JP2016185050A - Temperature estimation device for electric motor, and control device for electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for an electric motor capable of maintaining functions of the electric motor even when a temperature sensor for detecting the temperature of the electric motor fails.SOLUTION: An HEV-ECU 50 comprises: a pump discharge amount acquisition part 52 for determining discharge amounts of mechanical oil pump 32 and an electric oil pump 33 that increase pressure of oil and discharge it; an operation state acquisition part 53 for acquiring operation states of a first electric motor 11 and a second electric motor 12; an oil temperature estimation part 54 for estimating the temperature of the oil that has passed through an oil cooler 40 on the basis of the temperature of the oil stored in an oil pan 30, discharge amounts of the mechanical oil pump 32 and the electric oil pump 33 (an amount of oil that passes through the oil cooler 40), the ambient temperature, and a vehicle speed; and a motor temperature estimation part 55 for estimating the temperatures of the first electric motor 11 and the second electric motor 12 on the basis of the operation states of the first electric motor 11 and the second electric motor 12 and the estimated temperature of the oil that has passed through the oil cooler 40.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a temperature estimation device for an electric motor mounted on a vehicle, and a control device for an electric motor using the temperature estimation device for the electric motor.

  In recent years, hybrid vehicles (HEV) that can effectively improve the fuel consumption rate (fuel consumption) of a vehicle by using an engine and an electric motor in combination have been widely put into practical use. In addition, an electric vehicle (EV) that uses only an electric motor as a power source and does not discharge exhaust gas has been put into practical use.

  In such a hybrid vehicle or an electric vehicle, the temperature of the electric motor is monitored in order to prevent overheating of the electric motor (and thus demagnetization / demagnetization of the permanent magnet due to overheating), and when the temperature rises above a predetermined temperature. In addition, the output of the electric motor is limited (suppressed).

  For example, Patent Document 1 discloses a technique (an electric motor control device) that limits the output of an electric motor according to the temperature and the rotational speed of the electric motor. This motor control device calculates a torque command value based on a temperature sensor that detects the temperature of the motor (temperature of the stator), a rotation speed sensor that detects the rotation speed of the motor, and the accelerator opening, And a computer that limits the torque command value in accordance with the rotational speed and outputs it to the power control circuit.

  That is, in this motor control device, in order to prevent overheating of the motor, when the temperature of the motor rises, the original torque command value (torque command value determined from the accelerator opening) is limited, and the motor Even when the rotational speed increases, the original torque command value is limited. Therefore, according to the electric motor control device described in Patent Document 1, it is possible to protect the temperature of the electric motor and obtain a necessary torque even in a low rotation range.

JP 2000-184502 A

  However, in the motor control device described in Patent Document 1, when the temperature sensor that detects the temperature of the motor fails, the temperature of the motor becomes unknown, the output of the motor is restricted more than necessary, or the motor is driven. There is a risk of being stopped.

  The present invention has been made to solve the above-described problems, and is an electric motor that can maintain the function of an electric motor even when a temperature sensor that detects the temperature of the electric motor fails. It is an object of the present invention to provide a temperature estimation device and an electric motor control device using the temperature estimation device for the electric motor.

  An electric motor temperature estimating apparatus according to the present invention includes an oil-cooled electric motor mounted on a vehicle, oil temperature detecting means for detecting the temperature of oil stored in an oil pan, and boosting and discharging the oil. A pump discharge amount acquisition means for obtaining the discharge amount of the oil pump to be operated, an oil cooler for cooling the oil by exchanging heat between the oil discharged from the oil pump and the cooling medium, and an operation for acquiring the operating state of the electric motor The temperature of the oil after passing through the oil cooler based on the state acquisition means, the temperature of the oil stored in the oil pan, the discharge amount of the oil pump determined by the pump discharge amount acquisition means, and the temperature of the cooling medium Oil temperature estimating means for estimating the operating state of the electric motor acquired by the operating state acquiring means, and the oil after passing through the oil cooler estimated by the oil temperature estimating means Based on the temperature, characterized in that it comprises a motor temperature estimating means for estimating the temperature of the electric motor.

  According to the temperature estimation device for an electric motor according to the present invention, the temperature of the oil after passing through the oil cooler based on the temperature of the oil stored in the oil pan, the discharge amount of the oil pump, and the temperature of the cooling medium. Is estimated, and the temperature of the electric motor is estimated based on the operating state of the electric motor and the estimated temperature of the oil (supplied to the electric motor) after passing through the oil cooler. As a result, the function of the electric motor can be maintained even when the temperature sensor that detects the temperature of the electric motor fails.

  The temperature estimation device for an electric motor according to the present invention comprises a motor temperature detection means for detecting the temperature of the electric motor and a failure detection means for detecting a failure of the motor temperature detection means, and the failure detection means causes a failure of the temperature detection means. Is detected, the oil temperature estimation means estimates the temperature of the oil after passing through the oil cooler, and the motor temperature estimation means preferably estimates the temperature of the electric motor.

  In this way, when the motor temperature detecting means for detecting the temperature of the electric motor fails, the temperature of the oil after passing through the oil cooler is estimated, and the temperature of the electric motor is estimated. The function can be maintained.

  In the temperature estimation device for an electric motor according to the present invention, the oil pump is driven by the engine, and the pump discharge amount obtaining means obtains the number of revolutions of the oil pump based on the number of revolutions of the engine or the speed of the vehicle. It is preferable to obtain the discharge amount of the oil pump from the pump rotation speed. If it does in this way, the discharge amount of an oil pump can be calculated | required exactly.

  An electric motor temperature estimation device according to the present invention includes an outside air temperature detecting unit that detects the temperature of outside air, and the oil cooler is an air-cooled oil cooler that performs heat exchange between oil and outside air. It is preferable that the estimating means estimates the temperature of the oil after passing through the oil cooler based on the temperature of the oil stored in the oil pan, the discharge amount of the oil pump, the speed of the vehicle, and the temperature of the outside air.

  In this way, when an air-cooled oil cooler is used, the temperature of oil after passing through the oil cooler can be accurately estimated.

  The temperature estimation device for an electric motor according to the present invention includes a cooling water temperature detecting means for detecting the temperature of cooling water for cooling oil, and the oil cooler is a water-cooled type that exchanges heat between the oil and the cooling water. This is an oil cooler, and the oil temperature estimating means estimates the temperature of the oil after passing through the oil cooler based on the temperature of the oil stored in the oil pan, the discharge amount of the oil pump, and the temperature of the cooling water. It is preferable.

  In this way, when a water-cooled oil cooler is used, the temperature of the oil after passing through the oil cooler can be accurately estimated.

  The temperature estimation device for an electric motor according to the present invention further includes an electric oil pump that boosts and discharges oil, and the pump discharge amount acquisition means discharges the electric oil pump based on the electric power applied to the electric oil pump. It is preferable that the amount is further obtained, and the oil temperature estimating means further considers the discharge amount of the electric oil pump and estimates the temperature of the oil after passing through the oil cooler.

  In this way, even in the case of an electric oil pump in addition to the mechanical oil pump, the total discharge amount of both oil pumps can be obtained, and the temperature of the oil after passing through the oil cooler is accurately estimated. can do.

  An electric motor control device according to the present invention comprises any one of the above-described electric motor temperature estimation devices and motor control means for limiting the output of the electric motor based on the oil temperature estimated by the oil temperature estimation means. An electric motor control device comprising:

  The electric motor control device according to the present invention includes any one of the above-described electric motor temperature estimation devices, and the output of the electric motor is limited based on the estimated oil temperature. Therefore, as described above, even if the temperature sensor that detects the temperature of the electric motor fails, the function of the electric motor can be maintained.

  According to the present invention, the function of the electric motor can be maintained even when the temperature sensor that detects the temperature of the electric motor fails.

It is a block diagram which shows the structure of the control apparatus of the electric motor using the temperature estimation apparatus of the electric motor which concerns on embodiment. It is a flowchart which shows the process sequence of the temperature estimation process of an electric motor by the control apparatus of the electric motor using the temperature estimation apparatus of the electric motor which concerns on embodiment, and an output restriction process.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals are used for the same or corresponding parts. Moreover, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

  First, the configuration of an electric motor control device 1 using the electric motor temperature estimation device according to the embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of an electric motor control device 1 using an electric motor temperature estimation device. Here, the case where the electric motor control device 1 is applied to a series-parallel hybrid vehicle (HEV) will be described as an example.

  The engine 10 may be of any type, but for example, an engine whose thermal efficiency is improved by increasing the compression ratio by a high expansion ratio cycle is preferably used. The engine 10 is controlled by an engine control unit (hereinafter referred to as “ECU”) 80.

  The ECU 80 includes a crank angle sensor 81 that detects the rotational position of the crankshaft (engine speed), an accelerator pedal sensor 82 that detects the amount of depression of the accelerator pedal, that is, the opening of the accelerator pedal, and the coolant temperature of the engine 10. Various sensors such as a water temperature sensor 83 to detect (corresponding to the cooling water temperature detecting means described in the claims) are connected.

  The ECU 80 determines the fuel injection amount, ignition timing, electronically controlled throttle valve, and the like based on the acquired various information and control information from a hybrid vehicle / control unit (hereinafter referred to as “HEV-ECU”) 50 described later. The engine 10 is controlled by controlling these various devices. In addition, the ECU 80 transmits various information such as the accelerator pedal opening, the engine speed, and the coolant temperature to the HEV-ECU 50 via a CAN (Controller Area Network) 100.

  A power split mechanism 13 is connected to the crankshaft of the engine 10. The power split mechanism 13 is connected to a drive train 14 composed of a speed reducer and a first electric motor (motor generator) 11 that mainly operates as a generator (generator). The power split mechanism 13 has a planetary gear mechanism composed of, for example, a ring gear, a pinion gear, a sun gear, and a planetary carrier, and drives the driving force generated from the engine 10 to the drive train 14 and the first electric motor 11. Divide and transmit.

  On the other hand, the drive train 14 is also connected to a second electric motor (motor generator) 12 that mainly operates as a power source. With this configuration, the vehicle can drive the wheels (vehicles) with the two powers of the engine 10 and the second electric motor 12. Further, it is possible to switch between traveling by only the second electric motor 12 and traveling by the engine 10 and the second electric motor 12 according to the traveling condition. Furthermore, it is possible to generate electric power while traveling with the second electric motor 12.

  The first electric motor 11 is, for example, a three-phase AC type AC synchronous motor, and mainly operates as a generator as described above. The second electric motor 12 is, for example, a three-phase AC type AC synchronous motor, and mainly operates as a power source as described above. In the 1st electric motor 11 and the 2nd electric motor 12, the permanent magnet was used for the rotor and the coil was used for the stator. The first electric motor 11 and the second electric motor 12 are oil-cooled electric motors cooled by oil. In the first electric motor 11 and the second electric motor 12, a coil may be used for the rotor and a permanent magnet may be used for the stator. Further, as the first electric motor 11 and the second electric motor 12, for example, an AC induction motor or a DC motor may be used instead of the AC synchronous motor.

  A first temperature sensor 21 that detects the temperature of the stator (coil 11 a) of the first electric motor 11 is attached to the stator (coil 11 a) of the first electric motor 11. Similarly, a second temperature sensor 22 that detects the temperature of the stator (coil 12a) of the second electric motor 12 is attached to the stator (coil 12a) of the second electric motor 12. The first temperature sensor 21 and the second temperature sensor 22 function as motor temperature detection means described in the claims. As the first temperature sensor 21 and the second temperature sensor 22, for example, a thermistor whose resistance value varies with temperature is preferably used. The first temperature sensor 21 and the second temperature sensor 22 are connected to the HEV-ECU 50, and an electric signal (voltage value) corresponding to the temperature is read by the HEV-ECU 50.

  A third temperature sensor 23 that detects the temperature of oil stored in the oil pan 30 is attached to the oil pan 30 (or a pipe that communicates with the oil strainer 31 and the oil pumps 32 and 33). The 3rd temperature sensor 23 functions as an oil temperature detection means as described in a claim. As the third temperature sensor 23, for example, a thermistor whose resistance value varies with temperature is preferably used. The third temperature sensor 23 is also connected to the HEV-ECU 50, and an electric signal (voltage value) corresponding to the temperature is read by the HEV-ECU 50.

  The oil pan 30 stores oil for lubricating and cooling the first electric motor 11 and the second electric motor 12 and for lubricating the power split mechanism 13 and the drive train 14. In order to supply the oil stored in the oil pan 30 to the first electric motor 11, the second electric motor 12, and the like, a mechanical oil pump (hereinafter also simply referred to as “oil pump”) 32, and an electric motor An oil pump (EOP) 33 is provided in parallel.

  The mechanical oil pump 32 is driven by the engine 10, sucks up oil stored in the oil pan 30 through the oil strainer 31, boosts and discharges the oil. The discharged oil is pumped to the oil cooler 40. As the mechanical oil pump 32, for example, a coaxial internal gear / trochoid type or a chain drive type vane type is preferably used.

  For example, when the engine 10 is stopped, the electric oil pump 33 is driven by an electric motor (not shown), and boosts and discharges oil. The discharged oil is pumped to the oil cooler 40. The electric oil pump 33 is driven by the HEV-ECU 50.

  An oil cooler 40 is provided on the downstream side of the mechanical oil pump 32 and the electric oil pump 33 to cool the oil by exchanging heat between the oil discharged from both oil pumps and the cooling medium. In the present embodiment, an air-cooled oil cooler that performs heat exchange between oil and outside air is used as the oil cooler 40. As the oil cooler 40, for example, a water-cooled oil cooler that performs heat exchange between oil and cooling water (engine cooling water) may be used instead of the air-cooled oil cooler.

  The engine 10, the first electric motor 11, and the second electric motor 12 that are driving force sources of the vehicle are comprehensively controlled by the HEV-ECU 50.

  The HEV-ECU 50 includes a microprocessor that performs calculations, a ROM that stores a program for causing the microprocessor to execute each process, a RAM that stores various data such as calculation results, a backup RAM that holds the stored contents, And an input / output I / F or the like.

  The HEV-ECU 50 includes, for example, an outside air temperature sensor 58 that detects the temperature of outside air (corresponding to outside air temperature detecting means described in the claims), and a vehicle speed sensor 59 that detects vehicle speed (described in the claims). To the vehicle speed detecting means) is connected. The HEV-ECU 50 is connected to the ECU 80, the vehicle dynamic control unit (hereinafter referred to as “VDCU”), and the like that control the engine 10 via the CAN 100 so as to be able to communicate with each other. The HEV-ECU 50 receives various information such as the engine speed, the coolant temperature, and the accelerator pedal opening degree from the ECU 80 and the VDCU via the CAN 100.

  The HEV-ECU 50 comprehensively controls driving of the engine 10, the first electric motor 11, and the second electric motor 12 based on the acquired various pieces of information. For example, the HEV-ECU 50 determines the required output of the engine 10, the first electric motor 11, 2 The torque command value of the electric motor 12 is obtained and output. The ECU 80 adjusts, for example, the opening degree of the electronically controlled throttle valve based on the request output. Further, a power control unit (hereinafter referred to as “PCU”) 60 described later drives the first electric motor 11 and the second electric motor 12 via the inverter 61 based on the torque command value.

  The HEV-ECU 50 limits the torque command value according to the temperature of each of the first electric motor 11 and the second electric motor 12 when obtaining the torque command values of the first electric motor 11 and the second electric motor 12. . Here, even if the HEV-ECU 50 is a case where the first and second temperature sensors 21 and 22 that directly detect the temperatures of the first and second electric motors 11 and 12 have failed (failed), The second electric motors 11 and 12 have a (fault tolerance) function for maintaining the function (driving force output / power generation function). Therefore, the HEV-ECU 50 functionally includes a failure detection unit 51, a pump discharge amount acquisition unit 52, an operation state acquisition unit 53, an oil temperature estimation unit 54, a motor temperature estimation unit 55, and a motor control unit 56. . In the HEV-ECU 50, a program stored in the ROM is executed by the microprocessor, whereby a failure detection unit 51, a pump discharge amount acquisition unit 52, an operation state acquisition unit 53, an oil temperature estimation unit 54, and a motor temperature estimation unit. 55 and the functions of the motor control unit 56 are realized.

  The failure detection unit 51 detects a failure (fail) in each of the first temperature sensor 21 and the second temperature sensor 22. That is, the failure detection unit 51 functions as failure detection means described in the claims. For example, the failure detection unit 51 determines that the sensor or the harness is short-circuited when the detection value of each sensor continues for a predetermined time or longer and is equal to or lower than the lower limit value. Moreover, the failure detection unit 51 determines that the sensor or the harness is disconnected (open fail) when the detection value of each sensor continues for a predetermined time or longer and is equal to or higher than the upper limit value. Furthermore, the failure detection unit 51 determines that a failure (sticking failure) occurs even when the detection value of each sensor does not continuously change for a predetermined time or more. The failure detection results of the first temperature sensor 21 and the second temperature sensor 22 by the failure detection unit 51 are output to the oil temperature estimation unit 54, the motor temperature estimation unit 55, and the motor control unit 56. .

  The pump discharge amount acquisition unit 52 obtains the oil discharge amount of the mechanical oil pump 32. That is, the pump discharge amount acquisition unit 52 functions as a pump discharge amount acquisition unit described in the claims. More specifically, the pump discharge amount acquisition unit 52 obtains the rotation speed of the mechanical oil pump 32 based on the engine rotation speed and the gear ratio, and the oil discharge volume of the mechanical oil pump 32 from the pump rotation speed. Ask for. Instead of the engine speed, for example, the discharge amount of the mechanical oil pump 32 may be obtained based on the speed of the vehicle.

  The pump discharge amount acquisition unit 52 obtains the discharge amount of the electric oil pump 33 based on the duty of the voltage applied to the electric oil pump 33. The discharge amount of the mechanical oil pump 32 and the discharge amount of the electric oil pump 33 obtained by the pump discharge amount acquisition unit 52 are output to the oil temperature estimation unit 54.

  The operation state acquisition unit 53 acquires the operation states of the first electric motor 11 and the second electric motor 12, for example, output torque, motor rotation number, and the like. That is, the operation state acquisition unit 53 functions as an operation state acquisition unit described in the claims. Note that the output torque, motor rotation speed, and the like of each of the first electric motor 11 and the second electric motor 12 acquired by the operation state acquisition unit 53 are output to the motor temperature estimation unit 55.

  The oil temperature estimation unit 54 first obtains the oil passage amount of the oil cooler 40 based on the discharge amount of the mechanical oil pump 32 and the discharge amount of the electric oil pump 33. The oil flow rate of the oil cooler 40 is preferably determined in consideration of the pressure loss ratio of the circuit. Next, the oil temperature estimation unit 54 is based on the temperature of the oil stored in the oil pan 30, the amount of oil passing through the oil cooler 40, the temperature of the cooling medium (outside temperature), and the speed of the vehicle (vehicle speed). The temperature of the oil after passing through the oil cooler 40 (that is, the oil supplied to the first electric motor 11 and the second electric motor 12) is estimated. That is, the oil temperature estimating unit 54 functions as an oil temperature estimating unit described in the claims.

  Here, the oil temperature estimation unit 54 estimates the temperature of the oil after passing through the oil cooler 40 when a failure (failure) of the first temperature sensor 21 and / or the second temperature sensor 22 is detected. To do. The oil temperature estimated by the oil temperature estimation unit 54 is output to the motor temperature estimation unit 55. When the water cooler is used as the oil cooler 40, the oil temperature estimation unit 54 is based on the temperature of the oil stored in the oil pan 30, the discharge amount of the oil pump, and the temperature of the cooling water. The temperature of the oil after passing through the oil cooler 40 is estimated.

  The motor temperature estimation unit 55 determines the operating states (output torque, motor rotation speed, etc.) of each of the first electric motor 11 and the second electric motor 12, the estimated oil temperature after passing through the oil cooler 40, and the oil flow rate. Based on this, the temperature of the first electric motor 11 and / or the second electric motor 12 is estimated. That is, the motor temperature estimating unit 55 functions as a motor temperature estimating unit described in the claims. Here, the motor temperature estimation unit 55, when a failure (fail) of the first temperature sensor 21 and / or the second temperature sensor 22 is detected, the first electric motor 11 and / or the second electric motor. The temperature of the motor 12 (that is, the electric motor corresponding to the temperature sensor where the failure is detected) is estimated. The temperature of the first electric motor 11 and / or the second electric motor 12 estimated by the motor temperature estimation unit 55 is output to the motor control unit 56.

  For example, the motor control unit 56 determines each of the first electric motor 11 and the second electric motor 12 based on the accelerator pedal opening (driver's request), the driving state of the vehicle, the charging state (SOC) of the battery 70, and the like. Set the torque command value. In that case, the motor control part 56 restrict | limits a torque command value according to the temperature of the 1st electric motor 11 and the 2nd electric motor 12 (for example, 140-160 degreeC or more).

  When the failure (fail) of the first temperature sensor 21 and the second temperature sensor 22 is not detected, the motor control unit 56 detects the temperature of the first electric motor 11 detected by the first temperature sensor 21 and the first temperature sensor 21. The torque command value is limited according to the temperature of the second electric motor 12 detected by the two temperature sensor 22. On the other hand, when a failure (failure) of the first temperature sensor 21 and / or the second temperature sensor 22 is detected, the motor control unit 56 performs the first electric motor 11 estimated by the motor temperature estimation unit 55, and Alternatively, the torque command value is limited according to the temperature of the second electric motor 12. That is, the motor control unit 56 functions as motor control means described in the claims.

  The PCU 60 includes an inverter 61 that converts the DC power of the battery 70 into three-phase AC power and supplies it to the second electric motor 11 (first electric motor 12). As described above, the PCU 60 drives the first electric motor 11 and the second electric motor 12 via the inverter 61 based on the torque command value (set in the motor control unit 56) received from the HEV-ECU 50. To do. The inverter 61 converts the AC voltage generated by the first electric motor 11 and the second electric motor 12 into a DC voltage and charges the battery 70. Further, the PCU 60 includes a DC-DC converter 62 that steps down the DC high voltage of the battery 70 to 12 V in order to use it as a power source for auxiliary equipment and each ECU.

  Next, the operation of the electric motor control device 1 will be described with reference to FIG. FIG. 2 is a flowchart showing a processing procedure of an electric motor temperature estimation process and an output restriction process by the electric motor control apparatus 1 using the electric motor temperature estimation apparatus. This processing is repeatedly executed mainly at a predetermined timing in the HEV-ECU 50. Note that the processing contents of the first electric motor 11 and the second electric motor 12 are the same or similar, and therefore, the first electric motor 11 will be mainly described here.

  First, in step S100, the rotation speed Nm1, the torque Tm1, the temperature (stator temperature) Tst1 of the first electric motor 11 (second electric motor 12), and the temperature (oil temperature) To1 of the oil stored in the oil pan 30. Is read.

  Next, a determination is made as to whether a failure (failure) of the first temperature sensor 21 (second temperature sensor 22) has been detected. If no failure is detected, the process proceeds to step S104. On the other hand, when a failure is detected, the process proceeds to step S106.

  In step S104, the base temperature Tmb of the first electric motor 11 (second electric motor 12) is set according to the detection value of the first temperature sensor 21 (second temperature sensor 22). Thereafter, the process proceeds to step S120.

  On the other hand, in step S106, the vehicle speed V, the engine speed Ne, the outside air temperature Ta, and the drive duty of the electric oil pump 33 are read.

  Subsequently, in step S108, based on the vehicle speed V read in step S106, the engine speed Ne, and the temperature (oil temperature) To1 of the oil stored in the oil pan 30 read in step S100, the mechanical type is determined. The rotation speed Nmop and the discharge amount Qmop of the oil pump 32 are estimated.

  In the subsequent step S110, it is determined whether or not the electric oil pump 33 is in operation. Here, when the electric oil pump 33 is operating, in step S112, the discharge amount Qmop of the mechanical oil pump 32, the temperature (oil temperature) To1 of the oil stored in the oil pan 30, and the electric oil After the discharge amount Qeop of the electric oil pump 33 is estimated based on the drive duty of the pump 33, the process proceeds to step S114. On the other hand, when the electric oil pump 33 is not in operation, the process proceeds to step S114 as it is (zero is substituted as the discharge amount Qeop of the electric oil pump 33).

  In step S114, the total discharge amount (total flow rate) is calculated by adding the discharge amount Qmop of the mechanical oil pump 32 and the discharge amount Qeop of the electric oil pump 33, and based on the total discharge amount (total flow rate). Thus, the oil flow rate of the oil cooler 40 and the distribution flow rate between the first electric motor 11 and the second electric motor 12 are estimated.

  Next, in step S116, heat exchange is performed (cooled) in the oil cooler 40 based on the temperature To1 of the oil in the oil pan 30, the oil flow rate of the oil cooler 40, the outside air temperature Ta, and the vehicle speed V. The subsequent oil temperature To2 (that is, the temperature To2 of the oil supplied to the first electric motor 11 (second electric motor 12)) is estimated.

  Subsequently, in step S118, based on the operating state of the first electric motor 11 (second electric motor 12) and the oil temperature To2 estimated in step S116, the first electric motor 11 (second electric motor 12). Is estimated (stator temperature) Tst2. Thereafter, the process proceeds to step S120.

  In step S120, a determination is made as to whether or not the temperature of the first electric motor 11 (second electric motor 12) is equal to or higher than a predetermined MG allowable temperature Tml. Here, when the temperature is lower than the MG allowable temperature Tml, after the upper limit output Plim2 is set as the output upper limit value of the first electric motor 11 (second electric motor 12) in step S122, the process proceeds to step S126. Transition. On the other hand, when the temperature is equal to or higher than the MG allowable temperature Tml, in step S124, the upper limit output Plim1 is set as the output upper limit value of the first electric motor 11 (second electric motor 12), and then the process proceeds to step S126. The upper limit output Plim1 is smaller than the upper limit output Plim2. That is, when the temperature is equal to or higher than the MG allowable temperature Tml, the output upper limit value of the first electric motor 11 (second electric motor 12) is limited.

  In step S126, for example, the required rotation speed and the required torque of the first electric motor 11 (second electric motor 12) are set according to the accelerator pedal opening. Next, in step S128, the target of the first electric motor 11 (second electric motor 12) is determined according to the required rotation speed and required torque of the first electric motor 11 (second electric motor 12) set in step S126. A rotation speed and a target torque are set.

  Subsequently, in step S130, the torque of the first electric motor 11 (second electric motor 12) according to the target rotational speed and target torque of the first electric motor 11 (second electric motor 12) set in step S128. The command value is set. In the following step S132, calculation is performed so that the torque command value set in step S130 satisfies the upper limit output Plim2 set in step S122 or the upper limit output Plim1 set in step S124, and the temporary motor torque is calculated. (Step S134).

  Next, in step S136, a final torque designation value is set according to the temporary motor torque calculated in step S134. In subsequent step S136, the target rotational speed, target torque, and torque command value of the first electric motor 11 (second electric motor 12) are output to the PDU 60, and the first electric motor 11 (second electric motor 12) is driven. Is done. Thereafter, the process is temporarily exited.

  As described above in detail, according to this embodiment, when the first temperature sensor 21 and the second temperature sensor 22 that detect the temperatures of the first electric motor 11 and the second electric motor 12 fail, After passing through the oil cooler 40 based on the temperature of the oil stored in the pan 30, the discharge amount of the mechanical oil pump 32 and the electric oil pump 33 (oil flow rate of the oil cooler 40), the outside air temperature, and the vehicle speed. The oil temperature is estimated. The temperatures of the first electric motor 11 and the second electric motor 12 are estimated based on the operating states of the first electric motor 11 and the second electric motor 12 and the estimated oil temperature after passing through the oil cooler 40. The As a result, even if the first temperature sensor 21 and the second temperature sensor 22 that directly detect the temperatures of the first electric motor 11 and the second electric motor 12 fail, the first electric motor 11 and the second electric motor 11 It is possible to maintain the function (driving force output / power generation function) of the electric motor 12 (fault tolerance).

  According to the present embodiment, the rotational speed of the mechanical oil pump 32 is obtained based on the engine rotational speed, and the oil discharge amount of the mechanical oil pump 32 is obtained from the pump rotational speed. Therefore, the discharge amount of the mechanical oil pump 43 can be obtained accurately.

  Moreover, according to this embodiment, the temperature of the oil after passing through the oil cooler 40 is estimated in consideration of the discharge amount of the electric oil pump 33. Therefore, in the case of the configuration including the electric oil pump 33 in addition to the mechanical oil pump 32, the total discharge amount of both the oil pumps can be obtained, and the temperature of the oil after passing through the oil cooler 40 is accurately estimated. be able to.

  According to the present embodiment, as described above, based on the temperature of the oil stored in the oil pan 30, the discharge amounts of the mechanical oil pump 32 and the electric oil pump 33, the outside air temperature, and the speed of the vehicle, The temperature of the oil after passing through the cooler 40 is estimated. Therefore, when the air-cooled oil cooler 40 is used, the oil temperature after passing through the oil cooler 40 can be accurately estimated.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the above embodiment, the case where the electric motor control device 1 according to the present invention is applied to a series-parallel hybrid vehicle (HEV) has been described as an example. It can also be applied to hybrid vehicles and parallel hybrid vehicles. Further, it can be applied to an electric vehicle (EV), a fuel cell vehicle (FCV), and the like.

  Moreover, in the said embodiment, although it had two electric motors (the 1st electric motor 11 and the 2nd electric motor 12), the number of electric motors is not restricted to two, One or three or more It may be.

DESCRIPTION OF SYMBOLS 1 Control apparatus of electric motor 10 Engine 11 1st electric motor (motor generator)
12 Second electric motor (motor generator)
DESCRIPTION OF SYMBOLS 13 Driving force division mechanism 21 1st temperature sensor 22 2nd temperature sensor 23 3rd temperature sensor 30 Oil pan 32 Mechanical oil pump 33 Electric oil pump 40 Oil cooler 50 HEV-ECU
REFERENCE SIGNS LIST 51 Failure detection unit 52 Pump discharge amount acquisition unit 53 Operation state acquisition unit 54 Oil temperature estimation unit 55 Motor temperature estimation unit 56 Motor control unit 58 Outside air temperature sensor 59 Vehicle speed sensor 60 PCU
70 battery 80 ECU
81 Crank angle sensor 82 Accelerator pedal sensor 83 Water temperature sensor 100 CAN

Claims (7)

An oil-cooled electric motor mounted on the vehicle;
Oil temperature detecting means for detecting the temperature of oil stored in the oil pan;
A pump discharge amount obtaining means for obtaining a discharge amount of an oil pump for boosting and discharging the oil;
An oil cooler that cools oil by exchanging heat between the oil discharged from the oil pump and the cooling medium;
An operation state acquisition means for acquiring an operation state of the electric motor;
The temperature of the oil after passing through the oil cooler based on the temperature of the oil stored in the oil pan, the discharge amount of the oil pump obtained by the pump discharge amount acquisition means, and the temperature of the cooling medium Oil temperature estimating means for estimating
Motor temperature estimating means for estimating the temperature of the electric motor based on the operating state of the electric motor acquired by the operating state acquiring means and the temperature of the oil after passing through the oil cooler estimated by the oil temperature estimating means; A temperature estimation device for an electric motor, comprising: Motor temperature detecting means for detecting the temperature of the electric motor;
A failure detection means for detecting a failure of the motor temperature detection means,
When a failure of the temperature detection means is detected by the failure detection means, the oil temperature estimation means estimates the temperature of oil after passing through the oil cooler, and the motor temperature estimation means includes the electric motor The temperature estimation device for an electric motor according to claim 1, wherein the temperature of the motor is estimated. The oil pump is driven by an engine,
The pump discharge amount obtaining means obtains the number of revolutions of the oil pump based on the number of revolutions of the engine or the speed of the vehicle, and obtains the amount of discharge of the oil pump from the number of revolutions of the pump. The temperature estimation device for an electric motor according to claim 1 or 2. An outside air temperature detecting means for detecting the temperature of the outside air;
The oil cooler is an air-cooled oil cooler that exchanges heat between oil and outside air,
The oil temperature estimating means is configured to determine the amount of oil after passing through the oil cooler based on the temperature of the oil stored in the oil pan, the discharge amount of the oil pump, the speed of the vehicle, and the temperature of the outside air. The temperature estimation device for an electric motor according to any one of claims 1 to 3, wherein the temperature is estimated. With cooling water temperature detecting means for detecting the temperature of the cooling water for cooling the oil;
The oil cooler is a water-cooled oil cooler that exchanges heat between oil and the cooling water,
The oil temperature estimating means estimates the temperature of the oil after passing through the oil cooler based on the temperature of the oil stored in the oil pan, the discharge amount of the oil pump, and the temperature of the cooling water. The temperature estimation device for an electric motor according to any one of claims 1 to 3. An electric oil pump that boosts and discharges the oil;
The pump discharge amount acquisition means further determines the discharge amount of the electric oil pump based on the electric power applied to the electric oil pump,
The said oil temperature estimation means estimates the temperature of the oil after passing the said oil cooler further considering the discharge amount of the said electric oil pump, The any one of Claims 1-5 characterized by the above-mentioned. The temperature estimation apparatus of the described electric motor. The temperature estimation device for an electric motor according to any one of claims 1 to 6,
An electric motor control device comprising: motor control means for limiting the output of the electric motor based on the oil temperature estimated by the oil temperature estimation means.

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