JP2014113977A - Control unit of electric vehicle - Google Patents

Abstract

A control device for an electric vehicle with improved accuracy of estimating a magnet temperature of a rotating electrical machine is provided.
Electric vehicle 1 includes motor generators MG1 and MG2, an engine 4, and a power split mechanism 3 that performs power split between motor generators MG1 and MG2 and engine 4. Power split device 3 includes a first rotating element coupled to motor generator MG1, a second rotating element coupled to motor generator MG2, a third rotating element coupled to engine 4, and a brake for fixing the third rotating element. including. Control device 30 fixes the third rotating element with a brake and reduces the torque of one motor generator and increases the torque of the other motor generator when traveling by the outputs of motor generators MG1 and MG2. The magnet temperature Tm of the motor generator is estimated based on the induced voltage φ.
[Selection] Figure 1

Description

  The present invention relates to an electric vehicle control device, and more particularly to an electric vehicle control device including two rotating electric machines.

  Japanese Patent Laying-Open No. 2008-265600 (Patent Document 1) discloses a hybrid vehicle including two motors. In this hybrid vehicle, when the condition for turning on the clutch that fixes the crankshaft of the engine to be non-rotatable is satisfied, the engine operation is stopped and the clutch is turned on so that the accelerator opening, the vehicle speed, and the transmission speed change Based on the ratio, the torque distribution ratio of the two motors is set using a map that determines the torque distribution for driving the two motors most efficiently, and the two motors are controlled. As a result, the energy efficiency of the vehicle can be improved and traveling according to demand can be performed.

JP 2008-265600 A

  A permanent magnet is often used for a motor for driving a vehicle. This permanent magnet is demagnetized when the temperature rises. Therefore, in order to prevent demagnetization due to heat, it is desirable to control the motor so as to avoid overheating of the magnet by detecting the magnet temperature.

  However, the permanent magnet is often embedded in the rotor (rotor) of the motor. It is structurally difficult to provide a sensor that directly detects the temperature of the magnet in such a place, which is disadvantageous in terms of cost.

  Although it is conceivable to use a method of estimating the magnet temperature from an electrical equivalent circuit, it is difficult to accurately estimate the temperature because it is affected by a constantly changing torque (current).

  An object of the present invention is to provide a control device for an electric vehicle in which the estimation accuracy of the magnet temperature of the rotating electrical machine is improved.

  In summary, the present invention provides a control device for an electric vehicle, wherein the electric vehicle distributes power between the first and second rotating electric machines, the engine, and the first and second rotating electric machines and the engine. And a differential mechanism to perform. The differential mechanism includes a first rotating element coupled to the first rotating electrical machine, a second rotating element coupled to the second rotating electrical machine, a third rotating element coupled to the engine, and rotation of the third rotating element. And a rotation suppressing device for suppressing. The control device suppresses the rotation of the third rotating element by the rotation suppressing device and reduces the torque of one rotating electric machine and increases the torque of the other rotating electric machine when traveling by the outputs of the first and second rotating electric machines. Then, the magnet temperature of one rotating electric machine with reduced torque is estimated based on the induced voltage.

  Preferably, the control device controls the first and second rotating electric machines so that the torque of one rotating electric machine is reduced to zero and the other rotating electric machine compensates for the reduction in torque of the one rotating electric machine. .

  Preferably, the control device detects whether or not an abnormality has occurred in each of the first and second rotating electrical machines, reduces the torque of the rotating electrical machine in which the abnormality has been detected, and estimates the magnet temperature of the rotating electrical machine in which the abnormality has been detected. To do.

  More preferably, the control device detects whether or not an abnormality has occurred in the first and second rotating electrical machines based on the temperatures of the first and second rotating electrical machines, and the control device detects the first and second rotating electrical machines. The torque of the rotating electrical machine whose temperature reaches a certain value is reduced.

  More preferably, the first and second rotating electric machines are attached to the stator coils of the first and second rotating electric machines, and the first and second rotating electric machines transmit the temperature detection results of the first and second rotating electric machines to the control device. Each includes a second temperature sensor.

  According to the present invention, since the estimation accuracy of the magnet temperature is improved, it is possible to operate the rotating electrical machine to near the temperature limit limit, and it is possible to cause the rotating electrical machine to exhibit performance to the limit according to the operating state.

1 is a circuit diagram showing a configuration of a vehicle according to an embodiment of the present invention. It is a block diagram for demonstrating the structural example and input / output of the control apparatus 30 of FIG. FIG. 2 is a diagram showing details of motor generators MG1 and MG2 and power split mechanism 3 shown in FIG. It is an alignment chart of the power split mechanism at the time of HV traveling. It is a collinear diagram of a power split mechanism during EV travel. It is a flowchart for demonstrating the detection process of the magnet temperature performed with the control apparatus 30 of FIG. It is a figure for demonstrating the relationship between the induced voltage constant (phi) and the magnet temperature T. FIG. It is a flowchart for demonstrating control which restrict | limits the driving | operation of motor generator MG1. It is a flowchart for demonstrating control which restrict | limits the driving | operation of motor generator MG2. It is an operation waveform diagram for explaining an example in which the control is performed by the vehicle control device of the present embodiment.

  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.

FIG. 1 is a circuit diagram showing a configuration of a vehicle according to an embodiment of the present invention.
Referring to FIG. 1, vehicle 1 includes a battery MB as a power storage device, a voltage converter 12, smoothing capacitors C1, CH, voltage sensors 10, 13, 21, an air conditioner 40, and a DC / DC converter 6. And auxiliary machine 7, inverters 14 and 22, engine 4, motor generators MG 1 and MG 2, power split mechanism 3, wheels 2, and control device 30.

  Vehicle 1 further includes a positive electrode bus PL2 that supplies power to inverter 14 that drives motor generator MG2. Voltage converter 12 is a voltage converter that is provided between battery MB and positive electrode bus PL2 and performs voltage conversion. Air conditioner 40 and DC / DC converter 6 are connected to positive electrode bus PL1A and negative electrode bus SL2. For example, a DC voltage of 14 V is supplied as a power supply voltage from the DC / DC converter 6 to the auxiliary machine 7.

  Smoothing capacitor C1 is connected between positive electrode bus PL1 and negative electrode bus SL2. The voltage sensor 21 detects the voltage VL across the smoothing capacitor C <b> 1 and outputs it to the control device 30. The voltage converter 12 boosts the voltage across the terminals of the smoothing capacitor C1.

  Smoothing capacitor CH smoothes the voltage boosted by voltage converter 12. The voltage sensor 13 detects the inter-terminal voltage VH of the smoothing capacitor CH and outputs it to the control device 30.

  Inverter 14 converts the DC voltage applied from voltage converter 12 into a three-phase AC voltage and outputs the same to motor generator MG1. Inverter 22 converts the DC voltage applied from voltage converter 12 into a three-phase AC voltage and outputs the same to motor generator MG2.

  Power split device 3 is a differential mechanism that is coupled to engine 4 and motor generators MG1 and MG2 and splits power between them. As will be described later with reference to FIG. 3, for example, a planetary gear mechanism having three rotation shafts of a sun gear, a planetary carrier, and a ring gear can be used as the power split mechanism. In the planetary gear mechanism, when rotations of two rotation shafts among the three rotation shafts are determined, the rotation of the other one rotation shaft is forcibly determined according to the rotation difference between them. These three rotation shafts are connected to the rotation shafts of engine 4 and motor generators MG1, MG2, respectively. The rotating shaft of motor generator MG2 is coupled to wheel 2 by a reduction gear and a differential gear (not shown). Further, a reduction gear for the rotation shaft of motor generator MG2 may be further incorporated in power split device 3.

  Vehicle 1 further includes system main relay SMRB connected between positive electrode of battery MB and positive electrode bus PL1, and system main relay SMRG connected between negative electrode of battery MB (negative electrode bus SL1) and node N2. Including.

  System main relays SMRB and SMRG are controlled to be in a conductive / non-conductive state in accordance with a control signal supplied from control device 30.

  The voltage sensor 10 measures the voltage VB between the terminals of the battery MB. In order to monitor the state of charge of the battery MB together with the voltage sensor 10, a current sensor 11 for detecting a current IB flowing through the battery MB is provided. As the battery MB, for example, a secondary battery such as a lead storage battery, a nickel metal hydride battery, or a lithium ion battery, or a large capacity capacitor such as an electric double layer capacitor can be used. Negative electrode bus SL2 extends through voltage converter 12 toward inverters 14 and 22.

  Inverter 14 is connected to positive electrode bus PL2 and negative electrode bus SL2. Inverter 14 receives the boosted voltage from voltage converter 12 and drives motor generator MG1 to start engine 4, for example. Inverter 14 returns the electric power generated by motor generator MG 1 by the power transmitted from engine 4 to voltage converter 12. At this time, the voltage converter 12 is controlled by the control device 30 so as to operate as a step-down circuit.

  Current sensor 24 detects the current flowing through motor generator MG1 as motor current value MCRT1, and outputs motor current value MCRT1 to control device 30.

  Inverter 22 is connected in parallel with inverter 14 to positive electrode bus PL2 and negative electrode bus SL2. Inverter 22 converts the DC voltage output from voltage converter 12 into a three-phase AC voltage and outputs it to motor generator MG2 driving wheel 2. Inverter 22 returns the electric power generated in motor generator MG2 to voltage converter 12 in accordance with regenerative braking. At this time, the voltage converter 12 is controlled by the control device 30 so as to operate as a step-down circuit.

  Current sensor 25 detects the current flowing through motor generator MG2 as motor current value MCRT2, and outputs motor current value MCRT2 to control device 30.

  Control device 30 receives torque command values and rotational speeds of motor generators MG1 and MG2, current values of current IB and voltages VB, VL and VH, motor current values MCRT1 and MCRT2, and an activation signal IGON. Control device 30 outputs a control signal PWU for instructing voltage converter 12, a control signal PWD for instructing step-down, and a shutdown signal for instructing prohibition of operation.

  Further, control device 30 generates a control signal PWMI1 for instructing inverter 14 to convert a DC voltage, which is an output of voltage converter 12, into an AC voltage for driving motor generator MG1, and motor generator MG1 generates electric power. A control signal PWMC1 for performing a regeneration instruction for converting the AC voltage thus converted into a DC voltage and returning it to the voltage converter 12 side is output.

  Similarly, control device 30 converts control signal PWMI2 for instructing inverter 22 to drive to convert DC voltage into AC voltage for driving motor generator MG2, and AC voltage generated by motor generator MG2 to DC voltage. A control signal PWMC2 for instructing regeneration to be converted and returned to the voltage converter 12 side is output.

  Vehicle 1 further includes relays CHRB and CHRG for charging, charger 42 and connector 44. The connector 44 is connected to the commercial power supply 8 via a CCID (Charging Circuit Interrupt Device) relay 46. The commercial power source 8 is, for example, an AC 100V power source.

  Control device 30 instructs charger 42 on charging current IC and charging voltage VC. The charger 42 converts alternating current into direct current, regulates the voltage, and applies the voltage to the battery. In addition, in order to enable external charging, other methods such as connecting the neutral point of the stator coils of motor generators MG1 and MG2 to an AC power source may be used.

  Motor generators MG1 and MG2 are permanent magnet synchronous motors, and permanent magnets are embedded in each rotor. When the magnet becomes hot, it is necessary to limit the motor generator to prevent demagnetization due to heat. However, if the frequency of restriction is too high, the power performance of the motor generator cannot be fully exhibited.

  Therefore, it is desirable to detect the temperature of the magnet as accurately as possible. However, since the magnet is attached to the rotor, it is difficult to provide a sensor that directly detects the temperature of the magnet because a slip ring is required to extract a signal.

  Vehicle 1 includes a temperature sensor 81 for detecting stator temperature Ts (MG1) of motor generator MG1, a resolver 82 for detecting rotational speed ω1, a temperature sensor 83 for detecting stator temperature Ts (MG2) of motor generator MG2, And a resolver 84 for detecting the rotational speed ω2. In the present embodiment, as will be described later, control device 30 accurately estimates the magnet temperature of the motor generator in which an abnormality has occurred using stator temperatures Ts (MG1), Ts (MG2) and rotational speeds ω1, ω2. .

  FIG. 2 is a block diagram for explaining a configuration example and input / output of the control device 30 of FIG. Referring to FIG. 2, control device 30 includes an HV-ECU 31, an MG-ECU 32, and an engine ECU 33.

  HV-ECU 31 receives vehicle speed signal V, accelerator opening signal ACC, stator temperature Ts (MG1) of motor generator MG1, and stator temperature Ts (MG2) of motor generator MG2. Then, HV-ECU 31 outputs MG1 torque command Tcom1 and MG2 torque command Tcom2 to MG-ECU 32, and outputs engine torque command TcomE to engine ECU 33. The HV-ECU 31 further outputs a hydraulic pressure command Pbcr for a brake Bcr, which will be described later with reference to FIG.

  MG-ECU 32 outputs voltage command V1 * to inverter 14. Inverter 14 outputs a three-phase alternating current to motor generator MG1 and feeds back this current value I1 to MG-ECU 32. Further, the motor generator MG1 feeds back the rotation speed ω1 detected by the resolver to the MG-ECU 32.

  MG-ECU 32 outputs voltage command V <b> 2 * to inverter 22. Inverter 22 outputs a three-phase alternating current to motor generator MG2 and feeds back this current value I2 to MG-ECU 32. The motor generator MG2 feeds back the rotational speed ω2 detected by the resolver to the MG-ECU 32.

  The engine ECU 33 transmits an electronic throttle valve control signal and an ignition signal to the engine based on the engine torque command TcomE given from the HV-ECU 31.

  FIG. 3 is a diagram showing details of motor generators MG1, MG2 and power split mechanism 3 shown in FIG. Referring to FIG. 3, motor generator MG1 includes a rotor 54 and a stator 56. A permanent magnet 55 is embedded in the rotor 54. A stator coil (not shown) is wound around the stator 56, and a temperature sensor 81 for detecting the temperature Ts (MG1) of the stator coil is attached.

  Motor generator MG <b> 2 includes a rotor 74 and a stator 76. A permanent magnet 75 is embedded in the rotor 74. A stator coil (not shown) is wound around the stator 76, and a temperature sensor 83 for detecting the stator coil temperature Ts (MG2) is attached.

  The power split mechanism 3 includes a sun gear 62 connected to the rotor 54, a pinion gear 60 supported by a planetary carrier 61 connected to a rotating shaft 59 of the engine 4, and a member 58 formed with a ring gear 63 that meshes with the pinion gear 60. Including. An oil pump 52 is connected to the rotary shaft 59. An output gear 65 different from the ring gear 63 is formed on the member 58, and the output gear 65 meshes with the gear 64. Gear 64 also meshes with gear 66 connected to the rotation shaft of motor generator MG2. The rotation of the gear 64 is transmitted from the gear 68 attached to the same rotating shaft to the differential gear 70, and the wheel 2 is driven.

  Power split device 3 further includes a brake Bcr. The brake Bcr is a rotation suppression device that suppresses rotation so as not to rotate the rotation shaft 59 of the engine 4. For example, it is preferable to use a wet friction brake with good controllability as the rotation suppression device. As the rotation suppression device, a one-way clutch may be provided instead of the brake Bcr. The power split mechanism 3 can be variously modified in addition to the configuration illustrated in FIG.

  By stopping the engine 4 and fixing the rotating shaft 59 of the engine 4 so as not to rotate by the brake Bcr, EV traveling using both torques of the motor generators MG1 and MG2 can be easily performed. This makes it possible to output a required torque in a wider range than in the prior art during EV travel.

  FIG. 4 is a collinear diagram of the power split mechanism during HV traveling. Referring to FIGS. 3 and 4, during HV traveling, fuel is supplied to engine 4 and the rotational speed Ne of engine 4 becomes positive. Although the rotational speeds Ng and Nm of the motor generators MG1 and MG2 change according to the operating state, the rotational speeds Ng, Ne and Nm of the three rotary elements are collinear due to the characteristics of the power split mechanism 3 as shown by the line L1. They are arranged on a straight line in the figure. The state shown in line L1 in FIG. 4 shows a state in which the electric power generated by motor generator MG1 is used for torque generation of motor generator MG2. In this case, the wheel is rotated by the direct torque from the engine and the torque generated by motor generator MG2 while generating the reaction force by motor generator MG1.

  FIG. 5 is a collinear diagram of the power split mechanism during EV travel. Referring to FIGS. 3 and 5, during EV traveling, the engine 4 stops operating, so the rotation speed is zero. When the state of charge SOC of the main battery MB in FIG. 1 is sufficiently high and there is no need to start the engine 4, the rotation is suppressed so as not to rotate the rotation shaft of the engine by a rotation suppression device such as a brake Bcr. As a result, in the state where the rotational speed Ne = 0, the rotational speeds of the respective rotating elements are arranged on a straight line as indicated by lines L2 and L3 on the nomograph, so that the torque generated by the motor generator MG1 is motor generator MG2. Will be communicated directly to.

  4 and 5, the rotational speed of the ring gear of the power split mechanism 3 is indicated as Nm on the MG2 axis for convenience. However, the rotational speed of motor generator MG2 is actually a rotational speed obtained by multiplying the rotational speed indicated as MG2 in FIGS. 4 and 5 by a multiple (constant) determined by the gear ratio of gears 64 and 66 in FIG. .

  FIG. 6 is a flowchart for explaining the magnet temperature detection process executed by the control device 30 of FIG. The processing of this flowchart is called and executed from a predetermined main routine every predetermined time or every time a predetermined condition is satisfied when the engine is stopped and the EV running is executed by the motor generators MG1 and MG2.

  Referring to FIGS. 2 and 6, in the state where the process is started in step S <b> 10, the engine is stopped and EV traveling is executed by motor generators MG <b> 1 and MG <b> 2. In this state, the stator coil temperatures Ts (MG1) and Ts (MG2) are measured by the sensors 81 and 83, respectively.

  First, in step S20, it is determined whether or not an abnormality has occurred in motor generator MG1. In step S20, for example, it is determined that an abnormality has occurred in motor generator MG1 when stator coil temperature Ts (MG1) exceeds a predetermined threshold value. Note that an abnormality may be determined based on other abnormality signals indicating current, voltage, and the like. If it is determined in step S20 that an abnormality has occurred, the process proceeds to step S30. If it is determined that no abnormality has occurred, the process proceeds to step S50.

  In step S30, the HV-ECU 31 outputs torque commands Tcom1, Tcom2 to the MG-ECU 32 so that the torque of the motor generator MG1 is decreased from the current command value and the torque of the motor generator MG2 is increased.

  Subsequently, in step S40, the magnet temperature Tm (MG1) of the motor generator MG1 is estimated based on a predetermined formula in a state where the torque command value Tcom1 becomes small and the current value of the motor generator MG1 approaches zero.

For example, the following method can be used to estimate the magnet temperature.
The circuit equation of the equivalent circuit of the motor is expressed by the following equations (1) and (2).
Vd = R · Id + ω · Lq · Iq (1)
Vq = −ω · Ld · Id + R · Iq + ω · φ (2)
Here, Vd and Vq represent inverter voltages, R represents motor resistance, Ld represents motor d-axis inductance, Lq represents motor q-axis inductance, and ω represents motor electrical angular frequency (motor rotational speed). , Φ represents a motor induced voltage constant.

When the torque is zero (that is, the current is zero), the above equation (2) can be transformed into the following equation (3).
φ = Vq / ω (3)
As can be seen from Equation (3), the detection of the induced voltage constant φ is expressed in a form independent of the motor parameters (R, Ld, Lq) and current by controlling the torque to zero.

  FIG. 7 is a diagram for explaining the relationship between the induced voltage constant φ and the magnet temperature T. FIG. As shown in FIG. 7, the induced voltage constant φ and the magnet temperature T have a one-to-one relationship that is known in advance. For this reason, if induced voltage constant (phi) is calculated | required by Formula (3), magnet temperature T can be calculated | required from the relationship shown in FIG. The relationship shown in FIG. 7 is stored in any ECU as a map, for example.

  In step S40 of FIG. 6, Vq and ω in Expression (3) are obtained from the q-axis component of the voltage command value V1 * output from the MG-ECU 32 to the inverter 14 and the rotational speed ω1 measured by the resolver of the motor generator MG1. Therefore, the induced voltage constant φ can be calculated, and the corresponding magnet temperature Tm (MG1) can be determined from the relationship of FIG.

On the other hand, a case where the process proceeds from step S20 to step S50 will be described below.
First, in step S50, it is determined whether or not an abnormality has occurred in motor generator MG2. In step S50, for example, it is determined that an abnormality has occurred in motor generator MG2 when stator coil temperature Ts (MG2) exceeds a predetermined threshold value. Note that an abnormality may be determined based on other abnormality signals indicating current, voltage, and the like. If it is determined in step S50 that an abnormality has occurred, the process proceeds to step S60. If it is determined that no abnormality has occurred, the process proceeds to step S80.

  In step S60, the HV-ECU 31 outputs torque commands Tcom1, Tcom2 to the MG-ECU 32 so as to decrease the torque of the motor generator MG2 from the current command value and increase the torque of the motor generator MG1.

  Subsequently, in step S70, the magnet command temperature Tm (MG1) of the motor generator MG2 is estimated based on a predetermined formula in a state where the torque command value Tcom2 becomes small and the current value of the motor generator MG2 approaches zero. For the estimation of the magnet temperature, for example, the same method as that described in step S40 using equation (3) can be used.

  In step S70 of FIG. 6, Vq and ω in Expression (3) are obtained from the q-axis component of the voltage command value V2 * output from the MG-ECU 32 to the inverter 22 and the rotational speed ω2 measured by the resolver of the motor generator MG2. Therefore, the induced voltage constant φ can be calculated, and the corresponding magnet temperature Tm (MG2) can be determined from the relationship of FIG.

  When the magnet temperature is detected in step S40 or step S70, the process proceeds to step S80, and the control is returned to the main routine.

  FIG. 8 is a flowchart for illustrating control for limiting the operation of motor generator MG1. The processing of this flowchart is called and executed from a predetermined main routine every predetermined time or every time a predetermined condition is satisfied when the engine is stopped and the EV running is executed by the motor generators MG1 and MG2.

  Referring to FIG. 8, when the process is started in step S100, first, in step S101, whether or not magnet temperature Tm (MG1) estimated by the process of the flowchart of FIG. 6 has exceeded a predetermined threshold value Th1. Is judged.

  If Tm (MG1)> Th1 is satisfied in step S101, the process proceeds to step S102, where the torque of motor generator MG1 is set to zero and the operation is stopped, or the torque is limited. Here, the stop of the operation means that the motor generator MG1 is idling, and does not mean that the rotation is zero. If possible, motor generator MG2 is controlled to compensate for the torque that is limited or stopped by motor generator MG1.

  In step S101, if Tm (MG1)> Th1 is not satisfied, the process proceeds to step S103. In step S103, the operation of the motor generator that has been stopped or restricted in step S102 is resumed, or a process for returning from the restricted state to normal operation is performed.

  When the process of step S102 or step S103 ends, control is returned to the main routine in step S104.

  It should be noted that a difference may be provided between the threshold value for the determination to execute step S102 and the threshold value for the determination to execute step S103 so that hunting between the processing of step S102 and the processing of step S103 does not occur. good.

  FIG. 9 is a flowchart for illustrating control for limiting the operation of motor generator MG2. The processing of this flowchart is called and executed from a predetermined main routine every predetermined time or every time a predetermined condition is satisfied when the engine is stopped and the EV running is executed by the motor generators MG1 and MG2.

  Referring to FIG. 9, when the process is started in step S110, first, magnet temperature Tm (MG2) estimated by the same process as the flowchart of FIG. 6 in step S111 is set to a predetermined threshold value Th2. It is determined whether it has been exceeded.

  If Tm (MG2)> Th2 is satisfied in step S111, the process proceeds to step S112, where the torque of motor generator MG2 is set to zero and the operation is stopped, or the torque is limited. Here, the stop of operation means that motor generator MG2 is idling, and does not mean that rotation is zero. If possible, motor generator MG1 is controlled to compensate for the torque that is limited or stopped by motor generator MG2.

  In step S111, if Tm (MG2)> Th2 is not satisfied, the process proceeds to step S113. In step S113, the operation of the motor generator that has been stopped or restricted in step S112 is resumed, or a process of returning from the restricted state to normal operation is performed.

  When the process of step S112 or step S113 is completed, control is returned to the main routine in step S114.

  It should be noted that a difference may be provided between the threshold for determining to execute step S112 and the threshold for determining to execute step S113 so that hunting between the processing of step S112 and the processing of step S113 does not occur. good.

  FIG. 10 is an operation waveform diagram for explaining an example in which control is performed by the vehicle control apparatus of the present embodiment. In FIG. 10, in order, the engine rotational speed Ne, the stator coil temperature Ts (MG1) of the motor generator MG1, the stator coil temperature Ts (MG2) of the motor generator MG2, the torque of the motor generator MG1 (current I1 indicating torque), the motor Torque of generator MG2 (current I2 indicating torque), hydraulic pressure command value PBcr of brake Bcr, and estimated temperature Tm (MG1) of the magnet of motor generator MG1 are shown. In either case, time is shown on the horizontal axis.

  In FIG. 10, the engine rotational speed Ne = 0, and the hydraulic pressure command value PBcr is set to a value necessary for fixing the engine rotational shaft by the brake Bcr. As a result, EV traveling is performed by motor generators MG1 and MG2.

  At times t0 to t1, the torque for driving the wheels 2 is shared by the motor generator MG1 and the motor generator MG2. Due to the continued high load or poor heat dissipation, stator coil temperature Tm (MG1) of motor generator MG1 rises and reaches the threshold value at time t1. Then, it is determined in step S20 in FIG. 6 that an abnormality has occurred in motor generator MG1. As a result, the process of step S30 is executed, and at time t1 to t2, current I1 indicating the torque of motor generator MG1 decreases to zero, and current I2 indicating the torque of motor generator MG2 increases to compensate for this. .

  When current I1 indicating the torque of motor generator MG1 becomes zero at time t2, step S40 is executed to calculate magnet temperature Tm (MG1). The state where the current I1 indicating the torque of the motor generator MG1 is controlled to zero continues between the times t2 and t3, and the magnet temperature Tm (MG1) is continuously calculated during that time. By continuing to monitor the accurate magnet temperature Tm (MG1), it is possible to determine to restart the motor generator MG1 as soon as possible.

  At time t2 to t3, the torque of motor generator MG1 is limited, and as a result of EV running by motor generator MG2 alone, magnet temperature Tm (MG1) begins to drop, and at time t3, the return used in step S101 of FIG. To the threshold value Th1. In response to this, a process for returning to the torque command value for normal EV traveling is performed between times t3 and t4. As a result, after time t4, the torque sharing ratio of motor generators MG1 and MG2 is set to a ratio during normal EV traveling.

  As described above, in the present embodiment, the torque of the motor generator that is determined to have an abnormality is limited or zero, and the magnet temperature is detected with higher accuracy than in the past. As a result, since it can be accurately determined whether or not to continue the restriction, it can be expected to increase the EV travel time and improve the fuel efficiency.

  Finally, the present embodiment will be summarized with reference to the drawings again. Referring to FIGS. 1 and 3, electrically powered vehicle 1 of the present embodiment includes motor generators MG <b> 1 and MG <b> 2, engine 4, and a power split mechanism that distributes power among motor generators MG <b> 1 and MG <b> 2 and engine 4. 3. Power split device 3 includes a first rotating element (sun gear 62) connected to motor generator MG1, a second rotating element (ring gear 63) connected to motor generator MG2, and a third rotating element (planetary carrier) connected to engine 4. 61) and a brake Bcr for fixing the third rotating element. The control device 30 fixes the third rotating element by the brake Bcr and travels by one motor as shown in steps S30 and S60 of FIG. 6 and times t1 to t2 of FIG. 10 during traveling by the outputs of the motor generators MG1 and MG2. The torque of the other motor generator is increased by reducing the torque of the generator, and the magnet temperature Tm of one motor generator whose torque has been reduced is estimated based on the induced voltage φ as shown in step S40 or S70.

  Preferably, control device 30 controls motor generators MG1 and MG2 such that the torque of one motor generator is reduced to zero and the other motor generator compensates for the reduction in torque of one motor generator.

  Preferably, as shown in steps S20 and S50 of FIG. 6 and times t1 to t3 of FIG. 10, control device 30 detects whether or not motor generators MG1 and MG2 have malfunctioned, respectively, and the motor generator from which the malfunction has been detected is detected. And the magnet temperature Tm of the motor generator in which the abnormality is detected is estimated.

  By controlling in this way, it can be discriminated whether or not the abnormality is caused by demagnetization of the magnet, which can contribute to the determination of the limited travel.

  More preferably, as described in steps S20 and S50 of FIG. 6, control device 30 detects whether or not motor generators MG1 and MG2 are abnormal based on the temperatures of motor generators MG1 and MG2, and control device 30 Then, the torque of the motor generator whose temperature has reached a certain value among the motor generators MG1 and MG2 is reduced.

  Since there is a certain degree of correlation between the stator coil temperature of the motor generator and the magnet temperature, demagnetization of the magnet due to overheating can be prevented beforehand by controlling in this way.

  Further, when the magnet temperature Tm and the induced voltage value φ exceed the predetermined values, the subsequent operation of the motor generator may be stopped and a warning displayed on the driver. Thereby, it can prevent that damage of a failure expands by detecting demagnetization of a magnet and shifting to limited operation.

  More preferably, as shown in FIG. 3, motor generators MG1 and MG2 are attached to the stator coils of motor generators MG1 and MG2, and temperature sensors 81 for transmitting the temperature detection results of motor generators MG1 and MG2 to control device 30, 83.

  Further, as described with reference to FIGS. 8 and 9, when the magnet temperature falls below a predetermined value, the operation of the corresponding motor generator is resumed. As a result, it is possible to prevent the motor generator whose torque has not been reduced from overheating and stopping the vehicle (or limited travel). Further, the detection accuracy of the magnet temperature is improved, and the motor generator can be used up to the vicinity of the temperature limit. Conventionally, since the magnet temperature could not be accurately estimated, the restriction was determined by multiplying the magnet temperature estimated from the stator coil temperature, the rotational speed, the torque, and the like by a safety factor. Therefore, by improving the estimation accuracy of the magnet temperature, it is not necessary to consider the safety factor excessively, and the potential possessed by the vehicle can be maximized.

  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.

  1 vehicle, 2 wheels, 3 power split mechanism, 4 engine, 6 converter, 7 auxiliary machine, 8 commercial power supply, 10, 13, 21 voltage sensor, 11, 24, 25 current sensor, 12 voltage converter, 14, 22 inverter, 30 control device, 33 engine ECU, 40 air conditioner, 42 charger, 44 connector, 46, CHRB, CHRG relay, 52 oil pump, 54, 74 rotor, 55, 75 permanent magnet, 56, 76 stator, 58 member, 59 rotation Shaft, 60 pinion gear, 61 planetary carrier, 62 sun gear, 63 ring gear, 64, 66, 68 gear, 65 output gear, 70 differential gear, 81, 83 temperature sensor, 82, 84 resolver, Bcr brake, C1, CH for smoothing Capacitor, MG1, MG2 Motor generator , PL1, PL1A, PL2 positive bus, SL1, SL2 negative bus, SMRB, SMRG System main relay.

Claims (5)

An electric vehicle control device, wherein the electric vehicle includes first and second rotating electric machines, an engine, and a differential mechanism that performs power split between the first and second rotating electric machines and the engine. The differential mechanism includes a first rotating element coupled to the first rotating electrical machine, a second rotating element coupled to the second rotating electrical machine, and a third rotating element coupled to the engine. A rotation suppressing device for suppressing rotation of the third rotating element,
The control device suppresses the rotation of the third rotating element by the rotation suppressing device and reduces the torque of one rotating electric machine during traveling by the outputs of the first and second rotating electric machines, A control apparatus for an electric vehicle that estimates a magnet temperature of the one rotating electric machine that has increased torque and reduced torque based on an induced voltage.   The control device reduces the torque of the one rotating electric machine to zero, and causes the first rotating electric machine and the second rotating electric machine to compensate for the torque reduction of the one rotating electric machine. The control apparatus of the electric vehicle of Claim 1 which controls.   The control device detects whether or not an abnormality has occurred in each of the first and second rotating electrical machines, reduces the torque of the rotating electrical machine in which the abnormality is detected, and estimates the magnet temperature of the rotating electrical machine in which the abnormality is detected The control device for an electric vehicle according to claim 1 or 2. The control device detects whether or not an abnormality has occurred in the first and second rotating electrical machines based on the temperatures of the first and second rotating electrical machines;
The said control apparatus is a control apparatus of the electric vehicle of Claim 3 which reduces the torque of the rotary electric machine in which temperature reached the fixed value among the said 1st and 2nd rotary electric machines.   The first and second rotating electrical machines are attached to stator coils of the first and second rotating electrical machines, and transmit the temperature detection results of the first and second rotating electrical machines to the control device. The control device for an electric vehicle according to claim 4, each including a second temperature sensor.

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