voltage is individually detected and monitored.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a charging device and a charging method, and more particularly to a charging device and a charging method for storing electric energy in a capacitor block having a plurality of electric double layer capacitors as power elements.

[0002]

2. Description of the Related Art In recent years, it has been studied to apply a charging device provided with an electric double layer capacitor as a power source for driving an electric vehicle or the like. For example, JP-A-11-1228
As shown in FIG. 13, in Japanese Patent Application Laid-Open No. 11 (A), a predetermined charging current IB is supplied from a power supply circuit 10A to a capacitor bank (or capacitor block) 20A having a plurality of electric double layer capacitors C11 to C14. Thus, a technique is described in which electric charges corresponding to current values are stored in each of the electric double layer capacitors C11 to C14. Here, it is described that by performing a charging operation by connecting a plurality of electric double layer capacitors C11 to C14 in series, a charging device having a high-capacity capacitor bank can be configured while reducing the current value of the charging current. ing.

In general, a voltage (charging voltage) V between both ends of a capacitor including an electric double layer capacitor is represented by the following equation, where Q is a charge amount and C is a capacitor capacitance. V = Q / C (11) The charge amount Q is expressed by the following equation, where IB is a current flowing through the capacitor (charging current), and t is a charging time. Q = IB · t (12)

As described above, the amount of charge Q stored in the capacitor increases in proportion to the elapse of the charging time t, so that the charging voltage V of the capacitor also increases with the charging time t,
When the charging voltage V exceeds the withstand voltage of the capacitor, there is a problem that the capacitor is destroyed, and the charging device is broken or defective. Therefore, conventionally, as shown in FIG. 13, the charging voltage value is detected and monitored for each of the electric double layer capacitors C11 to C14 so that the charging voltage does not exceed the withstand voltage of the electric double layer capacitor. Voltage monitor circuits 30a to 30d for stopping the charging operation of the electric double layer capacitor when the value exceeds the withstand voltage (reference voltage) (specifically, bypassing the charging current) are provided.

[0005]

However, the above-mentioned prior art has the following problems. (1) In a configuration in which a plurality of electric double layer capacitors are connected in series, a voltage monitor circuit must be connected in parallel (parallel monitor) for each electric double layer capacitor when detecting and monitoring the charging voltage. As the number of capacitors increases, the same number of voltage monitor circuits is required, and the scale of the charging device becomes extremely large, resulting in an increase in product cost.

(2) In the case where the charging current is bypassed by the voltage monitoring circuit in detecting and monitoring the charging voltage, the charging current depends on the power consumption of the voltage monitoring circuit and the number of connections (ie, the number of double-layer capacitors). Since the amount of heat W is generated, miniaturization of the charging device has been made more difficult.
The amount of heat W generated by the charging current bypass is I
If B is a charging current, VL is a withstand voltage, and n is the number of voltage monitoring circuits (electric double layer capacitors), the heat quantity W increases in proportion to the number n of the voltage monitoring circuits as represented by the following equation. W = IB · VL · n (13)

(3) In particular, since the withstand voltage per electric double-layer capacitor currently available is very low, about 3 V, application to a drive power supply for an electric vehicle as described above was studied. In this case, it is necessary to increase the withstand voltage by increasing the number of connected electric double layer capacitors.
The problem (2) is inevitable. Accordingly, the present invention has been made in view of the above problems, and while increasing the number of electric double layer capacitors constituting a capacitor block, the number of voltage monitor circuits connected in parallel to each of the electric double layer capacitors, and By minimizing the increase in constituent elements,
It is an object of the present invention to provide a charging device and a charging method capable of reducing the size of the device and reducing the cost.

[0008]

According to a first aspect of the present invention, there is provided a charging apparatus comprising: a capacitor block having a capacitor stack in which a plurality of capacitors are stacked; a predetermined charging current supplied to the capacitor block; Charge control means for charging, and voltage monitoring means for detecting and monitoring the voltage charged in the capacitor, wherein the capacitor block connects a plurality of the capacitor stacks in series during a charging operation for charging the plurality of capacitors. Connect and detect the voltage charged in the plurality of capacitors,
At the time of the voltage monitoring operation to be monitored, the capacitors of each layer constituting the plurality of capacitor stacks are connected in parallel.

According to a second aspect of the present invention, in the charging apparatus according to the first aspect, the capacitor block includes a first switch for connecting a plurality of the capacitor stacks in series, and the plurality of capacitor stacks. A second switch means for connecting the capacitors of each layer in parallel to each other, wherein the first operation is performed during the charging operation.
And the second switch means is turned off to connect the plurality of capacitors in series. During the voltage monitoring operation, the first switch means is turned off and the second switch means is turned off. The second switch means is turned on to connect the capacitors of each layer constituting the plurality of capacitor stacks in parallel.

According to a third aspect of the present invention, in the charging apparatus according to the first or second aspect, the capacitor block detects and monitors the charged voltage during a charging operation for charging the plurality of capacitors. The monitoring operation is repeatedly performed at predetermined time intervals. The charging device according to claim 4 is the charging device according to any one of claims 1 to 3, wherein the voltage monitoring unit includes:
The charge voltage detected at the time of the voltage monitoring operation is compared with a preset reference voltage, and when the charge voltage is equal to or higher than the reference voltage, the charge supplied from the charge control unit to the capacitor block is It is characterized by interrupting current.

According to a fifth aspect of the present invention, in the charging device according to any one of the first to fourth aspects, the voltage monitoring means performs the voltage monitoring operation for each of the layers constituting the plurality of capacitor stacks during the voltage monitoring operation. It is characterized by comprising a plurality of voltage monitoring units connected corresponding to the parallel connection of the capacitors. The charging method according to claim 6, further comprising the steps of: connecting a capacitor stack in which a plurality of capacitors are stacked in series, and charging the plurality of capacitors; and at a predetermined time interval, for each layer constituting the plurality of capacitor stacks. The procedure of connecting the capacitors in parallel, detecting and monitoring the voltage charged in the capacitor, comparing the detected charging voltage with a preset reference voltage, and comparing the charging voltage with the reference voltage. Shutting off the charging current supplied to the capacitor when the voltage becomes equal to or higher than the voltage.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a charging device and a charging method according to the present invention will be described in detail with reference to embodiments. FIG. 1 is a schematic configuration diagram showing an embodiment of the charging device according to the present invention. As shown in FIG. 1, the charging device according to the present embodiment includes a charging control circuit 10 that configures a charging control unit,
It comprises a capacitor block 20 composed of a capacitor stack in which a plurality of electric double layer capacitors (hereinafter simply referred to as capacitors) are stacked (stacked), and a voltage monitor circuit 30 constituting voltage monitoring means. .

The charge control circuit 10 includes a commercial AC power supply (for example, AC 100 V) between the high-potential power line HL and the low-potential power line LL to which the capacitor block 20 is connected.
Is applied to the capacitor block 20.
Is supplied with a charging current IA. Note that a switch control unit (which will be described in detail later) that generates and outputs a control signal that controls switching of a switch unit that sets the connection state of the capacitor stack that forms the capacitor block 20 may be provided.

The capacitor block 20 includes a plurality of capacitors C11 to C31, C12 to C32, C13 to C3 between the high potential side power line HL and the low potential side power line LL.
3,... C1n to C3n are respectively connected in series (laminated)
Capacitor stacks CS1, CS2, CS3, ...
・ CSn and each capacitor stack CS1, CS2, C
S3,... Capacitors C11 to C3 constituting CSn
1, C12 to C32, C13 to C33, ..., C1n
Changeover switch group S for controlling the parallel connection of each layer of C3n
WA11-SWA1m, SWA21-SWA2m, SW
A31 to SWA3m and each capacitor stack CS1,
CS2, CS3,..., CSn, changeover switches SWB1 to SWBm for controlling series connection of each other, and switching for controlling connection between each capacitor stack CS1, CS2, CS3,. Switch group SW
A44 to SWA4m.

Specifically, the capacitor stack CS1
The capacitors C11 to C31 are connected in series via the contacts N21 and N31 between a contact N11 provided on the high potential power supply line HL and a contact N41 provided on the low potential power supply line LL. The capacitor stack CS2 includes a contact N12 provided on the high-potential-side power supply line HL.
And the contact N42 provided on the low potential side power supply line LL side,
Capacitors C12 to C32 are connected to contacts N22 and N3, respectively.
The capacitor stack CS3 includes a contact N13 provided on the high-potential power line HL and a contact N43 provided on the low-potential power line LL.
The capacitors C13 to C33 have a configuration in which the capacitors C13 to C33 are connected in series via contacts N23 and N33, respectively, and the capacitor stack CSn includes a high-potential-side power supply line HL.
Are connected in series via contacts N2n and N3n, respectively, between a contact N1n provided on the power supply line LL side and a contact N4n provided on the low potential side power supply line LL side.

Also, between the contact N11 and the contact N12 provided on the high potential side power supply line HL, between the contact N12 and the contact N13,
Between the contact N13 and the contact N14, and between the contact N1m and the contact N1n, changeover switches SWA11 and SWA1 are provided, respectively.
2, SWA13,..., SWA1m.
Similarly, a contact N41 provided on the low potential side power supply line LL side
And contact N42, between contact N42 and contact N43, and contact N4
3 and the contact N44, and between the contact N14 and the contact N4n, changeover switches SWA41, SWA42, SW
A43,... SWA4m are provided.

Also, the contact N21 between the contact N21 and the contact N22,
, SWA2, SWA23,... SWA2 between the contact N23 and the contact N23, between the contact N23 and the contact N24, and between the contact N2m and the contact N2n.
m is provided. Similarly, the contacts N31 and N32
Between the contacts N32 and N33, between the contacts N33 and N3
4, and between the contacts N3m and N3n, the changeover switches SWA31, SWA32, SWA33,.
-SWA3m is provided. Furthermore, the contact N41 and the contact N12, the contact N42 and the contact N13, the contact N43
Between the contact N14 and the contact N4m, and between the contact N4m and the contact N1n, the changeover switches SWB1, SWB2, SWB3,
... SWBm is provided. Note that the low-potential-side power supply line LL is connected to the contact N4n.

A switch SWC1 for controlling the supply of the charging current from the charge control circuit 10 to the capacitor block 20 and a switch SWC for controlling the connection between the capacitor block 20 and the load 40 are provided on the high potential side power supply line HL.
C2 is provided. Here, the changeover switch group SWA
11 to SWA1m, SWA21 to SWA2m, SWA3
1 to SWA3m and SWA44 to SWA4m are simultaneously turned on at a predetermined timing based on the same switching control signal.
/ OFF control. Further, the changeover switch group SWB1
2SWBm and the switch SWC1 are the changeover switch groups SWA11 to SWA1m, SWA21 to SWA2m,
The SWA 31 to SWA 3 m and the SWA 44 to SWA 4 m are simultaneously ON / OFF controlled at opposite timings.

The voltage monitor circuit 30 includes a high potential side power supply line H
The monitor circuit 31 is connected between the contact N1n and the contact N2n provided at L, the monitor circuit 32 is connected between the contact N2n and the contact N3n, and the monitor circuit 33 is connected between the contact N3n and the contact N4n. And monitor circuits 31, 3
2 and 33 are capacitor stacks CS1 to CSn, respectively.
Capacitors C11 to C1n and C21 to C2
n, the amount of charge accumulated in C31 to C3n is detected as a monitor voltage (charge voltage) value, and is compared with a predetermined reference voltage (guaranteed withstand voltage) value. It is determined whether or not it has reached. When the monitor voltage value becomes equal to or higher than the reference voltage value, the switching control signal PS is output to the switch SWC1, and the supply of the charging current IA from the charging control circuit 10 to the capacitor block 20 is cut off. In this embodiment, three electric double-layer capacitors are stacked as the capacitor stacks constituting the capacitor block. However, it is needless to say that the present invention is not limited to this. Absent.

Next, an operation state of the charging device having the above-described configuration will be described with reference to the drawings. (Charging Operation) FIG. 2 is a schematic circuit showing a connection state during the charging operation of the charging device according to the present embodiment, and FIG. 3 is an equivalent circuit showing a connection state during the charging operation. The charging operation is
As shown in FIG. 2, the switch SWC <b> 1 provided on the high-potential-side power supply line HL is controlled to be turned on so that the charge control circuit 10 and the capacitor block 20 are electrically connected. The switches SWB1 to SWBm are turned on, and the changeover switches SWA11 to SWA1m, SWA21 to SWA2m, S
WA31-SWA3m and SWA41-SWA4m
This is realized by simultaneously controlling the switching to the FF state. Here, the switch group consisting of the switch SWC1 and the changeover switches SWB1 to SWBm constitutes first switch means in the present invention, and the changeover switches SWA11 to SWA1m, SWA21 to SWA2
m, SWA31 to SWA3m and SWA41 to SWA4
The switch group consisting of m forms the second switch means in the present invention.

Such switches SWA11-SW
A1m, SWA21 to SWA2m, SWA31 to SWA
3m, SWA41 to SWA4m, and SWB1 to SW
Bm switching control allows the capacitor block 20
Is a high-potential-side power supply line HL as in the equivalent circuit shown in FIG.
And each of the capacitors C11,
C21, C31, C12, C22, ..., C2n, C3
n (hereinafter, abbreviated as respective capacitors C11 to C3n) are connected in series, and charging of the capacitors C11 to C3n is started by the charging current IA supplied from the charging control circuit 10 to the high potential side power supply line HL. You.

(Voltage Monitoring Operation) FIG. 4 is a schematic circuit showing a connection state during the voltage monitoring operation of the charging apparatus according to the present embodiment, and FIG. 5 is an equivalent circuit showing a connection state during the voltage monitoring operation. is there. As shown in FIG. 4, the voltage monitoring operation is performed by turning off the switch SWC1 provided on the high potential side power supply line HL.
The switching control is switched to the state, the charge control circuit 10 and the capacitor block 20 are electrically cut off, the changeover switches SWB1 to SWBm of the capacitor block 20 are turned off, and the changeover switches SWA11 to SWA are changed.
1m, SWA21 to SWA2m, SWA31 to SWA3
m and SWA41 to SWA4m are simultaneously controlled to be in the ON state.

Such changeover switches SWA11 to SWA
A1m, SWA21 to SWA2m, SWA31 to SWA
3m and SWA41 to SWA4m and SWB1 to S
The WBm switching control allows the capacitor block 20
Is a high-potential-side power supply line HL, as in the equivalent circuit shown in FIG.
And a signal line L1 connecting the contacts N21 to N2n,
Capacitors C11 to C1n of the same layer are connected in parallel, and capacitors C21 to C2n of the same layer are connected in parallel between the signal line L1 and the signal line L2 connecting the contacts N31 to N3n. Capacitors C31 to C3n of the same layer are connected in parallel with potential side power supply line LL. Capacitor groups C11 to C connected in parallel
1n, C21 to C2n, and C31 to C3n are connected to individual monitor circuits 31, 32, and 33, respectively, and the voltages charged in the capacitor groups C11 to C1n, C21 to C2n, and C31 to C3n are equalized and charged. Detected as voltage. Each of the capacitor groups C11 to C1n, C21 to C2n, detected by the monitor circuits 31, 32, 33,
When the voltage between both ends of C31 to C3n becomes equal to or higher than a reference voltage set in advance to guarantee the withstand voltage of the capacitor at any one point, the monitor circuit 31, 32, 33 sends the switching control signal PS to the switch SWC1. Output and OFF
The state is continued, the supply of the charging current is cut off, and the charging operation is stopped.

(Discharge Operation) FIG. 6 is a schematic configuration diagram showing a discharge operation state of the charging device according to the present embodiment. As shown in FIG. 6, in the configuration in which the capacitor block 20 and the voltage monitor circuit 30 are connected in parallel to the charge control circuit 10 via the high-potential-side power supply line HL and the low-potential-side power supply line LL, a discharging operation is performed. The switch SWC1 provided on the high-potential-side power supply line HL between the charge control circuit 10 and the capacitor block 20 is controlled to be turned off so that the charge control circuit 10 and the capacitor block 20 are electrically disconnected. The switch SWC2 provided between the capacitor block 20 and the load 40 is controlled to be turned on, and the capacitor block 20 and the load 40 are electrically connected. In this case, the capacitors C11 to C11 constituting the capacitor block 20
C31, C12 to C32, C13 to C33, ... C1
The connection state of n to C3n is controlled to be appropriately switched to a series connection state or a parallel connection state according to the state of the load 40, and an appropriate discharge voltage is supplied to the load 40.

Next, the connection state of the capacitors constituting the capacitor block and its operation will be described with reference to the drawings. FIG. 7 is a schematic circuit diagram showing the operation depending on the connection state of the capacitors constituting the capacitor block applied to the present embodiment. For example, the stored energy E in the case where a charging voltage V (V) is generated between both ends of a capacitor having a capacitance of C (F) is generally represented by the following equation. E = １ ／ · CV ² (1) That is, from equation (1), the stored energy E is proportional to the square of the charging voltage V. Here, the charging current is I (A),
Assuming that the charging time is t (s), the charge amount Q stored in the capacitor is expressed by the following equation. Q = ∫Id = I · t (2)

The relationship between the charge amount Q, the capacitance C, and the voltage V between both ends is generally expressed by the following equation. Q = CV (3) Therefore, according to the equations (2) and (3), the above (1)
The equation is expressed as the following equation. E = (１ ／) C · (Q / C) ² = (１ ／ C) · (I · t) ² (4) That is, from the above equation (4), if the stored energy E is constant, , The charging current I and the charging time (t) are inversely proportional. Further, by transforming the above equation (4),
The charging current I is represented by the following equation. I = √ (2EC) / t (5) From the above equation (5), when the stored energy E and the charging time t are constant, the charging current I in the charging operation is a square root (root) of the capacitance C of the capacitor. Is proportionally increased or decreased.

Here, as shown in FIG.
Is constituted by parallel connection of n (four in the figure) capacitors C1 to C4 (corresponding to the capacitor stacks CS1, CS2, CS3,..., CSn in the present invention) having a capacitance C / n. And
Energy E stored in these capacitors C1 to C4
7B, the capacitance C of the capacitor block 20 becomes 1 / (n ² ) times, as shown in FIG. 7B. When the capacitance C / (n ² ) is applied to the above equation (5), √ (2EC) / t = √ (2EC / n ² ) / t = I / n (6) , The charging current I becomes 1 / n times.

In general, in order to rapidly charge a single capacitor, it is necessary to flow a large charging current. For this reason, it is unavoidable to increase the size of the charging control circuit. However, in the charging device according to the present invention, As described above, when the amount of energy stored in the capacitor block 20 is constant, the capacitor block 20 is divided into a plurality of capacitors (in this embodiment, n capacitor stacks), and is connected in series. Accordingly, the capacitance value of the capacitor block 20 can be reduced by a factor of 1 / (n ² ). Therefore, when the charging time is fixed,
The charging current I is reduced by 1 /
It can be reduced by a factor of n and the size of the charging device can be reduced. When the charging current I is fixed,
The charging time t can be reduced to 1 / n, and a charging device capable of quick charging can be provided.

Further, according to the charging apparatus of the present embodiment, at the time of the voltage monitoring operation, the monitor circuit may be provided in correspondence with the parallel connection of the capacitors of each layer constituting the capacitor stack. As described above, it is possible to realize a high-voltage charging device without providing a monitor circuit for each capacitor, and to reduce the size and cost of the device. In addition, the monitor circuit applied to the present embodiment has a function of detecting the voltage charged in the capacitor block and interrupting the supply of the charging current to the capacitor block when the voltage exceeds the reference voltage. Therefore, as shown in the prior art, each capacitor is connected in parallel,
Since the charge current is not bypassed, heat generation from the monitor circuit can be significantly suppressed. Furthermore, the number of switches Nsw provided in the capacitor block applied to the present embodiment is relatively small because the number of capacitor stacks is represented by a and the number of stacked capacitors constituting each capacitor stack is represented by b, as follows: Switching control of the connection state of the capacitor in the charging operation and the voltage monitoring operation can be performed by the number of switches, and resistance loss due to the switches can be reduced as much as possible. Nsw = (a-1) × (b + 2) (7)

Next, a method for charging the charging device according to the present embodiment will be described with reference to the drawings. FIG. 8 is a flowchart illustrating a procedure of a method of charging a capacitor block applied to the present embodiment, and FIG. 9 is a timing chart illustrating control timing of a changeover switch provided in the capacitor block applied to the present embodiment. is there. (S101, S102) First, the switch SWC1 and the changeover switches SWB1 to SWBm are turned on, and the changeover switches SWA11 to SWA1m and SWA21 are turned on.
To SWA2m, SWA31 to SWA3m and SWA41
.. CS by switching SWA4m to OFF state.
n is connected in series, the charging control circuit 10 and the capacitor block 20 are connected, the charging current IA is supplied via the high-potential power supply line HL, and the charging operation is started.

(S103, S104) Next, after a predetermined time has elapsed after the start of the charging operation, the switch SWC1 and the changeover switches SWB1 to SWBm are turned off, and the changeover switches SWA11 to SWA1m, SWA21 are turned off.
To SWA2m, SWA31 to SWA3m and SWA41
SWA4m to the ON state, the charging control circuit 10 and the capacitor block 20 are electrically disconnected to interrupt the charging operation, and the capacitors forming the capacitor stacks CS1, CS2, CS3,. Capacitor groups C11-C1n, C21-C2n, C3 connected in parallel for each layer
1 to C3n are connected to the individual monitor circuits 31, 32, and 33 to execute a voltage monitoring operation for detecting a charged voltage.

(S105) Here, each monitor circuit 31,
32, 33 are the detected charging voltage (detected voltage) Vm,
Based on the withstand voltage of each of the capacitors C11 to C3n, a reference voltage (withstand voltage assurance voltage) Vs is compared with a preset voltage. , Switch SWC1, and changeover switches SWB1 to SWBm are in the ON state, and changeover switches SWA11 to SWA1m, SWA21
To SWA2m, SWA31 to SWA3m and SWA41
SWA4m is controlled to switch to the OFF state, and the charging operation is resumed and continued. (S106) On the other hand, when the detection voltage Vm becomes equal to or higher than the reference voltage Vs, the switching control signal PS is output from each of the monitor circuits 31, 32, and 33 to the switch SWC1, the switch SWC1 is turned off, and the charge control is performed. The charging current I supplied from the circuit 10 is cut off, and the charging operation ends.

As described above, the charging method according to the present embodiment, as shown in FIG. 9, uses the first switch group (first switch means) including the switch SWC1 and the changeover switches SWB1 to SWBm, Switch SWA
11 to SWA1m, SWA21 to SWA2m, SWA3
The second switch group (second switch means) composed of SWA1 to SWA3m and SWA41 to SWA4m is simultaneously turned on and off (complementarily) at opposite timings, and the capacitors C11 to C3n are connected in series. When
The charging operation is performed, and the capacitors C11 to C3n are connected in parallel for each layer of the capacitor stacks CS1 to CSn at a predetermined timing during the charging operation, and the voltage monitoring operation is performed. As shown in the above equation (12), since the charging voltage of the capacitor increases in proportion to the charging time, it is desirable to execute the voltage monitoring operation at regular time intervals.

Next, an example of the changeover switch applied to the charging device according to the present embodiment and an example of its control means will be briefly described. FIG. 10 is a circuit configuration diagram illustrating an example of a changeover switch applied to the charging device according to the present embodiment. The switches SWC1, SWC2,
And changeover switches SWA11 to SWA1m, SWA2
1 to SWA2m, SWA31 to SWA3m, SWA41
SWA4m and SWB1 to SWBm, as shown in FIG. 10, a photodiode PD that emits light of a predetermined wavelength based on a control signal for performing ON / OFF control of each switch. A so-called photocoupler (also referred to as an optical coupling transistor) including a phototransistor PS that receives light from the photodiode PD and conducts electricity electrically can be used.

According to the changeover switch having such a configuration, the input side (control signal) and the output side (switch operation) can be electrically separated, and the ON / OFF operation corresponding to the control signal accurately. Can be realized. Further, the changeover switch applied to the present embodiment is turned on.
As a control unit for generating and outputting a control signal for performing the / OFF control, for example, a microcomputer (hereinafter, referred to as a microcomputer) can be applied. The control signal is transmitted to the switch SWC1 and the switch SWC1 at the timing shown in FIG. Switches SWB1 to SWBm, SWA11 to SWA1m, S
WA21-SWA2m, SWA31-SWA3m, SW
By supplying the signals to A41 to SWA4m, the ON / OFF operation of each switch group is controlled simultaneously.

When such switch control means is applied, the switching control of the changeover switch and the switching control of the operation state can be performed at an arbitrary timing in accordance with the current supply capacity of the charge control circuit and the charge capacity of the capacitor block. , The appropriate charging operation and voltage monitoring operation can be realized. Note that the timing of the control signal supplied to each switch group may correspond to the procedure of the above-described charging method in which the charging operation and the voltage monitoring operation are repeated at regular time intervals as shown in FIG. Alternatively, based on the fact that the charging voltage of the capacitor rises in proportion to the charging time, the required time until the charging voltage reaches the reference voltage is estimated and calculated, and after the charging operation starts,
The voltage monitoring operation may be performed by detecting the elapse of the required time.

FIG. 11 is a schematic diagram showing another example of the switch control means applied to this embodiment.
2 is a waveform diagram showing a signal waveform of a control signal. FIG.
As shown in FIG.
A first signal generation unit that outputs a voltage waveform generated through a diode D1 and a protection resistor R1 as a first control signal SC1 based on an AC signal of a commercial AC power supply supplied to the charge control circuit 10; , Based on the AC signal,
A second signal generation unit that outputs a voltage waveform generated via the diode D2 and the protection resistor R2 as a second control signal SC2.

The first signal generator passes only the positive voltage component of the sine AC signal as shown in FIG. 12 by the diode D1 connected in the forward direction with respect to the input direction of the AC signal. Thus, a control signal SC1 having a positive voltage waveform is generated at a constant cycle, and supplied to the capacitor block 20 as a signal for simultaneously turning on / off the switches SWC1 and the changeover switches SWB1 to SWBm of the first switch group. . On the other hand, the second signal generator passes only the negative voltage component of the sine AC signal by the diode D2 connected in the opposite direction to the input direction of the AC signal, as shown in FIG. Invert to generate a control signal SC2 having a positive voltage waveform at a constant cycle,
Switches SWA11 to SWA of the switch groups
1m, SWA21 to SWA2m, SWA31 to SWA3
m and SWA41 to SWA4m are supplied to the capacitor block 20 as a signal for simultaneously controlling ON / OFF.

That is, the switch SWC is synchronized with the charging current supplied from the charging control circuit 10 to the capacitor block 20 based on the AC signal by the control signal SC1.
1 and the changeover switches SWB1 to SWBm are simultaneously ON-controlled, and the capacitor stacks CS1 to CSn are connected in series to perform a charging operation. On the other hand, the switching switches SWA11 to SWA1m and SWA21 are switched by the switching control signal SC2 at a timing opposite to that of the switching control signal SC1.
~ SWA2m, SWA31 ~ SWA3m, SWA41 ~
The SWA 4m is simultaneously turned ON, and the capacitors C11 to C11 of the respective layers constituting the capacitor stacks CS1 to CSn.
By setting C3n in a parallel connection state, monitor circuits 31, 32, and 33 connected corresponding to the capacitors of each layer,
A voltage monitoring operation is performed.

Therefore, when the switch control means according to this embodiment is applied, the switching control of the changeover switch is performed by using the AC signal supplied from the commercial AC power supply, and
Since it has a function to control the switching of the operating state,
The connection state of the capacitor is periodically switched in synchronization with the commercial AC power supply, so that the charging operation and the voltage monitoring operation can be repeatedly performed, and the charging operation to the capacitor block is performed satisfactorily with a simple configuration and a control method. be able to. In each of the above-described embodiments, an example in which a microcomputer is applied as the switch control means and an example in which a commercial AC power supply is applied have been described. However, the charging device according to the present invention is not limited thereto. Alternatively, the control signal generated based on the pulsating flow generated from the commercial AC power supply may be supplied to the changeover switch by the microcomputer at a predetermined timing. In this case, the duty of the control signal for switching the connection state of the capacitor can be set by arbitrarily changing the switching timing by the microcomputer, and a charging device that achieves a faster charging operation and a reduced charging current is provided. Can be.

[0041]

According to the first aspect of the present invention, a capacitor block including a capacitor stack in which a plurality of capacitors are stacked, charge control means for supplying a charging current to the plurality of capacitors, and a voltage charged in the capacitors Voltage monitoring means for detecting and monitoring the power supply.When the charging operation is performed, a plurality of capacitor stacks are connected in series, and during the voltage monitoring operation, the capacitors of each layer constituting the plurality of capacitor stacks are connected in parallel. With this configuration, the same amount of energy can be charged at a lower current or in a shorter time than when charging is performed with a capacitor connected in parallel. Performance can be improved. Further, since the capacitor block is constituted by a capacitor stack in which a plurality of capacitors are stacked, a high voltage suitable for practical use can be realized even if the withstand voltage per capacitor is low.

According to the second aspect of the present invention, the first switch means for connecting a plurality of capacitor stacks in series and the second switch for connecting the capacitors for each layer constituting the plurality of capacitor stacks in parallel. Means for turning on the first switch means during the charging operation, connecting the capacitors in series, and during the voltage monitoring operation,
Since the second switch is turned on to connect the capacitors of each layer constituting the capacitor stack in parallel with each other, a control signal to be supplied to the switch according to the operation state of the charging device is provided. By operating the charging device, it is possible to provide a charging device capable of easily switching the connection state of the capacitor and performing appropriate charging operation and voltage monitoring operation.

According to the third aspect of the present invention, the capacitor block is configured to repeatedly execute a voltage monitoring operation for detecting and monitoring the charged voltage at predetermined time intervals during a charging operation for charging the capacitor. As a result, the charging voltage of the capacitor, which rises as the charging time elapses, can be periodically detected and monitored, and appropriate charging operation and voltage monitoring operation can be realized. Further, at the time of the voltage monitoring operation, the capacitors are connected in parallel for each layer constituting the capacitor stack, so that the variation of the charging voltage in each capacitor can be made uniform, and the charging performance can be improved.

According to the fourth aspect of the present invention, the voltage monitoring means compares the charging voltage detected during the voltage monitoring operation with a predetermined reference voltage, and when the charging voltage becomes equal to or higher than the reference voltage. Since the charging current supplied from the charging control means to the capacitor block is interrupted, the charging operation is performed before the charging voltage of the capacitor, which rises with the elapse of the charging time, exceeds the withstand voltage of the capacitor. It can be stopped, and the destruction of the capacitor and the occurrence of failure or failure of the charging device can be prevented. In addition, the voltage monitoring means has a configuration in which the supply of current from the power supply means is interrupted instead of a configuration in which the current supplied to the capacitor block is bypassed. Can be. According to the invention described in claim 5,
The voltage monitoring means includes a plurality of voltage monitoring units connected in parallel with the capacitors of each layer constituting the capacitor stack during the voltage monitoring operation, so that a voltage monitoring means is required for each capacitor. The number of voltage monitoring means corresponding to the number of stacked capacitor stacks makes it possible to detect the charging voltage appropriately while equalizing the charging voltage of each capacitor, thereby reducing the size and cost of the charging device. Can be achieved.

According to the sixth aspect of the invention, a capacitor stack in which a plurality of capacitors are stacked is connected in series,
A procedure for charging a plurality of capacitors, a procedure for connecting capacitors in each layer constituting a plurality of capacitor stacks in parallel at predetermined time intervals, and detecting and monitoring a voltage charged in the capacitors. Charging voltage,
Comparing with a preset reference voltage, and interrupting the charging current supplied to the capacitor when the charging voltage becomes equal to or higher than the reference voltage, so that charging is performed with the capacitor connected in parallel. Compared to the case where the same amount of energy can be charged at a low current or in a short time, and the charging voltage of the capacitor, which rises as the charging time elapses, is periodically monitored, and the charging voltage is Before the voltage exceeds the withstand voltage of the capacitor, the charging operation is stopped, so that the destruction of the capacitor and the failure or failure of the charging device can be prevented, and an appropriate charging operation can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a charging device according to the present invention.

FIG. 2 is a schematic circuit illustrating a connection state during a charging operation of the charging device according to the embodiment.

FIG. 3 is an equivalent circuit showing a connection state during a charging operation of the charging device according to one embodiment.

FIG. 4 is a schematic circuit illustrating a connection state during a voltage monitoring operation of the charging device according to the embodiment.

FIG. 5 is an equivalent circuit showing a connection state during a voltage monitoring operation of the charging device according to one embodiment.

FIG. 6 is a schematic configuration diagram showing a discharging operation state of the charging device according to one embodiment.

FIG. 7 is a schematic circuit diagram showing an operation according to a connection state of capacitors constituting a capacitor block applied to one embodiment.

FIG. 8 is a flowchart illustrating a procedure of a method of charging a capacitor block applied to one embodiment.

FIG. 9 is a timing chart showing control timings of capacitors constituting a capacitor block applied to one embodiment.

FIG. 10 is a circuit configuration diagram showing a specific example of a changeover switch applied to the charging device according to one embodiment.

FIG. 11 is a schematic configuration diagram showing another example of the switch control means applied to the charging device according to one embodiment.

FIG. 12 is a waveform diagram showing a signal waveform of a control signal by a switch control unit according to another embodiment.

FIG. 13 is a schematic configuration diagram showing a conventional charging device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Charge control circuit 20 Capacitor block 30 Voltage monitor circuit 40 Load C11-C3n Electric double layer capacitor CS1-CSn Capacitor stack HL High potential side power line LL Low potential side power line

Claims (6)

[Claims] A capacitor block including a capacitor stack in which a plurality of capacitors are stacked; a charging control unit configured to supply a predetermined charging current to the capacitor block to charge the plurality of capacitors; Voltage monitoring means for detecting and monitoring a voltage, wherein the capacitor block connects a plurality of the capacitor stacks in series during a charging operation for charging the plurality of capacitors, and outputs a voltage charged in the plurality of capacitors. A charging device, wherein, during a voltage monitoring operation for detecting and monitoring, the capacitors for each layer constituting the plurality of capacitor stacks are connected in parallel. 2. The capacitor block comprises: a first switch for connecting a plurality of capacitor stacks in series; and a second switch for connecting the capacitors of each layer constituting the plurality of capacitor stacks in parallel. Means for turning on the first switch means and turning off the second switch means at the time of the charging operation to connect the plurality of capacitors in series, at the time of the voltage monitoring operation, 2. The method according to claim 1, wherein the first switch is turned off and the second switch is turned on to connect the capacitors of each of the plurality of capacitor stacks in parallel. 2. The charging device according to 1. 3. The method according to claim 2, wherein the capacitor block repeatedly performs a voltage monitoring operation for detecting and monitoring the charged voltage at a predetermined time interval during a charging operation for charging the plurality of capacitors. Item 3. The charging device according to Item 1 or 2. 4. The voltage monitoring means compares a charging voltage detected during the voltage monitoring operation with a preset reference voltage, and when the charging voltage becomes equal to or higher than the reference voltage, the charging control means The charging device according to any one of claims 1 to 3, wherein the charging current supplied from the means to the capacitor block is cut off. 5. The voltage monitoring means includes a plurality of voltage monitoring units connected in parallel with the parallel connection of the capacitors for each layer constituting the plurality of capacitor stacks during the voltage monitoring operation. The charging device according to claim 1, wherein: 6. A method of charging a plurality of capacitors by connecting in series a capacitor stack in which a plurality of capacitors are stacked, and connecting the capacitors of each layer constituting the plurality of capacitor stacks at predetermined time intervals. Connect in parallel,
The procedure of detecting and monitoring the voltage charged in the capacitor, and comparing the detected charging voltage with a preset reference voltage, when the charging voltage is equal to or higher than the reference voltage, A step of interrupting the supplied charging current.