JP2001061235A - Charging device and charging method - Google Patents

Abstract

(57) [PROBLEMS] To significantly reduce the size of a capacitor bank by reducing the number of voltage monitor circuits connected in parallel to each of the capacitors while reducing the current supplied to a plurality of capacitors constituting the capacitor bank. And a charging device capable of reducing cost. SOLUTION: A capacitor bank 20 including a plurality of capacitors C1 to C4, and a power supply circuit 10 which supplies a predetermined charging current IA to charge the capacitor bank 20.
And a voltage monitor circuit 30 for detecting and monitoring the voltage charged in the capacitor bank 20. During a charging operation, the capacitors C1 to C4 are connected in series to charge a current IA.
During the voltage monitoring operation, the supply of the charging current IA is cut off, and the capacitors C1 to C4 are connected in parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a charging apparatus and a charging method, and more particularly, to a charging apparatus and a charging method for storing electric energy in a capacitor bank 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
No. 11, as shown in FIG. 16, a predetermined charging current I is supplied from a power supply circuit 10A to a capacitor bank 20A having a plurality of electric double layer capacitors C11 to C14.
B, the electric double layer capacitor C11
A technique for accumulating electric charges in accordance with current values in each of C14 to C14 is described. 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. 16, 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 prior art described above has a configuration in which a plurality of electric double layer capacitors are connected in series.
When monitoring, it is necessary to connect a voltage monitor circuit in parallel for each electric double layer capacitor (parallel monitor), which causes a problem that the scale of the charging device becomes extremely large and the product cost increases. Was. Further, when the charging current is bypassed by the voltage monitoring circuit, the amount of heat W is generated according to the power consumption of the voltage monitoring circuit and the number of connected voltage monitoring circuits (double-layer capacitors). It was difficult. The amount of heat W generated by the bypass of the charging current is represented by the following equation, where IB is the charging current, VL is the withstand voltage, and n is the number of voltage monitoring circuits (electric double layer capacitors). The amount of heat W increases in proportion to the number. W = IB · VL · n (13)

Accordingly, the present invention has been made in view of the above problems,
While reducing the current supplied to the plurality of electric double layer capacitors constituting the capacitor bank, the number of voltage monitor circuits connected in parallel to each of the electric double layer capacitors is reduced, and the size is greatly reduced, and It is an object of the present invention to provide a charging device and a charging method capable of reducing costs.

[0007]

According to a first aspect of the present invention, there is provided a charging device, wherein a predetermined charging current is supplied to the capacitor bank based on an AC signal supplied from a commercial power supply. Power supply means for supplying and charging the plurality of capacitors, and voltage monitoring means for detecting and monitoring the voltage charged in the capacitor bank, wherein the capacitor bank is configured to perform a charging operation for charging the plurality of capacitors. In a voltage monitoring operation for detecting and monitoring the charged voltage by connecting the plurality of capacitors in series, the plurality of capacitors are connected in parallel with each other.

According to a second aspect of the present invention, in the charging apparatus according to the first aspect, the capacitor bank detects and monitors the charged voltage during a charging operation for charging the plurality of capacitors. Is repeatedly executed at predetermined time intervals. Claim 3
The charging device according to claim 1, wherein the capacitor bank has a changeover switch for switching a connection state of the plurality of capacitors, and the changeover switch is configured to switch the plurality of capacitors during the charging operation. It is characterized in that the capacitors are connected in series and are controlled so as to switch to a parallel connection state at predetermined time intervals.

According to a fourth aspect of the present invention, in the charging apparatus according to the third aspect, the changeover switch is configured to perform a half-wave rectification of an AC signal supplied from the commercial power supply based on a pulsating flow generated. A state in which the plurality of capacitors are connected in series,
Alternatively, switching control is performed to a parallel connection state. 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 unit may determine a charging voltage detected during the voltage monitoring operation and a preset reference voltage. In comparison, when the charging voltage becomes equal to or higher than the reference voltage, the supply of current from the power supply unit to the capacitor bank is cut off. According to a sixth aspect of the present invention, in the charging apparatus according to any one of the first to fifth aspects, the voltage monitoring unit is commonly connected to the plurality of capacitors connected in parallel during the voltage monitoring operation. It is characterized by having a single configuration.

According to a seventh aspect of the present invention, in the charging method for charging a capacitor bank with a charging current generated based on an AC signal supplied from a commercial power supply, a plurality of capacitors constituting the capacitor bank are connected in series. And charging at a predetermined time interval, switching the plurality of capacitors into a parallel connection state to detect and monitor the charged voltage, and the detected charging voltage and a predetermined reference. Comparing with a voltage, when the charging voltage is equal to or more than the reference voltage, a step of interrupting the supply of current from the power supply means to the capacitor bank,
It is characterized by including. In the charging method according to the eighth aspect, in the charging method according to the seventh aspect, the step of detecting and monitoring the charged voltage includes a step of half-wave rectifying an AC signal supplied from the commercial power supply to generate a pulse. The method is characterized in that the plurality of capacitors are switched to a parallel connection state based on a flow generation timing.

[0011]

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 apparatus according to the present embodiment includes a power supply circuit 10 constituting a power supply unit, a capacitor bank 20 including a plurality of electric double layer capacitors (hereinafter simply referred to as capacitors), And a voltage monitor circuit 30 that constitutes a means.

The power supply circuit 10 includes a high-potential power supply line HL and a low-potential power supply line LL to which the capacitor bank 20 is connected.
In the meantime, a predetermined DC voltage based on a commercial AC power supply (for example, AC 100 V) is applied to supply a charging current IA to the capacitor bank 20. The capacitor bank 20 includes a capacitor C1, a switch SW11, and a capacitor C between the high-potential power line HL and the low-potential power line LL.
2, the changeover switch SW12, the capacitor C3, the changeover switch SW13, and the capacitor C4 are sequentially connected to the contact N
11, N12, N21, N22, N31, and N32 are connected in series.

Then, the high potential side power supply line HL and the contact N1
2, between the high-potential-side power supply line HL and the contact N22, and between the high-potential-side power supply line and the contact N32, respectively.
1 to 23 are provided, and the low-potential-side power supply line LL and the contact N1 are provided.
1, between the low-potential power line LL and the contact N21, and between the low-potential power line LL and the contact N31.
W31 to W33 are provided. The high potential side power supply line HL includes capacitors C1 to C4 and a changeover switch SW.
A switch SW0 is provided for controlling the supply of a charging current to the series connection composed of 11 to SW13.

Here, the changeover switches SW11 to SW13
The switch SW0 and the switch SW0 are simultaneously ON / OFF controlled at a predetermined timing based on the same control signal. Also, changeover switches SW21 to SW23 and SW31 to SW33
Are ON / OFF controlled simultaneously with the changeover switches SW11 to SW13 at the opposite timing. The voltage monitor circuit 30 includes a high-potential-side power line HL and a low-potential-side power line L
L, the amount of charge stored in the capacitors C1 to C4 is detected as a monitor voltage (charging voltage) value, and is compared with a predetermined reference voltage (guaranteed withstand voltage) value. It is determined whether or not the reference voltage value has been reached. When the monitor voltage value reaches the reference voltage value, the control signal SC0 is output to the power supply circuit 10, and the supply of the charging current IA to the capacitor bank 20 is cut off.

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 SW0 of the high-potential-side power supply line HL is controlled to be turned on to electrically connect the power supply circuit 10 and the capacitor bank 20, and
Changeover switches SW11 to SW1 of capacitor bank 20
3 in the ON state, and changeover switches SW21 to SW2
3 and the switches SW31 to SW33 are simultaneously switched to the OFF state.

Such changeover switches SW0, SW11
To SW13, SW21 to SW23, SW31 to SW33
3 controls the capacitor bank 20 as shown in FIG.
As shown in the equivalent circuit shown in FIG. 7, the capacitors C1 to C4 are connected in series between the high-potential-side power line HL and the low-potential-side power line LL. The supplied charging current IA is determined by each capacitor C1.
To C4 to start charging.

(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 switching the changeover switch SW0 of the high-potential-side power supply line HL to the OFF state to control the power supply circuit 10 and the capacitor bank 20.
And the capacitor bank 20
Of the changeover switches SW11 to SW13, and the changeover switches SW21 to SW23 and SW31 to SW
This is realized by simultaneously switching and controlling W33 to the ON state.

Such changeover switches SW0, SW11
To SW13, SW21 to SW23, SW31 to SW33
5 controls the capacitor bank 20 as shown in FIG.
As shown in the equivalent circuit shown in FIG. 7, the capacitors C1 to C4 are connected in parallel between the high-potential-side power supply line HL and the low-potential-side power supply line LL.
The voltages connected to all the capacitors C1 to C4 are commonly connected, and the voltages charged in the capacitors C1 to C4 are equalized and detected as a charged voltage.

(Discharge Operation) FIG. 6 is a schematic configuration diagram showing a discharge operation state of the charging device according to the present embodiment. In the discharging operation, as shown in FIG. 6A, the load 35 is connected in parallel with the voltage monitor circuit 30 via the switch SW31 between the high potential side power supply line HL and the low potential side power supply line LL. Switch S of the high-potential-side power line HL
W0 is controlled to be turned off to electrically cut off the power supply circuit 10 and the capacitor bank 20;
A switch SW31 provided between the capacitor bank 20 and the load 35 is controlled to be switched to an ON state, and FIG.
As shown in (b), the capacitor bank 20 and the load 35
Are electrically connected to each other. In this case, the capacitors C1 to C1 of the capacitor bank 20
The connection state of 4 is appropriately switched and controlled in accordance with the state of the load 35, and appropriate stored energy is supplied to the load 35.

Next, the connection state of the capacitors constituting the capacitor bank and the operation thereof will be described with reference to the drawings. FIG. 7 is a schematic circuit diagram showing an operation depending on a connection state of capacitors constituting a capacitor bank 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 = 1/2 · CV ² (1)

That is, from equation (1), the stored energy E is proportional to the square of the charging voltage V. Here, assuming that the charging current is I (A) and the charging time is t (s), the charge amount Q accumulated in the capacitor is expressed as follows: Q = ∫Idt = I · t (2) The relationship between the charge amount Q, the capacitance C, and the voltage V between both ends is generally expressed as Q = CV (3). Therefore, the above equation (1) is expressed by 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)
Is inversely proportional. Further, when the above equation (4) is modified, the charging current I is expressed 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, in order to keep the stored energy E constant, as shown in FIG.
Divided into four (in the figure, four) capacitors C1 to C4,
Considering the case of series connection, the capacitor bank 20
Is 1 / (n ² ) times, and the capacitance C in this case is
Applying / (n ² ) to the above equation (5), √ (2EC) / t = √ (2EC / n ² ) / t = I / n (6) By connecting, 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 power supply circuit. However, according to the charging device of the present invention, As described above, when the amount of energy stored in the capacitor bank 20 is constant,
The capacitor bank 20 is configured by being divided by a plurality of (for example, n = 4) capacitors and connected in series, so that the capacitance value of the capacitor bank 20 is reduced by 1 /
Since (n ² ) = 1/16, the charging current I can be reduced to 1 / n = 1/4 according to the division ratio by the capacitor. In other words, when the charging current I is fixed, the charging time t can be reduced to 1 / n = 1/4.

On the other hand, as shown in FIG. 7B, considering the case where the n divided capacitors C1 to C4 are connected in parallel, the capacitance C of the capacitor bank 20 becomes n times and The voltage across the capacitors C1 to C4 (charging voltage) is made uniform. Here, by connecting both ends of the capacitor bank 20 connected in parallel to the voltage monitor circuit 30 and detecting the voltage between both ends, the charging voltages stored in the capacitors C1 to C4 can be changed to a single voltage monitor without variation. Detected by the circuit. Then, by switching between the series connection state and the parallel connection state of the capacitors, the charging operation by the series connection and the voltage monitoring operation by the parallel connection are executed at a predetermined timing, and both ends of the capacitor bank detected by the voltage monitoring circuit are detected. When the voltage reaches a reference voltage set in advance to guarantee the withstand voltage of each capacitor, a control signal is output from the voltage monitor circuit to the power supply circuit, and the supply of the charging current is cut off.
Stop charging operation.

According to the charging device of the present invention, during the voltage monitoring operation, the capacitor is switched to the parallel connection state,
Since the voltage (charging voltage) across each capacitor can be detected using a single voltage monitor circuit, there is no need for a voltage monitor circuit connected in parallel for each capacitor as shown in the prior art. Thus, the size and cost of the charging device can be significantly reduced. Further, the voltage monitor circuit applied to the present invention has a function of detecting the voltage charged in the capacitor bank and outputting a control signal for cutting off the supply of the charging current when the voltage exceeds the reference voltage. Therefore, as shown in the prior art, since each of the capacitors is connected in parallel and the charging current is not bypassed, heat generation from the voltage monitor circuit can be largely suppressed.

Next, a charging method of 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 bank applied to the present embodiment, and FIG. 9 is a timing chart illustrating control timing of capacitors forming the capacitor bank applied to the present embodiment. . (S101, S102) First, the changeover switches SW0, S
W11 to SW13 are turned on, and the changeover switches SW21 to SW13 are turned on.
By switching the switches SW23 and SW31 to SW33 to the OFF state, the capacitors C1 to C4 are connected in series, and the capacitor bank 20 and the power supply circuit 10 are connected to be supplied via the high potential side power supply line HL. A charging operation for charging the capacitors C1 to C4 with the charging current IA is started.

(S103, S104) Next, after a predetermined time has passed since the start of the charging operation, the changeover switches SW0, S
W11 to SW13 are OFF, changeover switch SW21
To SW23 and SW31 to SW33 in the ON state, the capacitors C1 to C4 are connected in parallel, the capacitor bank 20 and the power supply circuit 10 are electrically disconnected, and the charging operation is interrupted.
A voltage monitoring operation in which the voltage monitoring circuit 30 detects the voltages charged in 1 to C4 is executed.

(S105) Here, the voltage monitor circuit 30
Compares the detected charging voltage (detected voltage) Vm with a preset reference voltage (withstand voltage assurance voltage) Vs based on the withstand voltage of the capacitors C1 to C4. If the detected voltage Vm is not higher than the reference voltage Vs, After the voltage monitoring operation is completed, the changeover switches SW0, SW11 to SW13 are turned on again, and the changeover switches SW21 to SW23, SW31 to SW
33 is switched to the OFF state, and the charging operation is continued. (S106) On the other hand, when the detection voltage Vm is equal to or higher than the reference voltage Vs, the voltage monitor circuit 30
, The supply of the charging current from the power supply circuit 10 is interrupted, and the charging operation ends.

As described above, the charging method according to the present embodiment uses the changeover switches SW0 and SW11 as shown in FIG.
To SW13 and changeover switches SW21 to SW
23, the groups of SW31 to SW33 are simultaneously turned ON and OFF at the opposite timing, and the capacitors C1 to C4 are controlled.
Are connected in series, a charging operation is performed, and capacitors C1 to C4 are connected in parallel at predetermined time intervals during the charging operation.
Execute the voltage monitoring operation. 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, a changeover switch and its control means applied to the charging device according to the present embodiment will be described with reference to the drawings. FIG. 10 is a schematic configuration diagram showing a first example of switch control means applied to the charging device according to the present embodiment, and FIG. 11 is a circuit configuration diagram showing a specific example of a changeover switch. As shown in FIG. 10, the switch control means applied to the charging device according to the present embodiment is configured by a microcomputer (hereinafter, referred to as a microcomputer) 40, and the changeover switches SW0 and SW0 are controlled by a control signal SC1.
The ON / OFF operations of the groups of SW11 to SW13 are simultaneously controlled, and the changeover switch SW2 is controlled by the control signal SC2.
ON of a group of 1 to SW23, SW31 to SW33,
OFF operation is controlled all at once.

Here, as shown in FIG. 9, the output timings of the control signals SC1 and SC2 are set at fixed time intervals.
It may correspond to the procedure of a charging method in which the charging operation and the voltage monitoring operation are repeated, or until the charging voltage reaches the reference voltage based on the fact that the charging voltage of the capacitor rises in proportion to the charging time. May be calculated, and after the start of the charging operation, the elapse of the required time may be detected to execute the voltage monitoring operation.

When the switch control means according to the present embodiment is applied, as shown in FIG. 11, for example, a control signal (voltage) output from a microcomputer is used as the changeover switch SW.
A photodiode PD that emits light of a predetermined wavelength and a phototransistor PS that receives light from the photodiode PD and conducts electricity based on the photodiode PD. 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 from each other, and the ON / OFF operation appropriately corresponding to the control signal is realized. be able to.

FIG. 12 is a schematic configuration diagram showing a second example of the switch control means applied to the charging apparatus according to the present embodiment, and FIG. 13 shows a change in signal waveform due to half-wave rectification processing. 14 is a waveform diagram showing a signal waveform of a control signal, and FIG. 15 is a schematic circuit diagram showing a control signal supply control circuit. As shown in FIG. 12, the switch control unit applied to the charging device according to the present embodiment generates a pulsating flow by half-wave rectifying an AC signal supplied from a commercial AC power supply, and supplies the pulsating flow to the capacitor bank 20. A half-wave rectifier circuit 10a, a first signal system for outputting a voltage waveform generated through the diode D1 and the protection resistor R1 as the first AC control signal SC1, and a diode D2 A second signal system that outputs a voltage waveform generated via the protection resistor R2 as a second control signal SC2.

As shown in FIG. 13, the half-wave rectifier circuit 10a extracts only a positive signal voltage component from a sine AC signal supplied from a commercial AC power supply, and forms a positive voltage waveform at a constant cycle. A pulsating current having the pulsating current is generated and supplied to the capacitor bank 20 as a charging current, and is also supplied to the integrating circuit 10b and the stabilized power supply circuit 10c that generate the power for driving the changeover switch. The integration circuit 10b and the stabilized power supply circuit 10c generate a power supply voltage having a desired signal voltage based on the half-wave rectified pulsating current, and supply the power supply voltage as a drive power supply for a changeover switch in the capacitor bank 20.

A first signal system is provided for the AC signal.
By the diode D1 connected in the forward direction, as shown in FIG. 14, only the positive voltage component of the AC signal is passed to generate a control signal SC1 having a positive voltage waveform at a constant cycle, and the changeover switch SW0 And SW11 to SW13 are set to O
N, is supplied to the capacitor bank 20 as a signal for controlling OFF. On the other hand, the second signal system is constituted by a diode D2 connected in the opposite direction to the AC signal, as shown in FIG.
As shown in FIG. 4, the control signal SC2 having only a negative voltage component of the AC signal and having a positive voltage waveform at a constant cycle.
And switches SW21 to SW23 and SW3
1 to 33 are supplied to the capacitor bank 20 as signals for controlling ON and OFF.

That is, the control signal SC1 is synchronized with the pulsating flow shown in FIG.
To SW13 all at once to control the capacitors C1 to C4
Are connected in series, and a charging current based on the pulsating current is supplied to the capacitor bank 20, so that the charging operation is performed. On the other hand, the control signal SC2 is switched at the timing opposite to the pulsating flow shown in FIG.
To SW23 and SW31 to SW33 are simultaneously turned ON to connect the capacitors C1 to C4 in a parallel connection state.
Since the supply of the charging current to the capacitor bank 20 is cut off, the charging operation is interrupted, and the voltage monitoring circuit 30 executes the voltage monitoring operation.

As shown in FIG. 15, the control circuit for supplying the control signals SC1 and SC2 to the changeover switch has the control signal SC1 or SC2 as a base input, a switching transistor SWT having a collector connected to a simple power supply, and a base input. Lines (input lines for control signals SC1 and SC2) for preventing overvoltage from being applied to the switching transistor SWT, and photodiode current limiting resistors R11 and R12 connected to the emitter terminal of the switching transistor SWT, respectively. , R1
, And are connected in parallel via a switch SW having a photocoupler configuration, similarly to the switch shown in FIG.
And

In such a changeover switch SW, when a predetermined signal voltage is applied to the base input of the switching transistor SWT by the control signals SC1 and SC2,
The switching transistor SWT conducts, and a predetermined emitter current is supplied to the photodiode current limiting resistors R11, R12, and R3 according to the simple power supply applied to the connector.
R13,... Flows down to each changeover switch SW,
ON control is performed simultaneously. When the switch control unit according to the present embodiment is applied, since the switching control of the changeover switch and the switching control of the operation state are performed using an AC signal supplied from a commercial AC power supply, The capacitor can be switched between series connection and parallel connection periodically in synchronization with the AC power supply, and the charging operation and the voltage monitoring operation can be repeatedly performed, so that the charging operation to the capacitor bank can be favorably performed with a simple configuration. .

In each of the above-described embodiments, an example in which a microcomputer is used as the switch control means and an example in which a commercial AC power supply is applied are individually shown. However, the charging device according to the present invention is not limited to this. The present invention is not limited to this, and a microcomputer may output a control signal generated based on a pulsating flow generated from a commercial AC power supply to the changeover switch at a predetermined timing. In this case, the duty of the control signal for switching the connection state of the capacitor (FIG. 12,
(50% in FIG. 13), the switching timing can be arbitrarily changed and set by the microcomputer, and a charging device that realizes a faster charging operation and a reduced charging current can be provided.

[0041]

According to the first aspect of the present invention, a capacitor bank composed of a plurality of capacitors, power supply means for charging the plurality of capacitors, voltage monitoring means for detecting and monitoring the charged voltage, In the charging operation, a plurality of capacitors are connected in series, and in the voltage monitoring operation, the plurality of capacitors are connected in parallel with each other. The same amount of energy can be charged with a low current or in a short time, and the charging device can be reduced in size or the charging performance can be improved.

According to the second aspect of the present invention, since the capacitor bank is configured to repeatedly execute the voltage monitoring operation at predetermined time intervals during the charging operation, the capacitor which rises as the charging time elapses. Charging voltage can be periodically detected and monitored, and multiple capacitors are connected in parallel during the voltage monitoring operation. And a voltage monitoring operation can be realized.

According to the third aspect of the present invention, the capacitor bank has the changeover switch for switching the connection state of the plurality of capacitors. During the charging operation, the plurality of capacitors are connected in series and are connected in parallel at predetermined time intervals. The connection state of the plurality of capacitors can be easily switched according to the operation state of the charging device by the control signal to the changeover switch because the connection state is configured to be connected. A charging device capable of performing monitoring can be provided.

According to the fourth aspect of the present invention, the changeover switch connects a plurality of capacitors in series based on a pulsating current generated by half-wave rectification of an AC signal supplied from a commercial power supply, or Since it has a configuration for switching control to the parallel connection state, a plurality of capacitors can be periodically switched between series connection and parallel connection in synchronization with the commercial power supply, and the charging operation and the voltage monitoring operation can be repeatedly performed. It is possible to provide a charging device capable of favorably performing an operation of charging a capacitor bank with a simple circuit configuration.

According to the fifth aspect of the present invention, the voltage monitoring means compares the 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. Since the current supply from the power supply means to the capacitor bank is interrupted, the charging operation is stopped before the charging voltage of the capacitor, which rises as the charging time elapses, exceeds the withstand voltage of the capacitor. This can prevent the destruction of the capacitor, the failure of the charging device, and the occurrence of a defect. 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 bank is bypassed. Can be.

According to the sixth aspect of the present invention, the voltage monitoring means has a single configuration commonly connected to each of the plurality of capacitors connected in parallel during the voltage monitoring operation. Without the need for a voltage monitoring means for each capacitor, a single voltage monitoring means can evenly and accurately detect the charging voltage of each capacitor, greatly reducing the size and cost of the charging device. Can be planned.

According to the seventh aspect of the present invention, in a charging method for charging a capacitor bank with a charging current generated based on an AC signal supplied from a commercial power supply, a plurality of capacitors constituting the capacitor bank are connected in series. To perform a charging operation, switch a plurality of capacitors to a parallel connection state at predetermined time intervals, detect a charging voltage,
It includes a procedure for monitoring and comparing the charging voltage with the reference voltage and, when the charging voltage becomes equal to or higher than the reference voltage, cutting off the current supplied from the power supply means. 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 with the elapse of the charging time, is periodically monitored, and the charging voltage exceeds the withstand voltage of the capacitor. By stopping the charging operation beforehand, it is possible to prevent the destruction of the capacitor, the failure of the charging device, and the occurrence of a failure, thereby realizing an appropriate charging operation.

According to the eighth aspect of the present invention, the method includes a step of switching a plurality of capacitors to a parallel connection state based on a pulsating flow generated by half-wave rectification of an AC signal supplied from a commercial power supply. So, periodically switch multiple capacitors in series and parallel connection in synchronization with commercial power,
The charging operation and the voltage monitoring operation can be repeatedly executed, and the charging operation to the capacitor bank can be performed favorably by a simple switching control method.

[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 bank applied to one embodiment.

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

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

FIG. 10 is a schematic configuration diagram showing a first example of switch control means applied to the charging device according to one embodiment.

FIG. 11 is a circuit configuration diagram showing a specific example of a changeover switch applied to the charging device according to one embodiment.

FIG. 12 is a schematic configuration diagram showing a second example of the switch control means applied to the charging device according to one embodiment.

FIG. 13 is a waveform chart showing a change in a signal waveform due to half-wave rectification processing of the switch control means according to the second embodiment.

FIG. 14 is a waveform diagram showing a signal waveform of a control signal of a switch control unit according to the second embodiment.

FIG. 15 is a schematic circuit diagram showing a control signal supply control circuit of the switch control means according to the second embodiment.

FIG. 16 is a schematic configuration diagram showing a conventional charging device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 power supply circuit 10 a half-wave rectifier circuit 10 b integration circuit 10 c stabilized power supply circuit 20 capacitor bank 30 voltage monitor circuit 40 microcomputer C1 to C4 capacitors SC0, SC1, SC2 control signal HL high-potential-side power line LL low-potential-side power line

Claims (8)

[Claims] 1. A capacitor bank comprising a plurality of capacitors, and a power supply means for supplying a predetermined charging current to the capacitor bank based on an AC signal supplied from a commercial power supply to charge the plurality of capacitors. A voltage monitoring means for detecting and monitoring the voltage charged in the capacitor bank, wherein the capacitor bank connects the plurality of capacitors in series during a charging operation for charging the plurality of capacitors, and A charging device configured to connect the plurality of capacitors to each other in parallel during a voltage monitoring operation of detecting and monitoring the voltage. 2. The method according to claim 1, wherein the capacitor bank 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 7. The charging device according to Item 1. 3. The capacitor bank includes a changeover switch for switching a connection state of the plurality of capacitors. The changeover switch connects the plurality of capacitors in series during the charging operation and at a predetermined time interval. The charging device according to claim 1, wherein the charging device is controlled to switch to a parallel connection state. 4. The switch according to claim 1, wherein the plurality of capacitors are connected in series based on a pulsating current generated by half-wave rectifying an AC signal supplied from the commercial power supply, or
The charging device according to claim 3, wherein the charging device is controlled to switch to a parallel connection state. 5. 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 power supply means The charging device according to any one of claims 1 to 4, wherein supply of current from the power supply to the capacitor bank is interrupted. 6. The voltage monitoring means according to claim 1, wherein said voltage monitoring means has a single configuration commonly connected to said plurality of capacitors connected in parallel during said voltage monitoring operation. The charging device according to any one of the above. 7. A charging method for charging a capacitor bank with a charging current generated based on an AC signal supplied from a commercial power supply, comprising: connecting a plurality of capacitors constituting the capacitor bank in series; At a predetermined time interval, switching the plurality of capacitors to a parallel connection state, detecting and monitoring a charged voltage, and comparing the detected charging voltage with a preset reference voltage, A step of interrupting the supply of current from the power supply unit to the capacitor bank when the charging voltage becomes equal to or higher than the reference voltage. 8. The method of detecting and monitoring the charged voltage includes the steps of: detecting a plurality of capacitors based on a pulsating flow generated by half-wave rectifying an AC signal supplied from the commercial power supply; 8. The charging method according to claim 7, wherein switching is performed to a parallel connection state.