JP2012044765A - Battery controller and vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized and light-weighted battery controller, and to provide a vehicle incorporating the same.SOLUTION: The battery controller 1 designed to regulate charging and discharge of a battery B that is capable of charging electric power supplied by an external power source PS, includes: a power inverter circuit 12 that can perform a first conversion for converting DC power supplied by the battery B into AC power to be used to drive a motor MT and a second conversion for converting AC power supplied by the external power source PS into DC power to be used to charge the battery B; and a switcher 13 that switches a connection state of coils m1-m3 of the motor MT and connects the external power source PS to the power inverter circuit 12 via the coils m1-m3 of the motor MT, when the external power source PS is connected.

Description

  The present invention relates to a battery control device that controls charging / discharging of a battery that can be charged by electric power supplied from an external power source, and a vehicle including the device.

  In recent years, in order to realize a low-carbon society, research on hybrid vehicles (HV) that use both an engine and a motor as a power generation source and electric vehicles (EV: Electric Vehicle) that use only a motor as a power generation source has been active. Has been done. These hybrid vehicles and electric vehicles include a secondary battery (battery) such as a rechargeable lithium ion secondary battery that supplies electric power to the motor.

  An electric vehicle can be basically charged by attaching an external charging device to the electric vehicle. In addition, a so-called plug-in hybrid vehicle among hybrid vehicles includes a charging device (plug-in charging device) by itself, unlike an electric vehicle. For this reason, the plug-in hybrid vehicle can charge the battery by inserting a plug of an external power source (for example, a commercial AC power source having a voltage of 200 V) into an insertion port of the plug-in charging device.

  A charging device used for charging a battery included in an electric vehicle includes, for example, a PWM (Pulse Width Modulation) converter, a PWM inverter, and a rectifier, and is necessary for charging the battery from a commercial AC power supply having a voltage of 200V. DC power is generated. Therefore, when the charging device is attached to the electric vehicle, the DC power generated by the charging device is supplied to the electric vehicle and the battery is charged.

  A plug-in charging device included in a plug-in hybrid vehicle includes, for example, a PWM converter and a DC / DC converter, and generates direct-current power necessary for charging a battery from power supplied from an external power source. Therefore, when the plug of the external power supply is inserted into the insertion port of the plug-in charging device, DC power for charging the battery is generated by the plug-in charging device and the battery is charged. Patent Document 1 below discloses an example of a vehicle that includes a plug-in charging device and can charge a battery from the outside.

JP 2009-201197 A

  By the way, as the weight of the vehicle becomes heavier, more energy is required to accelerate and decelerate the vehicle, and thus fuel consumption generally tends to decrease. For this reason, measures are taken to reduce the weight of the vehicle in a vehicle type where fuel efficiency is important. Since the plug-in charging device described above is always mounted on a vehicle such as a plug-in hybrid vehicle where fuel efficiency is important, it is desirable that the plug-in charging device be as small and light as possible.

  Here, a plug-in charging device provided in a vehicle such as a plug-in hybrid vehicle is provided with a reactor for preventing an inrush current that flows when a plug of an external power source is inserted into an insertion port. And this reactor is provided for every phase of the alternating current power which an external power supply supplies. As described above, since the external power source is a commercial AC power source having a voltage of 200 V, for example, it is necessary to provide the plug-in charging device with a reactor having a large weight and shape. If this reactor can be omitted, it is considered that the plug-in charging device can be reduced in size and weight.

  This invention is made | formed in view of the said situation, and aims at providing the vehicle provided with the battery control apparatus which is small and lightweight, and the said apparatus.

In order to solve the above problems, a battery control device according to the present invention is a battery control device (1, 2) that controls charging / discharging of a battery (B) that can be charged by electric power supplied from an external power supply (PS). A first converter that converts DC power supplied from the battery into AC power used to drive a motor (MT); and DC power used to charge the battery using AC power supplied from the external power source. When the external power supply is connected to the power conversion unit (12) capable of performing the second conversion to be converted into the following, the connection state of the windings (m1 to m3) of the motor is switched, and the motor And a switching unit (13) for connecting the external power source to the power conversion unit via a winding.
In the battery control device of the present invention, the motor includes a three-phase winding having one end connected to the power conversion unit, and the switching unit includes the three-phase winding. The connection state of the windings of the motor is switched by short-circuiting or opening the ends.
Further, in the battery control device of the present invention, when the switching unit is not connected to the external power source, the other end of the three-phase winding is short-circuited to make the winding Y-connected, When the external power supply is connected, the other end of the three-phase winding is opened and the other end of the opened three-phase winding is connected to each phase of the external power supply. It is a feature.
The battery control device of the present invention further includes a detection unit (14) that detects whether or not the external power source is connected, and the switching unit is configured to perform the detection based on a detection result of the detection unit. It is characterized by switching the wiring connection state of the motor.
The battery control device of the present invention controls the switching of the connection state of the winding by the switching unit according to the detection result of the detection unit, and the power conversion unit performs the first and second conversions. A control unit (15) for controlling which of the conversions is performed is provided.
The vehicle according to the present invention is a vehicle including a motor (MT) as a power generation source and a battery (B) that can be charged by electric power supplied from an external power source (PS) and supplies electric power to the motor. The battery control device according to any one of the above aspects that controls charging / discharging of the battery is provided.

  According to the present invention, the first conversion for converting the DC power supplied from the battery into the AC power used for driving the motor, and the AC power supplied from the external power source is converted into the DC power used for charging the battery. A power conversion unit capable of second conversion is provided, and when an external power supply is connected, the switching state switches the connection state of the windings of the motor, and the external power supply is converted through the motor windings. I am trying to connect to the part. For this reason, the reactor for preventing the inrush current, which has been necessary in the past, can be substituted with the winding of the motor, and the power conversion unit is used for the motor drive control and the battery charge control. Therefore, the battery control device can be reduced in size and weight.

It is a circuit diagram which shows the principal part structure of the battery control apparatus by 1st Embodiment of this invention. It is a circuit diagram which shows the principal part structure of the battery control apparatus by 2nd Embodiment of this invention.

  Hereinafter, a battery control device and a vehicle according to an embodiment of the present invention will be described in detail with reference to the drawings. In the following, it is assumed that the vehicle is a plug-in hybrid vehicle, and the battery control device controls charging / discharging of a battery provided in the plug-in hybrid vehicle.

[First Embodiment]
FIG. 1 is a circuit diagram showing a main configuration of the battery control apparatus according to the first embodiment of the present invention. As shown in FIG. 1, the battery control device 1 of the present embodiment includes a capacitor 11, a power conversion circuit 12 (power conversion unit), a switch 13 (switching unit), a phase detection circuit 14 (detection unit), and a control circuit 15. (Control part) is provided, and charging / discharging of the battery B is controlled.

  Here, the battery B is a secondary battery such as a lithium ion secondary battery provided in the plug-in hybrid vehicle, and can be charged by the power supplied from the external power source PS. Electric power is supplied to a motor MT as a power generation source provided in the motor. The external power source PS is a commercial AC power source that supplies, for example, three-phase AC power having a voltage of 200 V, and a battery is inserted by inserting a plug into a charging port (not shown) provided in the plug-in hybrid vehicle. Connected to the control device 1.

  The motor MT has three-phase (U-phase, V-phase, and W-phase) windings m1 to m3, and power from the battery B (power conversion circuit 12) is supplied to each of these windings m1 to m3. The AC drive is rotated by being supplied. The windings m1 to m3 of the motor MT have one end connected to the power conversion circuit 12 and the other end connected to the switch 13. Although details will be described later, the wirings m <b> 1 to m <b> 3 of the motor MT are switched in the connection state when the other ends can be short-circuited or opened by the switch 13.

  The capacitor 11 is connected between the positive electrode and the negative electrode of the battery B, and smoothes the electric power supplied from the external power source PS and rectified by the power conversion circuit 12 when the battery B is charged into DC power. Provided for. The power conversion circuit 12 converts DC power supplied from the battery B into AC power (three-phase AC power) used for driving the motor MT under the control of the control circuit 15 (first conversion). Alternatively, AC / DC conversion (second conversion) for converting AC power (three-phase AC / AC power) supplied from the external power source PS into DC power used for charging the battery B is performed.

  The power conversion circuit 12 includes transistors 21a to 21f and diodes 22a to 22f. The transistors 21 a to 21 f are bipolar transistors, and the on state and the off state are controlled by the control circuit 15. Note that FET transistors (Field Effect Transistors) may be used as the transistors 21a to 21f.

  Transistors 21a, 21c, and 21e have collector electrodes connected to one electrode of capacitor 11, and emitter electrodes connected to collector electrodes of transistors 21b, 21d, and 21f, respectively. The transistors 21b, 21d, and 21f have emitter electrodes connected to the other electrode of the capacitor 11. Base electrodes of these transistors 21 a to 21 f are connected to the control circuit 15. The diodes 22a to 22f are connected between the collectors and emitters of the transistors 21a to 21f, respectively.

  By causing each of the transistors 21a to 21f to perform a switching operation (for example, a PWM switching operation) according to a preset rule, the DC power from the battery B is converted into AC power and output to the motor MT. Such DC / AC conversion is controlled by the control circuit 15 when the plug of the external power source PS is not inserted into the charging port (not shown) and the external power source PS is not connected. Done under.

  On the other hand, when AC power (AC power from the external power source PS) is supplied via the motor MT when the transistors 21a to 21f are all in the OFF state, the AC power is rectified by the diodes 22a to 22f. And is smoothed by the capacitor 11 to be converted into DC power and output to the battery B. Here, even when AC / DC conversion is performed in the power conversion circuit 12, the switching operation of the transistors 21a to 21f is performed when the power conversion amount is controlled. Note that such AC / DC conversion is performed under the control of the control circuit 15 when the external power supply PS is connected.

  The switch 13 is connected to the other ends of the windings m1 to m3 of the motor MT, and the windings m1 to m3 are controlled under the control of the control circuit 15 depending on whether or not the external power source PS is connected. Switch the connection status of. Specifically, when the external power source PS is not connected, the switcher 13 short-circuits the other ends of the windings m1 to m3 included in the motor MT to make the windings m1 to m3 Y-connected. The other ends of the shorted windings m1 to m3 are neutral points.

  On the other hand, when the external power supply PS is connected, the switch 13 opens the other ends of the windings m1 to m3 of the motor MT and switches the connection state of the windings m1 to m3. The external power source PS is connected to the power conversion circuit 12 via the MT windings m1 to m3. That is, for example, the U phase of the external power supply PS is connected to the power conversion circuit 12 via the winding m1, the V phase is connected to the power conversion circuit 12 via the winding m2, and the W phase is connected via the winding m3. Connected to the power conversion circuit 12. The windings m1 to m3 thus connected function as a reactor for preventing an inrush current that flows when the plug of the external power supply PS is inserted into the insertion port.

  In the present embodiment, an example in which switching of the switch 13 is controlled by the control circuit 15 will be described, but the switching control is not necessarily performed by the control circuit 15. For example, a switch for detecting whether or not a plug is inserted in a charging port (not shown) is provided, and when this switch is turned on, the switching of the switch 13 is automatically mechanically or electrically. It may be performed automatically.

  The phase detection circuit 14 is a circuit that detects the phase of each phase of AC power supplied from the external power supply PS when a plug is inserted into a charging port (not shown). The phase detection by the phase detection circuit 14 is performed when the plug is inserted into a charging port (not shown), and is not performed when the plug is not inserted. For this reason, the detection result of the phase detection circuit 14 is also used to determine whether or not a plug is inserted in the charging port (not shown).

  The control circuit 15 controls the power conversion circuit 12 so that the charge / discharge current of the battery B becomes a current instructed in advance while referring to the detection result of the phase detection circuit 14. Although not shown in FIG. 1, the battery control device 1 is provided with a voltage sensor for detecting the output voltage of the battery B and a current sensor for detecting the current flowing through the battery B. 15 controls the power conversion circuit 12 while also referring to the detection results of these sensors. The control circuit 15 also performs switching control of the switch 13 according to the detection result of the phase detection circuit 14.

  Next, the operation of the battery control device 1 having the above configuration will be described. The operation of the battery control device 1 is broadly divided into a driving operation when the motor MT is driven using the electric power of the battery B and a charging operation when charging the battery B using the external power source PS. Hereinafter, each operation will be described in order.

[Driving operation]
When the motor MT is driven using the power of the battery B, a plug (external power supply PS plug) is inserted into a charging port (not shown) provided in the plug-in hybrid vehicle. Absent. For this reason, since the phase detection circuit 14 does not perform phase detection, the control circuit 15 controls the switch 13 to short-circuit the other ends of the windings m1 to m3 provided in the motor MT. As a result, the windings m1 to m3 provided in the motor MT are Y-connected.

  When the control on the switch 13 is completed, the control circuit 15 starts the switching operation of each of the transistors 21a to 21f provided in the power conversion circuit 12. When the switching operation of the transistors 21a to 21f is started, the DC power from the battery B is converted into AC power. This AC power is supplied to each of the windings m1 to m3 of the motor MT via the switch 13, and thereby the motor MT is driven.

  Here, when the duty ratio, which is the ratio between the length of the switching cycle of the transistors 21a to 21f and the time during which the transistors 21a to 21f are on, is increased under the control of the control circuit 15, the average supplied to the motor MT is increased. The amount of electric power increases, and the rotational speed of the motor MT increases accordingly. On the other hand, when the duty ratio is reduced by the control of the control circuit 15, the average amount of electric power supplied to the motor MT is reduced, and thereby the rotational speed of the motor MT is lowered. In this way, drive control of the motor M is performed.

[Charging operation]
When charging the battery B using the power from the external power source PS, the user first inserts the plug of the external power source PS into a charging port (not shown) provided in the plug-in hybrid vehicle. Then, AC power from the external power source PS is supplied to the battery control device 1 through the plug, and the phase detection circuit 14 detects the phase of the AC power.

  When the detection result of the phase detection circuit 14 is output to the control circuit 15, the control circuit 15 controls the switch 13 to open the other ends of the windings m1 to m3 provided in the motor MT so as to open the windings m1 to m1. The connection state of m3 is switched, and the external power source PS is connected to the power conversion circuit 12 via the windings m1 to m3. By such control, the windings m1 to m3 functioning as the reactor are interposed between the external power source PS and the power / power conversion circuit 12, thereby preventing an inrush current.

  When the above control ends, the control circuit 15 starts the switching operation of each of the transistors 21a to 21f provided in the power conversion circuit 12 while referring to the detection result of the phase detection circuit 14 and the like. Note that the transistors 21a to 21f may be maintained in an off state depending on the specifications of the battery B and the state of charge.

  Here, in order to simplify the description, assuming that all of the transistors 21a to 21f are maintained in an off state, a three-phase full-wave rectifier circuit is configured by the diodes 22a to 22f provided in the power conversion circuit 12. The The AC power supplied from the external power source PS is input to the power conversion circuit 12 via the windings m1 to m3 of the motor MT, and is rectified by the diodes 22a to 22f constituting the three-phase full-wave rectification circuit. It is converted to DC power by being smoothed. The DC power converted in this way is supplied to the battery B, and the battery B is charged.

  Here, consider a case where the switching operations of the transistors 21a to 21f are performed at a certain duty ratio. In such a case, for example, by appropriately changing the duty ratio of the switching operation of each of the transistors 21a to 21f, the amount of power converted from AC power to DC power by the power conversion circuit 12 is increased or decreased, and the battery B The amount of power used for charging can be varied. In this way, charging control of the battery B is performed.

  As described above, in the present embodiment, when the external power supply PS is connected, the connection state of the windings m1 to m3 of the motor MT is switched by the switch 13, and the windings m1 to m3 of the motor M3 are switched. Thus, the external power source PS is connected to the power conversion circuit 12. For this reason, in this embodiment, when the external power supply PS is connected, the windings m1 to m3 of the motor MT can be used as a reactor for preventing an inrush current, and the battery control device 1 can be used. Small and lightweight.

  In the present embodiment, the DC power supplied from the battery B is converted to AC power used for driving the motor MT, and the AC power supplied from the external power source PS is used for charging the battery B. A power conversion circuit 12 capable of AC / DC conversion for converting to DC power is provided. For this reason, in this embodiment, since the power conversion circuit 12 can be shared by the case where the drive control of the motor MT is performed and the case where the charge control of the battery B is performed, the battery control device 1 is made small and light. Can do. Further, by providing the small and light battery control device 1 in the plug-in hybrid vehicle, the fuel efficiency of the plug-in hybrid vehicle can be improved.

[Second Embodiment]
FIG. 2 is a circuit diagram showing a main configuration of the battery control apparatus according to the second embodiment of the present invention. In FIG. 2, the same components as those shown in FIG. 1 are denoted by the same reference numerals. As shown in FIG. 2, the battery control device 2 of the present embodiment has a configuration in which a DC / DC converter 30 is added to the battery control device 1 shown in FIG. 1 and the control circuit 15 is replaced with a control circuit 40. The power conversion circuit 12 can only perform a boosting operation when charging the battery B using power from the external power source PS. Since it is necessary to reduce the voltage applied to the battery B depending on the specifications of the battery B, in this embodiment, the DC / DC converter 30 and the control circuit 40 are provided and correspond to the battery B having such specifications. .

  The DC / DC converter 30 is provided between the battery B and the capacitor 11. Under the control of the control circuit 40, the DC power supplied from the battery B or the DC power smoothed by the capacitor 11 is obtained. Perform power conversion. The DC / DC converter 30 includes a capacitor 31, a choke coil 32, transistors 33a and 33b, and diodes 34a and 34b. The capacitor 31 is connected between the positive electrode and the negative electrode of the battery B. The choke coil 32 has one end connected to one electrode of the capacitor 31 and the other end connected to a connection point between the emitter electrode of the transistor 33a and the collector electrode of the transistor 33b.

  The transistors 33 a and 33 b are bipolar transistors, and the ON state and the OFF state are controlled by the control circuit 40. Note that FET transistors may be used as the transistors 33a and 33b. The transistor 33a has a collector electrode connected to one electrode of the capacitor 11, and an emitter electrode connected to the collector electrode of the transistor 33b. The transistor 33 b has an emitter electrode connected to the other electrode of the capacitor 11. The base electrodes of the transistors 33a and 33b are connected to the control circuit 40. The diodes 34a and 34b are connected between the collectors and emitters of the transistors 33a to 33b, respectively.

  The DC / DC converter 30 operates as a non-insulated boost choke converter by turning off the transistor 33a and switching the transistor 33b (for example, PWM switching operation). For this reason, the output voltage of the battery B can be boosted. This operation is performed under the control of the control circuit 40 when the external power source PS is not connected.

  On the other hand, by turning off the transistor 33b and switching the transistor 33a (for example, PWM switching operation), the DC / DC converter 30 operates as a non-insulated step-down choke converter. For this reason, the voltage appearing on the capacitor 11 can be stepped down to a voltage suitable for the battery B. This operation is performed under the control of the control circuit 40 when the external power source PS is connected.

  Similar to the control circuit 15 shown in FIG. 1, the control circuit 40 controls the power conversion circuit 12 while referring to the detection result of the phase detection circuit 14, and the switch 13 according to the detection result of the phase detection circuit 14. Switching control is performed. In addition to these controls, the control circuit 40 causes each of the transistors 33a and 33b provided in the DC / DC converter 30 to perform a switching operation (PWM switching operation).

  Specifically, when the external power supply PS is not connected, for example, the transistor 33a is turned off and the transistor 33b is controlled to perform a switching operation. On the other hand, when the external power supply PS is connected, for example, the transistor 33b is turned off and the transistor 33a is controlled to perform a switching operation. Note that the duty ratio when the transistors 33a and 33b are PWM-switched is controlled according to the degree to which the voltage is raised or lowered.

  The operation of the battery control device 2 in the above configuration is that the output voltage of the battery B is boosted by the DC / DC converter 30 during drive control of the motor MT, and the voltage appearing at the capacitor 11 is stepped down during charge control of the battery B. Except for this, it is basically the same as the operation of the battery control device 1 of the first embodiment. For this reason, the details of the operation of the battery control device 2 are omitted here.

  Also in this embodiment, when the external power source PS is connected, the connection state of the windings m1 to m3 of the motor MT is switched by the switch 13, and the external power source is connected via the windings m1 to m3 of the motor M3. PS is connected to the power conversion circuit 12. For this reason, in this embodiment, when the external power supply PS is connected, the windings m1 to m3 of the motor MT can be used as a reactor for preventing an inrush current, and the battery control device 1 can be used. Small and lightweight.

  Also in this embodiment, DC / AC conversion for converting DC power supplied from the battery B into AC power used for driving the motor MT and AC power supplied from the external power source PS are used for charging the battery B. A power conversion circuit 12 capable of AC / DC conversion to be converted into DC power is provided. For this reason, since the power converter circuit 12 can be shared by the case where the drive control of the motor MT is performed and the case where the charge control of the battery B is performed, the battery control device 1 can be made small and light. Further, by providing the small and light battery control device 2 in the plug-in hybrid vehicle, the fuel efficiency of the plug-in hybrid vehicle can be improved.

  As mentioned above, although the battery control apparatus and vehicle by embodiment of this invention were demonstrated, this invention is not restrict | limited to the said embodiment, It can change freely within the scope of the present invention. For example, in the above embodiment, the case where the vehicle is a plug-in hybrid vehicle has been described as an example. However, the present invention can be generally applied to a vehicle including a battery that can be charged by electric power supplied from an external power source and a motor as a power generation source that generates power by the electric power supplied from the battery. For example, in addition to the plug-in hybrid vehicle described above, the present invention can also be applied to vehicles such as electric vehicles and electric heavy machinery.

DESCRIPTION OF SYMBOLS 1, 2 Battery control apparatus 12 Power conversion circuit 13 Switch 14 Phase detection circuit 15 Control circuit B Battery m1-m3 Winding MT Motor PS External power supply

Claims (6)

A battery control device that controls charging / discharging of a battery that can be charged by electric power supplied from an external power source,
A first conversion for converting DC power supplied from the battery into AC power used for driving a motor, and a second conversion for converting AC power supplied from the external power source into DC power used for charging the battery A power conversion unit capable of
A switching unit that switches a connection state of windings of the motor when the external power source is connected, and connects the external power source to the power conversion unit via the windings of the motor. A battery control device. The motor has three-phase windings each having one end connected to the power conversion unit,
The battery control device according to claim 1, wherein the switching unit switches a connection state of the windings of the motor by short-circuiting or opening the other end of the three-phase windings. When the external power supply is not connected, the switching unit short-circuits the other end of the three-phase winding to make the winding Y-connected,
When the external power supply is connected, the other end of the three-phase winding is opened and the other end of the opened three-phase winding is connected to each phase of the external power supply. The battery control device according to claim 2, wherein: A detection unit for detecting whether the external power supply is connected;
4. The battery control device according to claim 1, wherein the switching unit switches a connection state of windings of the motor based on a detection result of the detection unit. 5.   According to the detection result of the detection unit, the switching unit controls the switching of the wiring connection state of the winding, and which of the first conversion and the second conversion is to be performed by the power conversion unit. The battery control device according to claim 4, further comprising a control unit that controls the battery control device. A vehicle including a motor as a power generation source and a battery that can be charged by electric power supplied from an external power source and supplies electric power to the motor,
A vehicle comprising the battery control device according to any one of claims 1 to 5, which controls charging and discharging of the battery.

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