JP5794982B2 - Power supply device and charging circuit - Google Patents

Description

  The present invention relates to a power supply device and a charging circuit including a charging circuit that charges a chargeable / dischargeable secondary battery.

  For example, in an electric vehicle that runs using an electric motor or a hybrid electric vehicle that runs using an engine and an electric motor together, secondary batteries such as nickel-hydrogen batteries, lithium-ion batteries, and lead-acid batteries are used as unit cells. A battery pack in which a plurality of batteries are connected in series is used as a power source for the electric motor. In such an assembled battery, the terminal voltage based on the state of charge (SOC; also referred to as remaining capacity) of each unit cell varies as charging and discharging are repeated, and charging is performed with this being left as it is. If done, some unit cells may be overcharged. Further, the deterioration of the unit cell proceeds at an accelerated rate, and if it deteriorates, even if only a part of the unit cells is used, the entire assembled battery becomes unusable.

  For such a problem, an assembled battery charge state adjusting device as shown in Patent Document 1 has been proposed as a method of adjusting the variation in the charged state among a plurality of unit cells constituting a charged assembled battery. Yes. As shown in FIG. 26, the charging state adjusting device 90 is configured by connecting a plurality of unit cells 91 each including a secondary battery in series, and charging / discharging in a closed circuit state in which a load and a charger are connected to both ends. Adjust the state of charge of the assembled battery. In addition, the charge state adjusting device 90 cyclically connects each unit cell 91 to the equal charge capacitor 92 in an open circuit state of the assembled battery, and the equal charge capacitor 92 provided insulated from the load and the charger. And cyclic connection means 93. As a result, even if a plurality of unit cells 91 that are connected in series and constitute a battery pack have a variation in charge state, the unit cell 91 having a high cell voltage is connected to the cell voltage via the equal charging capacitor 92. By moving charges to the low unit cell 91, the voltage difference can be reduced.

JP 2002-17048 A

  However, the charge state adjustment device 90 of FIG. 26 only adjusts the variation of the charged unit cells 91, and once the unit cells 91 are charged, the variation is suppressed using the charge state adjustment device 90. Because of the configuration, the charging process and the adjustment process are required separately, which takes time, and the circuits for performing the charging and adjustment are also individually required, which causes a problem that the circuit configuration becomes complicated. .

  In addition, since the charge state adjusting device 90 can only adjust the charge state while sequentially switching the unit cells 91 in a cyclic manner, there is a drawback in that it takes time until the entire charging of the assembled battery is completed and the efficiency is deteriorated. . In particular, recently assembled batteries often use a large number of unit cells 91 in response to a demand for large capacity, and in such cyclic switching charging, charging is performed in proportion to the number of secondary batteries used. In addition to the long time, the switching operation of the unit cell 91 becomes complicated, which is not practical. Further, in the circuit example of FIG. 26, since a photo MOS transistor is used as the switching element, there is a problem that the drive circuit becomes complicated and the circuit cost increases. In particular, in order to perform equal charge control of each unit cell 91, it is necessary to configure a charging path that can charge each unit cell 91 individually. However, if a transistor is used to construct such a circuit, the circuit configuration becomes complicated. The problem arises.

  In addition, in this circuit, the charge is temporarily accumulated through the equal charge capacitor 92 and then the accumulated charge is transferred to the unit cell 91 having a low terminal voltage. Therefore, a large capacity equal charge capacitor 92 is essential. In addition, this equal charging capacitor 92 is a terminal voltage that is very close to and does not exceed the open circuit terminal voltage in the fully charged state of each unit cell 91 before the start of charging. There is a problem that it is necessary to be charged in advance by an alternator or the like, preparation for such charging is essential, and the configuration is further complicated.

  The present invention has been made in view of such conventional problems. A main object of the present invention is to provide a power supply device and a charging circuit capable of optimal charging by preventing overcharging of a secondary battery at a lower cost.

Means for Solving the Problems and Effects of the Invention

In order to achieve the above object , according to the power supply device of the first aspect of the present invention, a plurality of secondary battery bodies 10 each having a positive electrode and a negative electrode and connected in series with each other, and the secondary battery body A constant current source generation circuit 20 having a supply output terminal OT for supplying power for charging 10 and a supply input terminal IT, and the constant current source generation circuit 20 is individually different for each secondary battery body 10. And a selection switch switching circuit 30 capable of supplying a charging current. The selection switch switching circuit 30 is connected to each secondary battery body 10 to charge the secondary battery body 10. A selection switch 31 that can individually configure a charging path; and a control circuit 40 that controls ON / OFF of the plurality of selection switches 31. The control circuit 40 turns ON / OFF the selection switch 31. To control Thus, while constituting a charging path for an arbitrary secondary battery body 10 and releasing a charging path for another secondary battery, the constant current source generation circuit 20 includes the supply output terminal OT and the supply input terminal. A chopper circuit comprising: a reactor L connected between IT; and a charging switch 22 connected in series with the reactor L and controlled to be turned ON / OFF by the control circuit 40; A chopper circuit is connected to an external power supply EP so as to charge the secondary battery body 10, and the power supply device includes voltage detection means 26 for detecting the voltage across the reactor L, and the control circuit 40, each selection switch 3 arranged in the positive-side charging path PC and the negative-side charging path NC connecting the arbitrary secondary battery body 10 to the secondary battery body 10 and the reactor L. Are switched on and the other selection switch 31 is switched off, so that only the secondary battery body 10 is connected to the reactor L, whereby the battery voltage of the secondary battery body 10 is connected to the voltage detection means. 26 can be configured to be detectable. Thereby, the battery voltage of arbitrary secondary battery bodies can be detected with one voltage detection means. That is, since the battery voltage of each secondary battery body can be detected by only one voltage detection means, there is no need to provide a voltage sensor for each secondary battery body, and the circuit can be greatly simplified. can get.

Also, according to the power supply device according to the second aspect, the control circuit 40, in time division to measure the battery voltage of each secondary battery 10. Thereby, the battery voltage of all the secondary battery bodies can be sequentially detected by one voltage detection means.

Furthermore , according to the power supply device which concerns on a 3rd side surface, the said control circuit 40 can be comprised so that ON / OFF control of the said selection switch 31 is possible so that the arbitrary some secondary battery body 10 may be charged simultaneously. As a result, a plurality of secondary battery bodies can be controlled to be charged at the same time, and charging can proceed efficiently.

Furthermore, according to the power supply device according to the fourth aspect, the selection switch 31 can be an element having no self-extinguishing capability. Thus, the selection switch can be extinguished using the OFF period of the chopper circuit, and a special additional circuit for extinguishing the arc can be eliminated.

Furthermore, according to the power supply device according to the fifth aspect, the selection switch 31 can be constituted by the thyristor 32. As a result, it is possible to obtain an advantage that the secondary battery bodies connected in series can be individually charged without providing a charging circuit for each secondary battery body by using a thyristor having excellent reliability, particularly reverse breakdown voltage characteristics. .

Furthermore, according to the power supply device according to the sixth 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 equally even if the secondary battery body comprised by the some battery cell was connected in series.

Furthermore, according to the charging circuit according to the seventh aspect, the charging circuit is capable of charging a plurality of secondary battery bodies 10 each having a positive electrode and a negative electrode and connected in series to 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, and each secondary battery body 10 is charged by the constant current source generation circuit 20. A plurality of positive-side charging paths PC that can connect the positive electrode of the battery body 10 and the supply output terminal OT, respectively, and a plurality of negative-electrode sides that can connect the negative electrode of each secondary battery body 10 and the supply input terminal IT, respectively. A charging path NC; a plurality of thyristors 32 respectively provided in the positive side charging path PC and the negative side charging path NC; and a control circuit 40 capable of individually controlling ON control of the plurality of thyristors 32. The constant current source The circuit 20 includes a reactor L connected between the supply output terminal OT and the supply input terminal IT, a charging switch 22 connected in series with the reactor L, and ON / OFF controlled by the control circuit 40. The chopper circuit is configured to charge the secondary battery body 10 by connecting the chopper circuit to an external power source EP, and the charging circuit further includes a voltage across the reactor L. Voltage detecting means 26 for detecting the secondary battery body 10, and the control circuit 40 connects the secondary battery body 10 and the reactor L to the positive side charging path PC and the negative side charging path. Each of the selection switches 31 arranged in the NC is turned on and the other selection switches 31 are turned off, so that only the secondary battery body 10 is reacted. L and is connected, thereby detectably a battery voltage of the secondary battery 10 by the voltage detecting means 26. Thus, it is possible to charge any secondary battery body using one constant current source generation circuit, and the amount of charge can be adjusted according to the remaining capacity of the secondary battery body. Compared to the method of charging the entire secondary battery body, there is an advantage that the variation in the amount of charge between the secondary battery bodies is reduced, overcharging is avoided, and the secondary battery body can be used with high safety over a long period of time.

It is a block diagram which shows the power supply device which concerns on embodiment of this invention. It is a circuit diagram which shows the power supply device of FIG. It is a circuit diagram which shows a mode that 10 A of secondary battery bodies are charged with the power supply device of FIG. It is a circuit diagram which shows a mode that the secondary battery body 10B is charged with the power supply device of FIG. It is a circuit diagram which shows a mode that 10 C of secondary battery bodies are charged with the power supply device of FIG. It is a circuit diagram which shows a mode that secondary battery body 10D is charged with the power supply device of FIG. It is a circuit diagram which shows a mode that secondary battery body 10A, 10B is charged with the power supply device of FIG. It is a circuit diagram which shows a mode that secondary battery body 10A, 10C is charged with the power supply device of FIG. It is a circuit diagram which shows a mode that secondary battery body 10A-10D is charged with the power supply device of FIG. 1 is a circuit diagram illustrating a power supply device according to a first embodiment. It is a circuit diagram which shows the circuit example of the power supply device of FIG. FIG. 6 is a circuit diagram illustrating a power supply device according to a second embodiment. It is a circuit diagram which shows the circuit example of the power supply device of FIG. FIG. 6 is a circuit diagram illustrating a power supply device according to a third embodiment. It is a circuit diagram which shows the circuit example of the power supply device of FIG. FIG. 6 is a circuit diagram illustrating a power supply device according to a fourth embodiment. FIG. 17 is a circuit diagram illustrating a circuit example of the power supply device of FIG. 16. FIG. 9 is a circuit diagram illustrating a power supply device according to a fifth embodiment. It is a circuit diagram which shows the circuit example of the power supply device of FIG. FIG. 10 is a circuit diagram illustrating a power supply device according to a sixth embodiment. FIG. 21 is a circuit diagram illustrating a circuit example of the power supply device of FIG. 20. FIG. 10 is a circuit diagram illustrating a power supply device according to a seventh embodiment. It is a circuit diagram which shows the circuit example of the power supply device of FIG. 24A is a timing chart showing the state of charging one secondary battery body, FIG. 24B is a current path when the charging switch is ON, and FIG. 24C is a charging switch 22 being OFF. It is a circuit diagram which shows each the current pathway at the time of. FIG. 25 (a) is a timing chart for sequentially charging a plurality of secondary battery bodies, FIG. 25 (b) is when the charging switch is ON, and FIG. 25 (c) is when the first secondary battery body is selected. 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. It is a circuit diagram. It is a circuit diagram which shows the charge condition adjusting device of the conventional assembled battery.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a power supply device and a charging circuit for embodying the technical idea of the present invention, and the present invention does not specify the power supply device and the charging circuit as follows. In addition, the member shown by the claim is not what specifies the member of embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the constituent members described in the embodiments are not intended to limit the scope of the present invention only to the description unless otherwise specified. It is just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing. In addition, the contents described in some embodiments and examples may be used in other examples and embodiments.

1 to 10 show a power supply device 100 according to an embodiment. In these drawings, FIG. 1 is a block diagram of the power supply apparatus 100, FIG. 2 is a circuit diagram showing an example of the power supply apparatus 100 of FIG. 1, and FIG. 3 is a state in which the secondary battery body 10A is charged by the power supply apparatus 100 of 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 charging the secondary battery body 10D. FIG. 7 is a circuit diagram showing how the secondary battery bodies 10A and 10B are charged, FIG. 8 is a circuit diagram showing how the secondary battery bodies 10A and 10C are charged, and FIG. 9 is a secondary battery. FIG. 10 is a circuit diagram illustrating a power supply device 100 according to the first embodiment, and FIG. 11 is a circuit diagram illustrating a circuit example of the power supply device 100 of FIG. Yes. As shown in FIG. 1, the power supply device 100 generates a plurality of secondary battery bodies 10A to 10N and a constant current source that supplies power for charging the secondary battery body 10 connected to the external power source EP. The circuit 20 includes a selection switch switching circuit 30 connected between 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. This power supply device is connected to and drives a load LD. The external power supply EP is a power source that supplies power for charging to the power supply device. For example, when the present invention is applied to a rapid charging station of a hybrid vehicle, a hybrid vehicle driving battery provided in the rapid charging station is used. A charging battery for charging is applicable. Further, a rectified commercial power supply or the commercial power supply itself can be used as the external power supply EP. In the following example, 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 constituted by connecting a plurality of battery cells in series or in parallel, in addition to being constituted by a single battery cell. As the battery cell, a rechargeable secondary battery such as a lithium ion secondary battery, a nickel hydrogen battery, a nickel cadmium battery, or a lead storage battery can be used. In particular, a lithium ion secondary battery is preferable because it has a larger electric capacity per volume than a nickel metal hydride battery and is excellent in miniaturization and high output. In addition, in the example of FIGS. 2-11, although the structure which connects four secondary battery bodies 10 10A-10D is shown for easy explanation, the number of connections of a secondary battery body is limited to this. Needless to say, it can be 5 or more or 3 or less.
(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. Therefore, the constant current source generation circuit 20 includes a conversion circuit that converts the voltage of the external power supply 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, constant current charging is performed when the voltage of the secondary battery body 10 is lower than the first voltage, and switching to constant voltage charging is performed when the voltage exceeds the first voltage. Constant voltage charging is performed until reaching a higher second voltage, and when reaching the second voltage, it is determined that the battery is fully charged and charging is terminated. The charging control method is an example, and other known charging methods can be used as appropriate depending on the type of the secondary battery body to be used. Such charging control is performed by ON / OFF control of a charging switch 22 described later.
(Selection switch switching circuit 30)

The selection switch switching circuit 30 is connected to each of the secondary battery bodies 10 and is capable of individually configuring a charging path for charging the secondary battery body 10, and ON / OFF of the plurality of selection switches 31. And a control circuit 40 for controlling. Specifically, as shown in the circuit example of FIG. 2, a charging path for individually connecting the constant current source generation circuit 20 and each secondary battery body 10 is configured by ON / OFF of a plurality of selection switches 31. . More specifically, the selection switch switching circuit 30 includes a plurality of positive-side charging paths PC each connecting the positive electrode of each secondary battery body 10 and the supply output terminal OT, and the negative electrode and supply of each secondary battery body 10. ON / OFF of a plurality of negative charge paths NC respectively connected to the input terminal IT, a plurality of selection switches 31 provided respectively in the positive charge path PC and the negative charge path NC, and a plurality of selection switches 31 And a control circuit 40 to be controlled. As described above, 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, since each secondary battery is individually connected to the constant current source generation circuit 20, the amount of charge can be adjusted according to the remaining capacity of the secondary battery body 10, so that the entire secondary battery bodies connected in series are charged. Compared with the method, the variation in the charge amount between the secondary battery bodies can be reduced, and the advantage that the secondary battery bodies can be used with high safety over a long period of time by avoiding overcharging is obtained. Needless to say, the secondary battery bodies are not limited to be charged one by one, and a plurality of secondary batteries can be charged simultaneously.
(Selection switch 31)

As the selection switch 31, a semiconductor switching element can be used, and examples thereof include a thyristor, a GTO thyristor, an IGBT, a bipolar transistor, and an FET. A thyristor is preferably used. However, a self-extinguishing element having a self-extinguishing function such as a GTO thyristor or IGBT 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. In the examples of FIGS. 2 to 10, the selection switch 31 is schematically shown. For example, when the selection switch can be energized in both directions, a rectifying element such as a diode that prevents energization in the reverse direction is charged. Needless to say, it can be appropriately added to the route. The rectifying element is inserted in series with respect to the charging path, and can be provided at an arbitrary position as long as it is in the charging path. Further, when a semiconductor element having a rectifying characteristic such as a thyristor is used as the selection switch, such a rectifying element can be omitted.
(Thyristor 32)

  Here, FIG. 11 shows a circuit example in which the thyristor 32 is used as the selection switch 31 in the power supply apparatus 100 of FIG. In FIG. 11, thyristors 32A to 32H correspond to selection switches 31A to 31H, respectively. To turn on each thyristor 32, an ON signal is input from the control circuit 40 to the gate terminal of the thyristor 32. On the other hand, to turn off the thyristor 32, the charging switch 22 described later is turned off to stop the output of the chopper circuit, and the amount of current supplied to the thyristor 32 is made zero. By such an arc extinguishing operation, the thyristor 32 is turned off, and charging of the secondary battery body 10 can be stopped. Further, the thyristor 32 is excellent in reverse withstand voltage characteristics, and can be easily turned on and can simplify the drive circuit.

When an IGBT is used for the selection switch 31, ON / OFF switching control can be easily performed with a signal from the control circuit 40 by a self-extinguishing function. That is, the arc extinguishing operation for once stopping the current, such as the thyristor described above, can be made unnecessary. On the other hand, since reverse breakdown voltage characteristics are inferior to thyristors and the like, it is preferable to connect a 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 configured by an ASIC or the like. In this example, a charging path for an arbitrary secondary battery body 10 is configured by switching the selection switch 31 and, at the same time, a charging path for another 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, and the other secondary switches The battery body 10 can be charged according to the characteristics of the secondary battery body 10 </ b> A by being disconnected from the constant current source generation circuit 20. When the charging of the secondary battery body 10A is completed, the selection switches 31A and 31C are turned off and the selection switches 31B and 31E are turned on as shown in FIG. By connecting to the source generation circuit 20 and disconnecting the other secondary battery body 10 from the constant current source generation circuit 20, charging according to the characteristics of the secondary battery body 10B becomes possible. Similarly, when the charging of the secondary battery body 10B is completed, the selection switches 31B and 31E are turned OFF and the selection switches 31D and 31G are turned ON to charge the secondary battery body 10C as shown in FIG. Start. Further, when the charging of the secondary battery body 10C is completed, the selection switches 31D and 31G are switched to OFF as shown in FIG. 6, and the selection switches 31F and 31H are switched to ON to start charging the secondary battery body 10D. . Thus, all the secondary battery bodies 10 can be charged by switching ON / OFF of the selection switch 31 sequentially.

  As described above, an appropriate secondary battery body can be appropriately charged by the selection switch switching circuit 30 while using one constant current source generation circuit 20. In addition, in this method, since only the secondary battery body to be charged is connected to the constant current source generator, each secondary battery body to be charged is compared with the case where the secondary battery bodies to be charged are connected in parallel. The advantage that it is possible to individually perform appropriate charging according to the electrical characteristics and the like is obtained. Especially when the remaining capacity of each secondary battery is different, charging with the same current at the same time will charge a specific secondary battery body with a lot of remaining capacity quickly, so that all the secondary battery bodies will be charged until charging is completed. If the operation is continued, the secondary battery body that has been fully charged is overcharged, which may cause deterioration. On the contrary, when charging is completed in accordance with the secondary battery body having a small remaining capacity, a secondary battery body that is not fully charged is generated, and there is a problem that the available electric capacity is reduced. However, if a dedicated charging circuit is individually provided for each secondary battery body, the circuit configuration becomes complicated and the cost increases. Therefore, in the present invention, a single constant current source generation circuit is used, and individual connection with each secondary battery body is enabled by the selection switch switching circuit, so that a common constant current circuit can be provided without providing an individual charging circuit. The current source generation circuit enables individual charging.

  This method is particularly suitable for charging a nickel-metal hydride battery or a nickel cadmium battery having negative characteristics. That is, since the nickel hydride battery has a characteristic that the voltage decreases when it is fully charged, when trying to charge the nickel hydride battery in a state of being connected in parallel, the voltage of each nickel hydride battery gradually increases, Since the voltage of a nickel metal hydride battery or the like that has reached full charge first decreases, a large amount of current is supplied to the battery, which causes a decrease in voltage and makes it difficult to supply appropriate charging power. There was a problem of becoming. On the other hand, according to the method according to the above-described embodiment, since individual charging for each secondary battery body is possible, an excellent advantage that such a problem due to uniform charging can be solved is obtained. .

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

Moreover, it is not restricted to adjacent secondary battery bodies, The secondary battery body which was distant can also be charged simultaneously. For example, in the example shown in FIG. 8, the secondary battery bodies 10A and 10C can be charged simultaneously by turning on the selection switches 31A, 31C, 31D, and 31G and turning off the other selection switches 31. Furthermore, as shown in FIG. 9, by turning on the selection switches 31A and 31H and turning off the other selection switches 31, all of the secondary battery bodies 10A, 10B, 10C, and 10D can be charged simultaneously. By charging a plurality of secondary battery bodies at the same time as described above, the secondary battery bodies can be charged efficiently. In this circuit example, the electric power supplied from the external power supply side is constant, so that it does not theoretically lead to shortening of the time required for charging.
(Equalization regeneration operation)

  In the charging operation described above, equalizing charging that reduces variation in electric capacity between the secondary battery bodies obtained as a result can be realized by charging individual secondary battery bodies under appropriate conditions. On the other hand, when charging a plurality of secondary battery bodies at the same time, it is possible to more directly suppress variation in electric capacity between the secondary battery bodies. That is, in a state where a plurality of secondary battery bodies having different electric capacities are connected to the constant current source generating circuit, the amount of current flowing into the secondary battery body having a high battery voltage is reduced and flows into the secondary battery body having a low battery voltage. Since the amount of current increases by that amount, as a result, the secondary battery body having a low battery voltage is charged a lot, which affects the direction in which the difference in electric capacity is reduced.

  In addition, when the power supply side that supplies the charging power is capable of regenerative operation, the secondary battery body having a large electric capacity is discharged and regenerated to the constant current source generation circuit side. It can also be directed to charge the secondary battery body, which can further reduce the difference in electric capacity. Such regeneration operation is also referred to as equalization regeneration in this specification. For example, when a power source that performs a regenerative operation such as a hybrid vehicle or a plug-in hybrid vehicle is used, it is particularly advantageous because the regenerative operation can equalize the secondary battery bodies. The regenerative operation can be realized both when the secondary battery body is connected to the constant current source generating circuit alone and when the plurality of secondary battery bodies are connected to the constant current source generating circuit. Not too long.

In this way, by suppressing the variation in the electric capacity between the secondary battery bodies at the charging stage, all the secondary battery bodies can be appropriately charged up to the electric capacity as much as possible, and some secondary batteries are further charged. A situation where the battery body is overcharged can be avoided, and the secondary battery body can be protected and stably used over a long period of time with high reliability. Further, according to this configuration, since charging and capacity variation adjustment can be realized by the same circuit, it is possible to simplify the circuit configuration and the processing.
(Chopper circuit)

  Further, a detailed circuit example of the charging circuit is shown in FIG. The constant current source generating circuit 20 shown in this figure includes a chopper circuit including a reactor L and a charging switch 22 connected in series with the reactor L. The charging switch 22 is connected in series to the external power supply EP and the reactor L, and forms a closed circuit in which the external power supply EP, the reactor L, and the charging switch 22 are connected when the charging switch 22 is turned on. A semiconductor switching element is used for the charging switch 22. In the specific example shown in FIG. 11 described later, an IGBT is used as the semiconductor switching element. The IGBT can control the current of the reactor L so that the power can be stored in a direction in which the reactor L can supply power to the secondary battery body 10 (rightward in FIG. 10).

  The reactor L is connected between the supply output terminal OT and the supply input terminal IT, and realizes a chopping operation of power supplied from the external power supply EP by turning on / off the charging switch 22 connected in series. . That is, when the charging switch 22 is turned on, 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 electric energy stored in the reactor L is released. Then, it flows into the secondary battery body 10 side through the charging path and charging is performed. By repeating such ON / OFF operation of the charging switch 22, intermittent charging current is supplied to the secondary battery body 10, and pulse charging is realized. The control circuit 40 turns on / off the charging switch 22.

  In this example, the constant current source generation circuit 20 is configured by a boost chopper circuit. The step-up chopper circuit can charge the secondary battery body 10 to a high voltage using the low-voltage external power supply EP by the step-up chopping operation. However, the present invention is not limited to this configuration, and for example, a step-up / step-down chopper circuit can be used. In the case where the constant current source generation circuit 20 is caused to function as a step-up chopper, the condition is that the battery voltage (for example, 24V) of the secondary battery body 10 selected as the charging target is higher than the external power source EP (for example, 20V). It becomes. In the example of FIG. 10, the constant current source generation circuit 20 functions as a step-up / step-down chopper, and thus can be used more flexibly without such a voltage value limitation. Further, in the circuit example of FIG. 10, a circuit example using the thyristor 32 for the selection switch 31 is shown in FIG. According to this configuration, since the thyristor used as the selection switch 31 can be turned off using the OFF period of the boost chopper used as the constant current source generation circuit 20, the thyristor having no self-extinguishing capability can be specially extinguished. It can be realized without a commutation circuit, and charging control using a thyristor can be realized very suitably.

In the examples of FIGS. 2 and 10, the control circuit 40 controls the constant current source generation circuit 20 and the selection switch switching circuit 30. However, the present invention is not limited to this configuration. For example, a constant current source generation circuit control circuit that controls the constant current source generation circuit 20 and a selection switch circuit control circuit that controls the selection switch switching circuit 30 are individually provided. Needless to say, it can also be provided.
(Example 2 equalization charge and equalization regeneration)

Moreover, although the circuit example which mainly performs equalization charge was shown in FIG. 10 etc., equalization regeneration which advanced equalization more by regenerative operation as mentioned above is also realizable. A circuit example of a power supply device capable of realizing such equalization charging and equalization regeneration is shown in the circuit diagram of FIG. In the following example, only three secondary battery bodies 10 (10A to 10C) are shown for simplicity of explanation, and the other secondary battery bodies are not shown. As described above, the number of connections can be arbitrarily set. Moreover, the power supply device 200 shown in this figure is connected to a power source capable of regenerative operation (for example, a lithium ion battery installed in a quick charging station) as an external power source EP.
(Regeneration switch 24)

The constant current source generation circuit 20 of FIG. 12 has a regeneration switch 24 connected to the reactor L in addition to the charging switch 22 of FIG. Similarly to the charging switch 22, the regeneration switch 24 can use a semiconductor switching element such as an IGBT. The regenerative switch 24 defines the energizing direction of the regenerative switch 24 so that the current flows through the reactor L in the direction opposite to the charging switch 22 and in the direction discharged from the secondary battery body 10 (leftward in FIG. 12). . For this reason, the regenerative switch 24 has a rectifying function, or a rectifying 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 a thyristor 32 as the selection switch 31 and an IGBT as the charging switch 22 and the regeneration switch 24 is shown in FIG. Thus, when a rectifier is used for the charging switch 22 and the regeneration switch 24, the rectifier can be unnecessary. A diode is connected in antiparallel between the emitter and collector of each IGBT. These diodes have a function of protecting the IGBT having poor reverse breakdown voltage characteristics as a path for charging the energy accumulated in the reactor L to the secondary battery body 10 or regenerating it to the external power source EP. In the charging operation of the power supply device 200 shown in this figure, the relationship between the battery voltage E ₁₀ of the external power supply voltage E _EP and the secondary battery 10 of the external power supply EP is a rechargeable battery 10 and the constant current source generating circuit 20 Are individually connected, E _EP <E ₁₀ . On the other hand, in the regenerative operation, when the number of series connection of the secondary battery bodies 10 is n and the voltage variation of each secondary battery body is ignored, E _EP > E ₁₀ * n. In this way, during the charging operation, charging is possible with an external power supply voltage lower than each battery voltage, and even when power is taken out by regenerative operation, the external power supply voltage is the total voltage of the battery voltage bodies connected in series. Since it is necessary to be higher than the above, it is possible to perform the regenerative operation even with a low battery voltage, and an effective charge / discharge using the secondary battery body is realized.
(Example 3)

  Further, the regenerative switch 24 is not limited to the configuration of connecting to both ends of the reactor L as shown in the connection example of FIG. 12, and for example, is branched at one end of the reactor L as shown in FIG. 14 according to the third embodiment. Needless to say, it is also possible to connect in this manner. In addition, in the circuit example of the power supply apparatus 300 in FIG. 14, a circuit example in which the thyristor 32 is used for the selection switch 31 and the IGBT is used for the charging switch 22 and the regeneration switch 24 is shown in FIG. 15.

Although not shown, the regenerative switch 24 shown in these drawings is also connected to the control circuit 40, and ON / OFF is controlled by the control circuit 40. In the power supply devices 200 and 300 shown in FIG. 12 and FIG. 14, when the secondary battery body 10 is charged via the charging switch 22, the regenerative switch 24 is set by the control circuit 40 to be turned off. The On the other hand, at the time of the regenerative operation for discharging the surplus power of the secondary battery body 10 to the external power supply EP side, the discharge switch is turned off and the regenerative switch 24 is turned on. . Accordingly, the secondary battery body can be discharged to reduce the electric capacity, and the discharge energy can be supplied to the external power source and reused, so that the energy can be used efficiently. This is particularly effective for applications that require high energy efficiency, such as electric vehicles and hybrid vehicles.
Example 4

Conversely, when the regenerative operation is not performed, a circuit configuration as shown in FIG. The power supply apparatus 400 shown in this example includes a charging diode 23 between one end (right side in the figure) of the reactor L and the supply output terminal OT in addition to the charging switch 22 of FIG. Since the charging diode 23 prevents current from flowing from the secondary battery body 10 side to the external power supply EP side, the regenerative operation is prohibited in this circuit, and only equalization charging is performed. In the circuit example of FIG. 16, an example in which a thyristor 32 is used for the selection switch 31 and an IGBT is used for the charging switch 22 is shown in FIG.
(Example 5)

Further, the configuration is not limited to the circuit example of FIG. 16 and, for example, a configuration as shown in FIG. 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 another end instead of the same side as the charging switch 22. Even in this configuration, the charging diode 23 can similarly inhibit the inflow of current from the secondary battery body 10 side to the external power supply EP side. In the circuit example of FIG. 18, an example in which a thyristor 32 is used for the selection switch 31 and an IGBT is used for the charging switch 22 is shown in FIG.
(Example 6)

On the other hand, FIG. 20 shows a circuit example for performing only the equalizing regenerative operation as a sixth embodiment. In the power supply device 600 shown in this circuit example, the charging switch is not provided, and instead, the regeneration switch 24 and the regeneration diode 25 are connected to one end of the reactor L. In the circuit example of FIG. 20, a circuit example in which a thyristor 32 is used for the selection switch 31 and an IGBT is used for the regeneration switch 24 is shown in FIG.
(Example 7)

As Example 7, FIG. 22 shows a circuit example of another power supply device 700. In the seventh embodiment, as shown in FIG. 22, the connection position of the regeneration switch 24 is connected to the end of the reactor L not on the same side as the regeneration diode 25 but on the other end. Even in this configuration, the regeneration switch 24 prohibits the charging operation while the regeneration switch 24 allows the regeneration operation from the secondary battery body 10 side to the external power supply EP side. Further, in the circuit example of FIG. 22, FIG. 23 shows a circuit example in which the thyristor 32 is used as the selection switch 31 and the IGBT is used as the regeneration switch 24.
(Voltage detection means 26)

  Furthermore, voltage detectors 26 for detecting the voltage across the reactor are provided at both ends of the reactor L. The voltage detection means 26 can be constituted by, for example, a differential amplifier or a resistor. The voltage detection means 26 detects the voltage of the secondary battery body 10 by detecting the voltage across the reactor while the constant current source generation circuit 20 is connected to the arbitrary secondary battery body 10 by the selection switch switching circuit 30. can do. For example, in the circuit example of FIG. 10, only the selection switch 31A and the selection switch 31C are turned on and the other selection switches 31 are turned off under the control of the control circuit 40. When the secondary battery body 10A is charged in this state, the voltage appearing at the voltage across the reactor becomes equal to the battery voltage of the secondary battery body 10, and therefore the battery voltage of the secondary battery body 10 can be detected by the voltage detection means 26. Further, if 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 manner, the voltage detection means 26 can measure the battery voltages of all the secondary battery bodies 10 by scanning each secondary battery body 10 by the control circuit 40, that is, in a time division manner. In other words, the battery voltage of the plurality of secondary battery bodies 10 can be detected by the single voltage detection means 26, and the switching of the secondary battery bodies 10 can be performed using the above-described charging selection switch 31. The number of parts becomes almost unnecessary, and an advantage that the circuit configuration for detecting the battery voltage of all the secondary battery bodies 10 can be extremely simplified can be obtained.

  The 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 adjusted to an appropriate charging current. In addition, during charging, the state of charging can be monitored while the battery voltage of the secondary battery body 10 is detected by the voltage detection means 26 at an appropriate timing, for example, at a constant 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 at a constant period during charging. When the battery voltage of the secondary battery body 10 reaches a certain voltage, the control circuit 40 turns off the selection switch 31 and finishes charging the secondary battery.
(Timing chart)

Next, timing charts showing the operation of the power supply device according to the first embodiment are shown in FIGS. Here, the selection circuits and current paths of the thyristors 32A to 32N when the charging switch 22 is ON and OFF are shown. In the power supply apparatus, as an example, a sample hold circuit SH is connected to the voltage detection means 26. 24A to 24C show how the secondary battery body 10A is charged. FIG. 24A shows a timing chart showing waveforms of the respective parts. b) shows a current path when the charging switch 22 is ON, and FIG. 24C shows a current path when the charging switch 22 is OFF. In FIG. 24 (a), the as shown by in the column of the rectangular wave of the inductance L of the voltage waveform e _x (b), when the charging switch 22 ON, the increased current I _L to the inductance L, the thyristor The current I _32A does not flow through 32A and is turned OFF. On the other hand, when the charging switch 22 is OFF as shown by (c) in the column “ _ex” of FIG. 24A, the thyristor 32A is turned ON by the gate signal and the current I _32A flows, and the current to the inductance L flows. I _L decreases. In FIG. 24B to FIG. 24C, the ON state of the thyristor 32 is shown in black, and the OFF state is shown in white. Each time the charging switch 22 is turned on, the thyristor 32A can be turned off. The current I _{32A of the} thyristor 32A has a pulse waveform as shown in FIG. The voltage e _x across the inductance L, a rectangular wave voltage E _10A of the voltage E _P and the secondary battery body 10A of the external power supply EP is applied alternately as shown in FIG. 24 (a). Further, the voltage E _10A of the secondary battery body 10A can be detected by the sample hold operation for the voltage detection means 26.

  Moreover, Fig.25 (a)-FIG.25 (e) have shown a mode that the secondary battery bodies 10A-10N are charged. 25A is a timing chart showing the waveforms of the respective parts, FIG. 25B is a secondary battery body when the charging switch 22 is OFF, and FIG. 25C is the secondary battery body when the charging switch 22 is OFF. When 10A is selected, FIG. 25 (d) shows a case where the charging switch 22 is OFF and the secondary battery body 10B is selected. FIG. 25 (e) shows a case where the charging switch 22 is OFF and the secondary battery body. Current paths when 10N is selected are shown respectively.

In FIG. 25A, the period for charging the secondary battery body 10A is indicated by (b) / (c), and the above-described operation of FIG. 24 is performed. In this period, first when charging switch 22 as shown in FIG. 25 (b) is ON, it increases the current I _L to the inductance L, the result OFF no current flows in the thyristor 32a through 32n. Further, 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 by the gate signal and the current I _32A flows, and the inductance L is supplied. The current I _L decreases. In the meantime, since the operation of these figures 25 (b) and FIG. 25 (c) are repeated, the voltage e _x across the inductance L, the voltage E _10A of the voltage E _P and the secondary battery body 10A of the external power supply EP Becomes a rectangular wave applied alternately.

Furthermore, the period during which the secondary battery body 10B is charged is indicated by (b) / (d) in FIG. In the period (b) / (d), as in the period (b) / (c) described above, when the charging switch 22 is ON as shown in FIG. _{As L} increases, no current flows through the thyristors 32A to 32N and the thyristors 32A to 32N are turned OFF. In FIG. 25D, when the charging switch 22 is OFF and the secondary battery body 10B is selected, the thyristor 32B is turned ON by the gate signal and the current I _32B flows, and the current to the inductance L flows. I _L decreases. Voltage e _x across the inductance L in this (b) / (d) period, a rectangular wave voltage E _10B of the voltage E _P and the secondary battery body 10B of the external power supply EP is applied alternately.

Furthermore, the period during which the secondary battery body 10N is charged is indicated by (b) / (e) in FIG. In this (b) / (e) period, as in the above-described (b) / (c) period and (b) / (d) period, the charging switch 22 is ON as shown in FIG. time, the increased current I _L to the inductance L, the result OFF no current flows in the thyristor 32a through 32n. In FIG. 25 (e), when the charging switch 22 is OFF and the secondary battery body 10N is selected, the thyristor 32N is turned ON by the gate signal and the current I _32N flows, and the current to the inductance L flows. I _L decreases. As the voltage e _x across the inductance L in the period (b) / (e), the voltage E _P and the voltage E _10N of the external power supply EP are alternately applied.

Also in the example of FIG. 25, the voltage E _{10A to} E _10N of each selected secondary battery body can be detected from the output e _B of the sample and hold circuit SH by the sample and hold operation of the sample and hold circuit SH. The voltage detection means is not limited to the sample and hold circuit, and other configurations can be used as appropriate.

  As described above, according to the present invention, since it is possible to perform equalization charging control of each secondary battery body with a very simple circuit configuration, a DC voltage such as an electric vehicle that requires a high voltage or an uninterruptible power supply is used. In configuring the power source, the system configuration can be greatly simplified, and since overcharge / discharge does not occur, the life and safety of the secondary battery body can be increased, and the cost can be reduced.

  The power supply device and the charging circuit according to the present invention can be suitably used for a power source for driving a hybrid vehicle, a plug-in hybrid vehicle, an electric vehicle, or the like. Further, the power supply is not limited to a vehicle power supply, and can be used for other power supply devices such as an assist bicycle, a power tool, an uninterruptible power supply (UPS), and a large-capacity storage battery bank used for a power supply for driving a factory.

100, 200, 300, 400, 500, 600, 700 ... power supply device 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 detecting 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 supply OT ... Supply output terminal IT ... Supply input terminal LD ... Load PC ... Positive side charging path NC ... Negative side charging path L ... Reactor

Claims (7)

A plurality of secondary battery bodies (10) each provided with a positive electrode and a negative electrode and connected in series with each other;
A constant current source generating circuit (20) comprising a supply output terminal (OT) and a supply input terminal (IT) for supplying power for charging the secondary battery body (10);
A selection switch switching circuit (30) capable of supplying different charging currents individually to each secondary battery body (10) in the constant current source generation circuit (20),
A power supply device comprising:
The selection switch switching circuit (30) is connected to each secondary battery body (10), and a selection switch (31) capable of individually configuring a charging path for charging the secondary battery body (10),
A control circuit (40) for controlling ON / OFF of the plurality of selection switches (31);
Have
The control circuit (40) controls the ON / OFF of the selection switch (31), thereby forming a charging path for an arbitrary secondary battery body (10) and a charging path for other secondary batteries. Is to cancel,
The constant current source generation circuit (20)
A reactor (L) connected between the supply output terminal (OT) and the supply input terminal (IT);
A charging switch (22) connected in series with the reactor (L) and controlled ON / OFF by the control circuit (40);
It has a chopper circuit composed of
The chopper circuit is connected to an external power source (EP) and is configured to charge the secondary battery body (10),
The power supply device further includes voltage detection means (26) for detecting a voltage across the reactor (L),
The control circuit (40) includes an arbitrary secondary battery body (10), a positive side charging path (PC) and a negative side charging path (NC) connecting the secondary battery body (10) and the reactor (L). ) And the other selection switch (31) are turned OFF, so that only the secondary battery body (10) is connected to the reactor (L). Thus, the power supply apparatus is configured so that the battery voltage of the secondary battery body (10) can be detected by the voltage detection means (26). The power supply device according to claim 1,
The power supply device, wherein the control circuit (40) measures the battery voltage of each secondary battery body (10) in a time division manner. The power supply device according to claim 1 or 2 ,
The power supply apparatus, wherein the control circuit (40) is configured to be capable of ON / OFF control of the selection switch (31) so as to charge any plurality of secondary battery bodies (10) simultaneously. The power supply device according to any one of claims 1 to 3 ,
The power supply apparatus, wherein the selection switch (31) is an element having no self-extinguishing capability. The power supply device according to any one of claims 1 to 4 ,
The power supply apparatus, wherein the selection switch (31) is a thyristor (32). The power supply device according to any one of claims 1 to 5 ,
The power supply device, wherein the secondary battery body (10) is configured by connecting a plurality of battery cells in series or in parallel. A charging circuit comprising a plurality of secondary battery bodies (10) each provided with a positive electrode and a negative electrode and connected in series with each other,
A constant current source generating circuit (20) having a supply output terminal (OT) and a supply input terminal (IT) for supplying 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-side charging paths (PC) each capable of connecting the positive electrode of each secondary battery body (10) and the supply output terminal (OT), and
A plurality of negative-side charging paths (NC) each capable of connecting the negative electrode of each secondary battery body (10) and the supply input terminal (IT);
A plurality of thyristors (32) provided respectively in the positive electrode side charging path (PC) and the negative electrode side charging path (NC);
A control circuit (40) capable of individually controlling the ON control of the plurality of thyristors (32);
With
The constant current source generation circuit (20)
A reactor (L) connected between the supply output terminal (OT) and the supply input terminal (IT);
A charging switch (22) connected in series with the reactor (L) and controlled ON / OFF by the control circuit (40);
It has a chopper circuit composed of
The chopper circuit is connected to an external power source (EP) and is configured to charge the secondary battery body (10),
The charging circuit further comprises voltage detection means (26) for detecting the voltage across the reactor (L),
The control circuit (40) includes an arbitrary secondary battery body (10), a positive side charging path (PC) and a negative side charging path (NC) connecting the secondary battery body (10) and the reactor (L). ) And the other selection switch (31) are turned OFF, so that only the secondary battery body (10) is connected to the reactor (L). Thus , the charging circuit is configured so that the battery voltage of the secondary battery body (10) can be detected by the voltage detecting means (26) .

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