JP2000197277A - Power supply unit with built-in electric double-layer capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply unit with built-in electric double-layer capacitors wherein the safeties to their overchargings and dischargings are considered thoughtfully and their instantaneous charging or discharging currents are made large. SOLUTION: A voltage sensing portion 11 senses the voltage applied across positive and negative terminals 5A, 5B of electric double-layer capacitors 1 connected in series with each other. The voltage applied across the terminals 5A, 5B or the electric double-layer capacitors 1 is increased when the capacitors 1 are charged excessively. A voltage comparing portion 19 decides whether the voltage applied across the terminals 5A, 5B exceeds an upper limit voltage or not. In the meantime, the voltage applied across the terminals 5A, 5B of the electric double-layer capacitors 1 is decreased when the capacitors 1 are discharged excessively. A voltage comparing portion 15 decides whether the voltage applied across the terminals 5A, 5B drops beyond a lower limit voltage or not. The comparison results of the voltage comparing portions 19, 15 are sent to a control portion 21 of a charge/discharge limiting switch 7 to perform the ON/OFF of the switch 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device with a built-in electric double layer capacitor, and more particularly to a power supply device with a large instantaneous charge / discharge current in which safety against overcharge and overdischarge is considered.

[0002]

2. Description of the Related Art An electric double layer capacitor having a larger electric capacity than a conventional capacitor has attracted attention for use as a power storage type power supply for power. In particular, attention is paid to the rapid charging performance and rapid discharging performance of an electric double layer capacitor, and its application as a power supply device for powering electric vehicles and hybrid vehicles is drawing attention.

[0003]

However, in a power supply device using an electric double layer capacitor, its performance may be significantly deteriorated due to electrolysis of an electrolytic solution of a capacitor unit due to overcharging or overdischarging. . Also,
In a power supply device using an electric double layer capacitor that performs charging and discharging in which a large current flows instantaneously, there is a possibility that the cell may burst due to an increase in the internal pressure of the capacitor unit cell if the usage method is incorrect.

Therefore, the replacement and maintenance work of the power supply device using the electric double-layer capacitor has to be carried out carefully and time-consuming in consideration of safety. Confirmation and inspection after installation on site were also complicated. Furthermore, in the power supply device integrated with the charger, there is a possibility that the weight and the volume are large, and the burden on the operator is also increased.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a power supply device with a built-in electric double-layer capacitor which has a large instantaneous charging / discharging current while considering safety against overcharging and overdischarging. And

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention (claim 1) provides a power supply device with a built-in electric double layer capacitor which is connected to a separately prepared charger via an external terminal and is charged by the charger. And at least one electric double layer capacitor connected in series to the external terminal, and voltage detection for detecting a voltage between one or a plurality of serially connected terminals of the electric double layer capacitor. Means, when the terminal-to-terminal voltage detected by the voltage detecting means exceeds a predetermined upper limit voltage, stops charging by the charger or limits the charging current, and when the voltage falls below a predetermined lower limit voltage, the electric double layer capacitor. Charge / discharge control means connected between the external terminal and the electric double-layer capacitor for stopping discharge from or limiting a discharge current; and Accommodating the voltage detecting means and said discharge control means, constituted by a storage box to expose the external terminals.

The charger is prepared separately from the power supply device with a built-in electric double layer capacitor. One or a plurality of electric double layer capacitors may be connected in series. The voltage detecting means collectively collects a plurality of the electric double layer capacitors connected to each unit cell or in series, and detects a voltage between the terminals. The charge / discharge control means is connected between the external terminal and the electric double layer capacitor.

When the voltage between terminals detected by the voltage detecting means exceeds a predetermined upper limit voltage, the charging / discharging control means stops charging by the charger or limits the charging current. On the other hand, when the inter-terminal voltage detected by the voltage detecting means falls below a predetermined lower limit voltage, the discharge from the electric double layer capacitor is stopped or the discharge current is limited.

The storage box houses the electric double layer capacitor, the voltage detection means and the charge / discharge control means, and exposes external terminals. As described above, overcharge and overdischarge can be prevented. For this reason, it is possible to prevent the performance of the electric double layer capacitor from deteriorating due to electrolysis of the electrolytic solution due to overcharging or overdischarging.

In addition, since the safety function is provided inside the power supply device with a built-in electric double layer capacitor, the power supply device is safe regardless of erroneous wiring or installation method of the operator. Further, the possibility of erroneous wiring or the like is extremely small. The internal pressure of the capacitor unit cell does not rise due to a fire caused by a short circuit between the electrodes or a gas generated by decomposition of the electrolytic solution, and the cell does not burst. Just by connecting the external terminal to the charger, even workers without safety knowledge can easily install it.

Further, the safety function and the like are provided inside the power supply device with a built-in electric double layer capacitor, and have been inspected in the factory at the time of shipment, so that the inspection and inspection after installation on site can be largely labor-saving.

Further, since a power supply device capable of flowing a large current instantaneously can be provided as a single unit, replacement of each single unit is easy. Furthermore, the weight and volume of the power supply device with a built-in electric double-layer capacitor are determined substantially by the weight and volume of the electric double-layer capacitor, so that it can be made compact.

According to a second aspect of the present invention, there is provided an external charge / discharge control means for controlling charging from a separately prepared charger and discharging to a separately prepared load via an external terminal. An electric double-layer capacitor built-in power supply device charged by a charger, wherein at least one electric double-layer capacitor connected in series to the external terminal and one or more of the electric double-layer capacitors connected in series Voltage detecting means for detecting a plurality of inter-terminal voltages, and a signal for stopping or restricting charging by the charger when the inter-terminal voltage detected by the voltage detecting means exceeds a predetermined upper limit voltage. Charge / discharge control signal generating means for generating a signal for stopping or limiting discharge from the electric double layer capacitor when the voltage falls below a predetermined lower limit voltage; Signal output means for sending a signal generated by the signal generation means to the external charge / discharge control means via a charge / discharge control signal terminal; and the electric double layer capacitor, the voltage detection means, the charge / discharge control signal generation means, and A storage box that houses the signal output means and exposes the external terminal and the charge / discharge control signal terminal.

The external charge / discharge control means controls charging from a separately prepared charger and discharging to a separately prepared load. The external charge / discharge control means is connected between the charger and the load and the power supply device with a built-in electric double layer capacitor.
One or a plurality of electric double layer capacitors may be connected in series. The voltage detecting means detects the inter-terminal voltage of each unit cell of the electric double layer capacitor or a plurality of serially connected plural units and detects the inter-terminal voltage.

The charge / discharge control signal generating means generates a signal for stopping or limiting charging by the charger when the voltage between terminals detected by the voltage detecting means exceeds a predetermined upper limit voltage. On the other hand, when the terminal-to-terminal voltage detected by the voltage detecting means falls below a predetermined lower limit voltage, a signal for stopping or restricting discharge from the electric double layer capacitor to the load is generated. The signal output means sends the signal generated by the charge / discharge control signal generation means to the external charge / discharge control means via the charge / discharge control signal terminal.

The storage box houses an electric double layer capacitor, voltage detection means, charge / discharge control signal generation means, and signal output means. Then, the external terminal and the charge / discharge control signal terminal are exposed.

As described above, overcharge and overdischarge can be prevented. According to the invention of claim 2, in addition to the effect of the invention of claim 1, there is an effect that it is possible to flexibly respond to an external circuit. That is, the safety function is provided inside the electric power supply device with a built-in electric double layer capacitor, and the safety judgment is output to the outside, so that it is possible to flexibly cope with various forms of the external circuit including the charger.

Further, the weight and volume of the power supply device with a built-in electric double layer capacitor are substantially determined by the weight and volume of the electric double layer capacitor. Since the signal output means has a small number of parts and can be made light in weight, it can be made more compact.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a circuit configuration diagram of the first embodiment of the present invention. In FIG. 1, an electric double layer capacitor 1
Are connected in multiple stages in series. An equalizing resistance circuit 3 is connected between the terminals of the electric double layer capacitor 1 so that the terminal voltages of the electric double layer capacitors 1 connected in series are equalized. Electric double layer capacitor 1 connected in series
Is connected to an external terminal 9A via a charge / discharge limiting switch 7.

The charge / discharge limiting switch 7 is constituted by, for example, a thyristor. However, the present invention is not limited to the thyristor, and may be a semiconductor element or a relay capable of turning on and off a current. The negative terminal 5B of the electric double layer capacitor 1 is
It is connected to the external terminal 9B. The voltage detecting unit 11 is connected to the positive terminal 5 of the serially connected electric double layer capacitor 1.
A voltage between A and the negative terminal 5B is detected, and corresponds to voltage detection means.

The reference voltage source 13 is set to a lower limit voltage value allowed during discharging. The voltage comparison unit 15 compares the output voltage of the reference voltage source 13 with the voltage detected by the voltage detection unit 11 after being input, and determines whether the result is ON or O
The FF signal is output. On the other hand, the reference voltage source 17 has an upper limit voltage value allowed during charging.

The voltage comparator 19 compares the output voltage of the reference voltage source 17 with the voltage detected by the voltage detector 11 so that the result is output as an ON / OFF signal. Has become. Charge / discharge limit switch control unit 2
1 controls the charge / discharge limit switch 7 based on the output of the voltage comparison unit 15 and the output of the voltage comparison unit 19. Reference voltage source 13, voltage comparator 15, reference voltage source 1
7, the voltage comparison unit 19, the charge / discharge limit switch control unit 21, and the charge / discharge limit switch 7 correspond to charge / discharge control means.

The components from the electric double layer capacitor 1 to the charge / discharge limit switch control unit 21 are housed in one housing box 23. The external terminals 9A and 9B are exposed outside the storage box 23 and are connected to the external charger 25.

Next, the operation of the first embodiment of the present invention will be described. The voltage detector 11 detects the voltage between the positive terminal 5A and the negative terminal 5B of the electric double layer capacitor 1, but detects the voltage between the terminals of each capacitor unit cell constituting the electric double layer capacitor 1. Is also good. A plurality of voltages may be collectively detected.

When the electric double layer capacitor 1 is overcharged, the voltage between terminals rises. At this time, an upper limit voltage which should not be exceeded is preset in the reference voltage source 17. The upper limit voltage is set in consideration of, for example, the degree to which electrolysis occurs in the electrolytic solution. The voltage comparator 19 compares whether or not the voltage exceeds the upper limit voltage. When the voltage detected by the voltage detection unit 11 exceeds the upper limit voltage, an ON signal is output to the charge / discharge limit switch control unit 21.

On the other hand, when the electric double layer capacitor 1 is overdischarged, the voltage between terminals decreases. At this time, a lower limit voltage which should not be lower than that is set in the reference voltage source 13 in advance. The lower limit voltage is also set in consideration of, for example, the degree to which electrolysis occurs in the electrolytic solution. The voltage comparator 15 compares whether the voltage is lower than the lower limit voltage. Then, when the voltage detected by the voltage detection unit 11 falls below the lower limit voltage, an ON signal is output to the charge / discharge limit switch control unit 21.

The charge / discharge limit switch control section 21 sends, for example, an inverted output signal to the charge / discharge limit switch 7 when an ON signal is output from the voltage comparison section 15 or the voltage comparison section 19. When the charge / discharge limiting switch 7 is a thyristor, this output signal is input to the gate. At this time, the charge / discharge limit switch 7 is turned off.

Accordingly, overcharging and overdischarging of the electric double layer capacitor 1 can be prevented. For this reason, it is possible to prevent performance degradation due to electrolysis of the electrolyte during overcharge and overdischarge.
Further, since a protection circuit for safety is also stored in the storage box 23, there is no danger due to incorrect wiring or the like. Since this protection circuit has been inspected in the factory at the time of shipment,
Confirmation and inspection after on-site installation can save a lot of labor.

The external terminals 9A and 9B can be easily installed simply by connecting them to the external charger 25. Further, the storage box 23
The power supply device having a large instantaneous current capacity can be provided as a single unit by being housed therein, and the individual unit can be easily replaced.

The charge / discharge limit switch 7 is ON,
Although the description has been made assuming that the F operation is performed, control may be performed such that the amount of current is continuously reduced based on the ON signal input from the voltage comparison unit 15 or the voltage comparison unit 19.

Next, a circuit configuration diagram of a second embodiment of the present invention is shown in FIG. The same elements as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 2, the plus side terminal 5A of the electric double layer capacitor 1 connected in series
Is connected to the external terminal 9A. Outputs of the voltage comparison unit 15 and the voltage comparison unit 19 are sent to a signal output unit 27.

The signal output section 27 corresponds to signal output means. From the signal output unit 27, a charge / discharge control signal terminal 29
Signals are sent to the external charge / discharge control circuit 31 via a, 29b, 29c, and 29d. Reference voltage source 13, voltage comparator 15, reference voltage source 17, voltage comparator 1
9 corresponds to a charge / discharge control signal generating means.

Next, the operation of the second embodiment of the present invention will be described. In the second embodiment of the present invention, unlike the first embodiment of the present invention, the charge / discharge limit switch control unit 21 and the charge / discharge limit switch 7 are not provided inside the storage box 23. Thereby, the weight and the size can be further reduced.

The output signal of the voltage comparator 15 or the voltage comparator 19 is sent to the signal output unit 27 and sent to the external charge / discharge control circuit 31 via the charge / discharge control signal terminals 29a, 29b, 29c, 29d. . The external charge / discharge control circuit 31
It is assumed that the function of the charge / discharge limit switch is integrated with the charger. However, the charger and the charge / discharge limit switch may be provided separately,
The output signal may be directly input to a control unit mounted on the microcomputer.

Further, charge / discharge control signal terminals 29a, 29
b, 29c and 29d are the charge / discharge control signal terminals 2 when the external charge / discharge control circuit 31 controls only during charging.
9c and 29d may be connected. On the other hand, when control is performed only during discharge, the charge / discharge control signal terminal 29
Only a and 29b may be connected. Thus, it is possible to flexibly cope with various forms of the external charge / discharge control circuit 31.

[0036]

As described above, according to the present invention, the overcharge and overdischarge states of the electric double layer capacitor are detected on the power supply device side, and the overcharge and overdischarge states are prevented. It is possible to use the power supply device safely and with minimal performance degradation.

When the performance deteriorates, it can be replaced as a single unit independent of the charger. Further, by connecting a plurality of electric double layer capacitors in series, a power supply device having a large instantaneous current can be provided in a form in which safety is considered.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of a first embodiment of the present invention.

FIG. 2 is a circuit configuration diagram according to a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Electric double layer capacitor 7 Charge / discharge limit switch 9A, 9B External terminal 11 Voltage detection unit 13, 17 Reference voltage source 15, 19 Voltage comparison unit 21 Charge / discharge limit switch control unit 23 Storage box 25 External charger 27 Signal output unit 29a , 29b, 29c, 29d Terminal for charge / discharge control signal 31 External charge / discharge control circuit

Claims (2)

[Claims] 1. A power supply device with a built-in electric double layer capacitor connected to a separately prepared charger via an external terminal and charged by the charger, wherein at least the power supply device is connected in series to the external terminal. One electric double-layer capacitor, voltage detecting means for detecting one or more serially connected terminals of the electric double-layer capacitors, and a terminal voltage detected by the voltage detecting means. When the voltage exceeds a predetermined upper limit voltage, the charging by the charger is stopped or the charging current is limited, and when the voltage is lower than the predetermined lower limit voltage, the discharging from the electric double layer capacitor is stopped or the discharging current is limited. And charging and discharging control means connected between the electric double layer capacitor, and housing the electric double layer capacitor, the voltage detecting means and the charging and discharging controlling means, A power supply device with a built-in electric double layer capacitor, comprising: a storage box with the external terminals exposed. 2. An electric double layer connected via an external terminal to external charge / discharge control means for controlling charging from a separately prepared charger and discharging to a separately prepared load, and charged by the charger. A power supply device with a built-in capacitor, comprising: at least one electric double layer capacitor connected in series to the external terminal; and a voltage between one or more terminals of the electric double layer capacitors connected in series. A voltage detecting means for detecting, when a voltage between terminals detected by the voltage detecting means exceeds a predetermined upper limit voltage, a signal for stopping or limiting charging by the charger is generated, and when the voltage falls below a predetermined lower limit voltage; Charge / discharge control signal generating means for generating a signal for stopping or limiting discharge from the electric double layer capacitor; and a signal generated by the charge / discharge control signal generating means. A signal output means for sending out to the external charge / discharge control means via a charge / discharge control signal terminal, and containing the electric double layer capacitor, the voltage detection means, the charge / discharge control signal generation means and the signal output means, A power supply device with a built-in electric double layer capacitor, comprising: a storage box exposing the external terminal and the charge / discharge control signal terminal.