JP2018103658A - Motor drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit the voltage of a power line connected to an inverter from being unnecessarily kept limited.SOLUTION: A motor drive device is mounted on a hybrid vehicle together with an engine and a motor and comprises: an inverter for driving a motor; a power storage device; a step-up/step-down converter for exchanging power with a change in voltage between a first power line to which the power storage device is connected and a second power line to which the inverter is connected; and an atmospheric pressure sensor for detecting atmospheric pressure. The motor drive device controls the inverter and controls the step-up/step-down converter so that the voltage of the second power line becomes a voltage limited by a step-up limit value which is set by using the lower value of an atmospheric pressure estimated value based on the intake air quantity of the engine and an atmospheric pressure detected value detected by the atmospheric pressure sensor. When an outside temperature is a prescribed temperature or higher, the step-up limit value is set by using the atmospheric pressure detected value.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a motor drive device, and more particularly to a motor drive device mounted on a hybrid vehicle together with an engine and a motor.

  Conventionally, this type of motor drive device is mounted on a hybrid vehicle together with an engine and a motor, and includes an inverter, a power storage device (traveling battery), a step-up / down converter (boost converter), an intake pressure sensor, and an atmospheric pressure sensor. Have been proposed (for example, see Patent Document 1). The inverter drives a motor. The step-up converter is attached between the power line to which the power storage device is connected and the power line to which the inverter is connected. The intake pressure sensor detects the intake pressure of the engine. The atmospheric pressure sensor detects atmospheric pressure. In this device, the step-up / step-down converter is controlled so that the voltage of the power line connected to the inverter becomes a voltage limited by a boost limit value (upper limit value) corresponding to the atmospheric pressure sensor. Then, based on the intake pressure from the intake pressure sensor, it is diagnosed whether or not the atmospheric pressure sensor has failed. When the atmospheric pressure sensor has failed, the boost limit value is set to a predetermined value. Thereby, even when a failure occurs in the atmospheric pressure sensor, the control of the buck-boost converter is continued.

JP 2008-199769 A

  By the way, in the motor drive device that sets the boost limit value using the lower one of the estimated pressure value based on the intake air amount of the engine and the detected pressure value from the pressure sensor, the boost limit value is set appropriately. In some cases, the voltage of the power line connected to the inverter continues to be limited. For example, in a hybrid vehicle, when the vehicle is going downhill, the engine is normally stopped and travels with the power from the motor. Therefore, the period during which the engine is not started tends to be relatively long. In this case, the estimated atmospheric pressure value is maintained at a value immediately before the engine is stopped. When the estimated atmospheric pressure immediately before the engine is stopped is lower than the detected atmospheric pressure value, the pressure increase limit value is set using the estimated atmospheric pressure value, so that the atmospheric pressure gradually increases during the downhill. Unnecessarily, the voltage of the power line connected to the inverter continues to be limited.

  The motor drive device of the present invention is mainly intended to suppress the voltage of the power line connected to the inverter from being unnecessarily limited.

  The motor driving apparatus of the present invention employs the following means in order to achieve the main object described above.

The motor drive device of the present invention is
It is installed in a hybrid vehicle together with an engine and a motor,
An inverter for driving the motor;
A power storage device;
A buck-boost converter that exchanges power with a change in voltage between the first power line to which the power storage device is connected and the second power line to which the inverter is connected;
An atmospheric pressure sensor for detecting atmospheric pressure;
A control device for controlling the inverter and the buck-boost converter;
A motor drive device comprising:
The control device is configured to increase the voltage of the second power line using a lower value of an estimated pressure value based on an intake air amount of the engine and a detected pressure value detected by the pressure sensor. Controlling the buck-boost converter so that the voltage is limited by the limit value;
Further, when the outside air temperature is equal to or higher than a predetermined temperature, the control device sets the pressure increase limit value using the atmospheric pressure detection value.
This is the gist.

  In the motor drive device of the present invention, the voltage of the second power line is set using the lower value of the atmospheric pressure estimated value based on the intake air amount of the engine and the atmospheric pressure detected value detected by the atmospheric pressure sensor. The buck-boost converter is controlled so that the voltage is limited by the boost limit value. When the outside air temperature is equal to or higher than the predetermined temperature, the pressure increase limit value is set using the atmospheric pressure detection value. When the outside air temperature is equal to or higher than the predetermined temperature, it is considered that the hybrid vehicle is traveling in a lowland with relatively high atmospheric pressure. Therefore, even when the engine is not started for a relatively long period of time, such as downhill, and the atmospheric pressure estimated value is maintained at a low value, when the outside air temperature is equal to or higher than the predetermined temperature, the pressure increase limit value is set using the atmospheric pressure detection value. The boost limit value can be set appropriately. As a result, it is possible to suppress the voltage of the second power line connected to the inverter from being unnecessarily limited.

  In such a motor drive device of the present invention, the control device is configured such that the boost limit value is lower when the atmospheric pressure estimation value is lower than when it is higher and when the atmospheric pressure detection value is lower than when it is higher. It is good also as what sets so that it may become low.

  In the motor control device of the present invention, when the estimated atmospheric pressure value is lower than the detected atmospheric pressure value and the outside air temperature is equal to or higher than the predetermined temperature, the boost limit value is set using the detected atmospheric pressure value. May be.

The hybrid vehicle of the present invention
An engine that outputs driving power;
A motor that outputs driving power;
The motor drive device of the present invention according to any one of the aspects described above, that is, basically, an inverter that is mounted on the hybrid vehicle together with the engine and the motor, drives the motor, a power storage device, and the power storage device. A buck-boost converter that exchanges power with a change in voltage between a first power line connected to the second power line connected to the inverter, a barometric pressure sensor that detects atmospheric pressure, the inverter, and the And a control device that controls the step-up / down converter, wherein the control device uses a pressure estimation value based on an intake air amount of the engine and a pressure sensor so that the voltage of the second power line is The step-up / step-down voltage control is performed so that the voltage is limited by the boost limit value set using the lower one of the detected atmospheric pressure detection values. Controls converter, further, the control device, when the outside air temperature is higher than a predetermined temperature, sets the boosting limit value using the pressure detection value, and the motor drive unit,
When the accelerator is turned off, the hybrid control device controls the engine and the motor drive device so as to stop the operation of the engine and run with power from the motor;
It is a summary to provide.

  Since the hybrid vehicle of the present invention includes the motor drive device of the present invention according to any one of the aspects described above, the effect of the motor drive device of the present invention, for example, the voltage of the second power line connected to the inverter There is an effect of suppressing the unnecessarily being restricted.

It is a block diagram which shows the outline of a structure of the hybrid vehicle 20 carrying the motor drive device as an Example of this invention. 2 is a configuration diagram showing an outline of the configuration of an engine 22. FIG. It is a block diagram which shows the outline of a structure of the electric drive system containing motor MG1, MG2. 3 is a flowchart showing an example of a boost limit voltage setting process routine executed by a motor ECU 40.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 equipped with a motor drive device as an embodiment of the present invention. FIG. 2 is a configuration diagram showing an outline of the configuration of the engine 22. FIG. 3 is a configuration diagram showing an outline of the configuration of the electric drive system including the motors MG1 and MG2. As shown in FIG. 1, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG <b> 1 and MG <b> 2, inverters 41 and 42, a battery 50, a step-up / down converter 55, and a system main relay 56. And an electronic control unit for hybrid (hereinafter referred to as “HVECU”) 70.

  The engine 22 is configured as an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil. As shown in FIG. 2, the engine 22 sucks air purified by the air cleaner 122 through the throttle valve 124 and injects fuel from the fuel injection valve 126 to mix the air and fuel. Then, the air-fuel mixture is sucked into the combustion chamber via the intake valve 128 and is explosively burned by an electric spark by the spark plug 130. The reciprocating motion of the piston 132 pushed down by the energy is converted into the rotational motion of the crankshaft 26. . Exhaust gas from the combustion chamber is discharged to the outside air through a purification device 134 having a purification catalyst (three-way catalyst) that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). Is done.

  The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as “engine ECU”) 24. Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, and a communication port. . Signals from various sensors necessary for controlling the operation of the engine 22 are input to the engine ECU 24 via an input port. Examples of the signal input to the engine ECU 24 include a crank angle θcr from the crank position sensor 140 that detects the rotational position of the crankshaft 26 and a coolant temperature Tw from the coolant temperature sensor 142 that detects the coolant temperature of the engine 22. Can be mentioned. Further, the cam angles θci and θco from the cam position sensor 144 that detects the rotational position of the intake camshaft that opens and closes the intake valve 128 and the rotational position of the exhaust camshaft that opens and closes the exhaust valve can also be mentioned. Further, the throttle opening TH from the throttle valve position sensor 146 for detecting the position of the throttle valve 124, the intake air amount Qa from the air flow meter 148 attached to the intake pipe, and the temperature sensor 149 attached to the intake pipe. The intake air temperature Ta can also be mentioned. In addition, the air-fuel ratio AF from the air-fuel ratio sensor 135a attached to the exhaust pipe and the oxygen signal O2 from the oxygen sensor 135b attached to the exhaust pipe can also be mentioned. Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via an output port. Signals output from the engine ECU 24 include, for example, a drive control signal to the throttle motor 136 that adjusts the position of the throttle valve 124, a drive control signal to the fuel injection valve 126, and an ignition coil 138 integrated with the igniter. Drive control signals. The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotational speed Ne of the engine 22 based on the crank angle θcr from the crank position sensor 140.

  The planetary gear 30 is configured as a single pinion type planetary gear mechanism. The sun gear of planetary gear 30 is connected to the rotor of motor MG1. The ring gear of the planetary gear 30 is connected to a drive shaft 36 that is coupled to the drive wheels 38 a and 38 b via a differential gear 37. A crankshaft 26 of the engine 22 is connected to the carrier of the planetary gear 30 via a damper (not shown).

  The motor MG1 is configured as, for example, a synchronous generator motor, and the rotor is connected to the sun gear of the planetary gear 30 as described above. The motor MG2 is configured as, for example, a synchronous generator motor, and a rotor is connected to the drive shaft 36. Inverters 41 and 42 are connected to motors MG1 and MG2 and to high-voltage power line 54a. The motors MG1 and MG2 are driven to rotate by switching control of a plurality of switching elements (not shown) of the inverters 41 and 42 by a motor electronic control unit (hereinafter referred to as “motor ECU”) 40.

  As shown in FIG. 1 and FIG. 3, the inverter 41 is connected to the high voltage side power line 54a. The inverter 41 includes six transistors (switching elements) T11 to T16 and six diodes D11 to D16. Two transistors T11 to T16 are arranged in pairs so as to be on the source side and the sink side with respect to the positive and negative buses of the high-voltage power line 54a, respectively. The six diodes D11 to D16 are respectively connected in parallel to the transistors T11 to T16 in the reverse direction. The three-phase coils (U-phase, V-phase, W-phase) of the motor MG1 are connected to the connection points of the paired transistors T11 to T16. Therefore, when a voltage is applied to the inverter 41, the motor electronic control unit (hereinafter referred to as a motor ECU) 40 adjusts the ratio of the on-time of the paired transistors T11 to T16, so that three-phase A rotating magnetic field is formed in the coil, and the motor MG1 is driven to rotate.

  Similarly to the inverter 41, the inverter 42 is connected to the high-voltage power line 54a. Similarly to the inverter 41, the inverter 42 includes six transistors (switching elements) T21 to T26 and six diodes D21 to D26. When the voltage is applied to the inverter 42, the motor ECU 40 adjusts the ratio of the on-time of the paired transistors T21 to T26, whereby a rotating magnetic field is formed in the three-phase coil, and the motor MG2 is Driven by rotation.

  The step-up / down converter 55 is connected to the high-voltage power line 54a and the low-voltage power line 54b to which the battery 50 is connected. This step-up / down converter 55 has two transistors (switching elements) T31 and T32, two diodes D31 and D32, and a reactor L. The transistor T31 is connected to the positive bus of the high voltage side power line 54a. The transistor T32 is connected to the transistor T31 and the negative buses of the high voltage side power line 54a and the low voltage side power line 54b. The two diodes D31 and D32 are respectively connected in parallel to the transistors T31 and T32 in the reverse direction. The reactor L is connected to a connection point Cn between the transistors T31 and T32 and a positive bus of the low voltage side power line 54b. The step-up / down converter 55 adjusts the on-time ratio of the transistors T31 and T32 by the motor ECU 40 to boost the power of the low-voltage side power line 54b and supply the boosted power to the high-voltage side power line 54a. The power of the line 54a is stepped down and supplied to the low voltage side power line 54b.

  A high-voltage capacitor 57 is connected to the positive and negative buses of the high-voltage power line 54a. A low-voltage capacitor 58 is connected to the positive and negative buses of the low-voltage power line 54b.

  Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . Signals from various sensors necessary for driving and controlling the motors MG1, MG2 and the step-up / down converter 55 are input to the motor ECU 40 via the input port. As signals from the various sensors, currents that detect currents flowing in the rotational positions θm1 and θm2 from the rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2 and the phases of the motors MG1 and MG2 are detected. The phase current from a sensor can be mentioned. Further, the voltage VH of the high voltage side capacitor 57 (high voltage side power line 54a) from the voltage sensor 57a attached between the terminals of the high voltage side capacitor 57 and the low voltage from the voltage sensor 58a attached between the terminals of the low voltage side capacitor 58. Voltage VL of the side capacitor 58 (low voltage side power line 54b), current IL of the reactor L from the current sensor 55a attached between the connection point Cn of the step-up / down converter 55 and the reactor L (connection side from the reactor L side) Can be mentioned as a positive value).

  Various control signals for driving and controlling the motors MG1, MG2 and the step-up / down converter 55 are output from the motor ECU 40 through the output port. Examples of the various control signals include switching control signals to the transistors T11 to T16 and T21 to T26 of the inverters 41 and 42, switching control signals to the transistors T31 and T32 of the buck-boost converter 55, and the like.

  The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 drives and controls the motors MG1 and MG2 and the step-up / down converter 55 by a control signal from the HVECU 70. Further, the motor ECU 40 outputs data relating to the driving state of the motors MG1, MG2 and the step-up / down converter 55 to the HVECU 70 as necessary. The motor ECU 40 calculates the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2. Further, the motor ECU 40 stores the detected value of the current IL of the reactor L detected by the current sensor 55a from the present to a predetermined time before in a RAM (not shown).

  The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydride secondary battery, and is connected to the low-voltage power line 54b. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as “battery ECU”) 52.

  Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via the input port. Examples of signals input to the battery ECU 52 include a battery voltage Vb from a voltage sensor 51 a installed between terminals of the battery 50, a battery current Ib from a current sensor 51 b attached to an output terminal of the battery 50, and a battery 50. The battery temperature Tb from the temperature sensor 51c attached to can be mentioned. The battery ECU 52 is connected to the HVECU 70 via a communication port. Battery ECU 52 calculates power storage rate SOC based on the integrated value of battery current Ib from the current sensor. The storage ratio SOC is a ratio of the capacity of power that can be discharged from the battery 50 to the total capacity of the battery 50.

  The system main relay 56 is provided closer to the battery 50 than the low voltage side capacitor 58 in the low voltage side power line 54b. This system main relay 56 is on / off controlled by the HVECU 70 to connect and disconnect the battery 50 and the step-up / down converter 55 side.

  Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, and a communication port in addition to the CPU.

  Signals from various sensors are input to the HVECU 70 via input ports. Examples of the signal input to the HVECU 70 include an ignition signal from the ignition switch 80 and a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81. Further, the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, and the vehicle speed sensor 88 The vehicle speed V, the atmospheric pressure Pa from the atmospheric pressure sensor 90 that detects the atmospheric pressure, and the outside air temperature Ta from the temperature sensor 92 that detects the outside air temperature can be mentioned.

  As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port.

  In the hybrid vehicle 20 of the embodiment configured in this way, the vehicle travels in a travel mode such as a hybrid travel mode (HV travel mode) or an electric travel mode (EV travel mode). The HV traveling mode is a traveling mode in which traveling is performed with the operation of the engine 22 and the driving of the motors MG1 and MG2. The EV traveling mode is a traveling mode in which the engine 22 is stopped and the motor MG2 is driven to travel.

  In the HV travel mode, first, the HVECU 70 is requested for travel (to be output to the drive shaft 36) based on the accelerator opening Acc from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88. Set Tr *. Subsequently, the required power Trd * is calculated by multiplying the required torque Tr * by the rotational speed Np of the drive shaft 36. Here, as the rotational speed Np of the drive shaft 36, the rotational speed Nm2 of the motor MG2 and the rotational speed obtained by multiplying the vehicle speed V by a conversion factor can be used. Then, the required power Pe * required for the vehicle is calculated by subtracting the required charge / discharge power Pb * of the battery 50 (a positive value when discharging from the battery 50) from the travel power Pdrv *. Next, the target rotational speed Ne * and the target torque Te * of the engine 22 and the torques of the motors MG1 and MG2 are output so that the required power Pe * is output from the engine 22 and the required torque Tr * is output to the drive shaft 36. Commands Tm1 * and Tm2 * are set. Then, the target rotational speed Ne * and the target torque Te * of the engine 22 are transmitted to the engine ECU 24, and torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40. When the engine ECU 24 receives the target rotational speed Ne * and the target torque Te * of the engine 22, the intake air of the engine 22 is operated so that the engine 22 is operated based on the received target rotational speed Ne * and the target torque Te *. Perform quantity control, fuel injection control, ignition control, open / close timing control, and so on. When the motor ECU 40 receives the torque commands Tm1 *, Tm2 * of the motors MG1, MG2, the transistors (switching elements) T11 of the inverters 41, 42 so that the motors MG1, MG2 are driven by the torque commands Tm1 *, Tm2 *. Switching control of T16, T21 to T26 is performed. The motor ECU 40 drives the motors MG1 and MG2 based on the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 and the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 together with the switching control of the inverters 41 and 42. A required required voltage VHreq is set, and a lower voltage (a voltage obtained by limiting the required voltage VHreq with the boost limit voltage VHlim) between the required voltage VHreq and the boost limit voltage VHlim allowed for the voltage of the high-voltage side power line 54a is set. Set to target voltage VH *. Boost limiting voltage VHlim is a value for keeping the voltage of high-voltage side power line 54a low in consideration of the fact that the lower the atmospheric pressure, the easier the deterioration of insulation performance due to partial discharge of the insulators of motors MG1, MG2. is there. The setting of the boost limit voltage VHlim will be described later. Then, the target current IL * of the reactor L necessary for the voltage VH of the high-voltage side power line 54a to become the target voltage VH * is set, and the step-up / step-down converter is set so that the current IL flowing through the reactor L becomes the target current IL *. Switching control of 55 transistors T31 and T32 is performed. In this HV traveling mode, when the required power Pe * reaches the stop threshold value Pstop or less, it is determined that the stop condition of the engine 22 is satisfied, the operation of the engine 22 is stopped, and the EV traveling mode is entered. .

  In the EV travel mode, the HVECU 70 first sets the required torque Tr * as in the HV travel mode. Subsequently, a value 0 is set in the torque command Tm1 * of the motor MG1. Then, the torque command Tm2 * of the motor MG2 is set so that the required torque Tr * is output to the drive shaft 36 within the range of the input / output limits Win and Wout of the battery 50. Then, torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40. Motor ECU 40 performs switching control of transistors (switching elements) T11 to T16 and T21 to T26 of inverters 41 and 42 so that motors MG1 and MG2 are driven by torque commands Tm1 * and Tm2 *. Similarly to the HV running mode, the motor ECU 40 controls the switching of the inverters 41 and 42, and lowers the required voltage VHreq and the boost limit voltage VHlim (a voltage obtained by limiting the request voltage VHreq with the boost limit voltage VHlim). Set to target VH *, set target current IL * of reactor L necessary for voltage VH of high-voltage side power line 54a to be equal to target voltage VH *, and current IL flowing through reactor L becomes target current IL *. Thus, switching control of the transistors T31 and T32 of the step-up / down converter 55 is performed. In this EV travel mode, when the required power Pe * calculated in the same manner as in the HV travel mode reaches a start threshold value Pstart that is larger than the stop threshold value Pstop, it is determined that the start condition of the engine 22 is satisfied, The engine 22 is started and the mode is shifted to the HV traveling mode.

  Further, in the hybrid vehicle 20 of the embodiment, the engine ECU 24 executes the atmospheric pressure learning when a predetermined learning condition for learning the atmospheric pressure is satisfied. In the atmospheric pressure learning, the estimated intake air amount Qest of the engine 22 is set based on the operating state of the engine 22, for example, the engine speed Ne, the throttle opening SP, the valve timing, and the like. The estimated intake air amount Qest is a volume flow rate of air sucked into the engine 22 when the operation state of the engine 22 is in a steady state at the current rotational speed Ne, throttle opening SP, valve timing, and the like. Is converted into a mass flow rate when it is assumed that the atmospheric pressure learning value (atmospheric pressure estimated value) P1. In the embodiment, the estimated intake air amount Qest is obtained in advance by experiment or analysis, and stored in a ROM (not shown) as a map for the relationship between the rotational speed Ne, the throttle opening SP, the valve timing, and the volume flow rate. When a number Ne, throttle opening SP, valve timing, etc. are given, a corresponding volume flow rate is derived from the map, and this volume flow rate is multiplied by a coefficient corresponding to the current atmospheric pressure learning value P1 to estimate intake air Set the quantity Qest. Then, the estimated intake air amount Qest is subtracted from the intake air amount Q detected by the air flow meter 148 to calculate the air amount ΔQ, and when the air amount difference ΔQ is within a predetermined range, the atmospheric pressure learning value P1 is maintained, When the amount difference ΔQ is outside the predetermined range, a correction value corresponding to the air amount difference ΔQ is added to the current atmospheric pressure learning value (atmospheric pressure estimated value) P1 to update the atmospheric pressure learning value (atmospheric pressure estimated value) P1. The atmospheric pressure learning value (atmospheric pressure estimated value) P1 obtained in this way is used for operation control of the engine 22 and setting of a boost limiting voltage VHlim described later.

  Next, the operation of the hybrid vehicle configured as described above, particularly the operation when setting the boost limit voltage VHlim will be described. FIG. 4 is a flowchart showing an example of a boost limit voltage setting process routine executed by the motor ECU 40. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When this routine is executed, the motor ECU 40 executes a process of inputting the atmospheric pressure Pa, the atmospheric pressure learned value P1, and the outside air temperature Ta (step S100). As the atmospheric pressure Pa, a value detected by the atmospheric pressure sensor 90 is input. As the atmospheric pressure learning value P1, the value obtained by the above-described atmospheric pressure learning is input from the engine ECU 24 via the HVECU 70 by communication. As the outside air temperature Ta, a value detected by the temperature sensor 92 is input.

  Subsequently, it is determined whether or not the atmospheric pressure learning value P1 is higher than the atmospheric pressure Pa (step S110), and it is determined whether or not the outside air temperature Ta is equal to or higher than a determination threshold value Tref (step S120). The determination threshold value Tref is a threshold value for determining whether or not the vehicle is traveling on a high altitude with a relatively high altitude. For example, the determination threshold value Tref is set to 1 ° C., 3 ° C., 5 ° C., or the like. Therefore, the process of step S120 is a process of determining whether or not the vehicle is traveling on a highland.

  When it is determined in step S110 that the atmospheric pressure learning value P1 is higher than the atmospheric pressure Pa, the boost limiting voltage VHlim is set using the atmospheric pressure Pa which is the lower value of the atmospheric pressure learning value P1 and the atmospheric pressure Pa. (Step S130), and this routine is finished. In the process of step S130, the boost limiting voltage VHlim is set to be lower when the atmospheric pressure Pa is lower than when it is higher, that is, lower as the atmospheric pressure Pa is lower. This is because the lower the atmospheric pressure, the easier the deterioration of the insulation performance due to the partial discharge of the insulators of the motors MG1 and MG2, and the voltage of the high-voltage side power line 54a needs to be kept low. The atmospheric pressure Pa, which is the lower value of the atmospheric pressure learning value P1 and the atmospheric pressure Pa, is used because both the atmospheric pressure learning value P1 and the atmospheric pressure Pa are different from the actual atmospheric pressure due to calculation errors, detection errors, and the like. This is because there is a possibility, and the lower limit value is used to set the boost limiting voltage VHlim, so that the deterioration of the insulation performance can be more reliably suppressed. The motor ECU 40 that has set the boost limit voltage VHlim in this way sets the voltage obtained by limiting the required voltage VHreq with the boost limit voltage VHlim to the target VH *, so that the voltage VH of the high-voltage side power line 54a becomes the target voltage VH *. Switching control of the transistors T31 and T32 of the buck-boost converter 55 is performed. As described above, by setting the boost limit voltage VHlim using the atmospheric pressure Pa which is the lower value of the atmospheric pressure learning value P1 and the atmospheric pressure Pa, it is possible to more reliably suppress the deterioration of the insulation performance. .

  When the atmospheric pressure learning value P1 is not higher than the atmospheric pressure Pa (the atmospheric pressure learning value P1 is equal to or lower than the atmospheric pressure Pa) and the outside air temperature Ta is less than the determination threshold Tref in the process of step S110, the atmospheric pressure learning value P1. Is used to set the boost limit value VHlim (step S140), and this routine is terminated. In the process of step S140, the boost limiting voltage VHlim is set to be lower when the atmospheric pressure learning value P1 is lower than when it is higher, that is, lower as the atmospheric pressure learning value P1 is lower. The step S140 is used to set the boost limit value VHlim using the atmospheric pressure learning value P1 for the following reason. When the outside air temperature Ta is less than the determination threshold Tref, it is considered that the vehicle is traveling on a highland and not on a downhill. For this reason, the period during which the operation of the engine 22 continues to be stopped is not so long and there is a sufficient opportunity to learn the atmospheric pressure learning value P1. Therefore, the pressure increase limit value VHlim may be set using the atmospheric pressure learning value P1. . For this reason, the boost limit value VHlim is set using the atmospheric pressure learning value P1 in step S140. The motor ECU 40 that has set the boost limit voltage VHlim in this way sets the voltage obtained by limiting the required voltage VHreq with the boost limit voltage VHlim to the target VH *, so that the voltage VH of the high-voltage side power line 54a becomes the target voltage VH *. Switching control of the transistors T31 and T32 of the buck-boost converter 55 is performed. Thereby, deterioration of insulation performance can be suppressed more reliably.

  When the atmospheric pressure learning value P1 is not higher than the atmospheric pressure Pa in the process of step S110 (the atmospheric pressure learning value P1 is equal to or lower than the atmospheric pressure Pa) and the outside air temperature Ta is equal to or higher than the determination threshold Tref, the atmospheric pressure Pa is used. The boost limit value VHlim is set (step S130), and this routine ends. Here, the boost limit value VHlim is set using the atmospheric pressure Pa for the following reason. When the outside air temperature Ta is equal to or higher than the determination threshold Tref, it is considered that the vehicle is traveling downhill or traveling in a lowland. When downhill, the operation of the engine 22 may be stopped and the traveling in the EV traveling mode may continue. Since atmospheric pressure learning is not performed during traveling in the EV traveling mode, the atmospheric pressure learning value P1 is set immediately before stopping the operation of the engine 22, that is, when the altitude is high at the start of the downhill. Value. Therefore, if the atmospheric pressure learning value P1 set when the altitude is high at the start of the downhill when the vehicle is traveling on a relatively low ground on the downhill, the boost limit value VHlim is lower than necessary. As a result, the voltage of the high-voltage power line 54a continues to be unnecessarily limited. In the embodiment, even when the atmospheric pressure learning value P1 is not higher than the atmospheric pressure Pa (the atmospheric pressure learning value P1 is equal to or lower than the atmospheric pressure Pa), when the outside air temperature Ta is equal to or higher than the determination threshold Tref, the pressure is increased using the atmospheric pressure Pa. Since the limit value VHlim is set, it is possible to prevent the boost limit value VHlim from being set lower than necessary and the voltage of the high-voltage side power line 54a from being continuously limited unnecessarily.

  According to the hybrid vehicle 20 of the embodiment described above, when the outside air temperature Ta is equal to or higher than the determination threshold Tref, the boost limit value VHlim is set lower than necessary by setting the boost limit value VHlim using the atmospheric pressure Pa. It is possible to prevent the voltage of the high-voltage power line 54a from being set unnecessarily.

  In the hybrid vehicle 20 of the embodiment, when the atmospheric pressure learning value P1 is not higher than the atmospheric pressure Pa (the atmospheric pressure learning value P1 is equal to or lower than the atmospheric pressure Pa) and the outside air temperature Ta is equal to or higher than the determination threshold Tref, The boost limit value VHlim is set using Pa. However, the pressure increase limit value VHlim may be set using the atmospheric pressure Pa when the outside air temperature Ta is equal to or higher than the determination threshold Tref regardless of whether the atmospheric pressure learning value P1 is higher than the atmospheric pressure Pa.

  In the hybrid vehicle 20 of the embodiment, the battery 50 is used. However, any power storage device capable of storing electricity may be used, for example, a capacitor may be used.

   Although the hybrid vehicle 20 of the embodiment includes the engine ECU 24, the motor ECU 40, the battery ECU 52, and the HVECU 70, at least a part of these may be configured as a single electronic control unit.

  In the embodiment, the motor MG1 is connected to the sun gear of the planetary gear 30, the engine 22 is connected to the carrier, and the hybrid vehicle 20 is connected to the ring gear and the drive shaft 36 connected to the drive wheels 38a and 38b and the motor MG2. The present invention is applied to the motor drive device. The present invention may be applied to a motor drive device having any configuration as long as it is a motor drive device mounted on a hybrid vehicle including an engine and a motor. For example, the present invention may be applied to a motor drive device mounted on a hybrid vehicle in which a motor is connected to a drive shaft connected to a drive wheel via a transmission and an engine is connected to the motor via a clutch. Good.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to “engine”, the motor MG2 corresponds to “motor”, the inverter 42 corresponds to “inverter”, the battery 50 corresponds to “power storage device”, and the buck-boost converter 55 is The pressure sensor 90 corresponds to a “step-up / down converter”, the pressure sensor 90 corresponds to a “pressure sensor”, and the motor ECU 40 corresponds to a “control device”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. In other words, the interpretation of the invention described in the column of means for solving the problem should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problem. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the motor drive manufacturing industry.

  20 hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 30 planetary gear, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel, 40 motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation position detection sensor, 50 battery, 51a Voltage sensor, 51b Current sensor, 51c Temperature sensor, 52 Battery electronic control unit (battery ECU), 54a High voltage side power line, 54b Low voltage side power line 55 Buck-boost converter, 55a Current sensor, 56 System main relay, 57 High-voltage side capacitor, 58 Low-voltage side capacitor, 57a, 58a Voltage sensor, 70 Hybrid electronic control unit (HVE) U), 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, 90 atmospheric pressure sensor, 92, 149 temperature sensor, 122 air cleaner, 124 throttle valve, 126 fuel injection valve, 128 intake valve, 130 spark plug, 132 piston, 134 purification device, 135a air-fuel ratio sensor, 135b oxygen sensor, 136 throttle motor, 138 ignition coil, 140 crank position sensor, 142 Water temperature sensor, 144 Cam position sensor, 146 Throttle valve position sensor, 148 Air flow meter, Cn Connection point, D1 1 to D16, D21 to D26, D31, D32 Diode, L reactor, MG1, MG2 motor, T11 to T16, T21 to T26, T31, T32 transistors.

Claims (1)

It is installed in a hybrid vehicle together with an engine and a motor,
An inverter for driving the motor;
A power storage device;
A buck-boost converter that exchanges power with a change in voltage between the first power line to which the power storage device is connected and the second power line to which the inverter is connected;
An atmospheric pressure sensor for detecting atmospheric pressure;
A control device for controlling the inverter and the buck-boost converter;
A motor drive device comprising:
The control device is configured to increase the voltage of the second power line using a lower value of an estimated pressure value based on an intake air amount of the engine and a detected pressure value detected by the pressure sensor. Controlling the buck-boost converter so that the voltage is limited by the limit value;
Further, when the outside air temperature is equal to or higher than a predetermined temperature, the control device sets the pressure increase limit value using the atmospheric pressure detection value.
Motor drive device.

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