JP3414655B2 - Series switching capacitor power supply - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor power supply device that stores electric energy in a capacitor bank to supply power to a load.

[0002]

2. Description of the Related Art Electric double-layer capacitors, like chemical batteries such as lead batteries and nickel-cadmium batteries, which take a long time to be charged, can be rapidly charged by physical charging like other capacitors. . Moreover, the battery of the electric double layer capacitor has a great advantage that a large amount of energy can be stored, which is not available in the chemical battery.
= Has the characteristic that the terminal voltage varies greatly based on the relation of CV ^2/2. An electric power storage device using an ECS (Energy Capacitor System) that uses an electric double layer capacitor has a large amount of electric power stored in the electric double layer capacitor and can be effectively used as a power supply device for an electric vehicle or a large scale. It is receiving attention as an electric power storage device.

The ECS has already been used as a power energy storage system consisting of a capacitor, a parallel monitor and a current pump in various documents (eg, electronic technology, 1994-12, p1 to p1).
3, Electronics B, Vol. 115, No. 5, 1995, p504-6
10 etc.). Where the parallel monitor is
This is a device in which a plurality of capacitors are connected between the terminals of each capacitor of a capacitor bank connected in series and parallel, and the charging current is bypassed when the charging voltage of the capacitor bank exceeds the set value of the parallel monitor. Therefore, to make the capacitor bank usable up to the full withstand voltage,
The parallel monitor plays an extremely important role and is an essential device as a means for effectively utilizing the energy density. By connecting the parallel monitors, it is possible to equalize the maximum voltage, prevent backflow, detect and control the end-of-charge voltage, etc. even when there are variations in the characteristics of the capacitors and the magnitude of the residual charge. Therefore, all the capacitors in the capacitor bank are evenly charged to the set voltage, and the storage capacity of the capacitors can be almost 100% exhibited.

However, in a power supply device such as an electric double layer capacitor, which uses a battery having a large voltage fluctuation in which the voltage greatly decreases as energy is taken out from a fully charged state, in order to effectively utilize the storage capacity, the power supply side voltage It is essential to make the voltage constant. For this reason, a power supply device has been already proposed (see Japanese Patent Laid-Open No. 8-168182) in which serial / parallel switching of batteries is performed to reduce the voltage fluctuation range. FIG. 11 is a diagram showing a configuration example of a power supply device that performs series-parallel switching of capacitor batteries, in which the capacitor batteries are switched from parallel connection to series connection as the voltage drops. In such a power supply,
For example, if the series-parallel switching circuit of the capacitor batteries C1 and C2 shown in FIG. 11 (A) is cascade-connected in multiple stages as shown in FIG. 11 (B) and switching control is performed stepwise according to the charging / discharging state, the number of stages is matched. The voltage fluctuation range can be reduced.

[0005]

However, if the fluctuation range of the voltage is reduced as described above, the number of stages for switching from parallel connection to series connection increases, and as the number of stages increases, a correspondingly larger number of changeover switches Sp1. , Sp
2, Ss1 to Sp31, Sp32, and Ss31 are required. That is, as is apparent from FIG. 11A, since three change-over switches Sp1, Sp2, Ss1 are used in one stage, three-fold change-over switches are required.

Moreover, since these change-over switches are for power supplies, power semiconductors such as large electromagnetic contactors, giant transistors, IGBTs, GTOs, thyristors and the like are used. Therefore, the number of components including the drive circuit of the changeover switch and the heat dissipation plate is large, and it is necessary to secure a large space for mounting. As a result, the cost of the device increases, and reliability also becomes a problem.

Further, when switching from parallel connection to series connection, if the voltages of the capacitor batteries C1 and C2 are non-uniform, a large cross current flows between the capacitor batteries C1 and C2. As shown in C), a protection circuit A for preventing such cross curl
1, A2, and switching elements Q1 to Q that can support it
3 is required.

[0008]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems, and controls the connection of capacitors with a small number of switches to improve the utilization rate and reduce the cost of the device.
It is intended to improve reliability.

To this end, the present invention provides a plurality of capacitors
A serial switching type capacitor power supply device for controlling a voltage within an allowable fluctuation range by controlling a series connection of banks according to a charge / discharge state, and an output capacitor bank charged / discharged within a set range of an output voltage, A plurality of adjustment capacitor banks that are charged and discharged within the permissible fluctuation range; a switching means that serially connects and disconnects the output capacitor bank and the plurality of adjustment capacitor banks; and the output Voltage detecting means for detecting the voltage of the capacitor capacitor bank, and according to the voltage detected by the voltage detecting means, the plurality of adjusting capacitor banks are sequentially connected in series to the output capacitor bank during discharging. During charging, the plurality of adjustment capacitor banks connected in series are sequentially disconnected from the output capacitor bank. Control means for controlling the switching means so as to adjust the output voltage within an allowable fluctuation range, and relaxation charge for performing relaxation charge on the adjustment capacitor bank separated from the output capacitor bank at the time of charging. Means for controlling the switching order of the switching means in reverse at the time of discharging and at the time of charging, and the output capacitor bank and the plurality of adjusting capacitors.
It is characterized in that serial connection with the bank and disconnection of the connection are sequentially performed.

Further, the output capacitor bank is formed by connecting a plurality of capacitor banks in series, and the voltage detecting means measures a voltage between terminals of the output capacitor bank. Characterized in that the charging / discharging state is detected, and the voltage detecting means measures the voltage between terminals of the output capacitor bank to calculate the remaining amount of energy, and displays the remaining amount. Is.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a serial switching type capacitor power supply device according to the present invention,
C1 to C5 are capacitor banks, S1 to S3 are switches, A1 is a control circuit, 1 is a charger, 2 is an output control circuit,
3 indicates a load.

In FIG. 1, capacitor banks C1.about.
C5 is a capacitor (single cell) such as an electric double layer capacitor, which is connected in series or in parallel for electric energy storage, and is connected to each capacitor or bank. Is connected to a parallel monitor. Of these, the capacitor banks C1 to C3 are output capacitor banks that are charged and discharged within the rated voltage range of the load, and the capacitor banks C4 and C5 are charged and discharged within the load voltage fluctuation range allowable range. This is an adjustment capacitor bank. The switches S1 to S3 are provided in addition to the output capacitor banks C1 to C3 connected in series to connect the adjustment capacitor banks C4 and C5 in series in a stepwise manner or disconnect the connection. .

The control circuit A1 has a charging / discharging state (voltage) in the output capacitor banks C1 to C3 connected in series.
Is detected, and switches S1 to S3 are selected according to the charging / discharging state.
Is controlled to connect or disconnect the adjustment capacitor banks C4 and C5. Therefore, by always turning on only one of the switches S1 to S3 by the control circuit A1, the series connection of only the capacitor banks C1 to C3 to the series connection of the capacitor banks C4 and C5 is added. Up to the state
The number of banks connected in series is switched stepwise. Therefore, since the control circuit A1 switches between the three connection states, two detection levels E ₁ and E ₂ (for example, E ₁
<E ₂ ).

The charger 1 is a current source for charging the capacitor banks C1 to C5 connected in series from the power source with a constant current. The connection between the capacitor banks C4 and C5 is gradually disconnected, and finally the capacitor banks C1 and C5 are disconnected. The series circuit of the banks C1 to C3 is charged to the rated voltage and the charging is completed. The output control circuit 2 controls and regulates the current supplied from the capacitor banks C1 to C5 to the load 3 like the already known current hoop, or conversely acts as a current source (charger) from the load 3 as a capacitor. Charging banks C1-C5,
That is, the switching is performed in the case of regenerative braking in which the load 3 serves as a generator. Therefore, as the output control circuit 2, an electronic switch, a step-down chopper, a step-up chopper, or other DC / DC converter is used.
It can be omitted when the voltage is stabilized in a range that does not need to be adjusted from the viewpoint of the load 3 by controlling the connection switching of the capacitor banks C1 to C5, and is a particularly indispensable component for the present invention. Not a thing. Of course,
If the voltage fluctuation range is reduced by controlling the connection switching of the capacitor banks C1 to C5, the converter can be designed with high efficiency by combining it with a converter, and a power supply with high voltage stability can be realized.

Next, the charging / discharging operation of controlling the switches S1 to S3 in accordance with the voltage Vc3 of the capacitor banks C1 to C3 and switching the number of the capacitor banks C1 to C5 connected in series will be described. 2 is a diagram for explaining an example of a connection control processing routine, FIG. 3 is a diagram showing a configuration example of a control circuit, and FIG. 4 is a diagram showing a configuration example of a circuit for determining a voltage and generating a switching signal. . In the figure, 21, 22, 24,
Reference numeral 25 is a comparator, 23 and 28 are decoders, 26 is an inverter (inversion circuit), and 27 is an up / down counter.

In the control circuit A1, for example, as shown in FIG. 2, the voltage Vc3 at the upper end of the capacitor bank C3 is read (step S11), and this voltage Vc3 is used as a criterion for control to set preset levels E ₁ and E. _It is compared with ₂ (steps S12 and S14). Then, when the voltage Vc3 is lower than the first set level E ₁ , only the switch S3 is turned on to connect all the capacitor banks C1 to C5 in series (step S16). If the voltage Vc3 is lower than the second set level E ₂ and is equal to or higher than the first set level E ₁ , only the switch S2 is turned on and the capacitor banks C1 to C4 are connected in series except the capacitor bank C5. (Step S15). If the voltage Vc3 is equal to or higher than the second set level E ₂ , only the switch S1 is turned on and the capacitor banks C4 and C5 are excluded.
The banks C1 to C3 are connected in series (step S1).
3). The charge / discharge operation will be described below.

The charging operation will be described. Charging from all discharges is performed by turning on only the switch S3 as shown in FIG.
Start from the state of connecting in series. That is, the control circuit A1 turns on only the switch S3 unless the voltage Vc3 at the upper end of the capacitor bank C3 reaches the first set level E ₁ . Begins charging, the charging voltage Vc3 the control circuit A1 that rises to a set level E ₁ first detects, to turn on only the switch S2 turns off the switch S3, as shown in FIG. 1 (B) By disconnecting the capacitor bank C5, the capacitor banks C1 to C
4 connected in series. Further the charging voltage Vc3 increased and the second setting level E ₂ reached (exceeded a) the control circuit A1 that is detected, the switch S as shown in FIG. 1 (C)
2 is turned off and only switch S1 is turned on to disconnect the capacitor bank C4 and
The banks C1 to C3 are connected in series. Then, when the battery is charged to the rated voltage, this state becomes the full charge of the system.

The discharge operation will be described. Contrary to the charging operation, the discharge from full charge starts from the state where the three capacitor banks C1 to C3 are connected in series by turning on only the switch S1 as shown in FIG. 1 (C). Start. Discharge voltage Vc3 lowered by, the control circuit A1 that falls below the second set level E ₂ is detected, turning on only the switch S2 turns off the switch S1, as shown in FIG. 1 (B) Adds a capacitor bank C4 in series. When the control circuit A1 detects that the voltage Vc3 has dropped below the first set level E ₁ due to further discharge, the switch S2 is turned off and only the switch S1 is turned on as shown in FIG. Thus, the capacitor bank C5 is also added in series. By sequentially adding the capacitor banks C4 and C5 in series in this manner, the decrease in the output voltage is compensated.

In the fully charged state of the system, FIG.
As shown in, only switch S1 is turned on and the capacitor
Since the rated voltage is taken out by the series connection of the banks C1 to C3, the voltage of the capacitor bank C4 + C5 is piled up on the rated voltage, and the maximum voltage generated inside the circuit is correspondingly increased. In contrast to the circuit configuration shown in FIGS. 1A to 1C, in the circuit configuration shown in FIG. 1D, the voltage of the capacitor banks C4 + C5 is the capacitor bank C.
Since they are connected with the polarity subtracted from the voltage of the series circuit of 1 to C3, the maximum voltage generated inside the circuit can be suppressed low.

As described above, in the control circuit A1, the output capacitor bank C which is charged and discharged in the range of the rated voltage of the load.
The voltage Vc3 between the terminals 1 to C3 can be measured, and the charge / discharge state can be detected based on the determination of the voltage Vc3. However, the energy remaining amount can be obtained from the voltage V. FIG. 3 shows a configuration example of a control circuit having a circuit for displaying the remaining amount. In FIG. 3, the voltage detection circuit 11 measures the inter-terminal voltage Vc3 of the output capacitor banks C1 to C3. The voltage determination circuit 12 determines the voltage V
The voltage is determined (the charge / discharge state is determined) based on c3, and the switch control circuit 12 performs the on / off control of the switches S1 to S3 as described above based on the determination of the voltage determination circuit 12. Further, the remaining amount calculation circuit 14 calculates the remaining amount of energy based on the voltage Vc3,
The display circuit 15 displays the remaining energy amount calculated by the remaining amount calculation circuit 14.

As a circuit for judging a voltage and generating a switching signal, there is a circuit shown in FIG. 4, for example. Figure 4
The circuit of the example shown in (A) reads the voltage Vc3 at the upper end of the capacitor bank C3 as described above,
The switch S is compared by comparing c3 with the set levels E ₁ and E _2.
This is to control ON / OFF of 1 to S3. The set levels E ₁ and E ₂ are prepared for determining the switching levels of the first and second stage capacitor banks, and the comparators 21 and 22 are the capacitor banks C.
The voltage Vc3 at the upper end of 3 is compared with the set levels E ₁ and E ₂ . Then, the decoder 23 decodes the outputs of the comparators 21 and 22 and switches S1 to S3.
To generate an ON signal. Therefore, if the number of stages of the adjustment capacitor bank increases, the number of setting levels and the number of comparators corresponding to the number of stages are required.

Further, in the circuit of the example shown in FIG. 4B, the output voltage Vou is obtained by appropriately connecting the output capacitor banks C1 to C3 in series with the adjustment capacitor banks C4 and C5.
Read t, judge this voltage Vout, and switch S1
It is for controlling ON / OFF of Sn. The setting level V _H is a high value prepared for determining the switching level at the time of charging, and the setting level V _L is a low value prepared for determining the switching level at the time of discharging, and the comparator 24 , 25 are for comparing the output voltage Vout with the set levels V _H , V _L. Then, the up / down counter 27 performs up-counting by the output of the comparator 24 and down-counting by the output of the comparator 25, and the decoder 28 decodes the output of the up-down counter 27 to select one of the switches S1 to Sn. Is to generate an ON signal. Reset (re
set) is used when the circuit is started with the count value set to zero, such as at startup. Therefore, in the case of this circuit, if the up / down counter 27 and the decoder 28 are made to correspond to the number of adjustment capacitor banks,
It can be composed of two setting levels and two comparators 24 and 25 regardless of the number of adjustment capacitor banks.

In any of the above-mentioned methods, a phenomenon of output voltage fluctuation caused by internal resistance of the capacitor, so-called load fluctuation appears, but unnecessarily frequent bank switching occurs due to load fluctuation near the switching point. The comparator can be provided with an appropriate hysteresis characteristic so as not to occur.

An operation example from charging to discharging will be further described. FIG. 5 is a diagram showing an example of the voltage transition of each part from the full discharge state to constant current charging and constant power discharge completion, FIG. 6 is a diagram for explaining the relationship between the relaxation charge time and the self-discharge characteristic, and FIG. FIG. 8 is a diagram for explaining a decrease in utilization factor due to discharge, and FIG. 8 is a diagram showing an embodiment of a series switching type capacitor power supply device according to the present invention, which is provided with a relaxation charging circuit. Capacitor bank C with the same 1000F and 10V ratings
FIG. 5 shows an example of performing the charge / discharge test using 1 to C5. Here, the setting level of the control circuit A1 is E ₁
= 18V and E ₂ = 22.5V, the charger is 30
Use the constant current type (current source) of A and set the voltage limit value to 30.5
It was set to V and the discharge was a constant power load of 500W.

First, the transition of the output voltage and the voltage of each capacitor bank from the basic full discharge state, that is, from the state where the initial voltage of each capacitor bank is zero to the full charge, and from the full charge to the full discharge. 5, the output voltage is 1 (⋄), the upper end voltage of the capacitor bank C3 is 2 (□), the average voltage of the capacitor banks C1 to C3 is 3 (∇), the capacitor bank C4, The voltage of C5 is 4
(△), 5 (○). In this way, the output voltage 1 is 22.5V, which is the minimum voltage during the entire period from the point where the charging voltage of the capacitor banks C1 to C5 to the serial state reaches the rating to the point where the rated voltage is divided even if the capacitors are connected in series. The fluctuation range could be kept within 7.5 / 30 = 25%.

As is clear from the voltage trace 2 at the upper end of the capacitor bank C3, the terminal voltages of the capacitor banks C1 to C3 have a fixed relationship with the remaining amount of stored energy in the system. Therefore, from the energy U is the terminal voltage V accumulated in the capacitor of the capacitance C, utilizing the principle expressed by U = CV ^2/2, capacitor bank C1~C3
By measuring the terminal voltage of, the terminal voltage V can be converted into the remaining amount of stored energy, that is, the amount of stored electricity using the above calculation, or the squared, square-root broken line approximation circuit. The accurate display can be done with.

In the electric double layer capacitor, when the charging time is short, a characteristic self-charging, that is, a phenomenon of charging toward the subsequent stage of the own capacitor array remarkably occurs, and the terminal voltage decreases with time as shown in FIG. . The rate of this decrease can be reduced as the relaxation charge is performed for a long time. Therefore, in the above power supply device, the capacitor bank C5, which is sequentially disconnected from the series circuit during charging,
If the terminal voltage drop is large at C4, the storage capacity of the capacitor banks C5 and C4 will not be effectively utilized as shown in FIG. In FIG. 1, the capacitor bank C1 is now in the fully charged state and the switch S1 is on.
As the discharge of ~ C3 begins and the voltage drops, switch S1 turns off, switch S2 turns on and capacitor bank C5 or C4 is added in series. However, at that time, capacitor bank C5 or C
When 4 is self-discharged and the voltage is lowered, the voltage becomes lower with the lapse of time immediately after switching as shown in FIG. 7 corresponding to FIG.

In FIG. 8, the relaxation charge circuit 32 is a circuit for performing relaxation charge in order to prevent a subsequent drop in terminal voltage when the capacitor bank C5 or C4 is disconnected from the capacitor banks C1 to C3 during charging. And
As the current source, for example, a small-sized, small-capacity switching constant current circuit can be used. That is, the relaxation charging circuit 32 is a small capacity circuit that supplies a charging current of about 1/5 to 1 to 100 as compared with the normal charging current for the capacitor banks C1 to C5, and the control is charged. What is necessary is just to continue charging the capacitor banks C5 and C4 to the extent that they barely maintain the fully charged state.

FIGS. 9 and 10 are views for explaining another embodiment of the serial switching type capacitor power supply device according to the present invention. In the above-mentioned embodiment, for simplification of description, all the capacitor banks having the same capacitance and withstand voltage have been described, but as is clear from the traces 3, 4, and 5 shown in FIG. For fixed capacitor banks C1-C3, switched capacitors
The banks C4 and C5 are charged to voltages of 75% and 60%, respectively. Therefore, a capacitor bank having a low withstand voltage or a capacitor bank having a small number of series connections can be used here. When a bank with a small number of series connections is manufactured with a single cell having the same capacitance, the capacitance inevitably increases in proportion to the small number of series connections.

A switched capacitor bank C4,
A capacitance larger than the capacitor banks C1 to C3 fixed to C5 (C4 = 1 kF / 0.6, C5 = 1 kF / 0.
FIG. 9 shows an example of the voltage transition of each part in the case of using (75).
FIG. 10 shows an example of the voltage transition of each part when the electrostatic capacity (C4, C5 = 1 kF × 0.8) smaller than the fixed capacitor banks C1 to C3 is used for C4 and C5.
In these, □ is the voltage at the top of capacitor bank C3,
⋄ indicates an output voltage, ∘ indicates an average voltage of the capacitor banks C1 to C3, Δ indicates a voltage of the capacitor bank C4, and ∇ indicates a trace of the voltage of the capacitor bank C5.

As the capacitance of the switched capacitor banks C4 and C5 is increased or decreased, the amount of power that can be used at a certain voltage or more, that is, the utilization rate is increased or decreased, and the fluctuation range of the voltage is changed. Therefore, according to the present invention, the design should be selected according to the purpose, such as facilitating the manufacture by using the same capacitor, or adjusting the capacitance according to the part to use the stored electricity effectively. Is possible.

The present invention is not limited to the above embodiment, but various modifications can be made. For example, in the above-described embodiment, the adjustment capacitor bank is provided in series as a circuit for relaxing charging, but may be provided for each individual capacitor bank. Further, as a small current source (current bypass circuit having no power supply) for ensuring a current path for relaxation charging, a small switching constant current circuit is used for each capacitor as shown by 33 and 33 'in FIG. In that case, the upper bypass circuit may be a circuit that bypasses the current across the lower capacitors.
In addition, three capacitor banks were connected in series for output, and two capacitor banks were added in series for adjustment and disconnected according to the charge / discharge state. It goes without saying that the respective capacities can be adopted in any combination. For example, two capacitor banks may be serially added, and one capacitor bank may be serially added or disconnected. Generally, in order to reduce the variation, the number of non-switched capacitor banks C1 to C3 is increased.
That is, the voltage may be increased. This allows the voltage step to be a small percentage of the total output voltage when the switched capacitor bank is added.

[0033]

As is apparent from the above description, according to the present invention, the number of capacitor banks connected in series is increased or decreased. The number can be greatly reduced from 12 to 3 to 4 as compared with the conventional case of switching between parallel connection and series connection. Therefore, the loss of the switch, the mounting space, the cooling of heat generation, the switch drive circuit, and the cost can be significantly reduced, and the reliability can be significantly improved.
In addition, since the relaxation charge is performed on the capacitor bang that has been separated due to the increase in the charging voltage during charging, it is possible to prevent the use efficiency from being lowered due to the self-discharge and the decrease in voltage.

In particular, since the series-switching type capacitor power supply device of the present invention does not need a switching converter, it has no switching loss and is simple in device, and can be easily applied to a large-scale or super-large-scale system. In that case, the utilization efficiency of the capacitor bank can be improved by the relaxation charging circuit of 10% or less of the whole, and the existence value of the relaxation charging circuit is great.

Further, in the case of switching between the conventional parallel connection and the series connection, a means for preventing cross current from flowing due to the imbalance of the voltage at the time of switching to the parallel connection is required. According to this, since the number of capacitor banks connected in series is increased or decreased, such means becomes unnecessary.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a serial switching type capacitor power supply device according to the present invention.

FIG. 2 is a diagram illustrating an example of a connection control processing routine.

FIG. 3 is a diagram illustrating a configuration example of a control circuit.

FIG. 4 is a diagram illustrating a configuration example of a circuit that determines a voltage and generates a switching signal.

FIG. 5 is a diagram showing an example of the voltage transition of each part from the fully discharged state to the constant current charging and the constant power discharging completion.

FIG. 6 is a diagram for explaining a relationship between a relaxation charge time and a self-discharge characteristic.

FIG. 7 is a diagram for explaining a decrease in utilization rate due to self-discharge.

FIG. 8 is a diagram showing an embodiment of a series switching type capacitor power supply device according to the present invention, which includes a relaxation charging circuit.

FIG. 9 is a diagram for explaining another embodiment of the number-in-series control type power supply device according to the present invention.

FIG. 10 is a diagram for explaining another embodiment of the power supply device of serial number control type according to the present invention.

FIG. 11 is a diagram showing a configuration example of a power supply device that performs series-parallel switching of capacitor batteries.

[Explanation of symbols]

C1 to C5 ... Capacitor bank, S1 to S3 ... Switch, A1 ... Control circuit, 1 ... Charger, 2 ... Output control circuit,
3 ... load

Front Page Continuation (72) Inventor Masahiko Shinozuka 1-1-1 Fukuura, Kanazawa-ku, Yokohama-shi, Kanagawa Power System Co., Ltd. (56) Reference JP-A-9-292925 (JP, A) JP-A-50- 152601 (JP, A) JP 4-80677 (JP, A) JP 48-36057 (JP, B1) JP 49-49347 (JP, B1) JP 43-5631 (JP, B1) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H02J 1/00 H02J 7/00 H02J 7/36

Claims (4)

(57) [Claims] 1. A serial switching type capacitor power supply device for controlling a voltage within a permissible fluctuation range by controlling a series connection of a plurality of capacitor banks according to a charge / discharge state, wherein the charge / discharge is performed within a set range of an output voltage. Output capacitor bank, a plurality of adjustment capacitor banks charged and discharged with the allowable fluctuation range, a series connection of the output capacitor bank and the plurality of adjustment capacitor banks, and the connection Switching means for disconnecting, voltage detecting means for detecting the voltage of the output capacitor bank, and a plurality of adjustment capacitors for adjusting the output capacitor bank in the output capacitor bank according to the voltage detected by the voltage detecting means. The plurality of adjustment capacitors connected in series when the capacitor banks are connected in series, and are connected in series during charging.
Control means for controlling the switching means so as to sequentially disconnect the banks from the output capacitor bank and adjust the output voltage within an allowable fluctuation range; and the adjustment capacitor disconnected from the output capacitor bank during the charging. A soft charging means for performing a soft charge to the bank, and controlling the switching order of the switching means in reverse at the time of discharging and at the time of charging, thereby forming the output capacitor bank and the plurality of adjusting capacitor banks. A serial switching type capacitor power supply device characterized in that serial connection and disconnection of the connection are sequentially performed. 2. The serial switching type capacitor power supply device according to claim 1, wherein the output capacitor bank is a plurality of capacitor banks connected in series. 3. The serial switching type capacitor power supply device according to claim 1, wherein the voltage detecting means measures the voltage between terminals of the output capacitor bank to detect the charge / discharge state. 4. The serial switching type according to claim 3, wherein the voltage detecting means measures a voltage between terminals of the output capacitor bank to calculate a remaining energy amount and displays a remaining amount. Capacitor power supply.