JP2010081682A - Drive control device of electric motor, vehicle equipped with the same, and drive control method of electric motor - Google Patents

Abstract

An electric motor drive control apparatus that uses a rectangular wave control system in a state where a voltage on a motor drive circuit side is not boosted with respect to a voltage on a DC power supply side maintains good controllability of the electric motor.
In the hybrid vehicle of the present invention, it is determined that the boosted voltage VH should not be boosted with respect to the pre-boost voltage VL, and the target voltage phase when the motor is controlled using the rectangular wave control method. When ψ * exceeds the boost determination voltage phase ψref based on the motor rotation speed Nm2, boost converter 55 is controlled to boost boosted voltage VH with respect to pre-boost voltage VL (steps S120 and S160). ~ S190, S140, S150). As a result, the inverter can be controlled using a PWM control method that is superior in control accuracy compared to the rectangular wave control method, and even if a PWM control method with a relatively small modulation rate is used, the output of the motor is secured with good responsiveness. be able to.
[Selection] Figure 3

Description

  The present invention relates to an electric motor drive control device that drives and controls an electric motor using electric power from a DC power source, a vehicle including the electric motor, and an electric motor drive control method.

Conventionally, an electric vehicle having a DC power supply, a boost converter that boosts the output voltage of the DC power supply by switching of a switching element, and a traveling motor that is driven and controlled based on the output voltage of the boost converter is known. (For example, refer to Patent Document 1). In this electric vehicle, when the low fuel consumption driving instruction is received from the user by the fuel consumption switch, the boost operation by the boost converter is stopped to improve the efficiency by eliminating the switching loss in the boost converter, and the voltage from the DC power source is the inverter. Is converted into an AC voltage and supplied to the traveling motor. Further, conventionally, a boost converter that boosts the power supply voltage and outputs the boost voltage, an inverter that receives the boost voltage from the boost converter and drives the motor, and indicates the target value of the boost voltage to the boost converter. There is known a motor drive device including a control device that determines the control method as either rectangular wave control or non-rectangular wave control (see, for example, Patent Document 2). The control device of this motor drive device instructs a first boost target value for the same predetermined input signal indicating a torque request and performs non-rectangular wave control such as sine wave PWM control or overmodulation PWM control as a control method. A first operation mode to be designated and a second operation mode to designate a second boost target value lower than the first boost target value and to designate rectangular wave control as a control method are selectable. Yes.
JP 2007-159214 A JP 2007-306658 A

  Here, the rectangular wave control method used in the conventional motor driving device described above is capable of generating a fundamental wave component having the theoretical maximum amplitude (modulation rate) while reducing the switching loss. The output torque of the electric motor can be controlled by changing the phase (voltage phase) of the constant rectangular wave voltage according to the target torque. Therefore, if the inverter is controlled using the rectangular wave control system in a state where the voltage from the DC power supply is not boosted by the boost converter, the switching loss in the boost converter and the inverter is suppressed and the energy efficiency is improved while securing the output of the motor. It will be possible. However, since the rectangular wave control method is inferior to the control response and stability compared to the sine wave PWM control method, etc., in the state where the voltage from the DC power source is not boosted by the boost converter, environmental factors and the motor It is necessary to more appropriately use the rectangular wave control method so as not to impair the controllability of the electric motor while taking into consideration the operating point and the like.

  Therefore, the main object of the present invention is to maintain good controllability of an electric motor in an electric motor drive control device using a rectangular wave control system in a state where the voltage on the electric motor drive circuit side is not boosted with respect to the voltage on the DC power supply side. And

  The electric motor drive control device, the vehicle including the electric motor drive control device, and the electric motor drive control method according to the present invention employ the following means in order to achieve the main object described above.

An electric motor drive control device according to the present invention includes:
An electric motor drive control device for driving and controlling an electric motor using electric power from a DC power source,
An electric motor drive circuit capable of driving the electric motor by selectively using a PWM voltage and a rectangular wave voltage;
Voltage conversion means capable of boosting the voltage on the motor drive circuit side with respect to the voltage on the DC power source side;
A state in which the voltage on the motor drive circuit side is not boosted with respect to the voltage on the DC power supply side by the voltage conversion means, and a state in which the voltage on the motor drive circuit side is boosted with respect to the voltage on the DC power supply side The motor drive circuit so that the motor outputs a target torque by selectively using a PWM control method using the PWM voltage and a rectangular wave control method using the rectangular wave voltage. Drive circuit control means capable of controlling
Step-up determination means for determining whether or not to increase the voltage on the electric motor drive circuit side with respect to the voltage on the DC power source side by the voltage conversion means;
When the boost determination means determines that the voltage on the motor drive circuit side should be boosted with respect to the voltage on the DC power supply side, the voltage on the motor drive circuit side after the target boost corresponding to the target torque of the motor The voltage conversion means is controlled to be a voltage, and it is determined by the boost determination means that the voltage on the motor drive circuit side should not be boosted with respect to the voltage on the DC power supply side, and the motor drive circuit Is controlled by the drive circuit control means using the rectangular wave control method, and the target voltage phase of the rectangular wave voltage exceeds a predetermined threshold, the voltage on the DC power supply side is Voltage conversion control means for controlling the voltage conversion means so that the voltage on the electric motor drive circuit side is boosted;
Is provided.

  In this motor drive control device, when the boost determination means determines that the voltage on the motor drive circuit side should not be boosted with respect to the voltage on the DC power supply side, the voltage conversion means does not perform the boost operation, and the boost determination means When it is determined that the voltage on the motor drive circuit side should be boosted with respect to the voltage on the DC power supply side, the voltage conversion means so that the voltage on the motor drive circuit side becomes a target boosted voltage corresponding to the target torque of the motor. Is controlled. Then, both the state where the voltage on the motor drive circuit side is not boosted with respect to the voltage on the DC power source side by the voltage conversion means and the state where the voltage on the motor drive circuit side is boosted with respect to the voltage on the DC power source side Therefore, the motor drive circuit is controlled so that the motor outputs the target torque by selectively using the PWM control method using the PWM voltage and the rectangular wave control method using the rectangular wave voltage. Thereby, according to this electric motor drive control device, it becomes possible to improve energy efficiency, ensuring the output of an electric motor. Here, in the rectangular wave control method for controlling the output torque of the motor by changing the voltage phase, which is the phase of the rectangular wave voltage, according to the target torque, the output torque of the motor changes to the voltage phase when the voltage phase is relatively small. However, when the actual voltage phase increases to some extent, the linearity between the voltage phase and the output torque is lost, and the follow-up of the torque with respect to the voltage phase change, that is, the control responsiveness deteriorates. End up. Further, according to the study by the present inventors, it has been found that when an environmental factor such as the temperature of the motor changes, the operating point (output torque) of the motor corresponding to a certain voltage phase changes. For example, when the temperature of the electric motor (particularly the rotor) increases, the voltage phase corresponding to a certain operating point (output torque) increases. Based on these considerations, in this motor drive control device, it is determined that the voltage on the motor drive circuit side should not be boosted with respect to the voltage on the DC power supply side, and the motor drive circuit is controlled by the drive circuit control means in a rectangular wave control system. When the target voltage phase of the rectangular wave voltage exceeds a predetermined threshold value, the voltage conversion means is configured to boost the voltage on the motor drive circuit side with respect to the voltage on the DC power source side. Is controlled. Thus, when the actual voltage phase is increased to some extent due to the operating point (target torque) of the motor or environmental factors, the controllability of the motor in the rectangular wave control method may be deteriorated. If the voltage is boosted with respect to the voltage on the DC power supply side, the motor drive circuit can be controlled using the PWM control method that is superior in control accuracy compared to the rectangular wave control method, and the PWM control method with a relatively small modulation rate is used. Even in this case, the output of the motor can be secured with good response. As a result, it becomes possible to maintain good controllability of the electric motor in the electric motor drive control apparatus using the rectangular wave control method in a state where the voltage on the electric motor driving circuit side is not boosted with respect to the voltage on the DC power source side. The “PWM control method” here includes a sine wave PWM control method and an overmodulation PWM control method.

  The voltage conversion control means determines that the voltage on the motor drive circuit side should not be boosted with respect to the voltage on the DC power supply side by the boost determination means, and the motor drive circuit controls the drive circuit. When the target voltage phase of the rectangular wave voltage exceeds the threshold value when the rectangular wave control method is controlled by the means, the voltage on the motor drive circuit side is changed to the electric motor using the PWM control method. The voltage conversion means may be controlled so that the voltage is sufficient to control the motor drive circuit so that the target torque is output from the motor. As a result, it is possible to satisfactorily secure the output of the electric motor even when a PWM control method with a relatively small modulation rate is used.

  Further, the predetermined threshold value may be a variable value set based on the rotational speed of the electric motor, and the predetermined threshold value is set to tend to be smaller as the absolute value of the rotational speed of the electric motor is smaller. May be. Since the control cycle in the rectangular wave control method becomes shorter as the absolute value of the rotation speed of the electric motor becomes larger, the control responsiveness in the rectangular wave control method becomes better as the absolute value of the rotation speed of the electric motor becomes larger. Therefore, if the threshold value is a variable value set based on the rotation speed of the motor, it is determined by the boost determination means that the voltage on the motor drive circuit side should not be boosted with respect to the voltage on the DC power supply side. Sometimes it is possible to more appropriately determine whether or not the voltage on the motor drive circuit side should be boosted in relation to the voltage phase. If the threshold value is set so as to decrease as the absolute value of the motor speed decreases, the controllability of the motor when the absolute value of the motor speed is relatively small is improved and the motor speed is increased. When the absolute value of is relatively large, the rectangular wave control method can be used as much as possible to improve energy efficiency.

  The boost determination means includes a target operating point of the motor, a non-boosting area in which the voltage on the motor drive circuit side is not boosted with respect to the voltage on the DC power supply side by the voltage conversion means. The voltage conversion means uses the voltage boosting restriction to separate the voltage on the DC power supply side from the voltage on the DC power supply side, and the voltage on the motor drive circuit side by the voltage conversion means. It may be determined whether or not the voltage on the DC power supply side should be boosted.

  Further, the boosting constraint is that the loss due to driving of the motor when the voltage on the motor driving circuit side is not boosted is greater than the loss when boosting the voltage on the motor driving circuit side in the operating region of the motor. A region that becomes smaller may be the non-boosting region, and a region where the loss during the boosting may be smaller than the loss during the non-boosting may be the boosting region. As a result, the boosting constraint can be made more appropriate for improving energy efficiency.

  The vehicle according to the present invention includes any one of the above-described electric motor drive control devices, and can travel by power from the electric motor that is driven and controlled by the electric motor drive control device. Since the electric motor drive control device provided in the vehicle has the above-described effects, the vehicle can improve the running performance and energy efficiency satisfactorily.

An electric motor drive control method according to the present invention includes:
A DC power supply, a motor drive circuit capable of selectively driving a PWM voltage and a rectangular wave voltage, and voltage conversion capable of boosting the voltage on the motor drive circuit side with respect to the voltage on the DC power supply side An electric motor drive control method for driving and controlling the electric motor using means,
(A) The electric motor uses the rectangular wave control method using the rectangular wave voltage in a state where the voltage on the electric motor drive circuit side is not boosted with respect to the voltage on the DC power supply side by the voltage conversion means, and the electric motor has a target torque. Controlling the motor drive circuit to output
(B) While the voltage conversion means is controlling the motor drive circuit using the rectangular wave control method in a state where the voltage on the motor drive circuit side is not boosted with respect to the voltage on the DC power supply side. In addition, when the target voltage phase of the rectangular wave voltage exceeds a predetermined threshold value, the voltage conversion means is controlled so that the voltage on the motor drive circuit side is boosted with respect to the voltage on the DC power source side. And controlling the motor drive circuit so that the motor outputs a target torque using a PWM control method using the PWM voltage, and
Is included.

  When the actual voltage phase is increased to some extent due to the operating point (target torque) of the motor, environmental factors, etc., as in this method, the controllability of the motor in the rectangular wave control system may be deteriorated. If the voltage on the side is boosted with respect to the voltage on the DC power supply side, the motor drive circuit can be controlled using a PWM control method that has better control accuracy than the rectangular wave control method, and the PWM control method has a relatively small modulation rate Even if is used, the output of the electric motor can be secured with good responsiveness. As a result, it becomes possible to maintain good controllability of the electric motor in the electric motor drive control apparatus using the rectangular wave control method in a state where the voltage on the electric motor driving circuit side is not boosted with respect to the voltage on the DC power source side.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a schematic configuration diagram of a hybrid vehicle 20 as a vehicle according to an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of an electric drive system included in the hybrid vehicle 20. As shown in these drawings, the hybrid vehicle 20 of the embodiment includes an engine 22, a three-shaft power distribution and integration mechanism 30 connected to a crankshaft 26 that is an output shaft of the engine 22 via a damper 28, A motor MG1 capable of generating electricity connected to the power distribution and integration mechanism 30; a reduction gear 35 attached to a ring gear shaft 32a as a drive shaft connected to the power distribution and integration mechanism 30; and a ring gear shaft via the reduction gear 35 Motor MG2 connected to 32a, inverters 41 and 42 capable of converting DC power into AC power and supplying them to motors MG1 and MG2, and converting power from battery 50 into voltage 41 and being supplied to inverters 41 and 42 Step-up converter 55 and a hybrid electronic control unit (hereinafter referred to as hybrid control unit) that controls the entire hybrid vehicle 20. In which and a hybrid ECU ") 70, and the like.

  The engine 22 is an internal combustion engine that outputs power when supplied with hydrocarbon-based fuel such as gasoline or light oil. The fuel injection amount or ignition timing by an engine electronic control unit (hereinafter referred to as “engine ECU”) 24, Control of intake air volume etc. The engine ECU 24 receives signals from various sensors that are provided for the engine 22 and detect the operating state of the engine 22. The engine ECU 24 communicates with the hybrid ECU 70 to control the operation of the engine 22 based on a control signal from the hybrid ECU 70, a signal from the sensor, and the like, and to transmit data on the operation state of the engine 22 as necessary. It outputs to ECU70.

  The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotating elements. A crankshaft 26 of the engine 22 is connected to the carrier 34, a motor MG1 is connected to the sun gear 31, and a reduction gear 35 is connected to the ring gear 32 via a ring gear shaft 32a. The power distribution and integration mechanism 30 distributes the power from the engine 22 input from the carrier 34 to the sun gear 31 side and the ring gear 32 side according to the gear ratio when the motor MG1 functions as a generator. , The power from the engine 22 input from the carrier 34 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the wheels 39a and 39b, which are drive wheels, via the gear mechanism 37 and the differential gear 38.

  The motor MG1 and the motor MG2 are configured as a synchronous generator motor including a rotor in which a permanent magnet is embedded so as to have a reverse saliency and a stator around which a three-phase coil is wound. Power is exchanged with the battery 50 which is a direct current power source. As shown in FIG. 2, the inverters 41 and 42 include six transistors T11 to T16 or T21 to T26 and six diodes D11 to D16 or D21 connected in parallel to the transistors T11 to T16 or T21 to T26 in the reverse direction. To D26. Transistors T11 to T16 and T21 to T26 are arranged in pairs so that the inverters 41 and 42 are in pairs on the source side and the sink side with respect to the positive and negative buses 54a and 54b shared as the power line 54, respectively. Each of the three-phase coils (U-phase, V-phase, W-phase) of the motors MG1, MG2 is connected to each connection point between the paired transistors. Therefore, a rotating magnetic field is formed in the three-phase coil by controlling the on-time ratios of the transistors T11 to T16 and T21 to T26 that make a pair while a voltage is acting between the positive electrode bus 54a and the negative electrode bus 54b. Thus, the motors MG1 and MG2 can be driven to rotate. Moreover, since the inverters 41 and 42 share the positive electrode bus 54a and the negative electrode bus 54b, the electric power generated by either the motor MG1 or MG2 can be supplied to another motor. A smoothing capacitor 57 for smoothing the voltage is connected to the positive electrode bus 54a and the negative electrode bus 54b.

  Boost converter 55 is connected to battery 50 via system main relay 56. As shown in FIG. 2, two transistors T31 (upper arm), transistor T32 (lower arm), and transistors T31 and T32 are connected. It includes two diodes D31 and D32 connected in parallel in the reverse direction and a reactor L. The two transistors T31 and T32 are connected to the positive bus 54a and the negative bus 54b of the inverters 41 and 42, respectively, and the reactor L is connected to the connection point between the two. Reactor L and negative electrode bus 54 b are connected to a positive electrode terminal and a negative electrode terminal of battery 50 via system main relay 56, and smoothing capacitor 59 that smoothes the voltage on the battery 50 side of boost converter 55. Is connected. Further, a second voltage sensor 92 is installed between the terminals of the smoothing capacitor 59, and the voltage before boosting (voltage on the DC power supply side) VL of the boosting converter 55 is obtained using the detection value of the second voltage sensor 92. Is done. Thus, by switching control of the transistors T31 and T32, the voltage on the inverters 41 and 42 side can be boosted with respect to the voltage on the battery 50 side (voltage VL before boosting). In this case, the boosted voltage (voltage on the motor drive circuit side) VH by the boost converter 55 that can be applied to the inverters 41 and 42 is detected using the detection value of the third voltage sensor 93 installed between the terminals of the smoothing capacitor 57. To be acquired. In addition, by switching control of the transistors T31 and T32 of the boost converter 55, the DC voltage acting on the positive bus 54a and the negative bus 54b can be stepped down to charge the battery 50.

  The inverters 41 and 42 and the boost converter 55 are all controlled by a motor electronic control unit (hereinafter referred to as “motor ECU”) 40, thereby driving and controlling the motors MG 1 and MG 2. The motor ECU 40 includes, for example, signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, voltages VL and VH from the second and third voltage sensors 92 and 93, and current sensors. Signals necessary for driving control of the motors MG1, MG2, such as phase currents applied to the motors MG1, MG2 detected by 95v, 95w, 96v, 96w (see FIG. 2) are input. Further, the motor ECU 40 outputs a switching control signal to the inverters 41 and 42, a driving signal to the system main relay 56, a switching control signal to the boost converter 55, and the like. Further, the motor ECU 40 communicates with the battery ECU 52 and the hybrid ECU 70, and drives and controls the motors MG1 and MG2 using a signal from the battery ECU 52 and a control signal from the hybrid ECU 70 in addition to the signal from the sensor. In addition, the motor ECU 40 calculates and acquires data related to the operating state of the motors MG1 and MG2, such as the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2, based on the signals from the rotational position detection sensors 43 and 44. These data are output to the hybrid ECU 70 or the like.

  In the embodiment, the battery 50 is configured as a nickel-hydrogen secondary battery or a lithium ion secondary battery, and is managed by a battery electronic control unit (hereinafter referred to as “battery ECU”) 52. The battery ECU 52 includes a signal necessary for managing the battery 50, for example, a terminal voltage VB from the first voltage sensor 91 installed between the terminals of the battery 50, and a power line connected to the output terminal of the battery 50. A charge / discharge current from a current sensor (not shown) attached to 54, a battery temperature Tb from a temperature sensor 51 attached to the battery 50, and the like are input. The battery ECU 52 outputs data related to the state of the battery 50 to the hybrid ECU 70 and the engine ECU 24 by communication as necessary. Further, in order to manage the battery 50, the battery ECU 52 calculates the remaining capacity SOC based on the integrated value of the charging / discharging current detected by the current sensor, or requests charging / discharging of the battery 50 based on the remaining capacity SOC. The power Pb * is calculated, or the input limit Win as the charge allowable power that is the power allowed for charging the battery 50 based on the remaining capacity SOC and the battery temperature Tb, and the power allowed for discharging the battery 50. The output limit Wout as discharge allowable power is calculated. The input / output limits Win and Wout of the battery 50 set basic values of the input / output limits Win and Wout based on the battery temperature Tb, and the output limiting correction coefficient and the input limit based on the remaining capacity (SOC) of the battery 50. The correction coefficient can be set, and the basic value of the set input / output limits Win and Wout can be multiplied by the correction coefficient.

  The hybrid ECU 70 is configured as a microprocessor centered on the CPU 72, and includes a ROM 74 for storing a processing program, a RAM 76 for temporarily storing data, an input / output port and a communication port (not shown), and the like in addition to the CPU 72. The hybrid ECU 70 detects the ignition signal from the ignition switch (start switch) 80, the shift position SP from the shift position sensor 82 that detects the shift position SP that is the operation position of the shift lever 81, and the depression amount of the accelerator pedal 83. The accelerator opening Acc from the accelerator pedal position sensor 84, the brake pedal stroke BS from the brake pedal stroke sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 87, and the like are input via the input port. . The hybrid ECU 70 is connected to the engine ECU 24, the motor ECU 40, the battery ECU 52, and the like through the communication port as described above, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, the battery ECU 52, and the like. Yes.

  When the hybrid vehicle 20 travels, the hybrid ECU 70 basically outputs to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc corresponding to the depression amount of the accelerator pedal 83 and the vehicle speed V. The required torque Tr * to be calculated is calculated, and the target rotational speed Ne * and target torque Te * of the engine 22 and the target torque of the motor MG1 are indicated so that torque based on the required torque Tr * is output to the ring gear shaft 32a. Torque command Tm1 * and torque command Tm2 * indicating the target torque of motor MG2 are set. The operation control system between the engine 22 and the motors MG1 and MG2 in the hybrid vehicle 20 of the embodiment includes a torque conversion operation mode, a charge / discharge operation mode, a motor operation mode, and the like. Under the torque conversion operation mode, the hybrid ECU 70 sets the target rotational speed Ne * and the target torque Te * so that power corresponding to the required torque Tr * is output from the engine 22, and from the engine 22 Torque commands Tm1 * and Tm2 * for motors MG1 and MG2 are set so that all of the output power is torque-converted by power distribution and integration mechanism 30 and motors MG1 and MG2 and output to ring gear shaft 32a. In addition, under the charge / discharge operation mode, the hybrid ECU 70 outputs power (power) corresponding to the sum of the required torque Tr * and the charge / discharge required power Pb * required for charging / discharging the battery 50 from the engine 22. The target rotational speed Ne * and the target torque Te * are set so that all or part of the power output from the engine 22 when the battery 50 is charged / discharged is transmitted to the power distribution and integration mechanism 30 and the motors MG1 and MG2. Torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are set so that the torque is converted by the above and torque corresponding to the required torque Tr * is output to the ring gear shaft 32a. In the hybrid vehicle 20 of the embodiment, when a predetermined condition is satisfied under the torque conversion operation mode or the charge / discharge operation mode, intermittent operation for automatically stopping and starting the engine 22 is executed. Further, under the motor operation mode, the hybrid ECU 70 stops the operation of the engine 22 and causes only the motor MG2 to output a torque corresponding to the required torque Tr * to the ring gear shaft 32a. In this case, the hybrid ECU 70 sets the target rotational speed Ne *, the target torque Te * of the engine 22 and the torque command Tm1 * for the motor MG1 to the value 0, and sets the torque command Tm2 * for the motor MG2 to the required torque Tr * and It is set based on the gear ratio ρ of the power distribution and integration mechanism 30, the gear ratio Gr of the reduction gear 35, and the like. In addition, when the engine 22 is started in response to a start request of the engine 22 while the hybrid vehicle 20 is stopped or traveling under the motor operation mode, the hybrid ECU 70 causes the engine 22 to be cranked by the motor MG1. In addition, torque for the motors MG1 and MG2 is output so that torque based on the required torque Tr * is output to the ring gear shaft 32a while torque as a reaction force against the driving torque acting on the ring gear shaft 32a is canceled along with the cranking. Command Tm1 * and torque command Tm2 * are set.

  When the hybrid ECU 70 sets the target rotational speed Ne *, the target torque Te *, the torque command Tm1 * for the motor MG1, and the torque command Tm2 * for the motor MG2 as described above, the target rotational speed Ne * and the target rotational speed Ne * are set. Torque Te * is transmitted to engine ECU 24 and torque commands Tm1 * and Tm2 * are transmitted to motor ECU 40. Then, the engine ECU 24 controls the engine 22 so that the target rotational speed Ne * and the target torque Te * from the hybrid ECU 70 are obtained. In addition, motor ECU 40 controls switching of inverters 41 and 42 and boost converter 55 such that motor MG1 is driven according to torque command Tm1 * from hybrid ECU 70 and motor MG2 is driven according to torque command Tm2 * from hybrid ECU 70. To do.

  Here, the motor ECU 40 according to the embodiment generates a sine wave PWM control system using a sine wave PWM voltage and an overmodulation PWM voltage according to the torque commands Tm1 *, Tm2 * and the rotational speeds Nm1, Nm2 of the motors MG1 and MG2. The inverters 41 and 42 are subjected to switching control by any one of three control methods: an overmodulation PWM control method to be used and a rectangular wave control method to use a rectangular wave voltage. The sine wave PWM control method is generally referred to as “PWM control”, and the transistors T11 to T16 and the transistors T21 to T26 are turned on / off according to the voltage difference between the sine wave voltage command value and a carrier wave such as a triangular wave. This is a method of obtaining an output voltage (PWM voltage) having a sinusoidal fundamental wave component by controlling off. When the sine wave PWM control method is used, the modulation factor Kmd which is the ratio of the output voltage (amplitude of the fundamental wave component) to the boosted voltage (inverter input voltage) VH supplied from the boost converter 55 (smoothing capacitor 57) is approximately The value can be set within a range of 0 to 0.61. The overmodulation PWM control system performs control similar to the above-described sine wave PWM control system after distorting the carrier wave so as to reduce the amplitude, and the modulation factor is approximately 0.61 to .0. It can be set within the range of 78. Further, the rectangular wave control method can theoretically generate a fundamental wave component having the maximum amplitude, and the phase of the rectangular wave voltage having a constant amplitude (voltage phase with respect to the q axis) is set. The motor torque can be controlled by changing the torque according to the torque command. When this rectangular wave control method is used, the modulation factor Kmd is a constant value (approximately 0.78). The control accuracy (control responsiveness) of the inverters 41 and 42 (motors MG1 and MG2) decreases in the order of the sine wave PWM control method, the overmodulation PWM control method, and the rectangular wave control method. By using the wave control method, it is possible to improve the voltage utilization factor of the DC power supply and to improve the energy efficiency by suppressing the occurrence of copper loss and switching loss. In the high speed range where the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 increase, the rectangular wave control method is basically used as the control method. In this case, the voltage on the inverters 41 and 42 side is used. Field weakening control is performed to supply a field weakening current so that the post-boost voltage VH is higher than the induced voltage generated in the motors MG1 and MG2. In the hybrid vehicle 20 of the embodiment, the rated voltage (for example, DC150V) of the battery 50 is a predetermined voltage according to the target operating points of the motors MG1 and MG2 (current rotation speeds Nm1 and Nm2 and torque commands Tm1 * and Tm2 *). The step-up converter 55 is controlled by the motor ECU 40 so that the voltage is increased to (for example, a maximum of 650 V).

  Next, a procedure for controlling the boost converter 55 in the hybrid vehicle 20 of the embodiment and a procedure for setting a control method for the inverters 41 and 42 (motors MG1, MG2) will be described. Here, in order to simplify the description, the control procedure of the boost converter 55 under the motor operation mode in which power is output only from the motor MG2 to the ring gear shaft 32a, and the procedure for setting the control method of the inverters 41 and 42. Will be described.

  FIG. 3 is a flowchart illustrating an example of a boost control routine that is repeatedly executed at predetermined time intervals by the motor ECU 40 according to the embodiment. At the start of the boost control routine of FIG. 3, the CPU (not shown) of the motor ECU 40 performs a torque command Tm2 * for the motor MG2 from the hybrid ECU 70, the current rotational speed Nm2 of the motor MG2, the pre-boosting voltage VL, the post-boosting voltage VH, the inverter Input processing of data required for control such as a control method flag Fmod2 indicating a control method of 42 (motor MG2) and a target voltage phase ψ * when the inverter 42 is controlled by the rectangular wave control method is executed (step S100). The control method flag Fmod2 is set by a control method setting routine, which will be described later, and is controlled to a value of 0 when the inverter 42 is controlled using the sine wave PWM control method, and is controlled using the overmodulation PWM control method. The value is set to 1 when the control is performed, and is set to 2 when the control is performed using the rectangular wave control method. The target voltage phase ψ * is a rectangular wave voltage phase (referenced to the q axis) that is set separately based on the torque command Tm2 * (target torque) for the motor MG2 when the inverter 42 is controlled using the rectangular wave control method. Target phase). Here, since the relationship shown in the following equation (1) is established between the voltage phase ψ and the output torque Tm2 of the motor MG2, in the embodiment, the torque command Tm2 * is based on the equation (1). , The rotational speed Nm2, the boosted voltage VH, and the target voltage phase ψ * are predetermined and stored in a storage device (not shown) of the motor ECU 40 as a target voltage phase setting map (not shown). Are derived and set from the map corresponding to the given torque command Tm2 *, the rotational speed Nm2, and the boosted voltage VH. In Equation (1), p represents the number of pole pairs, φ represents the number of magnetic flux linkages, Ld represents the d-axis inductance, Lq represents the q-axis inductance, and ω represents the angular velocity of the motor.

  After the data input process in step S100, as shown in FIG. 4, the operation region of motors MG1 and MG2 is boosted by a boost converter 55 and the boosted region where boosted voltage VH is not boosted relative to pre-boosted voltage VL. The step-up switching determination torque Tref2 corresponding to the rotation speed Nm2 of the motor MG2 is derived and set from a step-up switching line (step-up restriction) determined in advance so as to be classified into (step S110). FIG. 4 shows an example of the boost switching line. This figure exemplifies a region (first quadrant) in which both the rotation speed of the boost switching line and the value of the torque command are positive. In the embodiment, for example, the target post-boost voltage setting map for the motor MG2 is Of the operating regions of the motor MG2, the region where the boosting of the post-boosting voltage VH is indispensable in order to output the torque according to the torque command Tm2 * from the motor MG2, and the operating points of the other regions ( For each rotation speed and torque command), when boosted voltage VH is not boosted with respect to pre-boosting voltage VL by boosting converter 55, and after boosting voltage VH is boosted with respect to pre-boosting voltage VL by boosting converter 55. The total loss of motors MG1 and MG2, the losses of inverters 41 and 42, and the loss of boost converter 55. Basically, an operating point at which the loss becomes smaller at the time of non-boosting than at the time of boosting is included in the non-boosting region, and an operation at which the loss becomes smaller at the time of boosting than at the time of non-boosting. Created by including points in the boost region. As a result, basically, the side where the absolute value of the motor rotational speed is low is defined as the non-boosting region by the boost switching line, and the side where the absolute value of the motor rotational frequency is high is defined as the boosting region (including on the boost switching line). Will be. In the example of FIG. 4, when the rotational speed Nm2 is relatively low, the boost switching determination torque Tref2 is set to a constant large value (for example, the rated maximum torque of the motor MG2) Tmax2, and when the rotational speed Nm2 increases to some extent, The step-up switching determination torque Tref2 is set to a smaller value as the rotational speed Nm2 increases, and is set to a value of 0 when the rotational speed Nm2 exceeds a predetermined value. The boost switching line used at the time of transition from the non-boosting region to the boosting region may be the same as the boost switching line used at the time of transition from the boosting region to the non-boosting region. Hysteresis may be provided between the two so that the shift to is executed in a region where the motor rotation speed is lower than the shift from the non-boosting region to the boosting region. Although not shown, the boost switching line for the motor MG1 is created in the same manner as that for the motor MG2.

  If the boost switching determination torque Tref2 is set in step S110, it is determined whether or not the absolute value of the torque command Tm2 * is less than the absolute value of the boost switching determination torque Tref2 (step S120). When the absolute value of the torque command Tm2 * is equal to or larger than the absolute value of the boost switching determination torque Tref2, the target operating point of the motor MG2 is included in the boosting region of FIG. Accordingly, if a negative determination is made in step S120, the relationship is created in advance so as to define the relationship between the rotational speed Nm2 of the motor MG2, the torque command Tm2 *, and the target boosted voltage VHtag that is the target value of the boosted voltage VH. A target post-boost voltage VHtag corresponding to the target operating point of the motor MG2 is derived and set from the target post-boost voltage setting map for the motor MG2 (not shown) (step S130). The target post-boosting voltage setting map for the motor MG2 of the embodiment (same for the motor MG1) also minimizes the loss of the electric drive system for each operating point of the motor MG2 in the boosting region and performs the operation. It is created so as to define a target boosted voltage VHtag, which is a target value of the boosted voltage VH that can cancel the induced voltage at the point. Subsequently, the smaller of the target boosted voltage VHtag set in step S130 and the value obtained by adding a predetermined boosting rate ΔV to the boosted voltage command VH * at the previous execution of this routine is set to the boosted voltage command VH. * Is set (step S140). The boost rate ΔV is a voltage change amount per unit time (the execution interval of this routine) when boosting the boosted voltage VH to the target boosted voltage VHtag, and may be a constant value or a variable value. It may be said. Then, based on the boosted voltage command VH * and the pre-boosted voltage VL and the boosted voltage VH input in step S100, the transistors T31 and T32 of the boost converter 55 so that the boosted voltage VH becomes the boosted voltage command VH *. Switching control is executed (step S150), and the processing after step S100 is executed again.

  If it is determined in step S120 that the absolute value of the torque command Tm2 * is less than the absolute value of the boost switching determination torque Tref2, the target operating point (the rotational speed Nm2 and the torque command Tm2 *) of the motor MG2 is determined. It is included in the non-boosting region of FIG. In this case, first, the value of the control method flag Fmod2 input in step S100 is checked to determine whether or not the inverter 42 is controlled using the rectangular wave control method (step S160). When the control is performed using the PWM control method or the overmodulation PWM control method, the processes of steps S130 to S150 described above are executed, and the processes after step S100 are executed again. On the other hand, when it is determined that the target operating point of the motor MG2 is included in the non-boosting region and the inverter 42 is controlled using the rectangular wave control method in step S160, the boost determination illustrated in FIG. The boost determination voltage phase ψref corresponding to the rotation speed Nm2 of the motor MG2 input in step S100 is derived and set from the voltage phase setting map (step S170). The boost determination voltage phase ψref is a threshold set based on the rotational speed Nm2 of the motor MG2 in order to determine whether or not the boosted voltage VH is boosted with respect to the pre-boost voltage VL, and is shown in FIG. Thus, the smaller the absolute value of the rotation speed Nm2 of the motor MG2, the smaller the setting is set. Next, it is determined whether or not the target voltage phase ψ * input in step S100 exceeds the boost determination voltage phase ψref (step S180).

  Here, in order to output a somewhat large torque from the motor MG2 using the rectangular wave control method in a state where the boosted voltage VH is not boosted with respect to the pre-boost voltage VL, as can be seen from FIG. 7, the target voltage phase ψ It is necessary to increase * so that the torque from the motor MG2 becomes closer to the limit phase ψlim that makes the maximum value Tm2max. However, in the rectangular wave control system in which the output torque of the motor MG2 and the like is controlled by changing the target voltage phase ψ * according to the torque command Tm2 * and the like, the output torque of the motor MG2 and the like is a voltage as shown in FIG. When the phase is relatively small, it changes linearly with respect to the target voltage phase ψ *. However, when the actual voltage phase increases to some extent, the linearity between the target voltage phase ψ * and the output torque is lost, and the target voltage phase The follow-up performance of the torque with respect to the change of ψ *, that is, the control responsiveness is deteriorated. Furthermore, according to research by the present inventors, it has been found that when an environmental factor such as the motor temperature changes, the operating point (output torque) of the motor corresponding to a certain voltage phase changes. For example, when the temperature of the motor MG2 (particularly the rotor) increases, the relationship between the voltage phase and the torque changes from the relationship shown by the solid line in FIG. 7 to the relationship shown by the two-dot chain line (output to the whole). As the torque decreases, the target voltage phase ψ * corresponding to a certain output torque Tx increases from the value ψx to the value ψx ′. Therefore, the control responsiveness may be deteriorated even when the actual voltage phase is increased due to such environmental factors.

  Based on these, in the embodiment, even if the post-boosting voltage VH is not boosted with respect to the pre-boosting voltage VL, if the target voltage phase ψ * exceeds the boosting determination voltage phase ψref, the boosting voltage VH is boosted. Boost converter 55 is controlled such that post-voltage VH is boosted with respect to pre-boosting voltage VL. That is, when the target voltage phase ψ * exceeds the boost determination voltage phase ψref, the boosted voltage VH is higher than the boosted voltage VL even if the target operating point of the motor MG2 is included in the non-boosted region of FIG. The target boosted voltage VHtag corresponding to the target operating point of the motor MG2 is derived and set so as to be boosted (step S190). In step S190, a second MG2 motor (not shown) for motor MG2, which is created in advance so as to define the relationship between the rotational speed Nm2 of the motor MG2, the torque command Tm2 *, and the target boosted voltage VHtag that is the target value of the boosted voltage VH. The target post-boost voltage setting map is used. This second target post-boost voltage setting map (same for the one for motor MG1) is basically a sine wave PWM except that the motor MG2 has a large boosting region and a predetermined high rotation region. Assuming that the control method is used, the target post-boost voltage VHtag corresponding to the target operating point of the motor MG2 is defined. If the target boosted voltage VHtag is thus set, the smaller of the target boosted voltage VHtag and the value obtained by adding the boost rate ΔV to the boosted voltage command VH * at the previous execution of this routine is set to the boosted voltage command VH *. (Step S140), the switching control of the transistors T31 and T32 of the boost converter 55 is executed so that the boosted voltage VH becomes the boost voltage command VH * (step S150), and the processing after step S100 is executed again. .

  Thereby, in the hybrid vehicle 20 of the embodiment, when the target operating point of the motor MG2 is included in the boosting region defined by the boosting switching line of FIG. 4, and the target operating point of the motor MG2 is determined by the boosting switching line of FIG. When the target voltage phase ψ * exceeds the boost determination voltage phase ψref when included in the prescribed non-boost region and the inverter 42 is controlled using the rectangular wave control method, the boosted voltage VH is the boost voltage command. Boost converter 55 is controlled to be VH *. If it is determined in step S180 that target voltage phase ψ * is equal to or lower than boost determination voltage phase ψref, step-up voltage command VH * used during switching control of boost converter 55 is stepped from the viewpoint of control. After setting the boosted voltage VH input in S100 (step S200), the switching control for boosting the boost converter 55 is not performed (maintained in the upper arm ON state), and again after step S100. Execute the process.

  Next, a procedure for setting the control method of the inverters 41 and 42 in the hybrid vehicle 20 of the embodiment will be described with reference to FIGS. 8 and 9. Here, in order to simplify the description, the procedure for setting the control method for the inverter 42 corresponding to the motor MG2 will be described. However, the procedure for setting the control method for the inverter 41 corresponding to the motor MG1 is similar to the following procedure. Executed.

  FIG. 8 is a flowchart illustrating an example of a control method setting routine that is repeatedly executed at predetermined time intervals by the motor ECU 40 according to the embodiment. At the start of the control method setting routine of FIG. 8, the CPU (not shown) of the motor ECU 40 controls the torque command Tm2 * for the motor MG2 from the hybrid ECU 70, the current rotational speed Nm2 of the motor MG2, and the modulation rate Kmd2 for the inverter 42. Input processing of data necessary for setting is performed (step S300). Here, the modulation factor Kmd2 is calculated from the following equations (2) and (3) using the d-axis voltage command value Vd * and the q-axis voltage command value Vq * generated in accordance with the switching control of the inverter 42. Is obtained separately by dividing the induced voltage (line voltage amplitude) Vamp by the boosted voltage VH according to the following equation (4). However, “ψ” is a voltage phase with respect to the q axis.

Vamp = | Vd * | ・ cosψ + | Vq * | ・ sinψ (2)
tanψ = Vq * / Vd * (3)
Kmd1 or Kmd2 = Vamp / VH (4)

  After the data input process in step S300, the torque command Tm2 * for the motor MG2, the rotation speed Nm2 of the motor MG2, and the control method setting map that is predetermined for the motor MG2 and stored in a storage device (not shown) of the motor ECU 40 And a control method flag indicating whether the determined control method is a sine wave PWM control method, an overmodulation PWM control method, or a rectangular wave control method. Fmod2 is set (step S310). In step S310, the control method flag Fmod2 is set to 0 if the control method derived corresponding to the target operating point of the motor MG2 (current rotation speed Nm2 and torque command Tm2 *) is a sine wave PWM control method. Value 1 is set for the overmodulation PWM control method, and value 2 is set for the rectangular wave control method.

  FIG. 9 shows an example of the control method setting map. This figure exemplifies a region (first quadrant) in which both the rotational speed and torque command value of the control method setting map are positive. As can be seen from FIG. 9, the control method setting map is associated with the boost switching line of FIG. 4 and the target post-boost voltage setting map used in step S130 of FIG. It is created so as to be divided into a region where the wave PWM control method is used, a region where the overmodulation PWM control method is used, and a region where the rectangular wave control method is used. In the embodiment, both the non-boosting region and the boosting region defined by the boost switching line are basically the same as the region in which the sine wave PWM control method is used, and the overmodulation PWM in order from the side where the motor rotation speed is low. The area is divided into an area where the control method is used and an area where the rectangular wave control method is used. That is, in the hybrid vehicle 20 of the embodiment, the sine wave PWM control method and the overmodulation PWM are performed under both the state where the boosted voltage VH is not boosted by the boost converter 55 with respect to the pre-boost voltage VL and the boosted voltage VL. The inverter 42 is controlled so that the motor MG2 outputs torque based on the torque command Tm2 * by selectively using the control method and the rectangular wave control method (the same applies to the motor MG1). Thus, the application range of the rectangular wave control method generally used only when boosted voltage VH is boosted by boost converter 55 with respect to pre-boosted voltage VL is extended to when boosted voltage VH is not boosted by boost converter 55. By expanding, it becomes possible to secure the output of the motor MG2 (MG1) even if the opportunity for boosting the boosted voltage VH to the boost converter 55 is reduced, and the energy efficiency associated with the drive control of the motor MG2 (MG1) is further improved. Can be made.

  After the process of step S310, it is determined whether or not the set control method flag Fmod2 is a value 2, that is, whether or not the rectangular wave control method is set as the control method of the inverter 42 in step S310 (step S320). . When the control method flag Fmod2 is a value 2, it is determined whether or not the modulation factor Kmd2 of the inverter 42 input in step S300 is equal to or lower than a predetermined upper threshold KH (step S330), and the modulation factor Kmd2 is If it is equal to or lower than the upper threshold value KH, it is further determined whether or not the modulation factor Kmd2 is equal to or higher than a predetermined lower threshold value KL (step S340). Here, the upper threshold value KH is determined as a value of 0.78, which is the upper limit modulation factor in the overmodulation PWM control system, or a value close thereto, and the lower threshold value KL is the lower limit modulation in the overmodulation PWM control system. It is determined as a value 0.61 or a value in the vicinity thereof. When the modulation factor Kmd2 is equal to or lower than the upper threshold value KH and equal to or higher than the lower threshold value KL, the control method flag Fmod2 is reset to a value 1 so that the control method of the inverter 42 becomes the overmodulation PWM control method. (Step S350), the processing after Step S300 is executed again. If the modulation factor Kmd2 is less than the lower threshold value KL, the control method flag Fmod2 is reset to 0 so that the control method of the inverter 42 becomes the sine wave PWM control method (step S360), and step again The processing after S300 is executed. If a negative determination is made in steps S320 and S330, the subsequent processing is skipped and the processing after step S300 is executed again.

  Thereby, even when the rectangular wave control method is determined as the control method of the inverter 42 from the control method setting map, the modulation rate Kmd2 decreases as the boosted voltage VH is boosted by the boost converter 55. In the case of going, the control method of the inverter 42 is set to the overmodulation PWM control method by the process of step S350, and if the modulation factor Kmd2 further decreases, the control method of the inverter 42 is set to the sine wave PWM control method. Will be. Therefore, as described above, when the target operating point of the motor MG2 is included in the non-boosting region defined by the boost switching line of FIG. 4 and the inverter 42 is controlled using the rectangular wave control method, the target voltage phase ψ When the post-boosting voltage VH is boosted with respect to the pre-boosting voltage VL because * exceeds the boosting determination voltage phase ψref, the rectangular wave control method is originally controlled by the control method setting map from the control method setting map. In spite of being determined as a method, the modulation rate Kmd2 decreases as the boosted voltage VH is increased, so that the control method of the inverter 42 is set to the overmodulation PWM control method, and further to the sine wave PWM control method. Will be. When the target operating point of the motor MG2 shifts from the boosting region to the non-boosting region, the control method of the inverter 42 is changed from the sine wave PWM control method to the rectangular wave control method by the control method setting map. It will be. In such a case, the modulation rate Kmd2 increases as the boosted voltage VH is no longer boosted by the boost converter 55, so that the control method of the inverter 42 is changed to the overmodulation PWM control method by the process of step S350. After that, the rectangular wave control method is set when the modulation factor Kmd2 further increases.

  As described above, in the hybrid vehicle 20 of the embodiment, when it is determined that the boosted voltage VH should not be boosted with respect to the pre-boost voltage VL, the boosting operation by the boost converter 55 is not performed (step S120, S160 to S180, S200) When it is determined that the boosted voltage VH should be boosted with respect to the pre-boost voltage VL, the boosted voltage VH becomes the target boosted voltage VHtag corresponding to the torque command Tm2 * of the motor MG2. Thus, boost converter 55 is controlled (steps S120 and S130 to S150). Then, the sine wave PWM control method using the sine wave PWM voltage and overmodulation both in the state where the boosted voltage VH is not boosted by the boost converter 55 and in the state where the boosted voltage VH is boosted. The inverter 42 is controlled so that the motor MG2 outputs torque corresponding to the torque command Tm2 * by selectively using the overmodulation PWM control method using the PWM voltage and the rectangular wave control method using the rectangular wave voltage. (FIG. 8). Thereby, in hybrid vehicle 20, it becomes possible to improve energy efficiency, ensuring the output of motor MG2 (MG1). Furthermore, in hybrid vehicle 20 of the embodiment, when it is determined that boosted voltage VH should not be boosted with respect to pre-boosted voltage VL, and inverter 42 is controlled by motor ECU 40 using a rectangular wave control method. When the target voltage phase ψ * exceeds the boost determination voltage phase ψref, the boost converter 55 is controlled to boost the boosted voltage VH with respect to the pre-boost voltage VL (steps S120, S160 to S190, S140, S150). In this way, when the torque command Tm2 * of the motor MG2 or environmental factors, etc., the actual voltage phase is increased to some extent, the controllability of the motor MG2 (inverter 42) in the rectangular wave control method may be deteriorated. If the post-voltage VH is boosted with respect to the pre-boosting voltage VL, the inverter 42 can be controlled using a sine wave PWM control method or an overmodulation PWM control method, which has better control accuracy than the rectangular wave control method, and the modulation rate is increased. Even if a relatively small sine wave PWM control method or the like is used, the output of the motor MG2 can be ensured with good responsiveness. As a result, even if the rectangular wave control method is used in a state where the boosted voltage VH is not boosted with respect to the pre-boost voltage VL, the controllability of the motor MG2 (MG1) can be kept good, and the hybrid vehicle The running performance and energy efficiency of the vehicle can be improved satisfactorily.

  In hybrid vehicle 20 of the embodiment, when it is determined that boosted voltage VH should not be boosted with respect to pre-boosted voltage VL, and inverter 42 is controlled by motor ECU 40 using a rectangular wave control method. When the target voltage phase ψ * exceeds the boost determination voltage phase ψref, a torque command Tm2 is output from the motor MG2 using the sine wave PWM control method (or overmodulation PWM control method) from the second target post-boost voltage setting map. A voltage value sufficient to output a torque corresponding to * is set as the target boosted voltage VHtag (step S190), and boost converter 55 is controlled so that boosted voltage VH becomes target boosted voltage VHtag (step S190). Steps S140 and S150). As a result, it is possible to satisfactorily secure the output of the motor MG2 (MG1) even when using a sine wave PWM control method or the like having a relatively small modulation rate. However, in step S190, instead of using the second target boost voltage setting map that defines the relationship between the target operating point of the motor MG2 and the target boosted voltage VHtag, the target boosted voltage VHtag is used as the rated voltage of the battery 50. It may be set to a predetermined constant value higher than that.

  Further, if it is determined that boosted voltage VH should not be boosted with respect to pre-boosted voltage VL if boosted determination voltage phase ψref is a variable value set based on rotation speed Nm2 of motor MG2. Thus, it is possible to more appropriately determine whether or not the boosted voltage VH should be boosted in relation to the target voltage phase ψ *. Further, if the boost determination voltage phase ψref is set to be smaller as the absolute value of the rotational speed Nm2 of the motor MG2 is smaller, the controllability of the motor MG2 is improved when the absolute value of the rotational speed Nm2 of the motor MG2 is relatively small. In addition, when the absolute value of the rotational speed Nm2 of the motor MG2 is relatively large, the rectangular wave control method can be used as much as possible to improve the energy efficiency. Further, the target operating point of the motor MG2 (MG1) and the operating region of the motor MG2 (MG1) are compared with the non-boosting region where the boosted voltage VH is not boosted by the boost converter 55 with respect to the pre-boosting voltage VL and the pre-boosting voltage VL. By using a boost switching line that is divided into boost regions where the boosted voltage VH is boosted, it is possible to more appropriately determine whether or not the boosted voltage VH should be boosted with respect to the pre-boost voltage VL. Further, as in the above embodiment, in the operating region of the motor MG2 (MG1), the loss due to the driving of the motor MG2 (MG1) when the boosted voltage VH is not boosted is more than the loss when the boosted voltage VH is boosted. If the region where the loss becomes smaller than the non-boosting region and the region where the loss during boosting becomes smaller than the loss during non-boosting becomes the boosting region, the boost switching line can be made more appropriate to improve energy efficiency. can do.

  In the hybrid vehicle 20 of the above embodiment, the ring gear shaft 32a as the drive shaft and the motor MG2 are connected via the reduction gear 35 that reduces the rotational speed of the motor MG2 and transmits it to the ring gear shaft 32a. Instead of the reduction gear 35, for example, a transmission that shifts the rotational speed of the motor MG2 having two shift stages of Hi and Lo or three or more shift stages and transmits it to the ring gear shaft 32a may be employed. . Moreover, although the hybrid vehicle 20 of an Example outputs the motive power of motor MG2 to the drive shaft connected to the ring gear shaft 32a, the application object of this invention is not restricted to this. That is, the present invention is different from the drive shaft (drive shaft to which the wheels 39a and 39b are connected) in which the power of the motor MG2 is connected to the ring gear shaft 32a as in the hybrid vehicle 120 as a modified example shown in FIG. You may apply to what outputs to a drive shaft (drive shaft connected to the wheels 39c and 39d in FIG. 10). Furthermore, the engine 22 may be of other types such as a hydrogen engine other than an internal combustion engine that receives a supply of hydrocarbon fuel such as gasoline or light oil and outputs power, and the motors MG1 and MG2 Other types such as induction motors other than the synchronous generator motor may be used. The hybrid vehicle 20 according to the above embodiment includes the engine 22 and the motor MG2 each capable of outputting driving power, but the vehicle according to the present invention is limited to such a hybrid vehicle 20. However, it goes without saying that the vehicle may be an electric vehicle including a motor capable of outputting driving power.

  Here, the correspondence between the main elements of the above embodiment and the main elements of the invention described in the column of means for solving the problems will be described. That is, in the above embodiment, the battery 50 corresponds to “DC power supply”, the motors MG1 and MG2 correspond to “motor”, the inverters 41 and 42 correspond to “motor drive circuit”, and the boost converter 55 The motor ECU 40 corresponding to the “conversion means” and controlling the inverters 41 and 42 in accordance with the control method determined by executing the control method setting routine of FIG. 8 corresponds to the “drive circuit control means”, and steps S110 and S120 of FIG. The motor ECU 40 that executes the above-described processing corresponds to “boosting determination means”, and the motor ECU 40 that executes the processing of steps S130 to S200 in FIG. 2 to control the boosting converter 55 corresponds to “voltage conversion control means”. However, the correspondence between the main elements of these embodiments and modifications and the main elements of the invention described in the column of means for solving the problem is described in the column of means for the embodiment to solve the problem. This is an example for specifically describing the best mode for carrying out the invention, and does not limit the elements of the invention described in the column of means for solving the problem. In other words, the examples are merely specific examples of the invention described in the column for means for solving the problem, and the interpretation of the invention described in the column for means for solving the problem is described in the description of the column. Should be done on the basis.

  The embodiments of the present invention have been described above using the embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention. Needless to say.

  INDUSTRIAL APPLICABILITY The present invention can be used in the motor drive control device and the manufacturing industry of vehicles equipped with the same.

1 is a schematic configuration diagram of a hybrid vehicle 20 as a vehicle according to an embodiment of the present invention. It is a schematic block diagram of an electric drive system including motors MG1 and MG2. It is a flowchart which shows an example of the pressure | voltage rise control routine performed by motor ECU40 of an Example. It is explanatory drawing which shows an example of a pressure | voltage rise switching line. It is explanatory drawing which illustrates the characteristic of the loss of an electric drive system. It is explanatory drawing which shows an example of the boost determination voltage phase setting map. It is explanatory drawing which illustrates the relationship between target voltage phase (psi) * and the output torque Tm2 of motor MG2. It is a flowchart which shows an example of the control system setting routine performed by motor ECU40 of an Example. It is explanatory drawing which shows an example of the map for control system setting. It is a schematic block diagram of the hybrid vehicle 120 which concerns on a modification.

Explanation of symbols

  20, 120 Hybrid vehicle, 22 engine, 24 electronic control unit (engine ECU) for engine, 26 crankshaft, 28 damper, 30 power distribution integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier, 35 Reduction gear, 37 gear mechanism, 38 differential gear, 39a-39d wheels, 40 electronic control unit for motor (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 51 temperature sensor, 52 for battery Electronic control unit (battery ECU), 54 power line, 54a positive bus, 54b negative bus, 55 boost converter, 56 system main relay, 57, 59 smoothing capacitor, 70 hybrid electronics Control unit (hybrid ECU), 72 CPU, 74 ROM, 76 RAM, 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal stroke sensor, 87 Vehicle speed sensor, 91 1st voltage sensor, 92 2nd voltage sensor, 93 3rd voltage sensor, 95v, 95w, 96v, 96w Current sensor, D11-D16, D21-D26, D31, D32 Diode, L reactor, MG1, MG2 Motor, T11-T16, T21-26, T31, T32 transistors.

Claims (8)

An electric motor drive control device for driving and controlling an electric motor using electric power from a DC power source,
An electric motor drive circuit capable of driving the electric motor by selectively using a PWM voltage and a rectangular wave voltage;
Voltage conversion means capable of boosting the voltage on the motor drive circuit side with respect to the voltage on the DC power source side;
A state in which the voltage on the motor drive circuit side is not boosted with respect to the voltage on the DC power supply side by the voltage conversion means, and a state in which the voltage on the motor drive circuit side is boosted with respect to the voltage on the DC power supply side The motor drive circuit so that the motor outputs a target torque by selectively using a PWM control method using the PWM voltage and a rectangular wave control method using the rectangular wave voltage. Drive circuit control means capable of controlling
Step-up determination means for determining whether or not to increase the voltage on the electric motor drive circuit side with respect to the voltage on the DC power source side by the voltage conversion means;
When the boost determination means determines that the voltage on the motor drive circuit side should be boosted with respect to the voltage on the DC power supply side, the voltage on the motor drive circuit side after the target boost corresponding to the target torque of the motor The voltage conversion means is controlled to be a voltage, and it is determined by the boost determination means that the voltage on the motor drive circuit side should not be boosted with respect to the voltage on the DC power supply side, and the motor drive circuit Is controlled by the drive circuit control means using the rectangular wave control method, and the target voltage phase of the rectangular wave voltage exceeds a predetermined threshold, the voltage on the DC power supply side is Voltage conversion control means for controlling the voltage conversion means so that the voltage on the motor drive circuit side is boosted;
An electric motor drive control device. In the electric motor drive control device according to claim 1,
The voltage conversion control means determines that the voltage on the motor drive circuit side should not be boosted with respect to the voltage on the DC power supply side by the boost determination means, and the motor drive circuit is determined by the drive circuit control means. When the target voltage phase of the rectangular wave voltage exceeds the threshold value when controlled using the rectangular wave control method, the voltage on the motor drive circuit side is changed from the motor using the PWM control method. An electric motor drive control device for controlling the voltage conversion means so that the voltage is sufficient to control the electric motor drive circuit so that a target torque is output. In the electric motor drive control device according to claim 1 or 2,
The electric motor drive control device, wherein the predetermined threshold is a variable value set based on a rotation speed of the electric motor. In the electric motor drive control device according to claim 3,
The electric motor drive control device in which the predetermined threshold value is set to be smaller as the absolute value of the rotation speed of the electric motor is smaller. In the motor drive control device according to any one of claims 1 to 4,
The boost determination means includes a target operating point of the motor and an operating area of the motor, a non-boosting area in which the voltage on the motor drive circuit side is not boosted with respect to the voltage on the DC power source side by the voltage conversion means, and the voltage The voltage conversion means converts the voltage on the motor drive circuit side by the voltage conversion means using a boosting restriction that divides the voltage on the DC power supply side by the conversion means into a boost region in which the voltage on the motor drive circuit side is boosted. An electric motor drive control device that determines whether or not to boost a voltage on a DC power supply side. In the electric motor drive control device according to claim 5,
The step-up constraint is that a loss due to driving of the motor when the voltage on the motor drive circuit side is not boosted is smaller than the loss when the voltage on the motor drive circuit side is boosted in the operating region of the motor. An electric motor drive control device in which a region is the non-boosting region, and a region in which the loss during the boosting is smaller than the loss during the non-boosting is the boosting region.   A vehicle comprising the electric motor drive control device according to any one of claims 1 to 5 and capable of traveling by power from the electric motor that is driven and controlled by the electric motor drive control device. A DC power supply, a motor drive circuit capable of selectively driving a PWM voltage and a rectangular wave voltage, and voltage conversion capable of boosting the voltage on the motor drive circuit side with respect to the voltage on the DC power supply side An electric motor drive control method for driving and controlling the electric motor using means,
(A) The electric motor uses the rectangular wave control method using the rectangular wave voltage in a state where the voltage on the electric motor drive circuit side is not boosted with respect to the voltage on the DC power supply side by the voltage conversion means, and the electric motor has a target torque. Controlling the motor drive circuit to output
(B) While the voltage conversion means is controlling the motor drive circuit using the rectangular wave control method in a state where the voltage on the motor drive circuit side is not boosted with respect to the voltage on the DC power supply side. In addition, when the target voltage phase of the rectangular wave voltage exceeds a predetermined threshold value, the voltage conversion means is controlled so that the voltage on the motor drive circuit side is boosted with respect to the voltage on the DC power source side. And controlling the motor drive circuit so that the motor outputs a target torque using a PWM control method using the PWM voltage, and
An electric motor drive control method.

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