WO2012032621A1

WO2012032621A1 - Power storage apparatus using capacitor, charging control apparatus therefor, and charging control method therefor

Info

Publication number: WO2012032621A1
Application number: PCT/JP2010/065419
Authority: WO
Inventors: 晴見竹田; 佳史竹田
Original assignee: Takeda Harumi; Takeda Yoshifumi
Priority date: 2010-09-08
Filing date: 2010-09-08
Publication date: 2012-03-15

Abstract

[Objective] To propose a power storage apparatus that uses a capacitor such as an EDLC as a power storage unit thereof, and wherein an appropriate charging control can be conducted from when the capacitor of the power storage unit is in a completely discharged state until the capacitor becomes a completely charged state. [Solution] A power storage apparatus of the present invention is provided with: a charge-controlling means for supplying direct current from an external power supply to a power storage unit; a signal outputting means; and a monitoring means for monitoring the charging state. The charge-controlling means is provided with: an initial charging mode wherein the direct current is supplied to the signal outputting means; a constant-current charging mode wherein the power storage unit is charged with constant-current charging, and the direct current from the external power supply or power stored in the power storage unit is supplied to the signal outputting means, the monitoring means, and the charge-controlling means; and a constant-voltage charging mode wherein the power storage unit is charged with constant-voltage charging, and the direct current from the external power supply or power stored in the power storage unit is supplied to the signal outputting means, the monitoring means, and the charge-controlling means. The power storage apparatus is configured to switch the mode of the charge-controlling means to either one of the charging modes, in accordance with the charged state.

Description

Power storage device using capacitor, charge control device thereof, and charge control method thereof

The present invention provides an initial drive for a control circuit for a power storage device at the start of power storage of the power storage device using a capacitor such as an electric double layer capacitor (hereinafter referred to as EDLC). The present invention relates to a power storage device, a charge control circuit, and a charge control method thereof that supply the electric power and also control charging of the capacitor.

In a power storage device using a capacitor such as an EDLC (hereinafter simply referred to as a capacitor), the rated voltage of the capacitor alone is as low as about 2.3 to 4.0 (V). In many cases, a single capacitor is connected in series. In many cases, they are connected in parallel to increase the storage capacity. That is, in a power storage device using a capacitor, a plurality of capacitors are often used in series-parallel connection.
However, since the capacitance error of capacitors is large, when a plurality of capacitors are connected in series, they are fully charged in order starting from the capacitor with the smallest capacitance during charging. The voltage between terminals of a capacitor with a small capacitance exceeds the rated voltage, which causes deterioration and destruction of the capacitor.
Therefore, in a power storage device using a capacitor, in the charging process, it is necessary to suppress (equalize) the variation in voltage between terminals of each capacitor due to the capacitance error of the capacitor constituting the power storage unit, It is necessary to perform control to prevent overcharging of the capacitor.
Therefore, in general, a power storage device using a capacitor suppresses variation in voltage between terminals of a power storage unit composed of a plurality of capacitors connected in series and parallel and the capacitor of the power storage unit, It is comprised from the control part which prevents charge.

Regarding the function of the control unit of the power storage device using the capacitor, in addition to the above, control for maintaining the output voltage of the power storage unit (hereinafter simply referred to as the power storage unit voltage) within the allowable input voltage range of the power converter, Various functions have been proposed so far for various purposes such as control of input current to the storage unit and control of output current to the load. Since it is configured by a control element such as a processor, PLD, or FPGA, a power source for driving the control unit itself is required.
However, there is little suggestion about power supply to such a control unit. Although there is a method of using a primary battery or a secondary battery as a power source for the control unit, the power storage device using a capacitor is characterized in that the cycle life of the capacitor is extremely longer than that of the battery in the first place, and requires little maintenance. Using a battery having a much shorter life than the capacitor as the power source of the control unit impairs the characteristics of the power storage device using the capacitor.

There is also a power storage device that presupposes that only the power stored in the capacitor of the power storage unit is used as the power source of the control unit. However, in this method, when the capacitor of the power storage unit is in a fully discharged state, no control is performed. In this state, charging of the capacitor of the power storage unit is started, and electric charges are gradually accumulated in the capacitor, and the control unit is in an operating state after the power storage unit voltage reaches a value that can be used as a power source of the control unit. become.
That is, the control unit cannot be operated for a while immediately after the start of charging of the capacitor of the power storage unit, and when the power storage unit is configured by a capacitor with a large capacitance, the power storage unit voltage is Since it takes a relatively long time to reach a value that can be used as the power supply of the control unit, the state of no control is continued for a long time.

However, the control unit is preferably in an operating state from the start of charging the power storage unit. The reason is described below.
Until now, regarding power storage devices using capacitors, it is possible to suppress variations in terminal voltages caused by capacitance errors and self-discharge of the capacitors constituting the power storage unit, and to align the voltages between terminals of all capacitors (below, Various methods have been proposed to prevent overcharging of the capacitor.
For example, a method using a voltage equalizing circuit (also called a parallel monitor) using resistors as in Patent Documents 1 to 3, a voltage equalizing circuit using a transformer or a coil as described in Patent Documents 4 to 7, As described in Patent Document 8 or Patent Document 9, there is a voltage equalizing circuit using a capacitor. The control unit controls these pressure equalizing circuits.

Japanese Patent No. 3418951 (Japanese Patent Laid-Open No. 11-215695) Series-parallel switching type power supply device Japanese Patent No. 3487780 (Japanese Patent Laid-Open No. 2000-253572) Connection switching control capacitor power supply Patent No. 3468924 A power storage device using a capacitor and a control method thereof PCT / JP2005 / 019208 WO2007046138 Japanese Patent No. 3854592 (Japanese Patent Laid-Open No. 2005-80469) Japanese Patent No. 3764633 (Japanese Patent Laid-Open No. 2002-10510) Electrical energy storage device, cell energy amount adjusting device, and cell energy amount adjusting method JP 2007-252078 JP Equal storage circuit Patent Document 1: JP 2006-296179 A Capacitor Power Storage Device and Charge / Discharge Method Japanese Unexamined Patent Publication No. 2007-006552 JP, 2006-109620, A Voltage control device of a capacitor, and a capacitor module provided with the same PCT / JP2010 / 057212 Power storage device using capacitor

However, regardless of which voltage equalization circuit is used, if the method using the power stored in the capacitor of the power storage unit is used as the power source of the control unit, charging of the capacitor of the power storage unit in a fully discharged state is started, Until the electric charge is gradually accumulated and the voltage reaches a value that can be used as the power source of the control unit, the non-control state is continued, and the voltage equalization circuit does not operate. When the non-control state continues for a long time, the variation in the voltage between the terminals of the capacitor of the power storage unit increases. Therefore, even if the voltage equalization circuit is operated when the voltage of the capacitor of the power storage unit reaches a value that can be used as the power source of the control unit and the control unit becomes operable, In order to suppress the variation in the inter-terminal voltage between the expanded capacitors, there may occur a situation where a lot of energy accumulated in the power storage unit must be consumed wastefully.

Further, as in Patent Documents 1 to 3, when a control method called serial-parallel switching is used in the power storage unit, when the capacitor of the power storage unit is in a completely discharged state, and the control unit is not operating, Even the switching control cannot be performed, and the power storage unit itself cannot be charged.
For the reasons described above, the control unit is in an operating state when charging of the capacitor of the power storage unit is started, and the voltage equalization operation by the control unit is performed simultaneously with the start of charging, so that variation in the inter-terminal voltage between the capacitors can be suppressed. Is preferred. By doing so, the power energy input to the capacitor of the power storage unit can be stored without waste, and the charging time can be shortened.

Generally, a power storage device 100 using a capacitor is configured as shown in FIG.
As described above, the control unit 140 controls the power storage unit voltage within the allowable input voltage range of the power converter 170, controls the input current to the power storage unit 130, and loads 180 via the power converter 170. Output current control, overcharge prevention control of each capacitor constituting the power storage unit 130, control for equalizing the voltage between terminals of each capacitor, and the like. The control unit 140 also requires a power source.
In general, the power stored in the power storage unit 130 is often used as the power source for the control unit 140. For example, as shown in FIG. 9, the electric power stored in the power storage unit 130 is supplied to the control unit 140 via the DC-DC converter 150.

However, the supply of charging current from the DC current source 160, which is an external power supply, to the capacitor of the power storage unit 130 in a fully discharged state is started, and power is accumulated in the power storage unit 130, so that the control unit 140 can be sufficiently driven. It takes time to reach Therefore, control unit 140 cannot be driven after charging of power storage unit 130 in the fully discharged state until the voltage of power storage unit 130 reaches a voltage that can sufficiently drive control unit 140. .
That is, when the power storage unit 130 is in a completely discharged state, or when the voltage and power that can sufficiently drive the control unit 140 are not stored in the power storage unit 130, the control unit 140 is not driven. The control state will be continued.

In view of this, the inventors have prepared a sub power storage unit for initial driving in a power storage device using a capacitor such as an EDLC as a power storage unit, in order to reliably drive the control unit before starting charging of the power storage unit. Then, an initial driving power source using a capacitor for the sub power storage unit has been proposed (see Patent Document 10).
In Patent Document 10, a power storage unit is referred to as a main power storage unit, and a capacitor used as a sub power storage unit for initial drive is referred to as an initial drive capacitor or a start capacitor.
The initial drive capacitor is a circuit that supplies drive power to the control circuit until at least the output voltage of the power storage unit reaches the drive voltage of the control circuit, and the output voltage of the power storage unit becomes the drive voltage of the control circuit. A circuit configuration that supplies drive power to the control circuit after reaching the control circuit, and a circuit that supplies drive power for the control circuit from the power storage unit after the output voltage of the power storage unit reaches the drive voltage of the control circuit. In any circuit configuration, after charging of the initial drive capacitor is completed and the control unit is ready to operate, the power storage unit (main power storage unit) is connected. Charging starts.

However, the power storage device using the initial drive capacitor as the initial drive power supply has the following problems.
(1) Depending on the configuration of the power storage device, the sub power storage unit (initial drive capacitor) is often used only when the main power storage unit is charged from a fully discharged state. It is necessary to prepare an initial driving capacitor that does not directly contribute.
(2) When the capacity of the initial drive capacitor is too small, the power stored in the initial drive capacitor is stored in the control unit before the power necessary for driving the control unit is stored in the main power storage unit. It is consumed and the control unit cannot be driven normally. Conversely, if the capacity of the initial drive capacitor is excessive, it takes time to charge the initial drive capacitor, and the start of charging the main power storage unit is delayed.

(3) A break contact switch (Normally Closed switch) is incorporated in the circuit that constitutes the sub power storage unit. If a malfunction occurs in the circuit, a close failure may occur and the circuit may continue to be maintained. is there.
(4) The circuit configuration is complicated and many circuit parts are required, which causes an increase in cost.
In addition to the above problems, in a power storage device using a capacitor such as an EDLC for the power storage unit, it is necessary to perform input current control and input voltage control to the power storage unit, and the initial drive power supply can perform these controls simultaneously. Is desirable.
In addition, when the external power source is a solar cell or the like, power is not supplied to the power storage device at night, but the discharge is often performed day or night, and discharge control by the control unit is required even during this discharge. The Therefore, even when power supply from the external power supply is temporarily interrupted, power for driving the control unit must be ensured.

Therefore, in the present invention, in the power storage device using a capacitor such as an EDLC for the power storage unit, the initial drive capacitor is not used, and even when the capacitor of the power storage unit is in a completely discharged state, power for driving the control unit ( Hereinafter, the initial drive power is supplied to the control unit to start charging the power storage unit, and even when the power supply from the external power supply is temporarily interrupted, the voltage is sufficient to drive the control unit. After the electric power is stored in the power storage unit, the power for driving the control unit is supplied from an external power source or the power storage unit, and the power storage unit is charged with a constant current. In order to avoid overcharging, a power storage device having an initial driving power source having a charge control function of performing constant voltage charging has been proposed.

A power storage device according to claim 1 of the present invention includes:
A power storage unit using a capacitor;
Charging control means for controlling a direct current flowing from an external power source based on a charging control signal and supplying the direct current as charging power to the power storage unit;
Signal output means for outputting the charge control signal to the charge control means;
Monitoring means for monitoring power storage status in the power storage unit;
In a power storage device comprising:
The charge control means includes
An initial charging mode for supplying the direct current as at least the driving power of the signal output means;
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant current, and at the same time, the DC output or the power stored in the power storage unit is supplied to the signal output unit and the monitoring unit. And a constant current charge mode to be supplied as drive power for the charge control means,
With
The signal output means switches the charge control means to either one of an initial charge mode or a constant current charge mode in accordance with a power storage status of the power storage obtained from the monitoring means, and A charging control signal for controlling charging is output.

In claim 2,
A power storage unit using a capacitor;
Charging control means for controlling a direct current flowing from an external power source based on a charging control signal and supplying the direct current as charging power to the power storage unit;
Signal output means for outputting the charge control signal to the charge control means;
Monitoring means for monitoring power storage status in the power storage unit;
In a power storage device comprising:
The charge control means includes
An initial charging mode for supplying the direct current as at least the driving power of the signal output means;
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant current, and at the same time, the DC output or the power stored in the power storage unit is supplied to the signal output unit and the monitoring unit. And a constant current charge mode to be supplied as drive power for the charge control means,
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant voltage, and the DC current or the power stored in the power storage unit is used as the signal output unit, the monitoring unit, and the charge control. A constant voltage charging mode to supply as driving power of the means;
With
The signal output means switches the charge control means to any one charge mode of an initial charge mode, a constant current charge mode, or a constant voltage charge mode according to the power storage status of the power storage unit obtained from the monitoring means. The charging control signal is output.

In claim 3,
The signal output means, according to the power storage status of the power storage unit obtained from the monitoring means,
When the power storage unit voltage is less than a second set voltage, the charge control unit is switched to an initial charge mode to charge the power storage unit,
When the power storage unit voltage is equal to or higher than a second set voltage, the charge control unit is switched from the initial charging mode to the constant current charging mode to charge the power storage unit,
When the power storage unit voltage becomes equal to or higher than a third set voltage, the charge control unit is switched from the constant current charging mode to the constant voltage charging mode to charge the power storage unit.

In claim 4,
Voltage conversion means is provided for converting drive power supplied from the external power source or the power storage unit into a predetermined voltage and supplying the drive power as drive power for the signal output means, the monitoring means, and the charge control means.

The charging control device according to claim 5 of the present invention is
In a charging control device configured to output a direct current flowing from an external power source as charging power for charging a power storage unit using a capacitor,
Charging control means for controlling a direct current flowing from the external power source based on the charging control signal and supplying the direct current as charging power to the power storage unit;
Signal output means for outputting the charge control signal to the charge control means;
Monitoring means for monitoring power storage status in the power storage unit;
With
The charge control means includes
An initial charging mode for supplying the direct current as at least the driving power of the signal output means;
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant current, and at the same time, the DC output or the power stored in the power storage unit is supplied to the signal output unit and the monitoring unit. And a constant current charge mode to be supplied as drive power for the charge control means,
With
The signal output means, according to the power storage status of the power storage unit obtained from the monitoring means,
The charge control means is configured to charge the power storage unit by switching to either one of an initial charge mode and a constant current charge mode.

In claim 6,
In a charging control device configured to output a direct current flowing from an external power source as charging power for charging a power storage unit using a capacitor,
Charging control means for controlling a direct current flowing from the external power source based on the charging control signal and supplying the direct current as charging power to the power storage unit;
Signal output means for outputting the charge control signal to the charge control means;
Monitoring means for monitoring power storage status in the power storage unit;
With
The charge control means includes
An initial charging mode for supplying the direct current as at least the driving power of the signal output means;
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant current, and at the same time, the DC output or the power stored in the power storage unit is supplied to the signal output unit and the monitoring unit. And a constant current charge mode to be supplied as drive power for the charge control means,
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant voltage, and the DC current or the power stored in the power storage unit is used as the signal output unit, the monitoring unit, and the charge control. A constant voltage charging mode to supply as driving power of the means;
With
The signal output means, according to the power storage status of the power storage unit obtained from the monitoring means,
The charging control means is configured to charge the power storage unit by switching to any one of three charging modes of an initial charging mode, a constant current charging mode, and a constant voltage charging mode.

In claim 7,
The signal output means, according to the power storage status of the power storage unit obtained from the monitoring means,
When the power storage unit voltage is less than a second set voltage, the charge control unit is switched to an initial charge mode to charge the power storage unit,
When the power storage unit voltage is equal to or higher than a second set voltage, the charge control unit is switched from the initial charging mode to the constant current charging mode to charge the power storage unit,
When the power storage unit voltage becomes equal to or higher than a third set voltage, the charge control unit is switched from the constant current charging mode to the constant voltage charging mode to charge the power storage unit.

In claim 8,
The signal output means is configured to output a pulse train signal having a duty ratio according to the power storage status of the power storage unit obtained from the monitoring means,
The charge control means includes
Switch means for receiving the pulse train signal and controlling on / off of the charging current to the power storage unit according to the duty ratio;
Smoothing means for smoothing the charging power output from the switch means and outputting to the power storage unit,
By changing the duty ratio, either one of the constant current charging mode and the constant voltage charging mode can be switched to one charging mode.

In claim 9,
Voltage conversion means is provided for converting drive power supplied from the external power source or the power storage unit into a predetermined voltage and supplying the drive power as drive power for the signal output means, the monitoring means, and the charge control means.

A power storage device control method according to claim 10 of the present invention includes:
A power storage unit using a capacitor;
Charge control means for controlling a direct current flowing from an external power source based on a charge control signal to charge the power storage unit;
Signal output means for outputting the charge control signal to the charge control means;
Monitoring means for monitoring power storage status in the power storage unit;
With
The charge control means includes
An initial charging mode for supplying the direct current as at least the driving power of the signal output means;
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant current, and at the same time, the DC output or the power stored in the power storage unit is supplied to the signal output unit and the monitoring unit. And a constant current charge mode to be supplied as drive power for the charge control means,
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant voltage, and the DC current or the power stored in the power storage unit is used as the signal output unit, the monitoring unit, and the charge control. A constant voltage charging mode to supply as driving power of the means;
In a charge control method for a power storage device using a capacitor comprising:
Using the monitoring means to monitor the power storage status of the power storage unit,
When the power storage unit voltage is less than a second set voltage, the signal output means outputs a charge control signal for switching the charge control means to the initial charge mode,
When the power storage unit voltage is equal to or higher than a second set voltage, the charge output signal for switching the charge control means from the initial charge mode to the constant current charge mode is output from the signal output means,
When the power storage unit voltage is equal to or higher than a third set voltage, by causing the signal output means to output a charge control signal for switching the charge control means from the constant current charge mode to the constant voltage charge mode,
The charge control means is operated in a charge mode according to the power storage status of the power storage unit.

In the power storage device according to claim 1 of the present invention,
A power storage unit using a capacitor;
Charging control means for controlling a direct current flowing from an external power source based on a charging control signal and supplying the direct current as charging power to the power storage unit;
Signal output means for outputting the charge control signal to the charge control means;
Monitoring means for monitoring power storage status in the power storage unit;
In a power storage device comprising:
The charge control means includes
An initial charging mode for supplying the direct current as at least the driving power of the signal output means;
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant current, and at the same time, the DC output or the power stored in the power storage unit is supplied to the signal output unit and the monitoring unit. And a constant current charge mode to be supplied as drive power for the charge control means,
With
The signal output unit charges the power storage unit by switching the charge control unit to either one of an initial charge mode or a constant current charge mode according to a power storage state of the power storage unit obtained from the monitoring unit. Because it is configured to output a charge control signal to control so that
In the initial charging mode, even when the power storage unit is in a fully discharged state or a state close thereto, a direct current is supplied as driving power for the signal output unit, the monitoring unit, and the charge control unit, thereby charging the power storage unit. From the start, the signal output means, the monitoring means, and the charge control means are normally driven to enable appropriate charge control.

In claim 2,
The charge control means includes
An initial charging mode for supplying the direct current as at least the driving power of the signal output means;
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant current, and at the same time, the DC output or the power stored in the power storage unit is supplied to the signal output unit and the monitoring unit. And a constant current charge mode to be supplied as drive power for the charge control means,
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant voltage, and the DC current or the power stored in the power storage unit is used as the signal output unit, the monitoring unit, and the charge control. A constant voltage charging mode to supply as driving power of the means;
With
The signal output means switches the charge control means to any one charge mode of an initial charge mode, a constant current charge mode, or a constant voltage charge mode according to the power storage status of the power storage unit obtained from the monitoring means. Since it is configured to output the charge control signal,
In addition to being able to perform appropriate charging according to the power storage status of the power storage unit, in the initial charge mode, even if the power storage unit is in a completely discharged state or a state close thereto, a direct current is output from the signal output means, the monitoring means, and the By supplying the drive power for the charge control means, the signal output means, the monitoring means, and the charge control means are normally driven from the start of charging the power storage unit, thereby enabling appropriate charge control.

In claim 3,
The signal output means, according to the power storage status of the power storage unit obtained from the monitoring means,
When the power storage unit voltage is less than a second set voltage, the charge control unit is switched to an initial charge mode to charge the power storage unit,
When the power storage unit voltage is equal to or higher than a second set voltage, the charge control unit is switched from the initial charging mode to the constant current charging mode to charge the power storage unit,
When the power storage unit voltage is equal to or higher than a third set voltage, the charging control unit is configured to charge the power storage unit by switching from the constant current charging mode to the constant voltage charging mode. ,
In addition to being able to perform appropriate charging according to the power storage status of the power storage unit, in the initial charge mode, even if the power storage unit is in a completely discharged state or a state close thereto, a direct current is output from the signal output means, the monitoring means, and the By supplying the drive power for the charge control means, the signal output means, the monitoring means, and the charge control means are normally driven from the start of charging the power storage unit, thereby enabling appropriate charge control.

In claim 4,
Since it comprises voltage conversion means for converting the drive power supplied from the external power supply or the power storage unit into a predetermined voltage and supplying it as drive power for the signal output means, the monitoring means and the charge control means,
The signal output means, the monitoring means and the charge control means can be operated normally even if the voltage of the driving power supplied from the external power supply or the power storage unit is too high or too low.

In the charge control device according to

claims

5, 6, and 7, the signal output means, the monitoring means, and the charge control means are provided from the start of charging to the power storage unit, similarly to the power storage device according to

claims

1, 2, and 3. Appropriate charge control is possible by operating normally in an appropriate charge mode.

In claim 8,
The signal output means is configured to output a pulse train signal having a duty ratio according to the power storage status of the power storage unit obtained from the monitoring means,
The charge control means includes
Switch means for receiving the pulse train signal and controlling on / off of the charging current to the power storage unit according to the duty ratio;
Since smoothing means for smoothing the charging current output from the switch means and outputting to the power storage unit,
By changing the duty ratio of the pulse train signal, one charging control means can be operated in a state suitable for each of the initial charging mode, the constant current charging mode, and the constant voltage charging mode.

In the ninth aspect, similar to the power storage device of the fourth aspect, the signal output means, the monitoring means, and the charge control are performed regardless of whether the voltage of the driving power supplied from the external power source or the power storage unit is too high or too low. The means can be operated normally.

According to the method of controlling the power storage device according to claim 10 of the present invention,
The charging control means has an initial charging mode, a constant current charging mode, and a constant voltage charging mode,
When the power storage unit voltage is less than a second set voltage, the signal output means outputs a charge control signal for switching the charge control means to the initial charge mode,
When the power storage unit voltage is equal to or higher than a second set voltage, the charge output signal for switching the charge control means from the initial charge mode to the constant current charge mode is output from the signal output means,
When the power storage unit voltage is equal to or higher than a third set voltage, by causing the signal output means to output a charge control signal for switching the charge control means from the constant current charge mode to the constant voltage charge mode,
Since the charging control means is operated in a charging mode according to the power storage status of the power storage unit,
Power can be supplied to the signal output means, the monitoring means, and the charge control means in the initial charge mode even when the power storage unit is in a fully discharged state, and charging can be appropriately performed while appropriately controlling charging power from the fully discharged state. it can.

1 is a basic configuration diagram of a power storage device according to the present invention. It is explanatory drawing explaining three charge modes of the electrical storage apparatus which concerns on this invention. FIG. 2 is a block diagram illustrating a specific circuit configuration example of the power storage device illustrated in FIG. 1. FIG. 4 is a block diagram illustrating a more specific circuit configuration example of the power storage device illustrated in FIG. 3. FIG. 3 is a block diagram illustrating a configuration example of a chopper type step-down DC-DC converter. It is a flowchart explaining the charge control method of the electrical storage apparatus which concerns on this invention. It is a figure which shows the time transition of the input voltage and electrical storage part voltage in the transition process from the initial charge mode of the electrical storage apparatus which concerns on this invention to the constant current charge mode. It is a figure which shows the time transition of the input voltage and electrical storage part voltage in the transition process from the constant current charge mode to the constant voltage charge mode of the electrical storage apparatus which concerns on this invention. It is a block diagram which shows the general structural example of the electrical storage apparatus using a capacitor.

Hereinafter, a power storage device using a capacitor according to the present invention will be described with reference to the drawings illustrating embodiments.
FIG. 1 shows a basic configuration example of a power storage device 1 using a capacitor.
As shown in FIG. 1, the power storage device 1 includes a charge control circuit 2, a power storage unit 3, a control unit 4, and a DC-DC converter 5.
In general, the capacitor is preferably charged from a current source rather than a voltage source. Therefore, a DC current source 6 is connected to the input side of the power storage device 1 as an external power source. As the DC current source 6, for example, a solar battery or the like is used. It is possible to use other power supply sources such as wind generators and engine generators, but in these cases there are AC output and DC output, and when the power supply is an AC power source. Is used by converting to DC.
The DC-DC converter 5 in the power storage device 1 supplies a voltage and electric power necessary for driving the control unit 4. Generally, the direct current source 6 and the power storage unit 3 are supplied from the supply voltage to the control unit 4. Since the output voltage is often higher, a step-down DC-DC converter is often used.
A power converter 7 such as a DC-DC converter or a DC-AC inverter is connected to the output side of the power storage device 1, and a load 8 is connected to the output side of the power converter 7.

As shown in FIG. 1, in the power storage device 1, the charge control circuit 2 is incorporated between the direct current source 6 and the power storage unit 3. The charging control circuit 2 is controlled based on a control signal (indicated by a broken arrow) output from the control unit 4.
As will be described later, the initial drive power for driving the control unit 4 is controlled from the DC current source 6 by the functions of the charge control circuit 2 and the control unit 4 even when the capacitor of the power storage unit 3 is in a completely discharged state. The power storage unit 3 is started to be charged at the same time, and charging of the power storage unit 3 is performed while gradually increasing the charging current while continuing to secure stable power supply to the control unit 4. Charge.
In addition, after the voltage and power sufficient to drive the control unit 4 are accumulated in the power storage unit 3, driving power for driving the control unit 4 is supplied from the DC current source 6 or the power storage unit 3, The power storage unit 3 is charged with a constant current by the charging power supplied from the DC current source 6. When the power storage unit 3 is fully charged, constant voltage charging is performed to prevent the capacitor of the power storage unit 3 from being overcharged. Note that, if necessary, input voltage information based on the input voltage to the power storage device 1 is input to the control unit 4 from the charge control circuit 2 as indicated by a dashed line. Is done.
In the above operation, the control unit 4 monitors the power storage status of the power storage unit 3 and obtains power storage information such as the power storage unit voltage (indicated by a broken arrow).
The charging control circuit 2 corresponds to charging control means described in the claims, and the control unit 4 corresponds to signal output means and monitoring means described in the claims, and the DC-DC The converter 5 corresponds to voltage conversion means described in the claims.

The power storage device 1 using the capacitor according to the present invention is composed of three kinds of charging modes. First, these three types of charging modes will be described. FIG. 2 shows the current flow in the power storage device 1 in each charging mode with arrows. In FIG. 2, in order to display the current flow in an easy-to-understand manner, the storage information and various signals between the control unit 4 and the charging control circuit 2 (such as the input voltage information Vi shown in FIG. The flow of signals etc. is omitted.

Hereinafter, three types of charging modes will be described with reference to FIG.
(1) Initial charging mode When the power storage unit 3 is in a completely discharged state or when the power storage unit voltage Vt is not a voltage that can sufficiently drive the control unit 4, as shown in FIG. The electric power from the direct current source 6 is supplied as drive power to the control unit 4 via the DC-DC converter 5 until the partial voltage Vt becomes a voltage that can sufficiently drive the control unit 4, and stored in parallel. The charging of the power storage unit 3 is started while gradually increasing the charging current while starting the charging of the unit 3 and continuously ensuring a stable power supply to the control unit 4.
In this state, sufficient power that can be supplied to the load is not stored in the power storage unit 3, so output of power from the power storage unit 3 to the power converter 7 and the load 8 is cut off.
This charging mode is called an initial charging mode.

(2) Constant Current Charging Mode After the storage unit voltage Vt reaches a voltage that can sufficiently drive the control unit 4 by charging in the initial charging mode, as shown in FIG. The power storage unit 3 is charged with constant current while supplying the power from the power source or the power stored in the power storage unit 3 to the control unit 4 via the DC-DC converter 5. This charging mode is called a constant current charging mode. In FIG. 2B, not only the power from the direct current source 6 but also the power stored in the power storage unit 3 is supplied to the control unit 4 via the DC-DC converter 5. Is for continuously driving the control unit even when the power supply from the DC current source 6 is temporarily interrupted due to sunset or rain when the DC current source 6 is a solar cell, for example. .
In this state, the power storage unit 3 stores power that can be supplied to the load, and thus power is output from the power storage unit 3 to the power converter 7 and the load 8.
This charging mode is called an initial charging mode.
(3) Constant voltage charging mode When the power storage unit 3 is fully charged by charging in the constant current mode, if the constant current charging is continued thereafter, the capacitor of the power storage unit 3 exceeds the rated voltage and becomes overcharged, causing deterioration. In some cases, or in the worst case, destruction may occur, so as shown in FIG. 2C, the constant current charging is shifted to the constant voltage charging.
In this state, the power storage unit 3 stores sufficient power that can be supplied to the load, so that power is output from the power storage unit 3 to the power converter 7 and the load 8.
This charging mode is called a constant voltage charging mode.
In FIG. 2C, not only the power from the direct current source 6 but also the power stored in the power storage unit 3 is supplied to the control unit 4 via the DC-DC converter 5. This is because the controller is continuously driven even when the power supply from the DC current source 6 is temporarily interrupted due to sunset or rain when the DC current source 6 is a solar cell, for example. .

Instead of the DC-DC converter 5, it is possible to employ another voltage conversion means according to the drive voltage required by the control unit 4. When a voltage appropriate for the operation of the control unit 4 is output from the direct current source 6, the constant voltage charging mode needs to be devised, but the DC-DC converter 5 can be omitted.

FIG. 3 is a block diagram of the power storage device 1 of the first embodiment in which the charge control circuit 2 shown in FIG. 1 is more specifically configured. In this figure, a portion surrounded by a broken line is the charging control circuit 2.
As shown in FIG. 3, the charge control circuit 2 includes a switch Si (switch means), a smoothing circuit 21 (smoothing means), a comparator 22 (comparator), a reference voltage generation circuit 23, and the like.
The switch Si is a make contact switch (Normally Open type switch).
Also, the diodes D1, D2, and D3 in FIG. 3 are backflow prevention diodes, and the resistors R1 and R2 are voltage dividing resistors. Further, the switch So is a discharge output switch. The discharge output switch So is also a make contact switch (Normally Open type switch).
In addition, when no direct current is supplied from the external power supply 6, for example, when the external power supply 6 is a solar battery or the like, and the nighttime or the like, the power stored in the power storage unit 3 must be supplied to the load. There are many cases that must be done. Therefore, the control unit 4 must always be in operation for discharge control or the like.

The path from the power storage unit 3 via the diode D2 to the DC-DC converter 5 causes the control unit 4 to operate even in the above-described case, that is, when no direct current is supplied from the external power supply 6. It is a circuit for supplying the electric power for electricity from the electrical storage part 3. FIG.
The configuration of the charging control circuit 2 shown in FIG. 3 is similar to the configuration of the chopper type step-down DC-DC converter 200 as shown in FIG. However, in the chopper type step-down DC-DC converter of FIG. 5, the output voltage is controlled by feeding back the output voltage Vo to the control circuit 210. However, the charge control circuit 2 shown in FIG. The input voltage information Vi based on the input voltage Vin is input to the control unit 4 to control the output voltage from the charge control circuit 2 to the power storage unit 3. This is because the input to the power storage device 1 is the DC current source 6, and therefore, the information based on the change in the input voltage Vin to the power storage device 1 is input to the control unit 4, whereby the charge control circuit 2 to the power storage unit 3. Therefore, it becomes possible to control the output voltage.
In the above operation, the control unit 4 obtains the storage information by monitoring the storage state of the storage unit 3 by the storage unit voltage Vt, and a voltage dividing circuit constituted by the resistor R1 and the resistor R2, The output voltage from the charge control circuit 2 to the power storage unit 3 is monitored by the input voltage information Vi obtained from the comparator 22 and the reference voltage generation circuit 23.

Below, with reference to FIG. 3, operation | movement of three charge modes is demonstrated.
<Charging operation in initial charging mode>
When the power storage unit 3 is in a fully discharged state, or when the power storage unit 3 is not charged to a voltage at which the power storage unit voltage Vt can sufficiently drive the control unit 4, the voltage that can sufficiently drive the control unit 4 The charging in the initial charging mode is performed until the power storage unit 3 is charged with electric power.
When the power storage unit 3 is in a fully discharged state or when the power storage unit 3 is not charged to a voltage at which the power storage unit voltage Vt can sufficiently drive the control unit 4, the control unit 4 is not in an operating state at the start of charging. The switch Si (make contact switch) in FIG. 3 is in an open state.
In this initial charging mode, the switch opening / closing signal has not yet been output from the control unit 4, and the discharge output switch So of the make contact switch is opened and is in the cut-off state.
When the control unit 4 is not in operation and the switch Si is open,
The output voltage of the DC current source 6, that is, the input voltage Vin to the power storage device 1 is the set maximum voltage, and the output current of the DC current source 6, that is, the input current Iin to the power storage device is the diode D 1. Therefore, the DC-DC converter 5 is operated, and the drive power converted into a predetermined voltage is started to be supplied as the control unit power supply of the control unit 4.

When drive power is supplied to the control unit 4 and the control unit 4 starts to operate, a switch open / close signal is output from the control unit 4 to the switch Si, and the switch Si starts to be controlled to open / close.
When the switch open / close signal is a signal for closing the switch Si, the switch Si is closed to be in an ON (conducting) state, and the current from the DC current source 6 passes through the smoothing circuit 21 and the backflow prevention diode D3 to be stored in the power storage unit 3. Flow into. When the switch opening / closing signal is a signal for opening the switch Si, the switch Si is opened to be in an OFF (non-conducting) state, and current flow from the DC current source 6 to the power storage unit 3 is prevented.
That is, the current from the DC current source 6 to the power storage unit 3 is pulse-width modulated by opening and closing the switch Si, and the pulse-width modulated current is smoothed by the smoothing circuit 21 and then passed to the power storage unit 3 via the diode D3. Supplied.
Therefore, by increasing the ON (conduction) time of the switch opening / closing signal output from the control unit 4, the charging current Ic flowing into the power storage unit 3 is increased, and the switch opening / closing signal output from the control unit 4 is turned OFF ( By increasing the (non-conduction) time, the charging current Ic flowing into the power storage unit 3 can be reduced.

Therefore, the ratio of the open time of the switch open / close signal within the fixed time T (that is, the duty ratio of the switch open / close signal) is changed from 0% (the switch Si is non-conductive) to the fixed time T1 (hereinafter, time interval T1). And charging is performed while increasing the charging current Ic flowing into the power storage unit 3 by increasing a preset ratio every time.
As the duty ratio of the switch opening / closing signal increases, the charging current Ic flowing into the power storage unit 3 increases. However, since the current exceeding the set current upper limit value Ilim is not output from the DC current source 6, eventually. The input voltage Vin to the power storage device 1 causes a voltage drop. When the input voltage Vin to the power storage device 1 falls below the lower limit value of the allowable input voltage range of the DC-DC converter 5, the DC-DC converter 5 cannot supply the driving power required by the control unit 4. The unit cannot operate normally.

Note that the duty ratio of the switch open / close signal is gradually increased from 0% every certain time T1 because the voltage obtained by subtracting the forward voltage drop of the diode D1 from the input voltage Vin to the power storage device 1 is DC− This is because the control unit 4 is prevented from falling into an operation stop state due to a drop below the lower limit value of the allowable input voltage range of the DC converter 5.
Therefore, the voltage drop of the input voltage Vin to the power storage device 1 is monitored by an input voltage monitoring circuit using the comparator 22 in FIG. The input voltage monitoring circuit includes a voltage dividing resistor including resistors R1 and R2, a comparator 22, and a reference voltage generation circuit 23.
When the input voltage Vin to the power storage device 1 falls below the first set voltage Vr1 generated by the reference voltage generation circuit 23, the input voltage information Vi is output from the comparator 22 to the control unit 4. When the control unit 4 receives the input voltage information Vi, the control unit 4 reduces the duty ratio of the switch open / close signal by a predetermined ratio to control the charging current Ic flowing into the power storage unit, thereby reducing the power storage device. The voltage drop of the input voltage Vin to 1 is suppressed, and the DC-DC converter 5 supplies the control unit 4 with voltage and power that can ensure the operation of the control unit 4 constantly.
A voltage obtained by adding the forward voltage drop of the diode D1 to the lower limit value of the allowable input voltage range of the DC-DC converter 5 may be used as the first set voltage Vr1.

By repeating the above operation every predetermined time T1 (time interval T1), the voltage obtained by subtracting the forward voltage drop of the diode D1 from the input voltage Vin to the power storage device 1 is used as the allowable input voltage of the DC-DC converter 5. The power storage unit 3 is charged without lowering below the lower limit of the range (that is, while ensuring the operation of the control unit 4). This series of operations is the initial charging mode.
This initial charging mode is continued until power is stored in the power storage unit 3 and the power storage unit voltage Vt reaches a voltage that can sufficiently drive the control unit 4. This is to secure electric power for stably operating the control unit 4 from the power storage unit 3 even when the supply of direct current from the external power source 6 is temporarily interrupted. In other words, the initial charging mode is a charging mode in which power is stored in the power storage unit 3 and the power storage unit voltage Vt reaches a voltage that can sufficiently drive the control unit 4.

<Charging operation in constant current charging mode>
Charging of the power storage unit 3 proceeds by charging in the initial charging mode, the power storage unit voltage Vt rises to be equal to or higher than the second set voltage Vr2, and voltage and power that can sufficiently drive the control unit 4 are accumulated in the power storage unit 3. When the control unit 4 confirms that this has been done, the duty ratio of the switch opening / closing signal output from the control unit 4 is set to 100% (that is, the switch Si is in a conductive state) and supplied from the DC current source 6. The operation proceeds to a constant current charging mode in which the power storage unit 3 is charged with a constant current.
A voltage that can sufficiently drive the charge control circuit 2 and the control unit 4 is defined as a second set voltage Vr2.
In this constant current charging mode, a part of the current from the direct current source 6 is passed through the diode D1 and the DC-DC converter 5, or the electric power stored in the power storage unit 3 is passed through the diode D2 and the DC-DC converter 5. The power storage unit 3 is charged while being stably supplied as drive power to the control unit 4 via.
In this constant current charging mode, the discharge output switch So is closed by the switch open / close signal output from the control unit 4, and the power to the load 8 is discharged from the power storage unit 3 via the power converter 7. ing.
If charging is continued at a constant current, the power storage unit 3 will eventually become fully charged. However, if constant current charging is continued further, the inter-terminal voltage of each capacitor constituting the power storage unit 3 will exceed the rated voltage and become overcharged. In the worst case, the capacitor may be destroyed.
Therefore, in the constant current charging mode, the control unit 4 checks whether or not the power storage unit voltage Vt is equal to or higher than the third set voltage Vr3 at every constant time T2 (hereinafter referred to as time interval T2). When the partial voltage Vt reaches the third set voltage Vr3, the constant current charging mode is terminated and the constant voltage charging mode is entered. Note that the full charge voltage of the power storage unit 3 may be the third set voltage Vr3.

<Charging operation in constant voltage charging mode>
The operation of the charging control circuit 2 in the constant voltage charging mode is the same as that of a general constant voltage output type DC-DC converter, and the output voltage of the charging control circuit 2 (that is, the power storage unit voltage Vt) The set voltage Vr4 is compared by the control unit 4 every predetermined time T3 (hereinafter referred to as time interval T3), and when the power storage unit voltage Vt becomes equal to or higher than the fourth set voltage Vr4, the duty ratio of the switch open / close signal is set in advance. The constant voltage charging is realized by performing control such that the duty ratio of the switch opening / closing signal is increased by a predetermined ratio when the ratio is decreased by a predetermined ratio and, conversely, when it becomes less than the fourth set voltage Vr4.
Even in this constant voltage charging mode, part of the current from the direct current source 6 is passed through the diode D1 and the DC-DC converter 5, or the electric power stored in the power storage unit 3 is transferred to the diode D2 and the DC-DC converter. The power storage unit 3 is charged while being supplied as drive power to the control unit 4 via 5.
In this constant voltage charging mode, the discharge output switch So is closed by the switch open / close signal from the control unit 4, and the power to the load 8 is discharged from the power storage unit 3 via the power converter 7. .
The full charge voltage of the power storage unit 3 can be set to the fourth set voltage Vr4.
In the above configuration, the charge control circuit 2 is a configuration corresponding to the charge control means described in the claims, and the configuration for outputting the switch open / close signal from the control unit 4 is described in the claims. Corresponding to the signal output means, the output voltage of the power storage unit 3 is input to the control unit 4 as the power storage unit voltage Vt, and the power storage unit voltage Vt is converted into the second set voltage Vr2 and the third set voltage by the comparison program of the control unit 4. The configuration monitored in comparison with Vr3 or the fourth set voltage Vr4 is a configuration corresponding to the monitoring means described in the claims.
The switch opening / closing signal has a configuration corresponding to a charge control signal described in the claims.

FIG. 4 is a configuration diagram of power storage device 1 showing a more specific circuit configuration example of charge control circuit 2 shown in FIG. 3. A portion surrounded by a broken line is the charge control circuit 2.
The charge control circuit 2 shown in FIG. 4 includes a P-type MOSFET 24, a coil L, a capacitor C, a comparator (comparator) 22, a reference voltage generation circuit 23, and the like. A smoothing circuit 21 is formed by the coil L and the capacitor C. Is formed.
The configuration of the charge control circuit 2 shown in FIG. 4 is similar to a chopper type step-down DC-DC converter. However, in the chopper type step-down DC-DC converter 200 as shown in FIG. 5, the output voltage is controlled by feeding back the output voltage to the control circuit 210. However, the charge control circuit 2 shown in FIG. Then, the input voltage information Vi based on the input voltage Vin to the power storage device 1 is input to the control unit 4 to control the output voltage from the charge control circuit 2 to the power storage unit 3. This is because the input power source is a DC current source 6, and input voltage information Vi based on the input voltage Vin to the charging control circuit 2 is input to the control unit 4, whereby the charging control circuit 2 to the power storage unit 3 is input. The output can be controlled.

In FIG. 4, diodes D1, D2, and D3 are backflow prevention diodes, and diode D4 is a flywheel diode. The resistors R1 and R2 are voltage dividing resistors, and the resistor R3 is a pull-up resistor.
In FIG. 4, when the transistor Tr is in the ON (conducting) state, the P-type MOSFET 24 is also in the ON (conducting) state, and the current energy flowing from the DC current source 6 is the coil L, the capacitor C, and the power storage unit (EDLC). Accumulated in. At this time, no current flows through the diode D4.
When the transistor Tr is turned off (non-conducting), the P-type MOSFET 24 is also turned off (non-conducting), and current energy flowing from the direct current source 6 toward the power storage unit 3 is cut off and stored in the coil L. The energy is supplied to the power storage unit 3 via the diode D4 and the capacitors C and D4, and the output voltage from the charge control circuit 2 to the power storage unit 3 is kept substantially constant.
The P-type MOSFET 24 and the transistor Tr correspond to the switching means described in the claims, and the coil L and the capacitor C correspond to the smoothing means described in the claims.

Below, with reference to FIG. 4, operation | movement of 3 types of charging modes is demonstrated.
<Charging operation in initial charging mode>
A charging operation in the initial charging mode in power storage device 1 shown in FIG. 4 will be described.
When the power storage unit 3 is in a fully discharged state or when the power storage unit 3 is not charged to a voltage at which the power storage unit voltage Vt can sufficiently drive the control unit 4, the control unit 4 is not in an operating state. With respect to the base of the transistor Tr shown in FIG. 4, a pulse width modulation signal (hereinafter referred to as a PWM signal) described later is not output from the control unit 4 (or is at a low potential level (L)), and the transistor Tr is in an OFF (non-conducting) state. Therefore, the P-type MOSFET 24 is also turned off (non-conducting). That is, the duty ratio of the PWM signal that is the charge control signal output from the control unit 4 is 0%.
When the control unit 4 is not in an operating state, the output voltage of the DC current source 6, that is, the input voltage Vin to the power storage device 1 is the set maximum voltage, and the output current of the DC current source 6, that is, Since the input current Iin to the power storage device 1 flows into the DC-DC converter 5 via the diode D1, the DC-DC converter 5 operates and the supply of drive power to the control unit 4 is started.
When the control unit 4 is driven, a PWM signal is output from the control unit 4 to the transistor Tr, and the transistor Tr is switched. Accordingly, the P-type MOSFET 24 is switched.
In this initial charging mode, the discharge output switch So is in an open state, and power output from the power storage unit 3 to the load 8 via the power converter 7 is interrupted.

That is, when the signal level of the PWM signal becomes the high potential level (H), the transistor Tr becomes conductive, and the collector potential of the transistor Tr, that is, the gate potential of the P-type MOSFET 24 becomes the low potential level (L). Is turned on (conductive), and the current from the DC current source 6 flows into the power storage unit 3.
Further, when the signal level of the PWM signal becomes a low potential level (L), the transistor Tr becomes non-conductive, and the collector potential of the transistor Tr, that is, the gate potential of the P-type MOSFET 24 becomes the high potential level (H). MOSFET 24 is turned off (non-conducting), and current flow from DC current source 6 to power storage unit 3 is blocked.
Therefore, when the duty ratio of the PWM signal output from the control unit 4 is increased, the charging current Ic flowing into the power storage unit 3 increases, and when the duty ratio of the PWM signal output from the control unit 4 is decreased, The charging current Ic flowing into the unit 3 decreases.

Therefore, charging is performed while increasing the charging current Ic flowing into the power storage unit 3 by increasing the predetermined ratio every predetermined time T1 (time interval T1) from the state where the duty ratio of the PWM signal is 0%. . As the duty ratio of the PWM signal increases, the charging current Ic flowing into the power storage unit 3 increases. However, since the current exceeding the set current upper limit value Ilim is not output from the DC current source 6, the power storage will eventually be performed. The input voltage Vin to the device 1 causes a voltage drop.
When the voltage obtained by subtracting the forward voltage drop of the diode D1 from the input voltage Vin to the power storage device 1 falls below the lower limit value of the allowable input voltage range of the DC-DC converter 5, the drive power to the control unit 4 is supplied become unable.

The duty ratio of the PWM signal is gradually increased from 0% every certain time T1 because the voltage obtained by subtracting the forward voltage drop of the diode D1 from the input voltage Vin to the power storage device 1 is a DC-DC converter. This is to prevent the control unit 4 from entering an operation stop state by dropping below the lower limit value of the allowable input voltage range of 5.

Therefore, the voltage drop of the input voltage Vin to the power storage device 1 is monitored by monitoring means using the comparator 22 (comparator) in FIG. That is, when the input voltage Vin to the power storage device 1 falls below the first set voltage Vr1 generated by the reference voltage generation circuit 23, the input voltage information Vi is output from the comparator 22 to the control unit 4. When the control unit 4 receives the input voltage information Vi, the control unit 4 reduces the duty ratio of the PWM signal by a predetermined ratio and suppresses the charging current Ic flowing into the power storage unit 3 to thereby supply power to the power storage device 1. The voltage drop of the input voltage Vin is suppressed, and the DC-DC converter 5 constantly supplies a voltage and driving power that can ensure the operation of the control unit 4.
A voltage obtained by adding the forward voltage drop of the diode D1 to the lower limit value of the allowable input voltage range of the DC-DC converter 5 may be used as the first set voltage Vr1.

By repeating the above operation every predetermined time T1 (time interval T1), the voltage obtained by subtracting the forward voltage drop of the diode D1 from the input voltage Vin to the power storage device 1 is used as the allowable input voltage of the DC-DC converter 5. The power storage unit 3 is charged without lowering below the lower limit of the range (that is, while ensuring the operation of the control unit 4). This series of operations is the initial charging mode.
This initial charging mode is continued until voltage and power that can sufficiently drive the control unit 4 are accumulated in the power storage unit 3.

<Charging operation in constant current charging mode>
Charging of the power storage unit 3 proceeds by charging in the initial charge mode, the power storage unit voltage Vt rises to be equal to or higher than the second set voltage Vr2, and voltage and power that can sufficiently drive the control unit 4 are accumulated in the power storage unit 3. If the control unit 4 constituting the monitoring means confirms that the duty ratio of the PWM signal output from the control unit 4 is set to 100% (that is, the transistor Tr and the P-type MOSFET 24 are always ON). , Transition to a constant current charging mode in which charging is performed at a constant current.
When electric power that can sufficiently drive the control unit 4 is accumulated in the power storage unit 3, the control unit 4 can be operated even when the supply of DC current from the external power source 6 is temporarily interrupted thereafter. become.
In this constant current charging mode, the current from the DC current source 6 passes through the diode D1 and the DC-DC converter 5, or the power stored in the power storage unit 3 passes through the diode D2 and the DC-DC converter 5. Thus, the power storage unit 3 is charged while being supplied as drive power to the control unit 4.
In the constant current charging mode, the discharge output switch So is closed, and the power to the load 8 is discharged from the power storage unit 3 via the power converter 7.
If charging is continued at a constant current, the power storage unit 3 will eventually become fully charged, but if the constant current charging is continued further, the voltage across the terminals of each capacitor constituting the power storage unit 3 will exceed the rated voltage, resulting in overcharging, It may cause deterioration of the capacitor or may be destroyed in the worst case.
Therefore, in the constant current charging mode, the control unit 4 checks whether or not the power storage unit voltage Vt is equal to or higher than the third set voltage Vr3 every constant time T2 (time interval T2). When the set voltage Vr3 is reached, the constant current charging mode is terminated and the constant voltage charging mode is entered. The full charge voltage of the power storage unit 3 can be set to the third set voltage Vr3.

<Charging operation in constant voltage charging mode>
The operation of the charging control circuit 2 in the constant voltage charging mode is the same as that of a general step-down DC-DC converter, and the output voltage (that is, the storage unit voltage Vt) of the charging control circuit 2 and the fourth set voltage Vr4 are obtained. The control unit 4 compares each constant time T3 (time interval T3), and if the storage unit voltage Vt becomes equal to or higher than the fourth set voltage Vr4, the PWM signal output from the control unit 4 to the base of the transistor Tr Constant voltage charging is realized by controlling the duty ratio to be decreased by a predetermined ratio, and conversely to increase the duty ratio of the PWM signal by a predetermined ratio when the voltage falls below the fourth set voltage Vr4. ing.
Also in this constant voltage charging mode, the current from the direct current source 6 passes through the diode D1 and the DC-DC converter 5, or the power stored in the power storage unit 3 passes through the diode D2 and the DC-DC converter 5. Thus, the power storage unit 3 is charged while being supplied as drive power to the control unit 4.
The full charge voltage of the power storage unit 3 can be set to the fourth set voltage Vr4.
In this constant voltage charging mode, the discharge output switch So is closed, and the power to the load 8 is discharged from the power storage unit 3 via the power converter 7.

The operation of the control unit 4 in the series of charging processes will be described with reference to the flowchart shown in FIG.
In step S <b> 1 of FIG. 6, when the power storage unit 3 is in a fully discharged state or a state close thereto, the charge control circuit 2 first supplies the drive power to the control unit 4 and supplies the power to the power storage unit 3 in the initial charge mode. Start supplying charging power. In the initial stage of the initial charging mode, at least the supply of driving power to the control unit 4 is most important, and the supply of charging power to the power storage unit 3 is not essential.
Therefore, by setting the duty ratio of the PWM signal to 0% in step S2, charging power is not supplied to the power storage unit 3, and after the elapse of the time interval T1 in step S3, the duty ratio of the PWM signal is set in step S4. The supply of charging power to the power storage unit 3 is started by increasing it by a predetermined rate.
In step S5, the input voltage Vin from the direct current source 6 to the charge control circuit 2 is compared with the first set voltage Vr1,
Input voltage Vin> first set voltage Vr1
In step S7, the process proceeds to step S7.
Input voltage Vin ≦ first set voltage Vr1
In this case, the routine proceeds to step S6, where the duty ratio of the PWM signal is decreased by a predetermined ratio to prevent the input voltage Vin from being lowered too much. Then, the process proceeds to step S7.

In step S7, the power storage unit voltage Vt is compared with the second set voltage Vr2,
Power storage unit voltage Vt ≧ second set voltage Vr2
The processing from step S3 is repeated until.
In step S7
Power storage unit voltage Vt ≧ second set voltage Vr2
Is confirmed, in step S8, the initial charging mode is terminated, and the process proceeds to step S9 to shift to the constant current charging mode.
In step S9, the constant current charging to the power storage unit is started in the constant current charging mode with the duty ratio of the PWM signal set to 100%.
In step S10, after elapse of a predetermined time interval T2, the process proceeds to step S11, and the power storage unit voltage Vt is compared with the third set voltage Vr3.
Power storage unit voltage Vt ≧ third set voltage Vr3
The processing from step S10 is repeated until.
In step S11,
Power storage unit voltage Vt ≧ third set voltage Vr3
Is confirmed, the process proceeds to step S12 to end the constant current charging mode, and the process proceeds to step S13 to start charging the power storage unit in the constant voltage charging mode.
When charging is started in the constant voltage charging mode in step S13, the process proceeds to step S14, and after a predetermined time interval T3 has elapsed, the process proceeds to step S15, where the power storage unit voltage Vt is compared with the fourth set voltage Vr4.
Power storage unit voltage Vt ≧ fourth set voltage Vr4
In this case, the duty ratio of the PWM signal is decreased by a predetermined ratio in step S16, and the process returns to step S14.
Power storage unit voltage Vt <fourth set voltage Vr4
In this case, the duty ratio of the PWM signal is increased by a predetermined ratio in step S17, and the process returns to step S14. In this way, charging in the constant voltage charging mode is continued.

<Experiment and results>
The power storage device 1 of FIG. 4 using the above-described charge control circuit 2 is connected to a power storage unit configured by arranging 10 EDLCs with a rated voltage of 2.7 [v] and a capacitance of 1700 [F] in 5 series and 2 in parallel. The characteristics of the charging control circuit 2 when configured and performing a charging operation will be described.
The full charge voltage of the power storage unit 3 is 13.5 [V] (= 2.7 [V] × 5), and the allowable input voltage range of the DC-DC converter is 6.0 [V] to 16.0 [V] ].
The first set voltage Vrl is 6.0 [V], the second set voltage Vr2 is 6.0 [V], the third set voltage Vr3 is 13.4 [V], and the fourth set voltage Vr4 is set. It was set to 13.4 [V]. Since the full charge voltage of the power storage unit 3 is 13.5 [V], the third set voltage Vr3 and the fourth set voltage Vr4 are set to 13.5 [V], and after reaching this voltage Although it is desirable to shift to the constant voltage charging mode, the third set voltage Vr3 and the fourth set voltage Vr4 are set for safety in consideration of the variation in the voltage between terminals of each capacitor due to the capacitance error of the capacitor. It was set to 13.4 [V], which is 0.1 [V] lower than 13.5 [V].

First, FIG. 7 shows temporal transitions of the input voltage Vin and the power storage unit voltage Vt from the direct current source 6 to the power storage device 1 in the transition process from the initial charge mode to the constant current charge mode.
From FIG. 7, in order to drive the control unit 4 reliably, the input voltage Vin to the power storage device 1 is set to 6.0 [V] which is the lower limit value of the allowable input voltage range of the DC-DC converter 5. Charging in the initial charging mode is performed in which the power storage unit 3 is charged by gradually increasing the duty ratio of the PWM signal from 0% while maintaining the voltage to be equal to or higher than the voltage obtained by adding the forward voltage drop. Recognize.
Further, when the power storage unit voltage Vt reaches the second set voltage Vr2 (6.0 [V] in this example) and sufficient voltage and power that can drive the control unit 4 are stored in the power storage unit 3, the initial charge is performed. It can be seen that the mode has shifted to the constant current charging mode.
The voltage difference between the input voltage Vin to the power storage device 1 and the power storage unit voltage Vt in the constant current charging mode in FIG. 7 is mainly due to the forward voltage drop characteristic of the backflow prevention diode D3 in FIG. is there.

FIG. 8 shows temporal transitions of the input voltage Vin from the direct current source 6 to the power storage device 1 and the power storage unit voltage Vt in the transition process from the constant current charging mode to the constant voltage charging mode.
From FIG. 8, it can be seen that when the power storage unit voltage Vt reaches the third set voltage Vr3 (13.4 [V] in this embodiment), the constant current charging mode is shifted to the constant voltage charging mode. In the voltage charging mode, the input voltage Vin to the power storage device 1 has reached a maximum of 15.3 [V], but the power storage unit voltage Vt maintains the set 13.4 [V].

Thus, since the charging is continued by shifting from the constant current charging mode to the constant voltage charging mode, the power storage unit 3 can be prevented from being overcharged, and the cause of the deterioration of the capacitor can be eliminated.

According to the power storage device 1 described above, the following effects can be obtained.
(1) Since it is not necessary to separately prepare an initial drive capacitor that does not directly contribute to the power storage of the power storage unit, the configuration is simplified and the cost increase can be suppressed.
(2) Since the control unit can always be operated in a normal state to perform charge control, stable charge control can be performed from the start of charge to the end of charge even when the capacitor of the power storage unit is in a completely discharged state. In addition, since the initial drive capacitor is unnecessary, the time required for the charge is not required, and charging control to the power storage unit is performed with the control unit operating normally even when the capacitor of the power storage unit is completely discharged. Can start.

(3) By configuring the charge control circuit with a P-type MOSFET, a coil, a capacitor, a comparator, and the like, the duty ratio of the pulse width modulation signal for controlling on / off of the P-type MOSFET is controlled in the range of 0% to 100%. By doing so, proper charging is always possible, a complicated circuit configuration is not required, and an increase in cost can be suppressed.

Thus, according to the present invention, in the power storage device using the capacitor such as EDLC for the power storage unit, the initial drive capacitor is not used, and the initial charge mode is used even when the capacitor of the power storage unit is in a completely discharged state. After the initial drive power for driving the control unit is supplied to the control unit to start charging the power storage unit and sufficient voltage and power to drive the control unit are accumulated in the power storage unit, the constant current In the charging mode, power for driving the control unit is supplied from the DC current source or the power storage unit, and after charging to the power storage unit is started, the power storage unit is charged with constant current by the power supplied from the DC current source to store the power. When the unit is fully charged, it is possible to provide a power storage device having an excellent charge control function of performing constant voltage charging in the constant voltage charging mode in order to prevent the capacitor of the power storage unit from being overcharged.

The present invention can be used for a purpose of appropriately charging a power storage device for various uses as long as it is a power storage device using a capacitor.

DESCRIPTION OF SYMBOLS 1 Power storage device 2 Charge control circuit, charge control means 3 Power storage part 4 Control part, signal output means, monitoring means 5 DC-DC converter, voltage conversion means 6 DC current source, external power supply 7 Power converter 8 Load Si switch, switch Means So Discharge output switch 24 P-type MOSFET, switch means Tr transistor, switch means L coil, smoothing means C capacitor, smoothing means 21 smoothing circuit, smoothing means 22 comparator 23 reference voltage generation circuit R1, R2 voltage dividing resistor R3 pull Up resistor D1, D2, D3 Backflow prevention diode D4 Flywheel diode

Claims

A power storage unit using a capacitor;
Charging control means for controlling a direct current flowing from an external power source based on a charging control signal and supplying the direct current as charging power to the power storage unit;
Signal output means for outputting the charge control signal to the charge control means;
Monitoring means for monitoring power storage status in the power storage unit;
In a power storage device comprising:
The charge control means includes
An initial charging mode for supplying the direct current as at least the driving power of the signal output means;
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant current, and at the same time, the DC output or the power stored in the power storage unit is supplied to the signal output unit and the monitoring unit. And a constant current charge mode to be supplied as drive power for the charge control means,
With
The signal output means controls the charge control means so as to switch to one of the initial charge mode and the constant current charge mode and charge according to the power storage status of the power storage unit obtained from the monitoring means. A power storage device using a capacitor is configured to output a charge control signal.
A power storage unit using a capacitor;
Charging control means for controlling a direct current flowing from an external power source based on a charging control signal and supplying the direct current as charging power to the power storage unit;
Signal output means for outputting the charge control signal to the charge control means;
Monitoring means for monitoring power storage status in the power storage unit;
In a power storage device comprising:
The charge control means includes
An initial charging mode for supplying the direct current as at least the driving power of the signal output means;
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant current, and at the same time, the DC output or the power stored in the power storage unit is supplied to the signal output unit and the monitoring unit. And a constant current charge mode to be supplied as drive power for the charge control means,
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant voltage, and the DC current or the power stored in the power storage unit is used as the signal output unit, the monitoring unit, and the charge control. A constant voltage charging mode to supply as driving power of the means;
With
The signal output means switches the charge control means to any one charge mode of an initial charge mode, a constant current charge mode, or a constant voltage charge mode according to the power storage status of the power storage unit obtained from the monitoring means. A power storage device using a capacitor, wherein the power storage device is configured to output a charge control signal.
The signal output means, according to the power storage status of the power storage unit obtained from the monitoring means,
When the power storage unit voltage is less than a second set voltage, the charge control unit is switched to an initial charge mode to charge the power storage unit,
When the power storage unit voltage is equal to or higher than a second set voltage, the charge control unit is switched from the initial charging mode to the constant current charging mode to charge the power storage unit,
The power storage unit is configured to charge the power storage unit by switching the charge control means from the constant current charging mode to the constant voltage charging mode when the power storage unit voltage is equal to or higher than a third set voltage. A power storage device using the capacitor according to claim 2.
2. A voltage conversion unit that converts driving power supplied from the external power source or the power storage unit into a predetermined voltage and supplies the driving power to the signal output unit and the monitoring unit. 4. The power storage device according to any one of items 1 to 3.
In a charging control device configured to output a direct current flowing from an external power source as charging power for charging a power storage unit using a capacitor,
Charging control means for controlling a direct current flowing from the external power source based on the charging control signal and supplying the direct current as charging power to the power storage unit;
Signal output means for outputting the charge control signal to the charge control means;
Monitoring means for monitoring power storage status in the power storage unit;
With
The charge control means includes
An initial charging mode for supplying the direct current as at least the driving power of the signal output means;
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant current, and at the same time, the DC output or the power stored in the power storage unit is supplied to the signal output unit and the monitoring unit. And a constant current charge mode to be supplied as drive power for the charge control means,
With
The signal output means, according to the power storage status of the power storage unit obtained from the monitoring means,
A charge control device for a power storage device using a capacitor, wherein the charge control means is configured to be charged by switching to one of an initial charge mode and a constant current charge mode.
In a charging control device configured to output a direct current flowing from an external power source as charging power for charging a power storage unit using a capacitor,
Charging control means for controlling a direct current flowing from the external power source based on the charging control signal and supplying the direct current as charging power to the power storage unit;
Signal output means for outputting the charge control signal to the charge control means;
Monitoring means for monitoring power storage status in the power storage unit;
With
The charge control means includes
An initial charging mode for supplying the direct current as at least the driving power of the signal output means;
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant current, and at the same time, the DC output or the power stored in the power storage unit is supplied to the signal output unit and the monitoring unit. And a constant current charge mode to be supplied as drive power for the charge control means,
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant voltage, and the DC current or the power stored in the power storage unit is used as the signal output unit, the monitoring unit, and the charge control. A constant voltage charging mode to supply as driving power of the means;
With
The signal output means, according to the power storage status of the power storage unit obtained from the monitoring means,
The charge control means is configured to charge by switching to one of three charge modes of an initial charge mode, a constant current charge mode, and a constant voltage charge mode. A charge control device for a power storage device using a capacitor.
The signal output means, according to the power storage status of the power storage unit obtained from the monitoring means,
When the power storage unit voltage is less than a second set voltage, the charge control unit is switched to an initial charge mode to charge the power storage unit,
When the power storage unit voltage is equal to or higher than a second set voltage, the charge control unit is switched from the initial charging mode to the constant current charging mode to charge the power storage unit,
When the power storage unit voltage is equal to or higher than a third set voltage, the charging control unit is configured to charge by switching from the constant current charging mode to the constant voltage charging mode. The charge control apparatus of the electrical storage apparatus using the capacitor of Claim 6.
The signal output means is configured to output a pulse train signal having a duty ratio according to the power storage status of the power storage unit obtained from the monitoring means,
The charge control means includes
Switch means for inputting on / off control of charging power to the power storage unit according to the duty ratio when the pulse train signal is input;
Smoothing means for smoothing the charging power output from the switch means and outputting to the power storage unit,
8. The capacitor according to claim 6, wherein the capacitor can be switched to one of a constant current charging mode and a constant voltage charging mode by changing a duty ratio. Charge control device for a power storage device using a battery.
It comprises voltage conversion means for converting drive power supplied from the external power source or the power storage unit into a predetermined voltage and supplying the drive power as the signal output means, the monitoring means, and the charge control means. The charge control device according to any one of claims 5 to 8.
A power storage unit using a capacitor;
Charge control means for controlling a direct current flowing from an external power source based on a charge control signal to charge the power storage unit;
Signal output means for outputting the charge control signal to the charge control means;
Monitoring means for monitoring power storage status in the power storage unit;
With
The charge control means includes
An initial charging mode for supplying the direct current as at least the driving power of the signal output means;
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant current, and at the same time, the DC output or the power stored in the power storage unit is supplied to the signal output unit and the monitoring unit. And a constant current charge mode to be supplied as drive power for the charge control means,
The DC current is supplied as charging power to the power storage unit to charge the power storage unit at a constant voltage, and the DC current or the power stored in the power storage unit is used as the signal output unit, the monitoring unit, and the charge control. A constant voltage charging mode to supply as driving power of the means;
In a charge control method for a power storage device using a capacitor comprising:
Using the monitoring means to monitor the power storage status of the power storage unit,
When the power storage unit voltage is less than a second set voltage, the signal output means outputs a charge control signal for switching the charge control means to the initial charge mode,
When the power storage unit voltage is equal to or higher than a second set voltage, the charge output signal for switching the charge control means from the initial charge mode to the constant current charge mode is output from the signal output means,
When the power storage unit voltage is equal to or higher than a third set voltage, by causing the signal output means to output a charge control signal for switching the charge control means from the constant current charge mode to the constant voltage charge mode,
A charge control method for a power storage device using a capacitor, wherein the charge control means is operated in a charge mode according to a power storage status of a power storage unit.