KR20130079419A - Power supply device and charge circuit - Google Patents

Abstract

[Problem] The secondary battery is prevented from being overcharged and optimally charged according to the electrical characteristics of each secondary battery.
[Measurement] The thyristor 32, which is a selector switch, in which a selector switch switching circuit 30 is connected to each of the secondary battery bodies 10, respectively, and which can individually configure a charging path for charging the secondary battery bodies 10. And a control circuit 40 for controlling the ON / OFF of the plurality of thyristors 32, and the control circuit 40 controls the ON / OFF of the thyristor 32 to provide an arbitrary secondary battery body ( The charge path for 10) is released, and the charge path for the other secondary battery is released, and the constant current source generation circuit 20 is connected between the supply output terminal OT and the supply input terminal IT. (L) and a chopper circuit connected to the reactor (L) in series and composed of a charge switch (22) for controlling ON / OFF by the control circuit (40). And the secondary battery body 10 are charged.

Description

Power Supply and Charging Circuit {POWER SUPPLY DEVICE AND CHARGE CIRCUIT}

The present invention relates to a power supply device and a charging circuit including a charging circuit for charging a secondary battery that can be charged and discharged.

For example, in an electric vehicle that runs using an electric motor, or a hybrid electric vehicle that runs in combination with an engine and an electric motor, a secondary cell such as a nickel-hydrogen battery, a lithium ion battery, or a lead acid battery is used as a unit cell. A plurality of battery packs connected in series is used as a power source for an electric motor. In such a battery pack, a gap occurs in the terminal voltage based on the state of charge (SOC; also referred to as residual capacity, etc.) of each unit cell while charging and discharging are repeated. Some unit cells may be in an overcharged state. Further, deterioration of the unit cell proceeds with acceleration, and when deteriorated, the entire assembled battery becomes unavailable even if only a part of the unit cell is deteriorated.

In response to such a problem, as a method for adjusting the difference in the state of charge between a plurality of unit cells constituting the charged battery unit, a battery state of charge adjusting device as shown in Patent Document 1 has been proposed. As shown in FIG. 26, this state of charge adjustment device 90 is constituted by connecting a plurality of unit cells 91 made of a secondary battery in series, and a closed circuit state in which a load and a charger are connected at both ends. In the battery pack is charged. In addition, the charging state adjusting device 90 equally charges each unit cell 91 in the open circuit state of the battery pack and the equalizing capacitor 92 provided insulated from the load and the charger. Cyclic connecting means 93 for cyclically connecting the capacitor 92 is provided. As a result, even if a difference in state of charge occurs between the unit cells 91 that are connected in series and constitute the assembled battery, the cell voltage is equalized through the equalizing capacitor 92 from the unit cell 91 having a high cell voltage. The voltage difference can be reduced by moving charges to this low unit cell 91.

Japanese Unexamined Patent Publication No. 2002-17048

However, the charging state adjusting device 90 of FIG. 26 only adjusts the gap between the unit cells 91 which have been charged to the last, and after the unit cell 91 is charged once, the charging state adjusting device 90 is used. In order to reduce the gap, the charging process and the adjustment process are required separately, which takes time, and the circuits that perform these charging and adjustments are also required separately, which leads to a complicated circuit configuration. .

In addition, in this state of charge adjustment device 90, since the state of charge can only be adjusted while cyclically switching the unit cells 91, it takes time to finish charging the entire assembled battery and the efficiency becomes worse. There are also drawbacks. In particular, in recent years, battery packs are often required to use a large number of unit cells 91 in accordance with the demand for larger capacity. In such cyclic switching charging, the charging time increases in proportion to the number of secondary batteries used. The switching operation of the unit cell 91 is also complicated, which is not practical. In addition, in the circuit example of FIG. 26, since a photo MOS transistor is used for the switching element, there is a problem that the driving circuit becomes complicated and the circuit cost becomes high. In particular, in order to perform equal charge control of each unit cell 91, it is necessary to configure a charging path capable of individually charging the unit cell 91. When a transistor is used to construct such a circuit, a circuit configuration is obtained. There is a problem of complexity.

In addition, in this circuit, since the accumulated charge is transferred to the unit cell 91 having a low terminal voltage after accumulating the charge through the equal charging capacitor 92, the large capacity equalizing capacitor 92 is In addition, the equalizing capacitor 92 is extremely close to and exceeds the open-circuit terminal voltage in the fully charged state of each unit cell 91 at the point before charging is started. It is necessary to be charged with an alternator or the like beforehand so that the terminal voltage is eliminated. There is also a problem that such preliminary preparation is necessary and the configuration is further complicated.

This invention is made | formed in view of such a conventional problem. The main object of the present invention is to provide a power supply device and a charging circuit which can prevent overcharging of a secondary battery at a lower cost and enable optimal charging.

In order to achieve the above object, according to the power supply apparatus according to the first aspect of the present invention, the plurality of secondary battery bodies 10 and the secondary battery bodies 10 each having a positive electrode and a negative electrode and connected in series with each other are provided. A constant current source generator circuit 20 having a supply output terminal OT and a supply input terminal IT for supplying electric power for charging a battery to the secondary battery bodies 10 in the constant current source generator circuit 20. And a select switch switching circuit 30 capable of supplying different charging currents separately, wherein the select switch switching circuit 30 is connected to each of the secondary battery bodies 10 and the secondary battery bodies 10, respectively. Has a selection switch 31 that can individually configure a charging path for charging the power supply; and a control circuit 40 for controlling ON / OFF of the plurality of selection switches 31, wherein the control circuit 40 includes: By controlling ON / OFF of the selection switch 31, the arbitrary secondary battery body 10 And a charge path for another secondary battery, and the constant current source generation circuit 20 is connected between the supply output terminal OT and the supply input terminal IT. (L) and a chopper circuit connected in series with the reactor (L) and composed of a charge switch (22) for controlling ON / OFF in the control circuit (40). May be connected to an external power source EP to charge the secondary battery body 10. This makes it possible to charge an arbitrary secondary battery body by using one constant current source generation circuit, and to obtain an advantage of appropriately charging appropriately according to the electrical characteristics of the secondary battery body. In addition, the chopper circuit can charge the secondary battery body at a high voltage using an external power source having a low voltage, for example, as a boost chopping operation.

Moreover, according to the power supply apparatus which concerns on a 2nd side surface, it is equipped with the positive electrode and the negative electrode, respectively, and supplies the electric power for charging the some secondary battery body 10 and the said secondary battery body 10 connected in series with each other. Each secondary battery body in order to charge each secondary battery body 10 in the constant current source generating circuit 20 and the constant current source generating circuit 20 having a supply output terminal OT and a supply input terminal IT. A plurality of positive electrode side charge paths (PC) connecting the positive electrode of (10) and the supply output terminal (OT), respectively, and a plurality of the negative electrode of each secondary battery body (10) and the supply input terminal (IT), respectively. ON / OFF of the plurality of selection switches 31 and the plurality of selection switches 31 provided in the cathode side charging path NC, the anode side charging path PC, and the cathode side charging path NC, respectively. It may be provided with a control circuit 40 for controlling the. This makes it possible to charge an arbitrary secondary battery body by using one constant current source generation circuit, and in addition, since the charge amount can be adjusted according to the remaining capacity of the secondary battery body, the entire secondary battery body connected in series Compared to the charging method, the gap between charges between secondary battery bodies can be reduced, overcharge can be avoided, and safety can be obtained over a long period of time and a secondary battery body can be used.

Moreover, according to the power supply apparatus which concerns on a 3rd side surface, it is provided with the voltage detection means 26 which detects the voltage of the both ends of the reactor L further, The said control circuit 40 is arbitrary secondary battery bodies ( 10), each of the selector switches 31 disposed on the positive electrode side charging path PC and the negative electrode side charging path NC connecting the secondary battery body 10 and the reactor L is turned ON, respectively. At the same time, by switching the other selection switch 31 to OFF, only the secondary battery body 10 is connected to the reactor L, whereby the battery voltage of the secondary battery body 10 is converted into the voltage detection means. (26) can be configured to be detectable. Thereby, the battery voltage of arbitrary secondary battery bodies can be detected by one voltage detection means. That is, since the battery voltage of each secondary battery body can be detected by only one voltage detecting means, there is no need to separately provide a voltage sensor for each secondary battery body, and the circuit can be greatly simplified. You can get it.

Moreover, according to the power supply apparatus which concerns on a 4th side surface, the said control circuit 40 can measure the battery voltage of each secondary battery body 10 by time division. Thereby, the battery voltage of all the secondary battery bodies can be detected sequentially by one voltage detection means.

Furthermore, according to the power supply device according to the fifth aspect, the control circuit 40 is configured such that the selection switch 31 can be ON / OFF controlled so as to simultaneously charge any of a plurality of secondary battery bodies 10. can do. Thereby, charging control of a plurality of secondary battery bodies can be carried out simultaneously, and charging can be advanced efficiently.

In addition, according to the power supply device according to the sixth aspect, the selection switch 31 can be an element having no self-extinguishing capability. This makes it possible to extinguish the selection switch by using the OFF period of the chopper circuit, and it is possible to make unnecessary a special additional circuit for the extinguishing.

In addition, according to the power supply apparatus according to the seventh aspect, the selection switch 31 can be configured by a thyristor 32. Thereby, the advantage that the secondary battery body connected in series can be individually charged, without providing a charging circuit for every secondary battery body, using the thyristor excellent also in reliability, especially reverse breakdown voltage characteristics, is provided. You can get it.

In addition, according to the power supply device according to the eighth aspect, the secondary battery body 10 can be configured by connecting a plurality of battery cells in series or in parallel. Thereby, it becomes possible to charge the secondary battery body which consists of several battery cells evenly connected in series.

Furthermore, according to the charging circuit according to the ninth aspect, the secondary battery body 10 is charged as a charging circuit having a positive electrode and a negative electrode, respectively, and capable of charging a plurality of secondary battery bodies 10 connected in series. In order to charge each secondary battery body 10 in the constant current source generating circuit 20 and the constant current source generating circuit 20 having a supply output terminal OT and a supply input terminal IT for supplying power for the same. A plurality of positive electrode side charge paths (PC) that can connect the positive electrode of each secondary battery body 10 and the supply output terminal (OT), respectively, the negative electrode of each secondary battery body 10 and the supply input terminal (IT) Of the plurality of negative side charging paths NC, the plurality of thyristors 32 respectively provided in the positive side charging path PC and the negative side charging path NC, and the plurality of thyristors 32 respectively. And a control circuit 40 capable of individually controlling the ON control. The current source generation circuit 20 is connected in series with the reactor L and the reactor L connected between the supply output terminal OT and the supply input terminal IT, and the control circuit 40 And a chopper circuit composed of a charging switch 22 for controlling ON / OFF, and the chopper circuit may be connected to an external power source EP to charge the secondary battery body 10. This makes it possible to charge an arbitrary secondary battery body by using one constant current source generation circuit, and to charge the entire secondary battery body connected in series because the amount of charge can be adjusted according to the remaining capacity of the secondary battery body. Compared to the method described above, the difference in charge amount between the secondary battery bodies can be reduced, and overcharge can be avoided, so that the secondary battery body can be used safely for a long time.

1 is a block diagram showing a power supply device according to an embodiment of the present invention.
FIG. 2 is a circuit diagram showing the power supply device of FIG. 1.
FIG. 3 is a circuit diagram showing a state of charging the secondary battery body 10A in the power supply device of FIG. 2.
FIG. 4 is a circuit diagram showing a state in which the secondary battery body 10B is charged by the power supply device of FIG. 2.
FIG. 5 is a circuit diagram showing a state of charging the secondary battery body 10C in the power supply device of FIG. 2.
FIG. 6 is a circuit diagram showing a state of charging the secondary battery body 10D in the power supply device of FIG. 2.
FIG. 7 is a circuit diagram showing a state in which the secondary battery bodies 10A and 10B are charged by the power supply device of FIG. 2.
FIG. 8 is a circuit diagram showing a state of charging the secondary battery bodies 10A and 10C in the power supply device of FIG. 2.
FIG. 9 is a circuit diagram showing a state of charging the secondary battery bodies 10A to 10D in the power supply device of FIG. 2.
10 is a circuit diagram showing a power supply device according to the first embodiment.
FIG. 11 is a circuit diagram illustrating a circuit example of the power supply device of FIG. 10.
12 is a circuit diagram showing a power supply device according to the second embodiment.
FIG. 13 is a circuit diagram illustrating a circuit example of the power supply device of FIG. 12.
Fig. 14 is a circuit diagram showing a power supply device according to the third embodiment.
FIG. 15 is a circuit diagram illustrating a circuit example of the power supply device of FIG. 14.
16 is a circuit diagram showing a power supply device according to a fourth embodiment.
17 is a circuit diagram illustrating a circuit example of the power supply device of FIG. 16.
18 is a circuit diagram showing a power supply device according to a fifth embodiment.
19 is a circuit diagram illustrating a circuit example of the power supply device of FIG. 18.
20 is a circuit diagram showing a power supply device according to a sixth embodiment.
21 is a circuit diagram illustrating a circuit example of the power supply device of FIG. 20.
Fig. 22 is a circuit diagram showing a power supply device according to the seventh embodiment.
FIG. 23 is a circuit diagram illustrating a circuit example of the power supply device of FIG. 22.
24A is a timing chart showing how one secondary battery body is charged, FIG. 24B is a current path when the charging switch is ON, and FIG. 24C is a charging switch. It is a circuit diagram which respectively shows the current path | route when 22 is OFF.
FIG. 25 is a timing chart of sequentially charging a plurality of secondary battery bodies, and FIG. 25B is a diagram illustrating a first secondary battery assembly when the charging switch is ON. When selected, Fig. 25 (d) shows a current path when the second secondary battery body 10B is selected, and Fig. 25 (e) shows a current path when the Nth secondary battery body is selected, respectively. It is a circuit diagram.
It is a circuit diagram which shows the charging state adjustment apparatus of the conventional assembled battery.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described based on drawing. However, embodiment shown below illustrates the power supply device and charging circuit for embodying the technical idea of this invention, and this invention does not identify a power supply device and a charging circuit as the following. On the other hand, the member shown in the claims is never specified by the member of the embodiment. In particular, the dimensions, materials, shapes, relative arrangements, etc., of the constituent members described in the embodiments are not intended to limit the scope of the present invention to only those examples, unless specifically stated otherwise. . In addition, the magnitude | size, positional relationship, etc. of the member which each figure shows may be exaggerated for clarity. In addition, in the following description, about the same name and code | symbol, the same or same member is shown, and detailed description is abbreviate | omitted suitably. Moreover, each element which comprises this invention may be made into the form which comprises several elements by the same member, and combines several elements by one member, and conversely implements the function of one member by multiple members, and implements it. have. In addition, the content described in some embodiments and examples may be used in other examples, embodiments, and the like.

1-10, the power supply apparatus 100 which concerns on one Embodiment is shown. 1 is a block diagram of the power supply device 100, FIG. 2 is a circuit diagram showing an example of the power supply device 100 of FIG. 1, and FIG. 4A is a circuit diagram showing a state of charging 10A), FIG. 4 is a circuit diagram showing a state of charging the secondary battery body 10B, FIG. 5 is a circuit diagram showing a state of charging the secondary battery body 10C, and FIG. 6 is a secondary battery body. A circuit diagram showing a state of charging 10D, FIG. 7 is a circuit diagram showing a state of charging secondary battery bodies 10A, 10B, and FIG. 8 is a circuit diagram showing a state of charging secondary battery bodies 10A, 10C. 9 is a circuit diagram showing the state of charging the secondary battery bodies 10A to 10D, FIG. 10 is a circuit diagram showing the power supply device 100 according to the first embodiment, and FIG. 11 is a circuit example of the power supply device 100 of FIG. The circuit diagram shown is shown, respectively. As shown in FIG. 1, the power supply device 100 is connected to a plurality of secondary battery bodies 10 of 10A to 10N and an external power source EP to supply electric power for charging the secondary battery assembly 10. Selection switch switching connected between the constant current source generation circuit 20, the constant current source generation circuit 20, and the secondary battery body 10, and capable of supplying different charging currents to the respective secondary battery bodies 10 individually. The circuit 30 is provided. This power supply is connected to the load LD and drives this. The external power source EP is a power source for supplying electric power for charging to a power supply device. For example, when the present invention is applied to a fast charging station of a hybrid car, the fast power station is used for driving a hybrid car. A rechargeable battery for charging the battery is applicable. In addition, it is also possible to rectify the commercial power source or use the commercial power source itself as the external power source EP. In the following examples, a DC voltage source is used as the external power source EP.

(Secondary battery body 10)

Each secondary battery body 10 includes a positive electrode and a negative electrode, and a plurality of secondary battery bodies 10 are connected in series. Each secondary battery body 10 can be configured not only by one battery cell but also by connecting a plurality of battery cells in series or in parallel. As the battery cell, rechargeable secondary batteries such as lithium ion secondary batteries, nickel hydride batteries, nickel cadmium batteries, and lead storage batteries can be used. In particular, lithium ion secondary batteries are preferable because they have a larger electric capacity per volume and excellent in miniaturization and high output than nickel hydrogen batteries. In addition, although the structure of connecting the secondary battery body 10 to four 10A-10D is shown in the example of FIGS. 2-11 for easy description, the connection number of a secondary battery body is not limited to this, Needless to say, more than five or less than three.

(Constant Current Source Generation Circuit 20)

The constant current source generation circuit 20 of FIG. 1 includes a supply output terminal OT and a supply input terminal IT, and charges each secondary battery body 10 with the selection switch switching circuit 30. For this reason, the constant current source generation circuit 20 includes a switching circuit for converting the voltage of the external power source EP into a current or voltage suitable for charging the secondary battery body 10. Here, a constant current is generated. For example, when charging a lithium ion secondary battery, it carries out constant current charging in the state in which the voltage of the secondary battery body 10 is lower than a 1st voltage, and when it exceeds a 1st voltage, it switches to constant voltage charging, and is higher than a 1st voltage. Constant voltage charging is performed until a 2nd voltage is reached, and when it reaches a 2nd voltage, it determines with full charge and complete | finishes charging. On the other hand, the charging control method is an example, and other existing charging methods can be appropriately used depending on the type of secondary battery body to be used. In addition, such charging control is performed by ON / OFF control of the charging switch 22 mentioned later.

(Selection switch switching circuit 30)

The selection switch switching circuit 30 is connected to each of the secondary battery bodies 10 and the selection switch 31 which can individually configure a charging path for charging the secondary battery bodies 10, and a plurality of selection switches. A control circuit 40 for controlling ON / OFF of the 31 is provided. Specifically, as shown in the circuit example of FIG. 2, the charge path for connecting the constant current source generation circuit 20 and each of the secondary battery bodies 10 individually is turned ON / OFF of the plurality of select switches 31. It consists of. More specifically, the selection switch switching circuit 30 includes a plurality of positive electrode side charging paths PC connected to the positive electrode of each secondary battery body 10 and the supply output terminal OT, respectively, and each secondary battery body ( 10. A plurality of selector switches 31 provided on the cathode side charge path NC and the anode side charge path PC and the cathode side charge path NC respectively connected to the cathode of the 10 and the supply input terminal IT, respectively. ) And a control circuit 40 for controlling ON / OFF of the plurality of selection switches 31. In this way, the plurality of secondary battery bodies 10 can be individually connected and charged by the selection switch 31 while using one constant current source generation circuit 20. In particular, by connecting each secondary battery to the constant current source generation circuit 20 individually, the amount of charge can be adjusted according to the remaining capacity of the secondary battery body 10, and thus the method of charging the entire secondary battery body connected in series. On the contrary, it is possible to reduce the gap of the charge amount between the secondary battery bodies, to avoid overcharging, and to obtain an advantage of using the secondary battery body with high safety for a long time. In addition, it is not limited to the structure which charges a secondary battery body one by one, It goes without saying that it is also possible to charge several secondary batteries simultaneously.

(Selection switch (31))

A semiconductor switching element can be used for the selection switch 31, and examples thereof include thyristors, GTO thyristors, IGBTs, bipolar transistors, and FETs. Suitably, thyristor is used. However, a self-protection element having a self-defense function, for example, a GTO thyristor, an IGBT, or the like can also be used. This is because the ON / OFF control of the selection switch 31 can be easily performed by the self-extinguishing function. On the other hand, in the example of FIGS. 2-10, the selection switch 31 is shown typically, For example, when a selection switch can energize bidirectionally, it charges a rectifying element, such as a diode which prevents electricity supply to a reverse direction. Needless to say, it can be added properly in the path. The rectifier element is inserted in series with respect to the charging path and can be provided at any position if it is in the charging path. Moreover, when using the semiconductor element which has a rectification characteristic like a thyristor as a selection switch, such a rectification element can be made unnecessary.

(Thyristor (32))

Here, an example of a circuit using the thyristor 32 as the selection switch 31 in the power supply device 100 of FIG. 10 is shown in FIG. 11. In Fig. 11, the thyristors 32A to 32H correspond to the selection switches 31A to 31H, respectively. In order to turn on each thyristor 32, the ON signal is input from the control circuit 40 to the gate terminal of the thyristor 32. On the other hand, in order to turn off the thyristor 32, the charging switch 22 mentioned later is turned off, the output of a chopper circuit is stopped, and the amount of electric current which energizes the thyristor 32 is zero. The thyristor 32 can be turned off and the charging to the secondary battery body 10 can be stopped according to this arc extinguishing operation. In addition, the thyristor 32 has excellent reverse breakdown voltage characteristics, and it is also easy to drive ON and obtains advantages of simplifying the driving circuit.

When the IGBT is used for the selection switch 31, the ON / OFF switching control can be easily performed by the signal from the control circuit 40 by the self-armoring function. That is, the extinguishing operation which stops electric current once, such as the thyristor mentioned above, can be made unnecessary. On the other hand, since it is inferior in reverse breakdown characteristic compared with a thyristor etc., it is preferable to connect the reverse blocking diode for protection in series.

(Control circuit 40)

The control circuit 40 controls ON / OFF of each selection switch 31 as shown in FIG. This control circuit is composed of an ASIC or the like. In this example, the charging path for the arbitrary secondary battery body 10 is configured by switching the selection switch 31, and the charging path for the other secondary battery is released. For example, in the example of FIG. 3, only the selection switches 31A and 31C are turned ON and the other selection switches 31 are turned OFF, so that only the secondary battery body 10A is connected to the constant current source generation circuit 20. The other secondary battery body 10 is removed from the constant current source generator circuit 20, and the secondary battery body 10 can be charged according to the characteristics of the secondary battery body 10A. When charging of the secondary battery body 10A is finished, the secondary switches are turned off by turning the selection switches 31A and 31C off and turning the selection switches 31B and 31E on, as shown in FIG. 4. Only the retardation 10B is connected to the constant current source generating circuit 20, and the other secondary battery body 10 is removed from the constant current source generating circuit 20, so that charging according to the characteristics of the secondary battery body 10B is possible. do. Similarly, when the charging of the secondary battery body 10B ends, as shown in FIG. 5, the selection switches 31B and 31E are turned off, and the selection switches 31D and 31G are turned on, and the secondary electric charge is turned on. The charging of the delay 10C is started. Furthermore, when the charging of the secondary battery body 10C ends, as shown in FIG. 6, the selection switches 31D and 31G are turned OFF, the selection switches 31F and 31H are turned ON, and the secondary battery body is turned on. The charging of 10D is started. In this way, all the secondary battery bodies 10 can be charged by sequentially turning ON / OFF the selection switch 31.

In this manner, while using one constant current source generation circuit 20, the selective switch switching circuit 30 enables appropriate charging of any secondary battery body. Furthermore, in this method, since only the secondary battery body to be charged is connected to the constant current source generator, it is appropriate to be charged according to the electrical characteristics of each secondary battery body to be charged, etc., as compared with the case where the secondary battery bodies to be charged are connected in parallel. It is possible to obtain the advantage of performing these separately. In particular, when the remaining capacity of each secondary battery is different, when charging with the same current at the same time, the specific secondary battery body with a large remaining capacity is rapidly charged, and if the charge is continued until the charging of all secondary battery bodies is finished, First, the secondary battery body which is fully charged may overcharge and deteriorate. On the contrary, when charging is completed in combination with a secondary battery body having a small residual capacity, a secondary battery body which is not fully charged this time occurs, and there arises a problem that the available electric capacity becomes small. However, if a dedicated charging circuit is separately provided for each secondary battery body, the circuit configuration becomes complicated and the cost also increases. Therefore, in the present invention, a single constant current source generating circuit is used, and the selective switch switching circuit enables individual connection with each secondary battery body, thereby generating a common constant current source without providing a separate charging circuit. The circuit allows individual charging.

This method is particularly suitable for charging nickel-metal hydride batteries or nickel-cadmium batteries with negative characteristics. That is, since nickel hydrogen batteries and the like have a characteristic that the voltage decreases when they are fully charged, when the nickel hydrogen batteries and the like are attempted to be charged while being connected in parallel, the voltages of the respective nickel hydrogen batteries and the like gradually increase, and the batteries are charged first. Since the voltage of a nickel hydride battery or the like decreases once, a large amount of current is supplied to the battery, which causes a decrease in the voltage and makes it difficult to supply appropriate charging power. On the other hand, according to the above-described method according to the present embodiment, since individual charging for each secondary battery body can be performed, an excellent advantage of eliminating such a problem caused by uniform charging can be obtained. .

In addition to charging the secondary battery body individually by connecting it to an external power source, the charging device can also charge a plurality of secondary battery bodies by connecting them to an external power source at the same time. For example, in the example shown in FIG. 7, the selection switches 31A and E are turned on and the other selection switches 31 are turned off in order to simultaneously charge the secondary battery bodies 10A and 10B. Thereby, the adjacent secondary battery body 10 can be charged simultaneously.

Moreover, it is not limited to the adjacent secondary battery bodies, It can also charge the separated secondary battery bodies simultaneously. For example, in the example shown in FIG. 8, the selection switches 31A, 31C, 31D, and 31G are turned ON, and the other selection switches 31 are turned OFF to charge the secondary battery bodies 10A and 10C at the same time. have. In addition, as shown in FIG. 9, the selection switches 31A and 31H are turned on and the other selection switches 31 are turned off to charge both of the secondary battery bodies 10A, 10B, 10C, and 10D simultaneously. have. As described above, by charging a plurality of secondary battery bodies at the same time, charging of the secondary battery bodies can be promoted efficiently. On the other hand, in this circuit example, since the power supplied from the external power supply side is constant, it is not theoretically connected to shortening of the time required for charging.

(Equalization regenerative motion)

In the above charging operation, by charging the respective secondary battery bodies under appropriate conditions, it is possible to realize equalization charging to reduce the difference in capacitance between the secondary batteries obtained as a result. On the other hand, when charging a plurality of secondary battery bodies at the same time, the difference in capacitance between secondary battery bodies can be suppressed more directly. That is, in a state where a plurality of secondary battery bodies having different capacitances are connected to the constant current source generation circuit, the amount of current flowing into the secondary battery body having a high battery voltage is reduced, and the amount of current flowing into the secondary battery body having a low battery voltage is as much as that. As a result, the secondary battery body with a low battery voltage is consequently charged a lot and depends on the direction in which the difference in capacitance decreases.

When the power supply side supplying the power for charging is capable of regenerative operation, the secondary battery body having a large capacitance is discharged and regenerated to the constant current source generation circuit side, and as a result, this discharge energy is charged to the charging of another secondary battery body. It can also be turned, and this can further reduce the difference in capacitance. This regeneration operation is also referred to as equalization regeneration in this specification. For example, when a power supply for regenerative operation such as a hybrid car or a plug-in hybrid car is used, equalization between secondary battery bodies can be achieved according to this regenerative operation, which is particularly advantageous. It goes without saying that the regenerative operation can be realized both in the case where the secondary battery body is connected to the constant current source generation circuit alone, and in the case where the plurality of secondary battery bodies are connected to the constant current source generation circuit.

In this way, by suppressing the gap in the capacitance between the secondary battery bodies at the stage of charging, all secondary battery bodies can be appropriately charged up to the possible capacitance, and also avoiding the situation where some secondary battery bodies are overcharged. The secondary battery body can be protected and used stably for a long time with high reliability. According to this configuration, since charging and capacity gap adjustment can be realized in the same circuit, the processing can be simplified along with the circuit configuration.

(Chopper circuit)

Furthermore, the detailed circuit example of a charging circuit is shown in FIG. 10 as Example 1. FIG. The constant current source generation circuit 20 shown in this figure includes a chopper circuit composed of a reactor L and a charge switch 22 connected in series with the reactor L. FIG. The charging switch 22 is connected in series with the external power supply EP and the reactor L, and the external power supply EP, the reactor L, and the charging device are turned on by turning on the charging switch 22. The closed circuit which connected the switch 22 is comprised. In addition, a semiconductor switching element is used for the charging switch 22. In the specific example shown in FIG. 11 mentioned later, IGBT is used as a semiconductor switching element. The IGBT can control the current of the reactor L so that the reactor L can accumulate power energy in the direction in which the reactor L can supply power to the secondary battery body 10 (the right direction in FIG. 10).

In addition, the reactor L is connected between the supply output terminal OT and the supply input terminal IT, and is supplied from the external power source EP by ON / OFF of the charging switch 22 connected in series. A chopping operation of the power to be realized is realized. That is, when the charging switch 22 is turned ON, the electric power from the external power source EP is supplied only to the reactor L. When the charging switch 22 is switched from ON to OFF in this state, the reactor L is turned on. Power energy accumulated in the battery is released, flows into the secondary battery body 10 through the charging path, and charging is performed. By repeating such ON / OFF operation of the charging switch 22, an intermittent charging current is supplied to the secondary battery body 10, and pulse charging is realized. The on / off of the charging switch 22 is performed by the control circuit 40.

In this example, the constant current source generation circuit 20 is constituted by a boost chopper circuit. The boost chopper circuit may charge the secondary battery body 10 at a high voltage by using an external power source EP having a low voltage according to the boost chopper operation. However, it is not limited to this structure, For example, a step-up chopper circuit can also be used. When the constant current source generation circuit 20 functions as a boost chopper, the battery voltage (for example, 24 V) of the secondary battery body 10 selected as the load, that is, the charging target, is greater than the external power source EP (for example, 20 V). This high condition becomes a condition. In the example of Fig. 10, since the constant current source generation circuit 20 functions as a step-up and chopper, there is no restriction on such a voltage value and it can be used more flexibly. In addition, in the circuit example of FIG. 10, the example of a circuit which used the thyristor 32 for the selection switch 31 is shown in FIG. According to this structure, the thyristor used as the selection switch 31 can be turned off by using the OFF period of the boost chopper used as the constant current source generation circuit 20, so that the arc current of the thyristor having no self-extinguishing capability can be specified. It can be realized without a circuit, and charging control using a thyristor can be realized extremely suitably.

In the example of FIG. 2, FIG. 10, etc., in one control circuit 40, the control of the constant current source generation circuit 20 and the selection switch switching circuit 30 are performed. However, the present invention is not limited to this configuration. For example, the control circuit for the constant current source generator circuit for controlling the constant current source generator circuit 20 and the control circuit for the selection switch circuit for controlling the selection switch switching circuit 30 are provided. It goes without saying that it is possible to arrange them individually.

Example 2 Equalization Filling and Equalization Regeneration

Moreover, although the circuit example which performs equalization charging mainly was shown in FIG. 10 etc., the equalization regeneration which further advanced equalization according to the regenerative operation as mentioned above can also be implement | achieved. The circuit example of the power supply device which can realize such equalization charge and equalization regeneration is shown in FIG. 12 as a second embodiment. In addition, in the following example, only three (10A-10C) of the secondary battery bodies 10 are shown for simplicity, and the illustration of another secondary battery body is abbreviate | omitted, but the number of connection of a secondary battery body can be set arbitrarily. It is as having mentioned above. In addition, the power supply device 200 shown in this drawing connects a power supply capable of regenerative operation (for example, a lithium ion battery installed in a quick charging station) as an external power supply EP.

(Regeneration switch 24)

In addition to the charging switch 22 of FIG. 10, the constant current source generation circuit 20 of FIG. 12 connects the regenerative switch 24 to the reactor L. FIG. The regenerative switch 24 may also use a semiconductor switching element such as an IGBT, similarly to the charging switch 22. The regenerative switch 24 is connected to the charging switch 22 in the reverse direction, so that the current flows through the reactor L in the direction of discharge from the secondary battery body 10 side (left direction in FIG. 12). The direction of energization of (24) is specified. For this reason, a regenerative function is provided to the regenerative switch 24 or a rectifier element such as a diode is connected to the regenerative discharge path in series with the regenerative switch 24. In the circuit example of FIG. 12, a circuit example using the thyristor 32 as the selector switch 31 and the IGBT as the charge switch 22 and the regenerative switch 24 is shown in FIG. 13. Thus, when a rectifying element is used for the charging switch 22 and the regenerative switch 24, a rectifying element can be made unnecessary. Moreover, diodes are connected in anti-parallel between the emitter collectors of each IGBT. Such a diode is a path for charging the energy accumulated in the reactor L with the secondary battery body 10 or regenerating it with an external power source EP, and has a function of protecting the IGBT having poor reverse breakdown voltage characteristics. In the charging operation of the power supply device 200 shown in this drawing, the relationship between the external power supply voltage E _EP of the external power supply _EP and the battery voltage E ₁₀ of the secondary battery body 10 is the secondary battery body. When E10 and the constant current source generation circuit 20 are individually connected, E _EP <E ₁₀ . On the other hand, in the regenerative operation, when the number of series connections of the secondary battery body 10 is n and the voltage difference between each secondary battery body is ignored, E _EP > E ₁₀ * n. In this way, the charging operation can be performed at an external power supply voltage lower than each battery voltage, and the external power supply voltage is higher than the total voltage of the battery voltage body connected in series even when the power is taken out externally in accordance with the regenerative operation. On the contrary, the regenerative operation can be performed even at a low battery voltage, and effective charge and discharge using the secondary battery body is realized.

(Example 3)

Moreover, as shown in the connection example of FIG. 12, the regenerative switch 24 is not limited to the structure connected to both ends of the reactor L, for example, as shown in FIG. 14 concerning Example 3, Similarly, it goes without saying that it is possible to connect so as to branch at one end of the reactor L. Moreover, in the circuit example of the power supply device 300 of FIG. 14, the circuit example which used the thyristor 32 for the selection switch 31, and used IGBT for the switch 22 for charge and the regeneration switch 24 is FIG. Shown in

In addition, although not shown, the regenerative switch 24 shown in this figure is also connected to the control circuit 40, and ON / OFF is controlled by the control circuit 40. FIG. In the power supply apparatuses 200 and 300 shown in FIG. 12 and FIG. 14, when the secondary battery body 10 is charged through the charging switch 22, the control circuit 40 is turned off so that the regenerative switch 24 is turned off. It is set by. On the other hand, in the regenerative operation of discharging surplus power of the secondary battery body 10 to the external power source EP side, on the contrary, the control circuit is switched so that the discharge switch is turned OFF and the regenerative switch 24 is turned ON. 40). As a result, the secondary battery body can be discharged to reduce the electric capacity, the discharge energy can be supplied to an external power source for reuse, and the energy can be efficiently used. In particular, it becomes extremely effective for the use which requires high energy efficiency, such as an electric vehicle and a hybrid vehicle.

(Example 4)

In contrast, when the regenerative operation is not performed, the circuit configuration shown in Fig. 16 can be adopted as the fourth embodiment. In addition to the charging switch 22 of FIG. 10, the power supply device 400 shown in this example includes a diode for charging between one end (right side in the drawing) of the reactor L and the supply output terminal OT. 23). In order to prevent current from flowing from the secondary battery body 10 side to the external power source EP side, the charging diode 23 is prohibited from regenerative operation in this circuit, and only equalization charging is performed. In the circuit example of FIG. 16, the example which used the thyristor 32 for the selection switch 31, and used IGBT for the switch 22 for charge is shown in FIG.

(Example 5)

Moreover, it is not limited to the circuit example of FIG. 16. As Example 5, the structure similar to FIG. 18 can also be employ | adopted. In the example of the power supply device 500 shown in FIG. 18, the charging diode 23 connected to the end of the reactor L is connected to the other end instead of the same side as the charging switch 22. Also in this configuration, similarly, the charging diode 23 can prohibit the inflow of current from the secondary battery body 10 side to the external power source EP side. In the example of the circuit of FIG. 18, the example which used the thyristor 32 for the selection switch 31, and used IGBT for the switch 22 for charge is shown in FIG.

(Example 6)

On the other hand, a circuit example for performing only the equalization regenerative operation is shown in FIG. 20 as the sixth embodiment. In the power supply device 600 shown in this circuit example, the regenerative switch 24 and the regenerative diode 25 are connected to one end of the reactor L instead of providing a charging switch. In the circuit example of FIG. 20, the circuit example which used the thyristor 32 for the selection switch 31, and IGBT for the regenerative switch 24 is shown in FIG.

(Example 7)

As a seventh embodiment, a circuit example of another power supply device 700 is shown in FIG. In the seventh embodiment, as shown in FIG. 22, the connecting position of the regenerative switch 24 is connected to the other end side of the reactor L rather than the same side as the regenerative diode 25. have. Also in this configuration, the regenerative diode 25 prohibits the charging operation while the regenerative switch 24 allows the regenerative operation from the secondary battery body 10 side to the external power source EP side. In addition, in the circuit example of FIG. 22, the circuit example which used the thyristor 32 for the selection switch 31, and IGBT for the regenerative switch 24 is shown in FIG.

(Voltage detection means 26)

In addition, voltage detection means 26 for detecting the voltage across the reactor is provided at both ends of the reactor L. This voltage detection means 26 can be comprised by a differential amplifier, a resistor, etc., for example. The voltage detecting means 26 detects the voltage across the reactor in a state where the constant current source generating circuit 20 is connected to an arbitrary secondary battery body 10 by the selection switch switching circuit 30. The voltage of (10) can be detected. For example, in the circuit example of FIG. 10, only the selection switch 31A and the selection switch 31C are turned on by the control of the control circuit 40, and the other selection switch 31 is turned off. When the secondary battery body 10A is charged in this state, the voltage appearing at the voltage across the reactor becomes the same as the battery voltage of the secondary battery body 10, so that the voltage detecting means 26 The battery voltage can be detected. In addition, when the charging path is switched by the control circuit 40, the battery voltage of each secondary battery body 10 can be detected sequentially. In this way, the voltage detecting means 26 scans each of the secondary battery bodies 10 by the control circuit 40, that is, by time division, it is possible to measure the battery voltages of all the secondary battery bodies 10. That is, the battery voltages of the plurality of secondary battery bodies 10 can be detected by one voltage detecting means 26, and the switching of the secondary battery bodies 10 is performed by the selection switch 31 for charging described above. Since the number of additional parts is largely unnecessary, the circuit configuration for detecting the battery voltages of all the secondary battery bodies 10 can be extremely simplified.

On the other hand, detection of the battery voltage of each secondary battery body 10 is preferably performed before the start of charging. In particular, since the SOC can be calculated based on the battery voltage of the secondary battery body 10, the remaining capacity of each secondary battery body 10 can be grasped in advance and then adjusted to an appropriate charging current. In addition, during charging, the state of charging can be monitored while detecting the battery voltage of the secondary battery body 10 with the voltage detecting means 26 at a suitable timing, for example, a fixed period.

As described above, the battery voltage of the secondary battery body 10 is detected at a predetermined timing, such as before the start of charging or during a predetermined period during charging. When the battery voltage of the secondary battery body 10 reaches a constant voltage, the control circuit 40 turns off the selection switch 31 and ends the charging of this secondary battery.

(Timing chart)

Next, the timing chart which shows the operation | movement of the power supply apparatus which concerns on Example 1 is shown in FIG. Here, the selection circuits and the current paths of the thyristors 32A to 32N when the charging switch 22 is ON and OFF are shown. In addition, the power supply device connects the sample hold circuit SH to the voltage detecting means 26 as an example. 24A to 24C show a state in which the secondary battery body 10A is charged, and FIG. 24A is a timing chart showing waveforms of respective parts. b) shows the current path when the switch 22 for charging is ON, and FIG. 24 (c) shows the current path when the switch 22 for charging is OFF. In Fig. 24A, as shown by (b) in the item of the rectangular wave of the voltage waveform e _x of the inductance L, the current to the inductance L when the charging switch 22 is ON. (I _L ) increases and the current I _32A does not flow to the thyristor 32A, so it is turned off. On the other hand, when the switch 22 for charging is OFF as shown by (c) in the item of e _x of FIG. 24 (a), the thyristor 32A is turned on in accordance with the gate signal, and the current I _32A flows. The current I _L to the inductance L is reduced. On the other hand, in FIG.24 (b)-FIG.24 (c), the ON state of the thyristor 32 is shown in black, and the OFF state is shown in white, respectively. Each time the charging switch 22 is turned on, the thyristor 32A can be turned off. The current I _32A of the thyristor 32A is a pulse waveform shown in Fig. 24A. The voltage e _x at both ends of the inductance L is equal to the voltage E _P of the external power supply EP and the voltage E 10 A of the secondary battery body 10A, as _{shown in} FIG. A rectangular wave shape is applied alternately. In addition, the voltage E _10A of the secondary battery body 10A can be detected by the sample hold operation with respect to the voltage detecting means 26.

25A to 25E show charging of the secondary battery bodies 10A to 10N. In this figure, Fig. 25 (a) shows a timing chart showing the waveform of each part. Fig. 25 (b) shows that the charging switch 22 is turned off when the charging switch 22 is on. 25 (d) shows that the charging switch 22 is OFF and the secondary battery body 10B is selected, and FIG. 25 (e) shows the charging switch (10A) when the secondary battery body 10A is selected. The current paths when 22) is OFF and the secondary battery body 10N is selected are shown, respectively.

In FIG. 25A, a period during which the secondary battery body 10A is charged is represented by (b) / (c), and the operation of FIG. 24 described above is performed. In this period, first, as shown in Fig. 25B, when the charging switch 22 is ON, the current I _L to the inductance L increases, and no current flows to the thyristors 32A to 32N. It is turned off. As shown in Fig. 25C, when the charging switch 22 is OFF and the secondary battery body 10A is selected, the thyristor 32A is turned on in response to the gate signal so that the current I _32A flows. , The current I _L to the inductance L decreases. During this period, since the operation of Figs. 25 (b) and 25 (c) is repeated, the voltage e _x at both ends of the inductance L is equal to the voltage E _P of the external power source EP. square wave is applied to the voltage (E _10A) of the secondary battery are alternately member (10A).

Moreover, the period during which the secondary battery body 10B is charged is shown by (b) / (d) in FIG. 25 (a). In this (b) / (d) period, inductance L when the switch 22 for charging is ON as shown in FIG. 25 (b), similarly to the above-mentioned (b) / (c) period. The current I _{L to} ) increases, and the current does not flow to the thyristors 32A to 32N and is turned OFF. In FIG. 25 (d), when the charging switch 22 is OFF and the secondary battery body 10B is selected, the thyristor 32B is turned on in accordance with the gate signal so that the current I _32B flows. The current I _L to the inductance L decreases. In this period (b) / (d), the voltage e _x at both ends of the inductance L is equal to the voltage E _P of the external power supply EP and the voltage E 10B of the secondary battery body _10B . A rectangular wave is applied alternately.

In addition, the period during which the secondary battery body 10N is charged is shown as (b) / (e) in FIG. Also in this (b) / (e) period, the charging switch 22 is shown in FIG. 25 (b) similarly to the above-mentioned (b) / (c) period or (b) / (d) period. Is turned ON, the current I _L to the inductance L increases, and no current flows to the thyristors 32A to 32N. In FIG. 25E, when the charging switch 22 is OFF and the secondary battery body 10N is selected, the thyristor 32N is turned on in response to a gate signal, and a current I _32N flows. The current I _L to the inductance L decreases. A (b) / (e) the voltage (e _x) at both ends of the inductance (L) of the period, the voltage of the external power supply (EP) (E _P) and voltage (E _10N) are applied alternately.

Also in the example of FIG. 25, according to the sample hold operation of the sample hold circuit SH, the outputs E _B of the sample hold circuit SH are supplied with voltages E _{10A to} E _10N of the selected secondary battery bodies. Can be detected. On the other hand, the voltage detection means is not limited to the sample hold circuit, and other configurations can be suitably used.

As described above, according to the present invention, since it is possible to control equalization and charging of each secondary battery body with an extremely simple circuit configuration, it is possible to construct a DC voltage source such as an electric vehicle or an uninterruptible power supply requiring a high voltage. In this way, the system configuration can be extremely simplified, and since overcharge and discharge are not caused, the lifespan and safety of the secondary battery body can be increased, and the cost can be achieved.

[Industrial Availability]

The power supply device and the charging circuit according to the present invention can be suitably used for driving power sources for hybrid vehicles, plug-in hybrid vehicles, electric vehicles and the like. Moreover, it is not limited to a vehicle power supply, but can also be used for other power supply apparatuses, such as a large capacity battery bank used for an assist bicycle, an electric tool, an uninterruptible power supply (UPS), a power supply for driving in a factory, etc.

100, 200, 300, 400, 500, 600, 700: power supply
10, 10A, 10B, 10C, 10D, 10N: secondary battery body
20: constant current source generation circuit
22: charging switch
23: charging diode
24: regenerative switch
25: regenerative diode
26: voltage detection means
30: selection switch switching circuit
31, 31A to 31H: Selection switch
32, 32A to 32H: Thyristor
40: control circuit
90: charge state adjusting device
91: unit cell
92: equal charging capacitor
93: cyclic connection means
EP: External Power
OT: Supply output terminal
IT: Supply input terminal
LD: Load
PC: anode side charge path
NC: negative side charge path
L: Reactor

Claims (9)

A plurality of secondary battery bodies 10 each having a positive electrode and a negative electrode and connected in series with each other;
A constant current source generation circuit 20 having a supply output terminal OT and a supply input terminal IT for supplying electric power for charging the secondary battery body 10;
In the constant current source generation circuit 20 is provided with a selection switch switching circuit 30 capable of supplying different charging currents individually to each of the secondary battery bodies 10,
The selection switch switching circuit 30 is connected to each of the secondary battery bodies 10 and the selection switch 31 which can individually configure a charging path for charging the secondary battery bodies 10,
It has a control circuit 40 for controlling the ON / OFF of the plurality of selection switches 31,
By controlling the ON / OFF of the selection switch 31, the control circuit 40 forms a charging path for an arbitrary secondary battery body 10 and releases the charging path for another secondary battery. To do that,
The constant current source generation circuit 20,
A reactor L connected between the supply output terminal OT and the supply input terminal IT;
And a chopper circuit connected in series with the reactor L and composed of a charge switch 22 for controlling ON / OFF in the control circuit 40,
And the chopper circuit connected to an external power source (EP) to charge the secondary battery body (10). A plurality of secondary battery bodies 10 each having a positive electrode and a negative electrode and connected in series with each other;
A constant current source generation circuit 20 having a supply output terminal OT and a supply input terminal IT for supplying electric power for charging the secondary battery body 10;
In order to charge each secondary battery body 10 in the constant current source generation circuit 20,
A plurality of positive electrode side charge paths (PC) connecting the positive electrode of each secondary battery body 10 and the supply output terminal OT, respectively;
A plurality of negative electrode side charging paths NC connected to the negative electrode of each secondary battery body 10 and the supply input terminal IT, respectively;
A plurality of selection switches 31 provided in the anode side charging path PC and the cathode side charging path NC, respectively;
And a control circuit (40) for controlling ON / OFF of the plurality of selection switches (31). The power supply device according to claim 1 or 2, furthermore,
And a voltage detecting means 26 for detecting a voltage at both ends of the reactor L,
The control circuit 40 connects the optional secondary battery body 10 to the positive side charge path PC and the negative side charge path NC connecting the secondary battery body 10 and the reactor L. By switching each of the arranged select switches 31 to ON and switching the other select switches 31 to OFF, only the secondary battery body 10 is connected to the reactor L, thereby A power supply device comprising the battery voltage of the secondary battery body (10) configured to be detectable by the voltage detecting means (26). A power supply device according to any one of claims 1 to 3,
And the control circuit (40) measures the battery voltage of each secondary battery body (10) by time division. The power supply device according to any one of claims 1 to 4,
And the control circuit (40) is configured to enable ON / OFF control of the selection switch (31) so as to simultaneously charge any of a plurality of secondary battery bodies (10). The power supply device according to any one of claims 1 to 5,
The power supply device characterized in that the selection switch (31) is an element having no self-protection capability. The power supply device according to any one of claims 1 to 6,
Power supply, characterized in that the selection switch (31) is a thyristor (32). A power supply device according to any one of claims 1 to 7,
The secondary battery body (10) is configured by connecting a plurality of battery cells in series or in parallel. As a charging circuit which has a positive electrode and a negative electrode, respectively, and can charge the some secondary battery body 10 connected in series,
A constant current source generating circuit 20 having a supply output terminal OT and a supply input terminal IT for supplying electric power for charging the secondary battery body 10,
In order to charge each secondary battery body 10 in the constant current source generation circuit 20,
A plurality of positive electrode side charge paths PCs each capable of connecting the positive electrode of each secondary battery body 10 and the supply output terminal OT, respectively;
A plurality of negative electrode side charge paths (NC) to which the negative electrode of each secondary battery body 10 and the supply input terminal IT are respectively connected;
A plurality of thyristors 32 respectively provided in the anode side charging path PC and the cathode side charging path NC;
A control circuit 40 capable of individually controlling ON control of the plurality of thyristors 32,
The constant current source generation circuit 20,
A reactor L connected between the supply output terminal OT and the supply input terminal IT;
And a chopper circuit connected in series with the reactor L and composed of a charge switch 22 for controlling ON / OFF in the control circuit 40,
And a chopper circuit connected to an external power source (EP) to charge the secondary battery body (10).

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