JP2001178009A - Capacitor-accumulating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain equivalent voltage sharing characteristic for a long period of time without large resistance loss in a capacitor accumulating apparatus of simplified structure connecting in series plural capacitors in plural stages. SOLUTION: This capacitor accumulating apparatus comprises capacitor cells C1, C2 of plural stages and voltage dividing resistors R1, R2 connected in series. For the resistance value of this voltage-dividing resistor, when a current dividing coefficient to the divided resistor at the initial charging time of the capacitor accumulating apparatus is reduced to 10% or less, it is defined as the setting reference of the lower limit value. Moreover, when such a current dividing coefficient is reduced to 10% or less of the leakage resistances R12, R22 of this capacitor, it is defined as the setting reference of the upper limit value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor power storage device comprising a plurality of capacitors connected in series in a plurality of stages, and more particularly to a technique for equalizing voltages of the capacitors in the plurality of stages.

[0002]

2. Description of the Related Art Recently, an electric double layer capacitor has attracted attention as a large-capacity capacitor having excellent charge / discharge characteristics.
However, this electric double layer capacitor has a low voltage of a single unit, and it is necessary to connect a plurality of electric double layer capacitors in series in a plurality of stages in order to use the capacitor as a practical voltage rated capacitor. In this case, the problem is the non-uniformity of the voltage of the capacitors in each stage due to the capacitance deviation of each capacitor. That is, when a constant current is supplied to a plurality of capacitors connected in series and charged, the voltage of the small-capacitance capacitor becomes higher than the voltage of the large-capacity capacitor, and the voltage of each capacitor is set to a specified voltage which is an allowable limit. If it is set below, it becomes impossible to charge all capacitors up to the specified voltage.

As a solution to this problem, a so-called resistance voltage dividing system in which voltage dividing resistors having a relatively low resistance value capable of eliminating voltage non-uniformity due to capacitance deviation of each capacitor is connected to each stage in series has conventionally been used. Widely known from. However,
In this method, a considerable amount of current always flows through the voltage dividing resistor, and therefore, the generated loss cannot be ignored, and a reduction in efficiency cannot be avoided.

In order to reduce the loss caused by the resistance, for example, a system shown in FIG. 14 has been developed. In this method, the voltage of a capacitor in each stage is detected, and only when this voltage reaches a specified voltage, the voltage is diverted to a resistor to make the voltage uniform. In the figure, 1 is a constant current source for supplying a charging current, 2 is a discharge resistor as a load, 3 and 4 are switches (S1, S2), 5 and 6 are capacitors connected in series with each other and connected to the constant current source 1. (Capacitances are assumed to be C1, C2), 7 and 8 are voltage detectors connected between terminals of the capacitors 5 and 6, respectively. When the voltage of the connected capacitor reaches a predetermined specified voltage, the voltage detector is connected to a semiconductor switch described later. An on signal is output, and an off signal is output when the voltage becomes lower than the specified voltage. 9, 10 are shunt resistances (R), 11, 12
Is a semiconductor switch (T1), and 13 and 14 are diodes (T2).

Next, the operation during charging will be described with reference to FIG. Assuming that the capacitance of the capacitor C1 is smaller than C2, charging at a constant current at time t1 starts at time t2.
C1 reaches the specified voltage E1, and the voltage rises when charged as it is. However, the voltage E1 is maintained by detecting the voltage, turning on the semiconductor switch T1, and causing the shunt resistor R to bypass the charging current. At time t3, the capacitor C2 is also charged to the voltage E1 and becomes the same voltage as C1. The triangular portion in the figure indicates the power bypassed during this time.
At this point, charging is completed, and the discharging-charging cycle is referred to as E.
It can be continued based on one voltage.

[0006]

However, after charging (initial charging) of the conventional capacitor power storage device,
For example, assuming an operation state in which a charging / discharging operation is repeated in accordance with a change in the DC power supply voltage based on a change in the load, which is connected to a DC power supply such as a railway feeder circuit, the following problems exist. That is, although each capacitor has a leakage resistance, its value also varies considerably among the individual capacitors manufactured. This leakage resistance has an equivalent circuit connected in parallel with a pure capacitor element. As will be described in detail later, this variation in leakage resistance
This will determine the voltage sharing of the capacitors in each stage over a relatively long span.

As a result, during the operation of the capacitor power storage device, a new voltage imbalance occurs in the capacitors in each stage based on the variation of the leakage resistance, the semiconductor switch T1 is turned on, and the bypass current flows through the shunt resistance R. Will flow. The bypass current in this case may fluctuate depending on the DC power supply voltage during operation, but generally becomes an extremely large value as compared with the value supplied from the constant current source at the time of initial charging. The current capacity of the bypass circuit device becomes large and expensive, and the generation loss also increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and it is possible to equalize the voltage sharing of a plurality of stages of capacitors during a long-term operation of a capacitor power storage device, and to reduce the capacitance deviation of the capacitors. When providing bypass means for equalizing the voltage at the time of initial charging based on the above, it is necessary to obtain a capacitor power storage device capable of realizing low cost and low loss while keeping the current capacity at a small level. Aim.

[0009]

A capacitor power storage device according to the present invention includes a voltage dividing resistor connected in parallel with a plurality of capacitors at each stage, and the resistance value of the voltage dividing resistor is an initial value of the capacitor power storage device. The lower limit of the voltage sharing ratio of each stage during charging is substantially equal to the voltage sharing ratio determined in accordance with the capacitance deviation of each capacitor. The fact that they are substantially equal in each stage is used as a reference for setting the upper limit.

A capacitor power storage device according to the present invention includes a voltage dividing resistor connected in parallel with a plurality of capacitors in each stage, and the resistance value of the voltage dividing resistor is determined when the capacitor power storage device is initially charged. The shunt rate to the voltage dividing resistor is 10
% Or less is set as a criterion for setting the lower limit value, and set to be 10% or less of the leakage resistance value of each capacitor is set as a criterion for setting the upper limit value.

Further, a capacitor power storage device according to the present invention is a capacitor power storage device operated by being connected to a DC power supply, and outputs a constant current to perform initial charging of the capacitor power storage device. A voltage detector for detecting the voltage of the capacitor of each stage; and a series connection of a shunt resistor and a shunt switch connected between the terminals of the plurality of capacitors of each stage. By disconnecting the connection and outputting a constant current from the charging device, during the initial charging, when the voltage of the capacitor reaches a predetermined specified voltage, the shunt switch connected to the capacitor is closed to close each of the plurality of capacitors. Charges all the voltages of the capacitors of the stage to the specified voltage, after the initial charging is completed, disconnects the charging device, connects to the DC power supply, and shifts to the operation operation. Than it is.

Further, according to the capacitor power storage device of the present invention, when the DC power supply is connected to the capacitor power storage device, the current flowing through the shunt resistor becomes equal to or less than the constant current value output from the charging device during initial charging. It sets the resistance value of the resistor.

[0013] Further, in the capacitor power storage device according to the present invention, after the initial charging is completed, the charging device is disconnected, the shunt switch is kept open regardless of the voltage of the capacitor, and connected to a DC power supply for operation. It shifts to.

A capacitor power storage device according to the present invention is a capacitor power storage device that is operated by being connected to a DC power supply, and outputs a constant current to perform initial charging of the capacitor power storage device. A voltage detector for detecting the voltage of the capacitor of each stage; and a series connection of an adjusting capacitor and a shunt switch connected between the terminals of the capacitors of each of the plurality of stages. By disconnecting the connection and outputting a constant current from the charging device, during the initial charging, when the voltage of the capacitor reaches a predetermined specified voltage, the shunt switch connected to the capacitor is closed to close each of the plurality of capacitors. After charging all the voltages of the capacitors of the stage to the specified voltage, and after initial charging, disconnect the charger and connect to the DC power supply to start operation. It is intended to.

The capacitor power storage device according to the present invention includes a bypass switch connected in parallel with the shunt switch, performs initial charging with the bypass switch open, disconnects the charging device after the initial charging is completed, The bypass switch is maintained in a closed state, and is connected to a DC power supply to shift to an operation operation.

A capacitor power storage device according to the present invention is a capacitor power storage device that is operated by being connected to a DC power supply, and outputs a constant current to perform initial charging of the capacitor power storage device. It has a voltage detector that detects the voltage of the capacitor of each stage, and the initial charge is
Disconnect the connection with the DC power supply and output a constant current from the charging device, perform the initial charging, disconnect the charging device, and connect to the DC power supply to shift to operation operation. When the voltage of the capacitor exceeds a predetermined overvoltage, the connection with the DC power supply is cut off.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Before describing the specific configuration of the present invention, the effect of variations in leakage resistance of capacitors connected in series in a plurality of stages on the voltage sharing of the capacitors in each stage will be described.

FIG. 1 shows a cell in which two cells which are units of a minimum module of an electric double layer capacitor are connected in series. In the figure, reference numeral 20 denotes a variable-voltage DC power supply, 21 denotes a switch, and 22 denotes an electric double-layer capacitor cell (C1).
, The capacitance C11, the series resistance R11, the leakage resistance R12
have. The cell 23 (C2) has a capacitance C
21, a series resistor R21 and a leakage resistor R22.
If all of these characteristic constants for each cell are the same, the voltage sharing in the circuits connected in series becomes uniform, but in the actual manufacturing process, in order to match all these constants, a large number of manufactured cells must be combined. It is necessary to selectively extract and combine specific cells from among them, which is not economical.

Therefore, variation of constants in a certain range is inevitable, and the variation causes a different shared voltage.
FIG. 2 shows that C11 is 3000F, C21 is 3300F, R1
1 and R21 are both 0.01Ω and R11 is 1000
Ω and R22 are assumed to be 2000Ω
The state of voltage sharing when the C6V voltage is continuously applied is shown. The charging voltage is DC6V, and the voltages of C1 and C2 are DC13.13V and DC2.87V, respectively, which are shared by the inverse ratio of the capacitance.
At 2.88V, there is almost no change. However, when the time further elapses, as shown in FIG. 3, the two voltages become the same around 0.6 × 10 ⁶ seconds, and then the two voltages are inverted. In a time of 2 × 10 ⁶ seconds, the voltage becomes 2.72 V DC and 3.28 V DC. This is a time 2 × 10 ⁷ seconds (about 2 × 10 ⁷ seconds) as shown in FIG.
(Corresponding to 31 days), the charging voltage is DC6V, the sharing voltage is DC2.0V and DC4.0V, respectively, which is proportional to the leakage resistance and is independent of the capacity ratio, and the voltage is shared regardless of the capacity ratio. Will be applied.

As described above, the characteristic that the shared voltage of the cell is determined in proportion to the leakage resistance with the lapse of time is that even if charging and discharging are repeated in the middle, the shared voltage is the inverse ratio of the original initial charge capacitance. Does not return to the voltage determined by This is shown in FIG. This shows the shared voltage of the cells in the electric double layer capacitor circuit of FIG. 1 when a constant voltage DC6V is applied from the DC power supply to the cells C1 and C2 and the cells are further discharged to a load not shown in FIG. ing. Time 0.25 × 1
0 ⁷ , 0.50 × 10 ⁷ , 1.0 × 10 ⁷ , 1.5 × 10 ⁷
And is charged from the DC power supply immediately afterwards. For example, at time 1.0 × 10 ⁷ , the cell C2 discharges from the shared voltage of 3.9 V to the load, and temporarily reaches DC 1.3.
After dropping to 9V, recharge to 3.9V DC
It returns to the shared voltage based on the leakage resistance, and is not reset to the shared voltage DC 2.87 V based on the capacitance deviation at the beginning of charging.

Similarly, the cell C1 has a shared voltage DC2.12.
Discharged from V to the load, once dropped to -0.63V DC, recharged to 2.12V DC and returned to the shared voltage based on leakage resistance, and shared voltage based on the capacitance deviation at the beginning of charging Not reset to 3.12 VDC.

FIG. 6 shows the change over time of the ratio of the applied voltages to the cells C1 and C2 obtained in FIG. This ratio is 1000Ω, the ratio of the leakage resistance R12 and R22 of each cell.
/ 2000Ω converges to 0.5. As described above, the voltage ratio shared by the inverse ratio of the capacitance at the beginning of charging changes to a ratio determined by the leakage resistance with the passage of time.

The present invention has been made in view of the above-described characteristics. By uniformly equalizing the leakage resistance of the capacitors connected in series, a uniform shared voltage can be stably maintained over a long period of time. It is a hurry.

Hereinafter, a capacitor power storage device according to Embodiment 1 of the present invention will be described with reference to FIG. In FIG. 7, C11 to C43 denote respective capacitor cells, which are not shown, but each have a series resistance and a leakage resistance as described in FIG. Here, four cells are connected in parallel for each stage, and the unit modules CM1 and CM
2. A CM3 is formed, and a voltage dividing resistor 24 is connected to this unit module. Then, this module and a voltage dividing resistor connected in parallel are connected in a plurality of stages (here, 3
(Stage) connected in series to form a capacitor power storage device.

The combination of the cells constituting each of the unit modules CM1 to CM3 is determined so that the capacitances of the modules are equal to each other as much as possible. The variation in the leakage resistance becomes small stochastically. The resistance value of the voltage dividing resistor 24 will be described in more detail later,
Since the parallel combined resistance value with the leakage resistance of the capacitor is set to a value that is substantially equal in each stage in the series, it depends on the variation of the leakage resistance of the capacitor. For this reason, for example, as shown in FIG. 8, a voltage dividing resistor 24 is connected to each cell, and the voltage dividing resistors 24 are connected in series in three stages to form a unit module CM1 and the like. When a capacitor power storage device having the same capacity as that of FIG. 7 is configured, the variation in the leakage resistance of the capacitor whose voltage is to be equalized has a relatively large value as a unit cell. Has to be set to a smaller value than in the case of FIG. 7, and there is a drawback that the loss generated by the voltage dividing resistor 24 increases accordingly.

Next, how to set the resistance value of the voltage dividing resistor will be described. As described above, the voltage-dividing resistor is for substantially eliminating the variation in the leakage resistance that determines the voltage sharing in the long time period of the capacitors connected in series at each stage. The resistance value must be set to a value at which the combined resistance value with the leakage resistance of the capacitor is substantially equal in each stage. Specifically, the leakage resistance may be about 1/10 or less of the leakage resistance value of the capacitor.

On the other hand, as the voltage dividing resistance value, the leakage resistance value of 1
If the ratio is set to / 10 or less, the condition of equalizing the combined resistance value is satisfied no matter how small it is, but the current shunted to the voltage dividing resistor, and hence the loss, increases, and the problem pointed out in the prior art is increased. To wake up. This is because the resistance value is so small that the voltage dividing resistor absorbs the voltage deviation accompanying the capacitance deviation of the capacitor. Therefore, it is necessary to keep the voltage dividing resistance at a value at which the voltage sharing ratio of the capacitors in each stage at the time of initial charging is substantially equal to the voltage sharing ratio determined according to the capacitance deviation of the capacitors in each stage. In other words, by connecting the voltage dividing resistor, the voltage sharing ratio of each stage at the time of initial charging is hardly affected. Specifically, it is set so that the shunt rate to the voltage dividing resistor at the time of the initial charging is about 10% or less.

To summarize the above, the resistance value of the voltage dividing resistor should be set in the following manner. That is, the voltage sharing ratio of each stage at the time of the initial charging of the capacitor power storage device is substantially equal to the voltage sharing ratio determined according to the capacitance deviation of the capacitor of each stage. Such a resistance value at which the shunt ratio to the piezoresistance becomes 10% or less is defined as the lower limit of the piezoresistance. Then, the combined resistance value with the leakage resistance of the capacitor becomes substantially equal in each stage. More specifically, when expressed as a numerical value, the resistance value becomes 10% or less of the leakage resistance value of each capacitor. Is the upper limit. By providing a voltage dividing resistor having a resistance value satisfying the above conditions, a highly reliable capacitor power storage device in which loss is small and voltage sharing of each stage is equalized over a long period of time can be realized.

FIG. 9 shows a configuration in which capacitor cells C1 and C2 having the same characteristics as those illustrated in FIG. 1 are connected to voltage dividing resistors R1 and R2 according to the present invention, respectively. , And the resistance values of the voltage dividing resistors R1 and R2 are set to 100Ω. That is, in an example of an actual electric double layer capacitor, the leakage resistance of the cell has a deviation of about ± 1000Ω around 2000Ω, and here, 100Ω which is 1/10 of the minimum value 1000Ω is divided by the voltage dividing resistor R.
1, R2 were set.

FIG. 10 shows the effect of equalizing the shared voltage when the voltage dividing resistors R1 and R2 are each used at the same value of 100Ω with the capacitor constant used in FIG. At the time of charging, C1 and C2 share the voltage of DC 3.13V and DC 2.87V, respectively, at the inverse ratio of the capacitance of the capacitor.
In proportion to 0.91Ω and 95.24Ω, the time is 2 × 10 ⁷ seconds (corresponding to about 231 days).
It becomes 7 V and is almost uniform and stable.

Although the value of 100 Ω as the voltage dividing resistor seems to be too small and the shunting (leakage) current seems to be large at first glance, since this type of capacitor cell is used in a DC 3 V circuit, it is about 3/100 = 30 mA. In a circuit in which the actual charge / discharge current is 10 A or more, the leakage current is 0.3% or less of the leakage current, which is not a level that causes a problem in overall efficiency. If the charging current is 10 A and the cell voltage is 3 V as in the conventional case where the charging current is all diverted to the shunt resistor and the voltage does not exceed the specified value, the shunt resistance is 3/10 = 0. It is necessary to set the resistance to 3Ω or less, and the capacity and the generation loss of the resistor must be extremely large.

As described above, the capacitor power storage device according to Embodiment 1 of the present invention, as shown in FIG. 7, has a configuration in which each stage module is configured by connecting a plurality of capacitor cells in parallel. The simple configuration of minimizing the capacitance deviation of each stage and connecting the voltage-dividing resistor set to the above-mentioned predetermined resistance value to each module of each stage minimizes the initial resistance without causing a large resistance loss. During charging and over a long period of time, the voltages of the capacitors in each stage are kept uniform, and the efficiency and reliability are improved.

Embodiment 2 FIG. FIG. 11 is a configuration diagram showing a capacitor power storage device according to Embodiment 2 of the present invention. It is provided with a protection measure when the capacitor power storage device is used continuously for a long time. That is, here, voltage detection circuits 27 and 28 for detecting the voltage of the capacitor cell of each stage are provided, and when the detected value exceeds a specified voltage set from the tolerance of the capacitor, the relay 29 or 30 is provided.
Operates to open its contact 29A or 30A to disconnect the capacitor power storage device from the DC power supply 20.

It is assumed that the leakage resistance and the capacitance of the capacitor cell are greatly changed due to the deterioration of the characteristics of the capacitor cell when the power is applied for a long period of time, and the shared voltage of each stage becomes non-uniform. This is intended to prevent a phenomenon in which the cells that exceed the voltage sequentially cause avalanche-like bank destruction. For example, as a countermeasure against power failure of the load, voltage is always applied.
When applied to a capacitor power storage device used in a so-called floating circuit, there is an advantage that the safety of the device is improved.

Embodiment 3 FIG. FIG. 12 is a configuration diagram showing a capacitor power storage device according to Embodiment 3 of the present invention. In the first embodiment, it is assumed that the capacitance deviation of the capacitors in each stage connected in series is kept within a certain limit. However, depending on the device, the capacitance deviation is not necessarily in a sufficiently small range. In some cases, the voltage of each stage capacitor at the time of the initial charge should be surely adjusted regardless of the capacity deviation. The third embodiment responds to such a case and demands, and provides a capacitor power storage device capable of surely equalizing the voltage of each stage for a long period of time from the time of initial charging.

In FIG. 12, the cells 22, 23 and the voltage dividing resistor 24 are the same as those in FIG. Further, voltage detectors 7, 8, shunt resistors 9, 10 (R), semiconductor switches 11, 12 (T1), diodes 13, 14 (T2)
Are the same as those in FIG. 14, and the individual description is omitted.
Numeral 31 assumes, for example, a railway feeder circuit, which is simulated by an equivalent circuit including a constant voltage source E (corresponding to a feeder substation), a variable load resistance RL (corresponding to a train), and line resistances RF1 and RF2. This is regarded as a DC power source as viewed from the capacitor power storage device, and is connected to the capacitor power storage device via the switch SW1. A charging device 32 supplies a constant charging current, and is connected to a capacitor power storage device via a switch SW2.

Next, the operation will be described. First, an initial charging operation for charging the capacitors C1 and C2 from a state where there is no charge to a specified voltage will be described. Switch S
When W1 is opened and the switch SW2 is closed, a constant charging current is supplied from the charging device 32 to the capacitors connected in series.

When, for example, the voltage of the cell C1 first reaches the specified voltage due to the capacitance deviation of the capacitor, the voltage detector 7
Detects this, turns on the semiconductor switch T1, shunts the charging current to the shunt resistor R, and keeps the voltage of the cell C1 at the specified voltage. Thereafter, when the voltage of the cell C2 reaches the specified voltage, the charging operation ends. By the way, the charging current value in this case can be set irrespective of the load current value flowing through each capacitor when the switch SW1 is closed to put the capacitor power storage device into the operating state, which will be described later. Therefore, a bypass circuit device such as the shunt resistor R and the semiconductor switch T1 that can set the charging current from the charging device 32, which can set the value sufficiently smaller than the load current, is sufficient. , Become economically easy.

When the initial charging is completed, the switch SW1 is closed and the switch SW2 is opened to shift to an operation operation as a capacitor power storage device, and the semiconductor switch T1 is turned off regardless of the voltage to keep the bypass circuit open. . In this operation operation, the charging operation from the DC power supply 31 to the capacitor power storage device and the discharging operation from the capacitor power storage device to the DC power supply 31 are repeated according to the voltage fluctuation based on the load fluctuation in the DC power supply 31. The voltage of the capacitor power storage device, that is, the voltage of each capacitor fluctuates along with the charging / discharging operation. At this point, at the end of the initial charging, the capacitor voltage of each stage is equalized, and the voltage dividing resistor 24 As a result, the leakage resistance of each capacitor is made substantially uniform, and as described earlier with reference to the characteristic diagram of FIG. 5, the voltage at the time of recovery after charging and discharging becomes uniform in the capacitors of each stage, and this state continues.

In the above description, the semiconductor switch T1 is always turned off during the operation of the capacitor power storage device. However, the voltage from the DC power supply 31 may be in an overvoltage state for some reason. In consideration of, for example, that a higher voltage than normal can be applied to other capacitors due to deterioration of the capacitor, when such an abnormality occurs, the semiconductor switch T1 is turned on to protect the capacitor and the voltage rise of the capacitor is suppressed. You may do so. In this case, the current flowing when the resistance value of the shunt resistor R is bypassed by the shunt resistor R when the capacitor power storage device is connected to the DC power supply 31 is changed to the charging device 32 during the initial charging.
, The current capacity of these bypass circuit devices can be kept within a range not exceeding the original duty at the time of the initial charging described above.

Embodiment 4 FIG. FIG. 13 is a configuration diagram showing a capacitor power storage device according to Embodiment 4 of the present invention. The only difference from the third embodiment shown in FIG. 12 is that an adjustment capacitor CP is connected instead of the shunt resistor R of the bypass circuit. That is, when the voltage of the small-capacity capacitor reaches the specified voltage based on the deviation of the capacitors of the cells C1 and C2, the semiconductor switch T1 is turned on and the adjustment capacitor CP is turned on to suppress the voltage rise.

Here, the capacitance of the adjustment capacitor CP is set, for example, in the following manner. That is, the nominal capacitance of each cell capacitor is Ca, and the capacitance variation with respect to this nominal capacitance is ±
pa%, the nominal capacitance of each adjustment capacitor is Cb, and the capacitance variation with respect to this nominal capacitance is ± pb%, a value is set that satisfies the following expression: Cb ≧ 2 · Ca · pa / (100−pb)

The operation related to the initial charging and the transition to the operation operation is the same as that of the third embodiment, and the description is omitted. However, during the operation, the semiconductor switch T1 is always turned on so as to form a bypass circuit. In this case as well, the same effects as in the third embodiment can be obtained, and the voltage equalization of each stage is performed by bypassing the adjustment capacitor CP. As a result, loss can be further reduced and efficiency can be improved.

Although not shown in consideration of the possibility of occurrence of overcurrent during the operation of the capacitor power storage device, by connecting a bypass switch in parallel with the semiconductor switch T1 in FIG. In general, the semiconductor switch T1 and the diode T2, which are generally strict in withstand current, can be protected from overcurrent. That is, the bypass switch is opened during the initial charging operation, the voltage is made uniform by the switching operation of the semiconductor switch T1 based on the above-described voltage detector, and after the initial charging is completed, the operation is shifted to the operation operation. Is maintained in a closed state. Thus, even if a current exceeding the constant current value at the time of initial charging flows through the bypass circuit of the adjustment capacitor CP, this current flows through the bypass switch connected in parallel with the semiconductor switch T1 and the diode T2.
1. No current flows through the diode T2. Therefore, by configuring this bypass switch with a metal conductor type that can easily realize a large current withstand capability, the required current withstand capability of the semiconductor switch T1 and the diode T2 can be reduced to the level of the constant current value at the time of initial charging. And it is easier to realize economically and technically.

In each of the above embodiments, the description has been given of the case where the electric double layer capacitor is used as the capacitor. However, the present invention is not limited to this. The series-parallel configuration of a plurality of unit capacitors for forming the capacitor power storage device is, of course, not limited to the example shown in each drawing. Further, the DC power supply to be operated by the capacitor power storage device is not limited to, for example, the one having the circuit configuration shown in FIG. 12 and the like, and is not limited to the one supposing a railway feeder circuit.

[0046]

As described above, a capacitor power storage device according to the present invention includes a voltage-dividing resistor connected in parallel with a plurality of capacitors in each stage, and the resistance value of the voltage-dividing resistor is equal to that of the capacitor power storage device. When the lower limit is set, the voltage sharing ratio of each stage at the time of initial charging is substantially equal to the voltage sharing ratio determined according to the capacitance deviation of each capacitor. Are set to be substantially equal in each stage, so that a uniform voltage sharing characteristic can be obtained over a long period of time with a simple configuration and without a large resistance loss.

Further, the capacitor power storage device according to the present invention includes a voltage-dividing resistor connected in parallel with a plurality of capacitors in each stage, and the resistance value of the voltage-dividing resistor is determined when the capacitor power-storage device is initially charged. The shunt rate to the voltage dividing resistor is 10
% Or less as the reference for setting the lower limit value, and 10% or less of the leakage resistance value of each capacitor as the reference for setting the upper limit value, it is easy to set the optimum voltage dividing resistor. You.

A capacitor power storage device according to the present invention is a capacitor power storage device that is operated by being connected to a DC power supply, and outputs a constant current to perform initial charging of the capacitor power storage device. A voltage detector for detecting the voltage of the capacitor of each stage; and a series connection of a shunt resistor and a shunt switch connected between the terminals of the plurality of capacitors of each stage. By disconnecting the connection and outputting a constant current from the charging device, during the initial charging, when the voltage of the capacitor reaches a predetermined specified voltage, the shunt switch connected to the capacitor is closed to close each of the plurality of capacitors. Charges all the voltages of the capacitors of the stage to the specified voltage, after the initial charging is completed, disconnects the charging device, connects to the DC power supply, and shifts to the operation operation. In to eliminate the voltage variations during initial charging based on capacitance deviation of a plurality of stages of capacitors, constantly stable uniform voltage distribution characteristics during operation over the subsequent long-term from the initial charge is obtained.

Further, according to the capacitor power storage device of the present invention, when the DC power supply is connected to the capacitor power storage device, the current flowing through the shunt resistance becomes equal to or less than the constant current value output from the charging device during the initial charging. Since the resistance value of the resistor is set, the required current resistance of the shunt resistor and the shunt switch can be kept at a low level after the initial charging, and the realization of these shunt circuit configurations is economically and technically easy.

In the capacitor power storage device according to the present invention, after the initial charging is completed, the charging device is disconnected, the shunt switch is kept open regardless of the voltage of the capacitor, and the power storage device is connected to a DC power supply for operation. , The current does not flow through the shunt circuit after the initial charging, and the shunt circuit configuration is economically and technically easy to realize.

A capacitor power storage device according to the present invention is a capacitor power storage device that is operated by being connected to a DC power supply, and outputs a constant current to perform initial charging of the capacitor power storage device. A voltage detector for detecting the voltage of the capacitor of each stage; and a series connection of an adjusting capacitor and a shunt switch connected between the terminals of the capacitors of each of the plurality of stages. By disconnecting the connection and outputting a constant current from the charging device, during the initial charging, when the voltage of the capacitor reaches a predetermined specified voltage, the shunt switch connected to the capacitor is closed to close each of the plurality of capacitors. After charging all the voltages of the capacitors of the stage to the specified voltage, and after initial charging, disconnect the charger and connect to the DC power supply to start operation. Since the voltage variation at the time of initial charging based on capacitance deviation of a plurality of stages of capacitors without resistive losses are eliminated, constantly stable uniform voltage distribution characteristics during operation over the subsequent long-term from the initial charge is obtained.

Also, the capacitor power storage device according to the present invention includes a bypass switch connected in parallel with the shunt switch, performs initial charging with the bypass switch open, disconnects the charging device after the initial charging is completed, Since the bypass switch is maintained in a closed state and connected to a DC power supply to start operation, even if a shunt switch is applied, for example, a semiconductor switch, its required current withstand capability can be kept at a low level at the time of initial charging. This makes it possible to economically and technically realize these shunt circuit configurations.

A capacitor power storage device according to the present invention is a capacitor power storage device that is operated by being connected to a DC power supply, and outputs a constant current to perform initial charging of the capacitor power storage device. It has a voltage detector that detects the voltage of the capacitor of each stage, and the initial charge is
Disconnect the connection with the DC power supply and output a constant current from the charging device, perform the initial charging, disconnect the charging device, and connect to the DC power supply to shift to operation operation. Since the connection to the DC power supply is cut off when the voltage of the capacitor exceeds a predetermined overvoltage, in the long-term operation of the capacitor power storage device, for example, when the overvoltage is applied based on the change in the capacitance or the leakage resistance due to the deterioration of the capacitor, the capacitor becomes The phenomenon of avalanche destruction can be prevented beforehand, and the safety of the equipment is improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a circuit in the case where two cells of a capacitor are connected in series and charged.

FIG. 2 is a diagram showing charging voltage characteristics in a relatively short time level in the circuit of FIG. 1;

FIG. 3 is a diagram showing a charging voltage characteristic at a relatively long time level in the circuit of FIG. 1;

FIG. 4 is a diagram showing charging voltage characteristics at a longer time level in the circuit of FIG. 1;

FIG. 5 is a diagram showing charging voltage characteristics when charging and discharging are repeated in the circuit of FIG. 1;

FIG. 6 is a diagram showing a time change characteristic of a voltage ratio of each capacitor in the case of FIG. 5;

FIG. 7 is a diagram showing a basic configuration of the capacitor power storage device according to Embodiment 1 of the present invention.

FIG. 8 is a diagram exemplarily illustrating a comparison with FIG. 7;

FIG. 9 is a diagram showing a capacitor power storage device according to Embodiment 1 of the present invention.

FIG. 10 is a diagram showing the long-term charging voltage characteristics of FIG.

FIG. 11 is a diagram showing a capacitor power storage device according to a second embodiment of the present invention.

FIG. 12 is a diagram showing a capacitor power storage device according to Embodiment 3 of the present invention.

FIG. 13 is a diagram showing a capacitor power storage device according to Embodiment 4 of the present invention.

FIG. 14 is a diagram illustrating a conventional capacitor power storage device.

FIG. 15 is a diagram showing the charge / discharge characteristics of FIG.

[Explanation of symbols]

7,8 Voltage detector, 9,10 Shunt resistance (R), 1
1,12 Semiconductor switch (T1), 13,14 Diode (T2), 20,31 DC power supply, 22,23
Capacitor cells (C1, C2), 24 divider resistors (R
1, R2), 27, 28 Voltage detection circuit, 29, 30
Relays (Ry1, Ry2), 32 charging devices, 33, 3
4 Adjustment capacitor (CP), R12, R22 Leakage resistance.

Claims (8)

[Claims] 1. A capacitor power storage device comprising a plurality of capacitors connected in series in a plurality of stages, comprising: a voltage dividing resistor connected in parallel with the capacitors in each of the plurality of stages; The lower limit of the capacitor power storage device at the time of initial charging is set such that the voltage sharing ratio of each stage is substantially equal to the voltage sharing ratio determined according to the capacitance deviation of each capacitor. Wherein the combined resistance value at each stage is substantially equal at each stage as a reference for setting the upper limit value. 2. A capacitor power storage device comprising a plurality of capacitors connected in series in a plurality of stages, comprising: a voltage dividing resistor connected in parallel with the capacitors in each of the plurality of stages; The lower limit value is set as a criterion for setting the lower limit of the shunt rate to the voltage dividing resistor to 10% or less during the initial charging of the capacitor power storage device, and the upper limit is set to 10% or less of the leakage resistance value of each capacitor. A capacitor power storage device, which is used as a reference for setting a value. 3. A capacitor power storage device operated by being connected to a DC power supply, wherein the charging device outputs a constant current to perform initial charging of the capacitor power storage device, and detects a voltage of a capacitor in each of a plurality of stages. A voltage detector, and a series connection of a shunt resistor and a shunt switch connected between the terminals of the capacitors in each of the plurality of stages. During the initial charging, when the voltage of the capacitor reaches a predetermined specified voltage, the shunt switch connected to the capacitor is closed to thereby set all the voltages of the capacitors in each of the plurality of stages to the specified value. 3. The key according to claim 1, wherein the battery is charged to a voltage, and after completion of the initial charging, the charging device is disconnected, connected to the DC power supply, and shifted to an operation operation. Capacitor power storage device. 4. The method according to claim 1, wherein the resistance value of the shunt resistor is set such that a current flowing through the shunt resistor when the DC power supply is connected to the capacitor power storage device is equal to or less than a constant current value output from the charging device during initial charging. The capacitor power storage device according to claim 3, wherein: 5. After the completion of the initial charging, disconnect the charging device,
4. The capacitor power storage device according to claim 3, wherein the shunt switch is kept open regardless of the voltage of the capacitor, and connected to a DC power supply to start operation. 6. A capacitor power storage device connected to a DC power supply and operated, the charging device outputting a constant current to perform initial charging of the capacitor power storage device, and detecting a voltage of a capacitor in each of a plurality of stages. A voltage detector, and a series connection of a regulating capacitor and a shunt switch connected between terminals of the capacitors in each of the plurality of stages; for initial charging, disconnection from the DC power source and constant current from the charging device During the initial charging, when the voltage of the capacitor reaches a predetermined specified voltage, the shunt switch connected to the capacitor is closed to thereby set all the voltages of the capacitors in each of the plurality of stages to the specified value. 3. The battery according to claim 1, wherein the battery is charged to a voltage, and after the completion of the initial charging, the charging device is disconnected, connected to the DC power supply, and shifted to an operation operation. On-board capacitor power storage device. 7. A bypass switch connected in parallel with a shunt switch, wherein initial charging is performed with the bypass switch open, and after completion of the initial charging, the charging device is disconnected and the bypass switch is maintained in a closed state. 7. The method according to claim 6, further comprising connecting to a DC power supply to shift to an operation operation.
A capacitor power storage device according to claim 1. 8. A capacitor power storage device operated by being connected to a DC power supply, comprising: a charging device that outputs a constant current to perform initial charging of the capacitor power storage device; and detects a voltage of a capacitor in each of a plurality of stages. The initial charging is performed by disconnecting the connection to the DC power supply and outputting a constant current from the charging device.After the initial charging is completed, the charging device is disconnected and connected to the DC power supply for operation. 3. The capacitor power storage device according to claim 1, wherein the operation shifts to an operation, and in this operation, when the voltage of the capacitor exceeds a predetermined overvoltage, the connection to the DC power supply is cut off.