JP2008252987A - Power supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure balance of output currents between a plurality of battery elements. <P>SOLUTION: A power supply system 100 includes a boosting converter 500 connected to an electrical load 200 and an electricity-storing mechanism 600 connected to the boosting converter 500. The electricity-storing mechanism 600 is structured with a battery element (1) 602 and another battery element (2) 604 connected in parallel. Each power supply line of the battery element (1) 602 and another battery element (2) 604 is magnetically connected. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power supply device that is connected to a converter and is configured by connecting a plurality of battery elements in parallel, and more particularly, to a technique for suppressing variations in output current during operation of the converter.

  2. Description of the Related Art Conventionally, an electric vehicle, a hybrid vehicle, and the like that travel using a driving force of a motor are known. Such an automobile is equipped with a power supply device composed of a secondary battery or the like in order to store electric power supplied to the motor. Such a power supply device connects a plurality of battery elements in parallel to supply electric power necessary for the vehicle to travel to an electric load such as a motor.

  For example, Japanese Patent Laid-Open No. 2000-156934 (Patent Document 1) discloses a power storage system that extends the life of battery units connected in parallel without overcharging them. This power storage system is a power storage system in which a plurality of battery units are connected in parallel to a commercial power source through a converter, and the power stored in each battery unit is supplied to a load as needed to level the power. In addition, a DC switch is provided for each branch path of each battery unit connected in parallel, and when storing power in the battery unit, the charging voltage of each battery unit is detected, and a desired battery unit is detected based on the detection signal. The DC switch is selectively opened sequentially.

According to the power storage system disclosed in the above-mentioned publication, a DC switch is provided for each branch path of each battery unit, the charging voltage of each battery unit is detected, and the DC switching of a desired battery unit is performed based on the detection signal. By selectively opening the battery, the battery units can be charged independently with the DC switch, so the battery units will not be overcharged. The service life of the unit can be extended, the reliability is greatly improved, and its practical value is great.
JP 2000-156934 A

  However, when a plurality of battery elements are connected in parallel, there is a possibility that the current is biased toward the battery element having the smaller internal resistance. This is due to the fact that the internal resistance varies among a plurality of battery elements due to variations in manufacturing, aging, and the like, and the difference in internal resistance increases due to use. Therefore, the balance of output current between the battery elements may be deteriorated. When the balance of the output current deteriorates, a relatively large current flows through some battery cell elements, the amount of heat generation increases, and the deterioration of chemical substances that make up the battery promotes the performance of the battery elements such as the lifetime. There is a problem that gets worse.

  In the power storage system disclosed in the above-mentioned publication, since no consideration is given to the deterioration of the balance of the output current between the battery elements, such a problem cannot be solved.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power supply device that ensures a balance of output currents among a plurality of battery elements.

  A power supply device according to a first aspect of the present invention includes a converter connected to an electrical device and a power storage mechanism connected to the converter. The power storage mechanism is configured by connecting a plurality of battery elements in parallel. Each power line of the plurality of battery elements is magnetically coupled.

  According to the first invention, since the plurality of battery elements are connected to the converter, if a change in current occurs during the operation of the converter, the respective power supply lines of the plurality of battery elements are magnetically coupled, so that the electromagnetic induction effect As a result, the currents flowing in the respective power supply lines of the plurality of battery elements become substantially the same current. Therefore, it is possible to suppress the current from being biased to some battery elements. Thereby, deterioration of performance, such as a lifetime of a battery element, can be suppressed. Therefore, it is possible to provide a power supply device that ensures a balance of output currents among a plurality of battery elements.

  In the power supply device according to the second invention, in addition to the configuration of the first invention, a plurality of coils are connected to each of the power supply lines of the plurality of battery elements. The plurality of coils are wound around the same core.

  According to the second invention, the power supply lines of the plurality of battery elements can be magnetically coupled by winding the same core around the coils connected to the power supply lines of the plurality of battery elements. Therefore, it is possible to suppress the current from being biased to some battery elements during the operation of the converter.

  In the power supply device according to the third invention, in addition to the configuration of the second invention, each of the plurality of coils has the same number of turns.

  According to the third invention, the currents flowing through the respective power supply lines of the plurality of battery elements can be made substantially the same by winding the plurality of coils with the same number of turns and winding them around the same core. .

  In the power supply device according to the fourth invention, in addition to the configuration of any one of the first to fourth inventions, the plurality of battery elements include the first battery element to which the first coil is connected, and the second battery element. And a second battery element to which a coil is connected. The first coil is wound around the core so as to be in a predetermined winding direction with respect to the winding direction of the second coil.

  According to the fourth invention, the first coil is wound around the core so as to be in a predetermined winding direction with respect to the winding direction of the second coil, whereby each power line of the plurality of battery elements is provided. Can be made to have substantially the same current.

  In the power supply device according to the fifth invention, in addition to the configuration of any one of the first to fourth inventions, the battery element is a lithium ion battery.

  According to the fifth invention, by applying the present invention to a power supply device composed of a lithium ion battery, it is possible to ensure the balance of the output current of each battery element, thereby suppressing deterioration of the life and performance of the battery element. be able to.

  A power supply device according to a sixth invention is mounted on a vehicle in addition to the configuration of any one of the first to fifth inventions.

  According to the sixth invention, by applying the present invention to the power supply device mounted on the vehicle, the balance of the output current of each battery element can be ensured, thereby suppressing the deterioration of the life and performance of the battery element. be able to.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<First Embodiment>
As shown in FIG. 1, power supply device 100 according to the present embodiment includes a boost converter 500 that is a boost chopper and a power storage mechanism 600. Power supply device 100 according to the present embodiment will be described as being mounted on a vehicle using a rotating electric machine such as an electric vehicle or a hybrid vehicle as a driving source, but the present invention particularly uses rotating electric machine as the driving source. The present invention is not limited to vehicles.

  An inverter 300 is connected to the power supply device 100. Smoothing capacitor 400 is connected to inverter 300 in parallel. An electric load 200 is connected to the inverter 300.

  The electrical load 200 is a rotating electrical machine in the present embodiment, but is not particularly limited to a rotating electrical machine as long as it is an electrical device.

  Boost converter 500 includes a boost power module 502 and a reactor 504. Boost power module 502 includes power semiconductor switching elements (hereinafter also simply referred to as “switching elements”) Q1 and Q2 and diodes D1 and D2. In the present embodiment, an IGBT (Insulated Gate Bipolar Transistor) or a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is typically applied as the power semiconductor switching element.

  Switching elements Q1, Q2 are connected in series between power supply line 203 and earth line 202. Anti-parallel diodes D1 and D2 are connected to the switching elements Q1 and Q2, respectively, so that current flows from the emitter side to the collector side. Reactor 504 has one end connected to power supply line 201 and the other end connected to a connection point of switching elements Q1 and Q2. Smoothing capacitor 400 is connected between power supply line 203 and ground line 202.

  Inverter 300 includes a U-phase arm, a V-phase arm, and a W-phase arm (all not shown) when the electric load is a three-phase AC synchronous rotating electric machine. U-phase arm, V-phase arm and W-phase arm are connected in parallel between power supply line 203 and earth line 202. Each phase arm is composed of a switching element and an antiparallel diode that allows current to flow from the emitter side to the collector side. An intermediate point of each phase arm is connected to each phase end of each phase coil of the rotating electrical machine.

  Boost converter 500 receives a DC voltage supplied from power storage mechanism 600 between power supply line 201 and ground line 202, and switches DC elements Q1 and Q2 to switch the DC voltage to power supply line 203. Output.

  Smoothing capacitor 400 smoothes the DC voltage of power supply line 203 and supplies it to inverter 300. The inverter 300 converts the DC voltage of the power supply line 203 into an AC voltage and supplies it to the electric load 200.

  An electronic control unit (ECU) (not shown) transmits a control signal to the drive circuit of the boost power module 502 of the boost converter 500, whereby the switching elements Q1 and Q2 are switched and supplied from the power storage mechanism 600. The DC voltage is boosted to the DC voltage set by the ECU. The DC voltage boosted in the inverter 300 is converted into an AC voltage and then supplied to the electric load 200.

  Power storage mechanism 600 is connected in parallel to battery element (1) 602, battery element (2) 604, filter capacitor 612 connected in parallel to battery element (1) 602, and battery element (2) 604. A filter capacitor 614 and a magnetic coupling circuit 620 are included.

  In the present embodiment, battery element (1) 602 and battery element (2) 604 are described as being lithium ion batteries. However, as long as the battery is a secondary battery or the like, the battery element (1) 602 and the battery element (2) 604 are particularly limited to lithium ion batteries. is not. For example, the present invention may be applied to a nickel metal hydride battery. In the present embodiment, a configuration in which a single battery cell is connected in parallel will be described as an example. However, two battery modules in which the same number of battery cells are connected in series may be connected in parallel.

  Further, the power supply device 100 is provided with a relay circuit (not shown), and power is supplied from the power supply device 100 to the inverter 300 and the electric load 200 by closing the relay circuit. At this time, an output current I (1) flows from the battery element (1) 602 via the power supply line to the boost converter 500 side, and an output current flows from the battery element (2) 604 via the power supply line to the boost converter 500 side. Let I (2) flow.

  In the vehicle having the above-described configuration, the present invention is characterized in that the power supply lines of the battery element (1) 602 and the battery element (2) 604 are magnetically coupled by the magnetic coupling circuit 620.

  Specifically, the magnetic coupling circuit 620 has one end connected to the power supply line of the battery element (1) 602 and one end connected to the power supply line of the battery element (2) 604. A coil (2) 624 and an annular core 626 around which the coil (1) 622 and the coil (2) 624 are wound. That is, coil (1) 622 and coil (2) 624 are each wound around the same core 626. Moreover, the coil (1) 622 and the coil (2) 624 are coils having the same number of turns.

  Furthermore, as shown in FIG. 1, the coil (1) 622 is wound around the core 626 so as to be in a predetermined winding direction with respect to the winding direction of the coil (2) 624.

  Specifically, when a current flows in the coil (1) 622 in the direction from the battery element (1) 602 side to the boost converter 500 side, the current flowing in the coil (2) 624 is induced by the induced electromotive force. Coil (1) 622 and coil (2) 624 are wound around core 626 so that the direction is the same as the direction of output current I (2). At this time, when a current flows in the coil (2) 624 in the direction from the battery element (2) 604 side to the boost converter 500 side, the direction of the current flowing in the coil (1) 622 by the induced electromotive force is The direction is the same as the direction of the output current I (1).

  The other end of coil (1) 622 and the other end of coil (2) 624 are connected to power supply line 201, respectively. The ground line of battery element (1) 602 and the ground line of battery element (2) 604 are connected to ground line 202, respectively.

  The operation of power supply apparatus 100 according to the present embodiment having the above structure will be described. Boost converter 500 is boosted to a voltage set according to the state of the electric load and the like by boost control according to a control signal from the ECU.

  That is, switching operation is performed in boost power module 502. According to the switching operation, the output current I (1) of the battery element (1) 602 and the output current I (2) of the battery element (2) 604 are repeatedly increased and decreased.

  At this time, the output current I (1) flowing through the coil (1) 622 and the output current I (2) flowing through the coil (2) 624 have the same number of turns of the coil (1) 622 and the coil (2) 624. Therefore, the magnetic coupling circuit 620 becomes substantially equal due to the electromagnetic induction action.

  Therefore, even if the internal resistances of the battery element (1) 602 and the battery element (2) 604 are different, the output current I (1) and the output current I (2) due to the switching operation are caused by the electromagnetic induction action in the magnetic coupling circuit 620. ) Difference is suppressed. Therefore, it is possible to suppress the current from being biased to either battery element (1) 602 or battery element (2) 604.

  As described above, according to the power supply device according to the present embodiment, the power supply lines of battery element (1) and battery element (2) are magnetically coupled. As a result, the currents flowing through the respective power supply lines of the battery element (1) and the battery element (2) become substantially the same current. Therefore, it is possible to suppress the current from being biased to some battery elements. Thereby, deterioration of performance, such as a lifetime of a battery element, can be suppressed. Therefore, it is possible to provide a power supply device that ensures a balance of output currents among a plurality of battery elements.

  The coil (1) is wound around the core so as to be in a predetermined winding direction with respect to the winding direction of the coil (2), whereby each of the battery element (1) and the battery element (2) is wound. The currents flowing in the power supply line can be made substantially the same.

<Second Embodiment>
Hereinafter, the power supply device according to the second embodiment will be described. Compared with the configuration of the power supply device according to the first embodiment described above, the power storage device 600 further includes a battery element (3) 606 and a coil (3) 628 as compared with the configuration of the power supply device according to the first embodiment described above. Is different. The other configuration is the same as the configuration of the power supply device according to the first embodiment described above. They are given the same reference numerals. Their functions are the same. Therefore, detailed description thereof will not be repeated here.

  In the present embodiment, as shown in FIG. 2, power storage mechanism 600 further includes battery element (3) 606 and coil (3) 628 in addition to power storage mechanism 600 shown in FIG. At this time, it is assumed that the output current I (3) flows from the battery element (3) 606 to the boost converter 500 side via the power supply line.

  Specifically, the magnetic coupling circuit 620 in the present embodiment has one end connected to the power supply line of the battery element (3) 606 in addition to the configuration of the magnetic coupling circuit 620 described in the first embodiment. It further includes a connected coil (3) 628. The coil (3) 628 is wound around the annular core 626. That is, coil (1) 622, coil (2) 624, and coil (3) 628 are each wound around the same core 626. In addition, the coil (1) 622, the coil (2) 624, and the coil (3) 628 are coils having the same number of turns.

  Coil (1) 622, coil (2) 624, and coil (3) 628 are wound around core 626 so as to have a predetermined winding direction with respect to the winding direction of the other coils.

  Specifically, when a current flows in the coil (1) 622 in the direction from the battery element (1) 602 side to the boost converter 500 side, the current flowing in the coil (2) 624 is induced by the induced electromotive force. The direction is the same as the direction of the output current I (2), and the direction of the current flowing through the coil (3) 628 by the induced electromotive force is the same as the direction of the output current I (3). , Coil (1) 622, coil (2) 624 and coil (3) 628 are wound around core 626.

  At this time, when a current flows through the coil (2) 624 in the direction from the battery element (2) 602 side to the boost converter 500 side, the direction of the current flowing through the coil (1) 622 by the induced electromotive force is The direction of the output current I (1) is the same direction, and the direction of the current flowing through the coil (3) 628 by the induced electromotive force is the same as the direction of the output current I (3).

  Furthermore, when a current flows in the coil (3) 628 in the direction from the battery element (3) 606 side to the boost converter 500 side, the direction of the current flowing in the coil (1) 622 by the induced electromotive force is The direction of the output current I (1) is the same direction, and the direction of the current flowing through the coil (2) 624 by the induced electromotive force is the same as the direction of the output current I (2).

  The other end of the coil (3) 628 is connected to the power supply line 201. In addition, the earth line of the battery element (2) 604 is connected to the earth line 202.

  The operation of power supply apparatus 100 according to the present embodiment having the above structure will be described. Boost converter 500 is boosted to a voltage set according to the state of the electric load and the like by boost control according to a control signal from the ECU.

  That is, switching operation is performed in boost power module 502. Depending on the switching operation, the output current I (1) of the battery element (1) 602, the output current I (2) of the battery element (2) 604, and the output current I (3) of the battery element (3) 606 are respectively Repeat increasing and decreasing.

  At this time, the output current I (1) flowing through the coil (1) 622, the current I (2) flowing through the coil (2) 624, and the output current I (3) flowing through the coil (3) 628 are the coil (1) 622. Since the number of turns of the coil (2) 624 and the coil (3) 628 is the same, they are substantially equalized by the electromagnetic induction action in the magnetic coupling circuit 620.

  Therefore, even if a difference occurs in the internal resistances of the battery element (1) 602, the battery element (2) 604, and the battery element (3) 606, the output current I (1 due to the switching operation is caused by the electromagnetic induction action in the magnetic coupling circuit 620. ) To (3) are prevented from expanding. Therefore, it is possible to suppress the current from being biased to any of battery element (1) 602, battery element (2) 604, and battery element (3) 606.

  As described above, according to the power supply device according to the present embodiment, the same effect as that produced by the power supply device according to the first embodiment described above is exhibited.

  In the present embodiment, the power storage mechanism is described as being configured by connecting three battery elements in parallel. However, the power storage mechanism is not particularly limited to three, and the power storage mechanism includes three or more battery elements. May be connected in parallel.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is an electric circuit diagram which shows the principal part of the power supply device which concerns on 1st Embodiment. It is an electric circuit diagram which shows the principal part of the power supply device which concerns on 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 Power supply device, 200 Electric load, 201,203 Power supply line, 202 Ground line, 300 Inverter, 400 Smoothing capacitor, 500 Boost converter, 502 Boost power module, 504 Reactor, 600 Power storage mechanism, 602, 604, 606 Battery element, 612 , 614 filter capacitor, 620 magnetic coupling circuit, 622, 624, 628 coil, 626 core, D1, D2 diode, Q1, Q2 switching element.

Claims (6)

A converter connected to electrical equipment;
A power storage mechanism connected to the converter,
The power storage mechanism is configured by connecting a plurality of battery elements in parallel,
A power supply device in which power supply lines of the plurality of battery elements are magnetically coupled. A plurality of coils are connected to each of the power lines of the plurality of battery elements,
The power supply device according to claim 1, wherein each of the plurality of coils is wound around the same core.   The power supply device according to claim 2, wherein each of the plurality of coils has the same number of turns. The plurality of battery elements include a first battery element to which a first coil is connected, and a second battery element to which a second coil is connected,
5. The power supply device according to claim 1, wherein the first coil is wound around the core so as to be in a predetermined winding direction with respect to a winding direction of the second coil.   The power supply device according to claim 1, wherein the battery element is a lithium ion battery.   The power supply device according to any one of claims 1 to 5, wherein the power supply device is mounted on a vehicle.

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