JP2008278557A - Controller of electric vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control a temperature rise in a motor when power is delivered to/from the outside of a vehicle by using a drive motor. <P>SOLUTION: The electric vehicle comprises a power supply system 100 having a power accumulator 10, a section 110 for generating a driving force by power from the power supply system 100, and a supply line ACL for connecting the driving force generating section 110 and the outside of a vehicle electrically. The driving force generating section 110 includes motor generators MG1, MG2 having a rotor to which a permanent magnet is attached, and inverters 20, 22. The supply line ACL connects the neutrals N1, N2 of the motor generators MG1, MG2 and the outside of a vehicle electrically. A drive ECU 80 controls the inverters 20, 22 to convert AC power supplied between the neutrals N1, N2 into DC power, and operates an electric oil pump 120 such that heat exchange takes place between the refrigerant and the motor generators MG1, MG2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device for an electric vehicle, and more particularly, to a control device for an electric vehicle configured to be able to exchange power with the outside of the vehicle.

  In recent years, in consideration of environmental problems, electric vehicles using an electric motor as a driving force source, such as an electric vehicle, a hybrid vehicle, and a fuel cell vehicle, have attracted attention. Such an electric vehicle is equipped with a power storage unit consisting of a secondary battery, an electric double layer capacitor, etc., for supplying electric power to the motor or for storing kinetic energy by converting it into electric energy during regenerative braking. Has been.

  In a vehicle using such an electric motor as a driving force source, it is desirable to increase the charge / discharge capacity of the power storage unit in order to improve traveling performance such as acceleration performance and traveling distance. Therefore, for example, JP-A-9-233709 (Patent Document 1), JP-A-8-126121 (Patent Document 2), and JP-A-4-295202 (Patent Document 3) disclose commercial vehicles outside an electric vehicle. A method for charging a power storage unit using a power source is disclosed.

According to these patent documents, the coil of the motor for driving the vehicle is used as the reactor, and the power storage unit is charged from the commercial power source by controlling the circuit element of the inverter that controls the motor. Yes.
JP-A-9-233709 JP-A-8-126121 JP-A-4-295202 JP 2006-14438 A

  According to the charging method disclosed in the above-mentioned patent document, the parts already existing in the electric vehicle (vehicle driving motor and inverter) are used as the charging device, so the number of newly mounted parts is reduced and the size of the vehicle is increased. And an increase in weight can be suppressed.

  On the other hand, when the coil of the drive motor is energized and the power storage unit is charged while the vehicle is stopped, the temperature of the drive motor rises due to Joule heat generated in the coil. For this reason, when a permanent magnet motor in which a permanent magnet is disposed as a driving motor is used, the magnet temperature may rise and demagnetization may occur in the permanent magnet.

  Due to the occurrence of demagnetization, the permanent magnet motor has a problem that the driving efficiency (rotational efficiency, power generation efficiency) is lowered when the electric vehicle travels after charging is completed. Therefore, in order to increase the energy efficiency of the electric vehicle, it is necessary to be able to cool the drive motor even when the vehicle is stopped.

  However, in JP-A-9-233709 (Patent Document 1), JP-A-8-126121 (Patent Document 2) and JP-A-4-295202 (Patent Document 3), a coil of a driving motor is used. Only a configuration for charging the power storage unit with electric power supplied from a commercial power source is disclosed, and no means for solving such a problem is disclosed.

  As a motor cooling system, Japanese Patent Laid-Open No. 2006-14438 (Patent Document 4) supplies ATF (Automatic Transmission Fluid) of a hydraulic circuit of an automatic transmission to the inside of a traveling motor, A technique for cooling a traveling motor using ATF as a cooling oil is disclosed.

  However, Japanese Patent Laying-Open No. 2006-14438 (Patent Document 4) merely discloses a configuration for performing control for cooling the traveling motor using the ATF from the automatic transmission when the vehicle is traveling, as described above. No mention is made of cooling measures for the traveling motor while the vehicle is stopped.

  Therefore, the present invention has been made to solve such a problem, and an object of the present invention is to provide an electric motor that transmits and receives electric power to / from the outside of the vehicle using an electric motor configured to generate a vehicle driving force. An object of the present invention is to provide a control device for an electric vehicle capable of suppressing an increase in temperature of the electric motor during power transfer.

  According to an aspect of the present invention, the control device for an electric vehicle is a control device for an electric vehicle configured to be able to exchange power with the outside of the vehicle. The electric vehicle includes a power supply system having a power storage unit configured to be chargeable / dischargeable, a driving force generation unit that generates driving force by receiving electric power supplied from the power supply system, and the driving force generation unit and the outside of the vehicle are electrically connected. And a supply line for connection. The driving force generator includes a rotating electrical machine configured to include a star-connected stator, a rotor on which a permanent magnet is mounted, and an inverter for driving the rotating electrical machine. The supply line is configured to electrically connect the neutral point of the rotating electrical machine and the outside of the vehicle. The control device includes a power conversion control unit that controls a switching operation in the inverter so as to perform power conversion between the DC power from the power supply system and the AC power input / output to / from the supply line, and control by the power conversion control unit And a cooling control means for operating the cooling device so that heat is exchanged between the refrigerant and the rotating electrical machine.

  According to the control device for an electric vehicle described above, when power is transferred between the power supply system mounted on the electric vehicle and the outside of the vehicle via the neutral point of the rotary electric machine, Is cooled by heat exchange with the refrigerant. As a result, since the temperature rise of the rotating electrical machine can be suppressed, demagnetization of the permanent magnet attached to the rotor of the rotating electrical machine can be prevented.

  Preferably, the cooling device includes a refrigerant path through which the refrigerant flows and an electric pump that circulates the refrigerant in the refrigerant path. The rotating electrical machine is disposed in the refrigerant path. The cooling control means operates the electric pump during execution of control by the power conversion control means.

  According to the above control device for an electric vehicle, when electric power is transferred between the power supply system and the outside of the vehicle, the electric rotating machine is operated to cool the rotating electric machine by heat exchange with the refrigerant. be able to.

  Preferably, the electric pump circulates the refrigerant in the refrigerant passage in response to electric power exchanged between the vehicle exterior and the power supply system.

  According to the above control device for an electric vehicle, the electric pump can be efficiently operated using electric power exchanged between the vehicle exterior and the power supply system.

  Preferably, at least a part of the refrigerant path is formed so that the refrigerant flows from the hollow shaft constituting the rotating shaft of the rotating electrical machine toward the rotor.

  According to the control device for an electric vehicle described above, heat exchange is directly performed between the refrigerant supplied to the rotating electrical machine and the rotor, so that the permanent magnet mounted on the rotor can be efficiently cooled. it can.

  Preferably, the control device for the electric vehicle further includes temperature acquisition means for acquiring the temperature of the rotating electrical machine. The cooling control unit sets a target value of the refrigerant supply amount in the cooling device according to the temperature of the rotating electrical machine acquired by the temperature acquisition unit, and controls the cooling device so that the refrigerant supply amount matches the target value. To do.

  According to the above-described control device for an electric vehicle, the cooling device is controlled so as to have an appropriate cooling capacity for the rotating electrical machine that rises in temperature in response to power exchange with the outside of the vehicle. Thereby, power saving of a cooling device can be achieved, ensuring the cooling property of a rotary electric machine. As a result, the power loss that occurs in the power transfer path can be reduced, so that the energy efficiency of the power supply system can be improved.

  Preferably, the electric vehicle further includes a connector for ensuring an electrical connection between the supply line and the outside of the vehicle. The power conversion control means starts the switching operation in response to securing of the electrical connection between the supply line and the outside of the vehicle by closing the connector. The cooling control unit operates the cooling device when execution of control by the power conversion control unit is started.

  According to the above control device for an electric vehicle, since the cooling device operates in conjunction with the start of power transfer with the outside of the vehicle, the temperature rise of the rotating electrical machine can be reliably suppressed.

  Preferably, the electric vehicle further includes a connector for ensuring an electrical connection between the supply line and the outside of the vehicle. The power conversion control means starts the switching operation in response to securing of the electrical connection between the supply line and the outside of the vehicle by closing the connector. The cooling control unit operates the cooling device when the temperature of the rotating electrical machine acquired by the temperature acquisition unit becomes equal to or higher than a predetermined threshold after the execution of control by the power conversion control unit is started.

  According to the control device for an electric vehicle described above, the cooling device operates when the temperature of the rotating electrical machine becomes equal to or higher than a predetermined threshold value. Therefore, the power consumption of the cooling device is further reduced while ensuring the cooling performance of the rotating electrical machine. be able to. As a result, the energy efficiency of the power supply system is further improved.

  Preferably, the electric vehicle further includes a connector for ensuring an electrical connection between the supply line and the outside of the vehicle. The power conversion control means performs the switching operation when the electrical connection between the supply line and the outside of the vehicle is ensured by closing the connector, and the temperature of the rotating electrical machine acquired by the temperature acquisition means falls below a predetermined threshold. Let it begin.

  According to the above-described control device for an electric vehicle, when the rotating electrical machine is in a high temperature state immediately after the vehicle stops, power transfer with the outside of the vehicle is prohibited, so that the temperature increase of the rotating electrical machine is more reliably suppressed. can do.

  Preferably, the power conversion control means sets a target value of power exchanged between the outside of the vehicle and the power storage unit according to the temperature of the rotating electrical machine acquired by the temperature acquisition means, and between the outside of the vehicle and the power storage unit. The switching operation is controlled so that the power exchanged in step 1 matches the target value.

  According to the control device for an electric vehicle described above, the temperature increase of the rotating electrical machine can be reliably suppressed by controlling the electric power exchanged with the outside of the vehicle according to the temperature of the rotating electrical machine.

  Preferably, when the temperature of the rotating electrical machine acquired by the temperature acquisition unit is equal to or higher than a predetermined threshold, the power conversion control unit sets a target value of power transferred between the outside of the vehicle and the power storage unit to charge the power storage unit. It sets so that it may become lower than discharge allowable power.

  According to the above control device for an electric vehicle, since the electric power exchanged with the outside of the vehicle is limited when the rotating electrical machine is in a high temperature state, the rotating electrical machine can be prevented from being overheated.

  Preferably, the rotating electric machine includes first and second rotating electric machines each including a stator that is star-connected and a rotor on which a permanent magnet is mounted. The inverter includes first and second inverters for driving the first and second electric motors. The supply line is configured to electrically connect the neutral point of the first rotating electrical machine and the neutral point of the second rotating electrical machine to the outside of the vehicle.

  According to the above control device for an electric vehicle, since it is not necessary to newly provide an inverter, the configuration of the vehicle can be simplified. As a result, the power supply system can be constructed at a low cost.

  According to the present invention, in an electric vehicle that transfers electric power to and from the outside of the vehicle using an electric motor configured to generate a vehicle driving force, an increase in temperature of the electric motor at the time of electric power transfer can be suppressed. . As a result, demagnetization of the permanent magnet mounted on the rotor of the electric motor can be prevented.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
(Configuration of electric vehicle)
FIG. 1 is a schematic configuration diagram showing a main part of an electric vehicle to which a control device according to Embodiment 1 of the present invention is applied.

  Referring to FIG. 1, an electric vehicle includes a power supply system 100, a converter 18, inverters 20 and 22, motor generators MG1 and MG2, a battery ECU (Electrical Control Unit) 30, a converter ECU 40, and a drive ECU 80. Is provided.

  Inverters 20, 22, motor generators MG 1, MG 2, and drive ECU 80 constitute drive force generator 110 that generates the drive force of the vehicle. In the present embodiment, the vehicle travels by transmitting a driving force generated by electric power supplied from power supply system 100 to driving force generation unit 110 to wheels (not shown). Further, at the time of regeneration, the vehicle generates electric power from the kinetic energy by the driving force generation unit and collects it in the power supply system 100.

  In the present embodiment, as an example of power storage unit 10, power supply system 100 including a secondary battery configured to be chargeable / dischargeable, such as a nickel metal hydride battery or a lithium ion battery, or an electric double layer capacitor will be described. Power supply system 100 exchanges DC power with a driving force generator through main positive bus MPL and main negative bus MNL.

  Inverters 20 and 22 are connected in parallel to main positive bus MPL and main negative bus MNL, and transfer power to and from power supply system 100, respectively. That is, inverters 20 and 22 convert drive power (DC power) received via main positive bus MPL and main negative bus MNL into AC power and supply it to motor generators MG1 and MG2, respectively, while motor generators MG1 and MG2 AC power generated by the power is converted to DC power and supplied to the power supply system 100 as regenerative power. Inverters 20 and 22 are constituted by bridge circuits including switching elements for three phases, for example, and perform switching (circuit opening / closing) operations in accordance with switching commands PWM1 and PWM2 received from drive ECU 80, respectively. , Generate three-phase AC power.

  Motor generators MG1 and MG2 can generate rotational driving force by receiving AC power supplied from inverters 20 and 22, respectively, and can generate electric power by receiving external rotational driving force. As an example, motor generators MG1 and MG2 are three-phase AC rotating electric machines including a rotor in which permanent magnets are embedded. Motor generators MG1 and MG2 are coupled to power split mechanism PSD, respectively, and transmit the generated driving force to wheels (not shown) by drive shaft 28.

  When drive force generation unit 110 is applied to a hybrid vehicle, motor generators MG1 and MG2 are also connected to an engine (not shown) via power split mechanism PSD or drive shaft 28. Then, control is executed by drive ECU 80 so that the drive force generated by the engine and the drive force generated by motor generators MG1, MG2 have an optimal ratio. When applied to such a hybrid vehicle, motor generator MG1 can function exclusively as a generator, and motor generator MG2 can function exclusively as an electric motor.

FIG. 2 is a schematic diagram for explaining the details of the driving force generator 110 in FIG.
Referring to FIG. 2, driving force generator 110 rotates in accordance with the rotation of motor generator MG2, reduction gear RD connected to the rotation shaft of motor generator MG2, and the rotation shaft decelerated by reduction gear RD. The vehicle includes an axle, an engine 4, a motor generator MG1, a speed reducer RD, and a power split mechanism PSD that distributes power between the engine 4 and the motor generator MG1. Reducer RD has a reduction ratio from motor generator MG2 to power split device PSD of, for example, twice or more.

  The crankshaft 50 of the engine 4, the rotor 32 of the motor generator MG1, and the rotor 37 of the motor generator MG2 rotate about the same axis.

  The power split mechanism PSD is a planetary gear in the example shown in FIG. 2, and is supported so as to be rotatable coaxially with the crankshaft 50 and a sun gear 51 coupled to a hollow sun gear shaft penetrating the crankshaft 50 through the shaft center. The ring gear 52 is disposed between the sun gear 51 and the ring gear 52, and revolves while rotating around the outer periphery of the sun gear 51. The pinion gear 53 is coupled to the end of the crankshaft 50 and supports the rotation shaft of each pinion gear 53. A planetary carrier 54.

  In the power split mechanism PSD, a sun gear shaft coupled to the sun gear 51, a ring gear case coupled to the ring gear 52, and a crankshaft 50 coupled to the planetary carrier 54 serve as power input / output shafts. When the power input / output to / from any two of the three axes is determined, the power input / output to the remaining one axis is determined based on the power input / output to the other two axes.

  A counter drive gear 70 for taking out power is provided outside the ring gear case, and rotates integrally with the ring gear 52. Counter drive gear 70 is connected to power transmission reduction gear RG. Power is transmitted between the counter drive gear 70 and the power transmission reduction gear RG. The power transmission reduction gear RG drives the differential gear DEF. On the downhill or the like, the rotation of the wheel is transmitted to the differential gear DEF, and the power transmission reduction gear RG is driven by the differential gear DEF.

  Motor generator MG1 includes a stator 31 that forms a rotating magnetic field, and a rotor 32 that is disposed inside stator 31 and has a plurality of permanent magnets embedded therein. The stator 31 includes a stator core 33 and a three-phase coil 34 wound around the stator core 33. Rotor 32 is coupled to a sun gear shaft that rotates integrally with sun gear 51 of power split device PSD. The stator core 33 is formed by laminating thin magnetic steel plates and is fixed to a case (not shown).

  Motor generator MG1 operates as an electric motor that rotationally drives rotor 32 by the interaction between the magnetic field generated by the permanent magnet embedded in rotor 32 and the magnetic field formed by three-phase coil 34. Motor generator MG1 also operates as a generator that generates electromotive force at both ends of three-phase coil 34 due to the interaction between the magnetic field generated by the permanent magnet and the rotation of rotor 32.

  Motor temperature Tmot1, which is the internal temperature of motor generator MG1, is detected by temperature detector 24 (FIG. 1) and output to converter ECU 40 and drive ECU 80. The temperature detection unit 24 is configured by a thermistor or the like disposed at the coil end portion of the stator core 33.

  Motor generator MG2 includes a stator 36 that forms a rotating magnetic field, and a rotor 37 that is disposed inside stator 31 and has a plurality of permanent magnets embedded therein. The stator 36 includes a stator core 38 and a three-phase coil 39 wound around the stator core 38.

  The rotor 37 is coupled to a ring gear case that rotates integrally with the ring gear 52 of the power split mechanism PSD by a reduction gear RD. Stator core 38 is formed, for example, by laminating thin magnetic steel plates, and is fixed to a case (not shown).

  Motor generator MG2 also operates as a generator that generates electromotive force at both ends of three-phase coil 39 by the interaction between the magnetic field generated by the permanent magnet and the rotation of rotor 37. Motor generator MG2 operates as an electric motor that rotationally drives rotor 37 by the interaction between the magnetic field generated by the permanent magnet and the magnetic field formed by three-phase coil 39.

  Motor temperature Tmot2, which is the internal temperature of motor generator MG2, is detected by temperature detector 26 (FIG. 1) and output to converter ECU 40 and drive ECU 80. The temperature detection unit 26 is configured by a thermistor disposed at the coil end portion of the stator core 38.

  The speed reducer RD performs speed reduction by a structure in which a planetary carrier 66 that is one of rotating elements of a planetary gear is fixed to a case of a vehicle drive device. That is, the reduction gear RD includes a sun gear 62 coupled to the shaft of the rotor 37, a ring gear 68 that rotates integrally with the ring gear 52, and a pinion gear 64 that meshes with the ring gear 68 and the sun gear 62 and transmits the rotation of the sun gear 62 to the ring gear 68. Including.

  For example, by making the number of teeth of the ring gear 68 more than twice that of the sun gear 62, the reduction ratio can be made more than twice.

  Referring to FIG. 1 again, the drive ECU 80 executes a program stored in advance, so that a signal transmitted from each sensor (not shown), a traveling state, a rate of change of the accelerator opening, a stored map, and the like Based on the above, torque target values TR1, TR2 and rotation speed target values MRN1, MRN2 of motor generators MG1, MG2 are calculated. Then, drive ECU 80 generates switching commands PWM1 and PWM2 so as to generate torque and rotation speed of motor generators MG1 and MG2 at torque target values TR1 and TR2 and rotation speed target values MRN1 and MRN2, respectively. 22 is controlled. Further, drive ECU 80 outputs calculated torque target values TR1, TR2 and rotation speed target values MRN1, MRN2 to power supply system 100.

  Further, in the present embodiment, neutral points N1 and N2 of motor generators MG1 and MG2 are electrically connected to a commercial power supply in house 200 outside the vehicle via supply line ACL and connector 90, and the commercial power supply It is configured to be able to transfer power to and from.

  Under such a configuration, inverters 20 and 22 will be described later in a mode (hereinafter also referred to as an external charging mode) in which power storage unit 10 included in power supply system 100 is charged by a commercial power supplied from the outside of the vehicle. The method receives commercial power supplied from the outside of the vehicle via the connector 90 and the supply line ACL, and generates DC power to be supplied to the power supply system 100. In addition, in a mode in which power supplied from power supply system 100 is supplied to house 200 (hereinafter referred to as power supply mode), inverters 20 and 22 receive alternating current from power supply system 100 and supply AC to house 200. Generate power.

  The supply current detector 84 interposed in the positive supply line ACLp detects the supply current IAC from the commercial power supply and outputs the detected value to the drive ECU 80. The supply voltage detection unit 82 connected between the positive supply line ACLp and the negative supply line ACLn detects the supply voltage VAC from the commercial power source and outputs the detected value to the drive ECU 80.

  The open / close detection unit 92 detects the closing of the connector 90, that is, the electrical connection between the vehicle and the commercial power supply, generates a signal CS indicating the detection result, and outputs the signal CS to the power supply system 100.

(Power system configuration)
Referring to FIG. 1, power supply system 100 includes smoothing capacitor C, converter 18, power storage unit 10, charge / discharge current detection unit 16, charge / discharge voltage detection unit 14, temperature detection unit 12, and battery ECU 30. And a converter ECU 40.

  Smoothing capacitor C is connected between main positive bus MPL and main negative bus MNL, and reduces the fluctuation component included in the driving power output from converter 18 and the regenerative power output from the driving force generator.

  Converter 18 is provided between main positive bus MPL and main negative bus MNL and power storage unit 10, and performs a power conversion operation between power storage unit 10 and main positive bus MPL and main negative bus MNL. Specifically, converter 18 boosts the discharge power from power storage unit 10 to a predetermined voltage and supplies it as driving power, while reducing the regenerative power supplied from driving force generation unit 110 to a predetermined voltage. The power storage unit 10 is charged. As an example, converter 18 is configured by a step-up / step-down chopper circuit.

  Power storage unit 10 is connected to main positive bus MPL and main negative bus MNL via converter 18. The power storage unit 10 includes, for example, a secondary battery configured to be chargeable / dischargeable, such as a nickel metal hydride battery or a lithium ion battery, or an electric double layer capacitor.

  Charging / discharging current detection unit 16 is interposed in one power line PL (or NL) connecting power storage unit 10 and converter 18 to detect charge / discharge current value Ib used when charging / discharging power storage unit 10, The detection result is output to battery ECU 30 and converter ECU 40.

  Charging / discharging voltage detection unit 14 is connected between power lines PL and NL connecting power storage unit 10 and converter 18, detects charge / discharge voltage value Vb of power storage unit 10, and outputs the detection result to battery ECU 30 and converter ECU 40. Output.

  Temperature detection unit 12 is disposed in the vicinity of a battery cell or the like constituting power storage unit 10, detects power storage unit temperature Tb that is the internal temperature of power storage unit 10, and outputs the detection result to battery ECU 30. The temperature detection unit 12 is configured to output a representative value by an averaging process or the like based on detection results of a plurality of detection elements arranged in association with a plurality of battery cells constituting the power storage unit 10. May be.

  Battery ECU 30 is based on charge / discharge current value Ib received from charge / discharge current detection unit 16, charge / discharge voltage value Vb received from charge / discharge voltage detection unit 14, and storage battery temperature Tb received from temperature detection unit 12. Then, the state of charge (SOC) of power storage unit 10 is calculated.

  Various well-known techniques can be used for the configuration for calculating the SOC of the power storage unit 10, but as an example, the battery ECU 30 determines from the provisional SOC calculated from the open circuit voltage value and the integrated value of the charge / discharge current value. The SOC is derived by adding the calculated corrected SOC. Specifically, the battery ECU 30 calculates the open circuit voltage value of the power storage unit 10 from the charge / discharge current value Ib and the charge / discharge voltage value Vb at each point in time, and the open circuit calculated value is measured in advance through experiments. The provisional SOC of the power storage unit 10 is calculated by applying to the reference charge / discharge characteristics indicating the relationship between the SOC in the reference state of the unit 10 and the open circuit voltage value. Further, the battery ECU 30 calculates the corrected SOC by integrating the charge / discharge current value Ib, and derives the SOC by adding the provisional SOC to the corrected SOC.

  Further, battery ECU 30 derives allowable power (charge allowable power Win and discharge allowable power Wout) based on the derived SOC of power storage unit 10. The charge allowable power Win and the discharge allowable power Wout are short-time limit values of the charge power and the discharge power at each time point, which are defined by the chemical reaction limit.

  Therefore, battery ECU 30 stores a map of allowable power defined using SOC and power storage unit temperature Tb of power storage unit 10 obtained experimentally in advance as parameters, and based on the calculated SOC and power storage unit temperature Tb. Thus, the allowable power at each time point is derived. The map that defines the allowable power may include parameters other than the SOC and the power storage unit temperature, for example, the deterioration level of the power storage unit.

  Then, battery ECU 30 outputs derived SOC of power storage unit 10, charge allowable power Win, and discharge allowable power Wout to converter ECU 40.

  Converter ECU 40 performs charge / discharge control for power storage unit 10 in power transfer between power supply system 100 and a commercial power supply outside the vehicle. When converter 40 receives charge request signal DMN transmitted from house 200 via modem 86, converter 18 provides a switching command PWC1 for converter 18 so that power is transferred between power storage unit 10 and the commercial power supply by a method described later. Is generated. Further, converter ECU 40 determines target supply power PAC * for the commercial power source and outputs it to drive ECU 80.

(Power transfer in external charging mode)
In the following description, the case where the external charging mode is executed among the two modes related to the power transfer with the outside of the vehicle will be described in detail.

  In the external charging mode, the vehicle is connected to the power outlet of the house 200 by the connector 90 via the supply line ACL. The vehicle is supplied with commercial power supplied to the house 200 via the commercial power line 210. The power storage unit 10 is charged by a commercial power source provided from the house 200.

  Specifically, the supply line ACL and the commercial power line 210 are electrically connected by coupling the connector 90 and the power outlet of the house 200. House 200 includes a modem 202 and a control unit 204.

  Modem 202 transmits and receives information to and from electrically connected vehicles. The modem 202 is connected between the commercial power lines 210, modulates an information signal provided from the control unit 204, and superimposes it on the current flowing through the commercial power line 210, while being included in the current flowing through the commercial power line 210. The modulated signal is extracted, demodulated into an information signal, and output to the control unit 204.

  Control unit 204 is configured to manage the state of charge of power storage unit 10 in the vehicle by transmitting and receiving information to and from the vehicle and to accept a charge request from a user or the like. Then, when the charging request is given, the control unit 204 transmits a charging request signal DMN to the vehicle via the modem 202. In addition, when a charge stop request is given in accordance with, for example, that the state of charge of power storage unit 10 has reached a desired state, control unit 204 transmits a charge stop request STP to the vehicle via modem 202.

  In the vehicle, a modem 86 is connected between the positive supply line ACLp and the negative supply line ACLn, so that information can be transmitted to and received from the house 200. When converter ECU 40 receives charge request signal DMN transmitted from house 200 via modem 86, converter ECU 40 generates switching command PWC 1 for converter 18. Further, converter ECU 40 determines target supply power PAC * for the commercial power source and outputs it to drive ECU 80.

  Drive ECU 80 generates switching commands PWM1 and 2 for inverters 20 and 22 based on given target supply power PAC *. Thereby, power transfer is started between the power storage unit 10 and the commercial power source.

  As described above, motor generators MG1 and MG2 are three-phase AC rotating electric machines including a rotor in which permanent magnets are embedded. Further, in the present embodiment, a three-phase coil is provided with a Y-connected (star-connected) stator. In this Y connection, points where the coils are connected to each other correspond to neutral points N1, N2 of motor generators MG1, MG2.

  As described above, inverters 20 and 22 are configured by a bridge circuit including switching elements for three phases. That is, each of inverters 20 and 22 includes three switching elements on the upper arm (positive side) and three switching elements on the lower arm (negative side). When three-phase AC power is generated from the inverters 20 and 22, one of the switching elements on the upper arm side and one of the switching elements on the lower arm side are switched over in time and turned on. To drive.

  On the other hand, on each of the upper arm side and the lower arm side, the three switching elements can be collectively turned on / off. In such an operation mode, the three switching elements on the upper arm can be regarded as being in the same switching state (all on or all off), and the three switching elements on the lower arm side are also mutually connected. It can be regarded as the same switching state.

  In such an operation mode, the respective phase voltages are equal to each other, so that a zero voltage vector based on the neutral point can be defined.

  FIG. 3 is a zero-phase equivalent circuit of inverters 20 and 22 and motor generators MG1 and MG2 when a zero voltage vector is generated.

  Referring to FIG. 3, when the inverters 20 and 22 execute the operation mode in which the zero voltage vector is generated as described above, the three switching elements TR on the upper arm side in the inverter 20 are defined as the upper arm ARM1p. The three switching elements TR on the lower arm side in the inverter 20 are collectively shown as a lower arm ARM1n. Similarly, the three switching elements TR on the upper arm side in the inverter 22 are collectively shown as an upper arm ARM2p, and the three switching elements TR on the lower arm side in the inverter 22 are collectively shown as a lower arm ARM2n.

  The zero-phase equivalent circuit shown in FIG. 3 can be regarded as a single-phase PWM inverter that receives AC commercial power supplied to the neutral points N1 and N2 via the positive supply line ACLp and the negative supply line ACLn. Therefore, by changing the zero voltage vector in time in each of the inverters 20 and 22 and performing switching control so that each of the inverters 20 and 22 operates as each phase arm of the single-phase PWM inverter, the AC commercial power is converted to DC. It can be converted into electric power and supplied to the power supply system 100.

  As described above, according to the present embodiment, inverters 20 and 22 are used to drive motor generators MG1 and MG2 and to convert AC commercial power into DC power. Since there is no need to newly provide an inverter, the configuration of the vehicle can be simplified. As a result, the power supply system according to the present invention can be constructed at low cost.

  On the other hand, since the stator coils of motor generators MG1 and MG2 are energized during the execution of power exchange with the outside of the vehicle, the inside of motor generators MG1 and MG2 is caused by Joule heat generated in the stator coils. There arises a problem that the motor temperatures Tmot1 and Tmot2, which are temperatures, rise.

  Such a rise in the motor temperature is caused by the means for suppressing the rise in the motor temperature because the motor cooling system for cooling the motor generators MG1 and MG2 is also stopped when the vehicle is stopped. Not because.

  Specifically, some motor cooling systems are configured to exchange heat between the cooling oil discharged from a mechanical oil pump driven by engine operation and the motor. In this configuration, the mechanical oil pump is attached to the planetary carrier 54 (FIG. 2) via a gear, and operates using the driving force of the engine. Therefore, since the engine is also stopped while the vehicle is stopped, the mechanical oil pump does not operate and it becomes impossible to supply cooling oil to the motor. As a result, the temperature of the permanent magnets embedded in the rotors of motor generators MG1 and MG2 increases during execution of power transfer with the outside of the vehicle as described above, and there is a possibility that demagnetization of the permanent magnets may occur. .

  Therefore, the electric vehicle according to the present embodiment further includes a motor cooling system configured to include an electric oil pump described below. Then, the control device for the electric vehicle controls the motor cooling system so that heat is exchanged between the permanent magnet embedded in the rotor and the cooling oil during power transfer between the vehicle and the outside of the vehicle. Operate.

(Motor cooling system)
FIG. 4 is a block diagram conceptually showing a motor cooling system mounted on the electric vehicle shown in FIG.

  Referring to FIG. 4, the motor cooling system includes a driving force generator 110, an oil cooler 124, an electric oil pump 120, a pump drive circuit 122, and oil circulation paths 126, 128, and 130.

  An oil circulation path 130 is provided between the first port of the oil cooler 124 and the driving force generator 110, and an oil circulation path 126 is provided between the driving force generator 110 and the electric oil pump 120. An oil circulation path 128 is provided between 120 and the second port of the oil cooler 124.

  The electric oil pump 120 is a pump for circulating the cooling oil, and circulates the cooling oil in the direction of the arrow shown in the figure. As shown in FIG. 1, electric oil pump 120 is connected in parallel with inverters 20 and 22 with respect to main positive bus MPL and main negative bus MNL. A pump drive circuit 122 for driving and controlling the electric oil pump 120 is provided between the electric oil pump 120 and the main positive bus MPL and the main negative bus MNL. Upon receiving the drive signal DRV from the drive ECU 80, the pump drive circuit 122 converts the power output between the main positive bus MPL and the main negative bus MNL into the drive power of the electric motor built in the electric oil pump 120 by a method described later. Convert.

  In the present embodiment, the electric pump is operated using the electric power exchanged between the outside of the vehicle and the power supply system, so that the stored power of the entire power supply system is suppressed from being consumed. In addition to this configuration, a separate power supply may be provided.

  The oil cooler 124 has a structure in which a plurality of fins are arranged, and cools the cooling oil that has circulated through the motor generators MG1 and MG2 of the driving force generator 110.

  As the driving force generator 110, FIG. 4 shows a cross-sectional view of each case where the motor generator MG2, the reduction gear RD, and the differential gear DEF are accommodated.

  The cooling oil is stored at the bottom of the case 400 up to the oil level OL. This case bottom corresponds to an oil pan. In addition, you may make it a structure which attaches an oil pan separately to a case bottom part.

  While the electric vehicle is traveling, the counter drive gear 70 in FIG. 2 is rotated according to the rotation of the rotor 37 and the like. The counter driven gear 132 is rotated by the counter drive gear 70, and the differential gear DEF is rotated according to the rotation of the counter driven gear 132. Then, differential gear DEF scoops up the cooling oil and guides it to stator 36 of motor generator MG2 via the upper portion of case 400.

  On the other hand, during the execution of power exchange with the outside of the vehicle, the above-described circulation path cannot be formed because the rotor 37 is not rotating. Therefore, in the motor cooling system according to the present embodiment, by forming a cooling oil circulation path as described below, motor generators MG1 and MG2 are efficiently cooled while power is being exchanged with the outside of the vehicle. ing.

FIG. 5 is a partial cross-sectional view taken along line V-V in FIG.
Referring to FIG. 5, motor generator MG <b> 2 includes a rotor portion including a rotor 37 rotatably supported by a bearing (not shown), and a stator 36 including a stator core 38 installed in the outer circumferential direction of rotor 37. . The rotor 37 is supported by a bearing, and transmits rotational torque about a rotation shaft 60 to a drive shaft (not shown).

  A stator core 38 is provided at a position corresponding to the rotor 37 through a slight gap. A coil is wound around the stator core 38 in a slit provided so as to penetrate the stator core 38 in a direction parallel to the rotation shaft 60. The ends of the coils wound around the stator core 38 are formed as coil ends 39 on both sides of the stator core 38.

  Current is passed through the coil wound around the stator core 38, and the stator core 38 generates a magnetic field for rotating the rotor 37. At this time, Joule heat is generated by the current flowing in the coil of the stator 36, and the stator coil and the coil end 39 are heated.

  In addition, Joule heat is generated by the current flowing in the coils of stator 36 by the commercial power supplied to neutral points N1 and N2 of motor generators MG1 and MG2 even during execution of power transfer with the outside of the vehicle.

  In the rotor 37, permanent magnets 372 are embedded in a rotor core 370 configured by laminating a number of electromagnetic steel plates. The permanent magnet 372 generates an eddy current due to a change in magnetic flux when the stator coil is energized, and the temperature rises.

  The rotating shaft 60 of the rotor 37 includes an inner hollow shaft 610 (oil pump shaft) and an outer hollow shaft 602 (rotor shaft). The hollow portion of the inner hollow shaft 610 constitutes the rotating shaft cooling oil passage 612. The rotating shaft cooling oil path 612 is connected to the oil circulation path 130 (FIG. 4), and the cooling oil that has passed through the oil circulation path 130 is supplied to the rotating shaft cooling oil path 612.

  The cooling oil supplied to the rotating shaft cooling oil passage 612 flows through the inner hollow shaft 610 through an oil passage 614 provided in a direction perpendicular to the rotating shaft and an oil passage 604 provided in the outer hollow shaft 602. And then circulated inside the case 400.

  As shown by arrows A and B in the figure, the cooling oil flows through the oil passage 604 and then flows along the side surface of the rotor 37 to be supplied to the stator core 38 and the coil end 39. At this time, the cooling oil exchanges heat with the rotor 37. Thereby, rotor core 370 and permanent magnet 372 are cooled. Then, when the cooling oil after heat exchange is stored in an oil pan provided at the bottom of the case 400, it is supplied again to the rotating shaft cooling oil passage 612 by the electric oil pump 120.

  As shown in FIG. 5, by forming a cooling oil circulation path so that the cooling oil is supplied to the rotor 37 via the rotary shaft cooling oil path 612, power is being exchanged with the outside of the vehicle. Even when the rotor 37 is not rotating, the motor generators MG1 and MG2 can be cooled.

  Further, by providing the oil passage 604 so as to directly connect the rotary shaft cooling oil passage 612 and the rotor 37, heat exchange is directly performed between the cooling oil and the permanent magnet 372 embedded in the rotor 37. Can be done. Therefore, it becomes possible to cool the permanent magnet 372 efficiently.

  In the motor cooling system shown in FIGS. 4 and 5, when the cooling oil after heat exchange is stored in an oil pan provided at the bottom of case 400, it is cooled using case 400 as a heat radiation destination. . Further, it is cooled by an oil cooler 124 provided outside the case 400. Since the heat capacity of the case 400 that houses the driving force generator 110 is large, the cooling performance of the cooling oil can be ensured.

(Control structure of control device)
Next, drive control of the electric oil pump 120 in the motor cooling system according to the embodiment of the present invention thus configured will be described.

  FIG. 6 is a block diagram showing a control structure of converter ECU 40 and drive ECU 80 of FIG.

  Referring to FIG. 6, converter ECU 40 includes a charge command generation unit 402, a target value determination unit 404, a subtraction unit 406, an integration unit 408, a proportional control unit (PI) 410, and a modulation unit (MOD) 412. Including.

  When charging command generation unit 402 receives charging request signal DMN transmitted from house 200 via modem 86 and receives signal CS instructing closing of connector 90 from open / close detection unit 92, The charging command CHG is generated, and the generated charging command CHG is output to the target value determination unit 404. Furthermore, charge command generation unit 402 outputs charge command CHG to drive ECU 80.

  In addition, when the charge command generation unit 402 receives a charge stop request signal STP transmitted from the house 200 via the modem 86, the charge command generation unit 402 generates a charge stop command CED for the power storage unit 10, and the generated charge stop Command CED is output to target value determination unit 404 and drive ECU 80.

  Target value determination unit 404 receives charge command CHG from charge command generation unit 402 and receives allowable power (charge allowable power Win and discharge allowable power Wout) of power storage unit 10 from battery ECU 30 (not shown). Then, target value determining unit 404 determines target charging power Pin * in power storage unit 10 based on the allowable power in accordance with charging command CHG. At this time, the target value determination unit 404 determines the target charging power Pin * of the power storage unit 10 as the allowable charging power Win. Moreover, the target value determination unit 404 determines a target supply power PAC * for a commercial power supply (not shown) based on the determined target charging power Pin *.

  The target charging power Pin * determined by the target value determining unit 404 in this way is output to the subtracting unit 406. Target supply power PAC * is output to drive ECU 80.

  Subtraction unit 406 calculates a power deviation between target charging power Pin * and charging power Pin (actual value) of power storage unit 10, and outputs the result to proportional control unit (PI) 410. The accumulating unit 408 calculates the charging power Pin of the power storage unit 10 by multiplying the charging / discharging voltage value Vb from the charging / discharging voltage detection unit 14 and the charging / discharging current value Ib from the charging / discharging current detection unit 16. .

  The proportional control unit (PI) 410 is configured to include at least a proportional element and an integral element, and generates a duty command according to the input power deviation. The duty command is a control command that defines the on-duty of the transistor that constitutes the lower arm of the converter 18.

  Modulator (MOD) 412 compares a carrier wave generated by an oscillating unit (not shown) with a duty command, generates switching command PWC, and controls converter 18.

  The drive ECU 80 includes a subtraction unit 802, an integration unit 804, a proportional control unit (PI) 806, a modulation unit (MOD) 808, a motor temperature management unit 810, and an oil pump control unit that drives and controls the electric oil pump 120. 812.

  The subtraction unit 802 calculates a power deviation between the target supply power PAC * and the supply power PAC (actual value) from the commercial power source, and outputs the power deviation to the proportional control unit (PI) 806. Note that the supply power PAC of the commercial power supply is calculated by the integrating unit 804 by multiplying the supply voltage value VAC from the supply voltage detection unit 82 and the supply current value IAC from the supply current detection unit 84.

  Modulation section (MOD) 808 compares a carrier wave (carrier wave) generated by an oscillation section (not shown) with a duty command, generates switching commands PWM1 and PWM2, and controls inverters 20 and 22, respectively.

  When motor temperature management unit 810 receives charge command CHG from charge command generation unit 402, motor temperature management unit 810 generates a signal (hereinafter also referred to as a pump operation signal) OPE for operating electric oil pump 120 to oil pump control unit 812. Output.

  When oil pump control unit 812 receives pump operation signal OPE from motor temperature management unit 810, oil pump control unit 812 drives electric oil pump 120 based on motor temperatures Tmot1 and Tmot2 from temperature detection units 24 and 26 (FIG. 1). The signal DRV is generated and output to the electric oil pump 120 (not shown).

  Specifically, the oil pump control unit 812 sets the target flow rate of the cooling oil that circulates through the oil circulation paths 126 to 130 based on the detected values of the motor temperatures Tmot1 and Tmot2. The setting of the target flow rate at this time is performed according to the relationship between the motor temperatures Tmot1 and Tmot2 obtained in advance and the target flow rate. The oil pump control unit 812 generates a signal DRV for driving the electric oil pump 120 so that the cooling oil circulates at the set target flow rate, and outputs the signal DRV to the electric oil pump 120. The electric oil pump 120 is controlled in rotation speed according to the signal DRV from the oil pump control unit 812, and circulates cooling oil having a flow rate that matches the target flow rate through the oil circulation paths 126 to 130.

  As described above, according to the control device for an electric vehicle according to the present embodiment, power is supplied between power supply system 100 and the outside of the vehicle using neutral points N1 and N2 of motor generators MG1 and MG2 in accordance with charge command CHG. When the transfer is started, the electric oil pump 120 also starts to operate. Electric oil pump 120 is driven and controlled to circulate appropriate cooling oil according to the amount of heat generated by motor generators MG1, MG2 through oil circulation paths 126-130. As a result, motor generators MG1 and MG2 are efficiently cooled during the execution of the external charging mode, so that an increase in motor temperatures Tmot1 and Tmot2 is suppressed. As a result, demagnetization of the permanent magnets embedded in the rotors of motor generators MG1 and MG2 can be prevented.

(Control flow)
FIG. 7 is a flowchart for illustrating a control structure of converter ECU 40 and drive ECU 80 of FIG.

  Referring to FIG. 7, when a series of controls is started, converter ECU 40 determines whether or not connector 90 is closed based on signal CS from open / close detection unit 92, that is, whether the vehicle and the commercial power supply are connected. It is determined whether or not they are electrically connected (step S01).

  When it is determined that connector 90 is closed, converter ECU 40 further determines whether or not charging request signal DMN transmitted from house 200 has been acquired (step S02).

  When it is determined in step S02 that charging request signal DMN has been acquired, converter ECU 40 generates charging command CHG for power storage unit 10 (step S03). The generated charging command CHG is given to the drive ECU 80.

  Next, converter ECU 40 determines target charging power Pin * of power storage unit 10 as charging allowable power Win of the power storage unit (step S04).

  Furthermore, converter ECU 40 determines target value (supply power target value) PAC * of commercial power supplied from house 200 as target charging power Pin * for power storage unit 10 determined in step S04, and outputs the target charging power Pin * to drive ECU 80. (Step S05).

  Drive ECU 80 controls inverters 20 and 22 by generating switching commands PWM1 and PWM2 for inverters 20 and 22 in accordance with supply power target value PAC * from converter ECU 40 (step S06).

  Converter ECU 40 generates switching command PWC for converter 18 in accordance with target charging power Pin * determined in step S04, and controls converter 18 (step S07).

  Further, drive ECU 80 starts operation of electric oil pump 120 in response to charge command CHG given from converter ECU 40 (step 08). Then, the drive ECU 80 generates a signal DRV for driving the electric oil pump 120 based on the motor temperatures Tmot1 and Tmot2 from the temperature detectors 24 and 26, and drives and controls the electric oil pump 120 (step S09). .

  After step S09, converter ECU 40 determines whether or not charging end request STP from house 200 has been acquired (step S10). When it is determined that charging end request STP has not been acquired, converter ECU 40 returns to the process of step S04.

  On the other hand, when it is determined in step S10 that the charge termination request STP has been acquired, converter ECU 40 generates a charge stop command CED for stopping power transfer with the outside of the vehicle, and converter 18 and inverter 20, 22 is stopped (step S11). Furthermore, converter ECU 40 stops the operation of electric oil pump 120 (step S12).

  As described above, according to the first embodiment of the present invention, when power is transferred between the electric vehicle and the outside of the vehicle using the neutral point of the motor generator mounted on the electric vehicle, the motor By operating the cooling system, heat exchange is performed between the motor generator and the cooling oil. As a result, since the temperature rise of the motor generator can be suppressed, demagnetization of the permanent magnet embedded in the rotor can be prevented.

[Embodiment 2]
FIG. 8 is a block diagram showing a control structure of a control device for an electric vehicle according to Embodiment 2 of the present invention.

  The control device according to the present embodiment is applied to the electric vehicle shown in FIG. The control structure shown in FIG. 8 is obtained by changing converter ECU 40 and drive ECU 80 in the control structure shown in FIG. 6 to converter ECU 40A and drive ECU 80A, respectively. Therefore, detailed description of common parts will not be repeated.

  Referring to FIG. 8, converter ECU 40A includes a charge command generation unit 402, a target value determination unit 404A, a subtraction unit 406, an integration unit 408, a proportional control unit (PI) 410, and a modulation unit (MOD) 412. Including. Converter ECU 40A replaces target value determination unit 404 of converter ECU 40 in FIG. 6 with target value determination unit 404A.

  The drive ECU 80A also includes an oil pump that drives and controls the subtraction unit 802, the integration unit 804, the proportional control unit (PI) 806, the modulation unit (MOD) 808, the motor temperature management unit 810A, and the electric oil pump 120. And a control unit 812. The drive ECU 80A is obtained by replacing the motor temperature management unit 810 of the drive ECU 80 in FIG. 6 with a motor temperature management unit 810A.

  In the present embodiment, when motor temperature management unit 810A receives charge command CHG from charge command generation unit 402, motor temperature management unit 810A generates pump operation signal OPE in accordance with motor temperatures Tmot1 and Tmot2 from temperature detection units 24 and 26.

  Specifically, motor temperature management unit 810A generates pump operation signal OPE in response to at least one of motor temperatures Tmot1 and Tmot2 exceeding a predetermined threshold T_th. That is, the motor temperature management unit 810A starts the operation of the electric oil pump 120 when the motor temperatures Tmot1 and Tmot2 exceed a predetermined threshold value T_th. Predetermined threshold T_th is set such that motor temperatures Tmot1 and Tmot2 do not exceed a predetermined allowable temperature that causes demagnetization of permanent magnets embedded in the rotors of motor generators MG1 and MG2.

  As described above, the motor temperature management unit 810A sets the timing for operating the electric oil pump 120 according to the motor temperature, and the electric oil pump is linked to the start of power transfer with the outside of the vehicle. This is different from the motor temperature management unit 810 according to the first embodiment that operates 120.

  Further, the motor temperature management unit 810A limits the power exchanged with the outside of the vehicle to the target value determination unit 404A when at least one of the motor temperatures Tmot1 and Tmot2 exceeds a predetermined threshold T_th. Signal (hereinafter also referred to as a power limit signal) LMT is generated and output.

  When target value determination unit 404A receives power limit signal LMT from motor temperature management unit 810A, target value determination unit 404A determines target charging power Pin * of power storage unit 10 to be a predetermined power lower than allowable charging power Win of the power storage unit. Further, the target value determination unit 404A determines a target supply power PAC * for a commercial power supply (not shown) based on the determined target charging power Pin *.

  As described above, according to the present embodiment, when the motor temperatures Tmot1 and Tmot2 rise above the predetermined threshold T_th during execution of power transfer with the outside of the vehicle, the electric oil While the pump 120 operates, the electric power exchanged with the outside of the vehicle is limited.

  According to this, in order to operate the electric oil pump 120 so as to have an appropriate cooling capacity with respect to the motor temperatures Tmot1 and Tmot2 that rise in response to power transfer, in conjunction with the start of power transfer with the outside of the vehicle. Compared with the case where the electric oil pump 120 is operated, power saving of the motor cooling system can be achieved.

  Thereby, since the power loss which generate | occur | produces in the electric power transmission / reception path | route between the power supply system 100 and the vehicle exterior can be reduced, the energy efficiency of the power supply system 100 can be improved.

  Further, when motor generators MG1 and MG2 are at a high temperature, in parallel to operating electric oil pump 120, electric power transferred to and from the outside of the vehicle is limited, so that motor temperatures Tmot1 and Tmot2 are reduced to permanent magnets. It is possible to keep the temperature range in which demagnetization can be suppressed.

  Therefore, according to the present embodiment, it is possible to achieve both improvement of energy efficiency in the power supply system and ensuring of the reliability of the electric vehicle.

  FIG. 9 is a flowchart for illustrating the control structure of converter ECU 40 and drive ECU 80 of FIG.

  Referring to FIG. 9, when a series of controls is started, converter ECU 40 </ b> A determines whether connector 90 is closed based on signal CS from open / close detection unit 92, that is, whether the vehicle and the commercial power supply are connected. It is determined whether or not it is electrically connected (step S21).

  When it is determined that connector 90 is closed, converter ECU 40A further determines whether or not charging request signal DMN transmitted from house 200 has been acquired (step S22).

  When it is determined in step S22 that charging request signal DMN has been acquired, converter ECU 40A generates charging command CHG for power storage unit 10 (step S23). The generated charging command CHG is given to the drive ECU 80A.

  Next, converter ECU 40A determines target charging power Pin * of power storage unit 10 as charge allowable power Win of the power storage unit (step S24).

  Further, converter ECU 40A determines target value (supply power target value) PAC * of commercial power supplied from house 200 as target charging power Pin * for power storage unit 10 determined in step S24, and outputs the target charging power to driving ECU 80A. (Step S25).

  Drive ECU 80A generates switching commands PWM1 and PWM2 for inverters 20 and 22 according to supply power target value PAC * from converter ECU 40 to control inverters 20 and 22 (step S26).

  Converter ECU 40A generates switching command PWC for converter 18 in accordance with target charging power Pin * determined in step S24 to control converter 18 (step S27).

  Further, after step S27, the drive ECU 80A determines whether or not at least one of the motor temperatures Tmot1 and Tmot2 exceeds a predetermined threshold T_th (step S28).

  If it is determined in step S28 that at least one of the motor temperatures Tmot1 and Tmot2 exceeds the predetermined threshold T_th, the drive ECU 80A starts the operation of the electric oil pump 120 (step 29). And drive ECU80A produces | generates the signal DRV for driving the electric oil pump 120 based on motor temperature Tmot1, Tmot2 from the temperature detection parts 24 and 26, and drive-controls the electric oil pump 120 (step S30). .

  Further, converter ECU 40A determines target charging power Pin * of power storage unit 10 to be a predetermined power lower than allowable charging power Win of the power storage unit in accordance with power limit signal LMT transmitted from drive ECU 80A (step S31). Then, converter ECU 40A returns to the process of step S25, and determines the target value (supply power target value) PAC * of the commercial power supplied from house 200 as target charge power Pin * for power storage unit 10 determined in step S31. And output to the drive ECU 80A.

  On the other hand, in step S28, when it is determined that neither of the motor temperatures Tmot1 and Tmot2 exceeds the predetermined threshold T_th, the drive ECU 80A stops the operation of the electric oil pump 120 (step 32).

  Then, converter ECU 40A determines whether or not charging end request STP from house 200 has been acquired (step S33). When it is determined that charging end request STP has not been acquired, converter ECU 40A returns to the process of step S24.

  On the other hand, when it is determined in step S33 that charging end request STP has been acquired, converter ECU 40A generates charging stop command CED for stopping power transfer with the outside of the vehicle, and converter 18 and inverter 20, 22 is stopped (step S34).

[Modification]
FIG. 10 is a block diagram showing a control structure of an electric vehicle control apparatus according to a modification of the second embodiment of the present invention.

  The control device according to the present embodiment is applied to the electric vehicle shown in FIG. The control structure shown in FIG. 10 is obtained by changing converter ECU 40A in the control structure shown in FIG. 8 to converter ECU 40B. Therefore, detailed description of common parts will not be repeated.

  Referring to FIG. 10, converter ECU 40B includes a charge command generation unit 402B, a target value determination unit 404A, a subtraction unit 406, an integration unit 408, a proportional control unit (PI) 410, and a modulation unit (MOD) 412. Including. Converter ECU 40B is obtained by replacing charging command generation unit 402 of converter ECU 40A in FIG. 8 with charging command generation unit 402B.

  In this modification, charging command generation unit 402B receives charging request signal DMN transmitted from house 200 via modem 86, and receives signal CS instructing closing of connector 90 from open / close detection unit 92. Then, it is determined whether or not the motor temperatures Tmot1, Tmot2 acquired from the temperature detectors 24, 26 are equal to or lower than a predetermined reference value T_std. When it is determined that both motor temperatures Tmot1 and Tmot1 are equal to or lower than predetermined reference value T_std, charging command generation unit 402B generates charging command CHG for power storage unit 10.

  As described above, the control device for the electric vehicle according to the present modification prohibits execution of power transfer with the outside of the vehicle when at least one of the motor temperatures Tmot1 and Tmot2 exceeds the predetermined reference value T_std. Configured to do.

  According to this, when the motor generators MG1 and MG2 are in a high temperature state, such as immediately after the vehicle is stopped after performing high-load traveling such as acceleration traveling or uphill traveling, It is possible to suppress the motor generators MG1 and MG2 from becoming even higher temperature by performing the power transfer at. Therefore, demagnetization can be reliably prevented from occurring in the permanent magnets embedded in the rotors of motor generators MG1 and MG2, so that the reliability of the electric vehicle can be further improved.

  FIG. 11 is a flowchart for illustrating a control structure of converter ECU 40B and drive ECU 80A of FIG. In the flowchart shown in FIG. 11, step S220 is added between step S22 and step S23 in the flowchart shown in FIG. Therefore, detailed description of common steps will not be repeated.

  Referring to FIG. 11, when a series of controls is started, converter ECU 40B determines whether or not connector 90 is closed based on signal CS from open / close detection unit 92, that is, whether the vehicle and the commercial power supply are connected. It is determined whether or not it is electrically connected (step S21).

  When it is determined that connector 90 is closed, converter ECU 40B further determines whether or not charging request signal DMN transmitted from house 200 has been acquired (step S22).

  When it is determined in step S22 that charging request signal DMN has been acquired, converter ECU 40B determines whether motor temperatures Tmot1 and Tmot2 are equal to or lower than a predetermined reference value T_std (step S220).

  When it is determined in step S220 that both motor temperatures Tmot1 and Tmot2 are equal to or lower than predetermined reference value T_std, converter ECU 40B generates charge command CHG for power storage unit 10 (step S23). Then, converter ECU 40B gives the generated charging command CHG to drive ECU 80A.

  In Embodiments 1 and 2, the control structure of the power transfer and motor cooling system has been described by taking as an example the case of executing the external charging mode in which power storage unit 10 included in power supply system 100 is charged by a commercial power supply. However, the same control structure can be applied when executing the power supply mode in which the power supplied from the power supply system 100 is supplied to the house 200.

  When the power supply mode is executed, the discharge power from power supply system 100 is controlled based on motor temperatures Tmot1 and Tmot2 with discharge allowable power Wout of power storage unit 10 as the upper limit. Further, in the motor cooling system, the electric oil pump 120 operates during the execution of the power supply mode, and is controlled to have an appropriate cooling capacity for the motor temperatures Tmot1 and Tmot2.

  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.

  The present invention can be applied to an electric vehicle control apparatus configured to be able to exchange power with the outside of the vehicle.

It is a schematic block diagram which shows the principal part of the electric vehicle to which the control apparatus according to Embodiment 1 of this invention is applied. It is a schematic diagram for demonstrating the detail of the driving force generation | occurrence | production part in FIG. It is a zero phase equivalent circuit of an inverter and a motor generator when generating a zero voltage vector. It is a block diagram which shows notionally the motor cooling system mounted in the electric vehicle shown by FIG. It is a fragmentary sectional view in VV of FIG. It is a block diagram which shows the control structure of converter ECU and drive ECU of FIG. 2 is a flowchart for illustrating control structures of a converter ECU and a drive ECU in FIG. 1. It is a block diagram which shows the control structure of the control apparatus of the electric vehicle by Embodiment 2 of this invention. FIG. 9 is a flowchart for illustrating control structures of a converter ECU and a drive ECU in FIG. 8. It is a block diagram which shows the control structure of the control apparatus of the electric vehicle by the modification of Embodiment 2 of this invention. 11 is a flowchart for illustrating control structures of converter ECU and drive ECU of FIG. 10.

Explanation of symbols

  4 engine, 10 power storage unit, 12, 24, 26 temperature detection unit, 14 charge / discharge voltage detection unit, 16 charge / discharge current detection unit, 18 converter, 20, 22 inverter, 28 drive shaft, 30 battery ECU, 31, 36 stator , 32, 37 Rotor, 33, 38 Stator core, 34, 39 Three-phase coil, 40, 40A, 40B Converter ECU, 50 Crankshaft, 51 Sun gear, 52 Ring gear, 53 Pinion gear, 54 Planetary carrier, 60 Rotating shaft, 62 Sun gear, 64 pinion gear, 66 planetary carrier, 68 ring gear, 70 counter drive gear, 80, 80A drive ECU, 82 supply voltage detection section, 84 supply current detection section, 86 modem, 90 connector, 92 open / close detection section, 100 power supply system, 110 drive Force generator, 120 Electric oil pump, 122 Pump drive circuit, 124 Oil cooler, 126, 128, 130 Oil circulation path, 132 Counter driven gear, 200 Housing, 202 Modem, 204 Control unit, 210 Commercial power line, 370 Rotor core, 372 Permanent magnet, 400 cases, 402, 402B Charge command generation unit, 404, 404A Target value determination unit, 406, 802 Subtraction unit, 408, 804 Integration unit, 602, 610 Hollow shaft, 604, 614 Oil passage, 612 Rotating shaft cooling Oil path, 810, 810A Motor temperature management unit, 812 Oil pump control unit, ACL supply line, ACLn negative supply line, ACLp positive supply line, C smoothing capacitor, DEF differential gear, MG1, MG2 motor generator, MNL main negative bus, MPL main positive bus, N1, N2 neutral point, PL, NL power line, PSD power split mechanism, RD reducer, RG power transmission reduction gear, TR switching element.

Claims (11)

An electric vehicle control device configured to be able to exchange electric power with the outside of the vehicle,
The electric vehicle is
A power supply system having a power storage unit configured to be chargeable / dischargeable;
A driving force generator for generating driving force by receiving power supplied from the power supply system;
Including a supply line for electrically connecting the driving force generator and the outside of the vehicle,
The driving force generator is
A rotating electrical machine configured to include a star-connected stator and a rotor on which a permanent magnet is mounted;
An inverter for driving the rotating electrical machine,
The supply line is configured to electrically connect a neutral point of the rotating electrical machine and the outside of the vehicle,
The controller is
Power conversion control means for controlling a switching operation in the inverter so as to perform power conversion between DC power from the power supply system and AC power input to and output from the supply line;
A control device for an electric vehicle, comprising: cooling control means for operating a cooling device so that heat is exchanged between the refrigerant and the rotating electrical machine during execution of control by the power conversion control means. The cooling device is
A refrigerant path through which the refrigerant flows;
An electric pump for circulating the refrigerant in the refrigerant path,
The rotating electrical machine is disposed in the refrigerant path,
The control device for an electric vehicle according to claim 1, wherein the cooling control unit operates the electric pump during execution of control by the power conversion control unit.   The electric vehicle control device according to claim 2, wherein the electric pump receives electric power exchanged between the vehicle exterior and the power supply system and circulates the refrigerant through the refrigerant path.   The control apparatus for an electric vehicle according to claim 2, wherein the refrigerant path is formed so that at least a part thereof causes the refrigerant to flow from a hollow shaft constituting a rotating shaft of the rotating electrical machine toward the rotor. . A temperature acquisition means for acquiring the temperature of the rotating electrical machine;
The cooling control unit sets a target value of the refrigerant supply amount in the cooling device according to the temperature of the rotating electrical machine acquired by the temperature acquisition unit, and the refrigerant supply amount matches the target value. The control apparatus of the electric vehicle of any one of Claims 1-4 which controls the said cooling device so that it may do. The electric vehicle further includes a connector for securing an electrical connection between the supply line and the outside of the vehicle,
The power conversion control means starts the switching operation in response to the electrical connection between the supply line and the vehicle being secured by closing the connector,
6. The control device for an electric vehicle according to claim 5, wherein the cooling control unit operates the cooling device when execution of control by the power conversion control unit is started. The electric vehicle further includes a connector for securing an electrical connection between the supply line and the outside of the vehicle,
The power conversion control means starts the switching operation in response to the electrical connection between the supply line and the vehicle being secured by closing the connector,
The cooling control unit operates the cooling device when the temperature of the rotating electrical machine acquired by the temperature acquisition unit exceeds a predetermined threshold after the execution of control by the power conversion control unit is started. The control device for an electric vehicle according to claim 5. The electric vehicle further includes a connector for securing an electrical connection between the supply line and the outside of the vehicle,
In the power conversion control unit, after the electrical connection between the supply line and the outside of the vehicle is ensured by closing the connector, the temperature of the rotating electrical machine acquired by the temperature acquisition unit falls below a predetermined threshold value. The control device for an electric vehicle according to claim 5, wherein the switching operation is sometimes started.   The power conversion control means sets a target value of power exchanged between the outside of the vehicle and the power storage unit according to the temperature of the rotating electrical machine acquired by the temperature acquisition means, and The control device for an electric vehicle according to any one of claims 5 to 8, wherein the switching operation is controlled so that electric power exchanged between power storage units matches the target value.   When the temperature of the rotating electrical machine acquired by the temperature acquisition unit is equal to or higher than a predetermined threshold, the power conversion control unit outputs a target value of power exchanged between the outside of the vehicle and the power storage unit. The control device for an electric vehicle according to claim 9, wherein the control device is set so as to be lower than a charge / discharge allowable power of a part. The rotating electrical machine includes first and second rotating electrical machines each including a stator connected in a star shape and a rotor mounted with a permanent magnet,
The inverter includes first and second inverters for driving the first and second electric motors,
The said supply line is comprised so that the neutral point of a said 1st rotary electric machine and the neutral point of a said 2nd rotary electric machine, and the said vehicle exterior may be electrically connected. The control apparatus of the electric vehicle of any one of these.

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