JP5708361B2 - Rotating electrical machine temperature estimation system - Google Patents

Description

  The present invention relates to a rotating electrical machine temperature estimation system including a temperature sensor that measures the temperature of the rotating electrical machine.

  Conventionally, in an electric vehicle such as a hybrid vehicle, an electric vehicle, a fuel cell vehicle, etc., in which an engine and a traveling motor are mounted and wheels are driven using at least one of the engine and the traveling motor as a drive source, a motor, a generator, etc. The use of rotating electrical machines has been performed. Such a rotating electrical machine may have reduced performance depending on the temperature during use. For this reason, it is desired to accurately detect the temperature of the rotating electrical machine, for example, the temperature of the stator.

  On the other hand, in Patent Document 1, the temperature of the stator is detected by a thermistor mounted on the stator of the motor, the reference thermal time constant and the reference thermal resistance of the thermistor are stored in advance in a storage means, and a predetermined value of the stator is stored. There is described a temperature measuring device that calculates an estimated temperature Tcal of the thermistor with respect to the amount of heat generation and determines whether or not the absolute value of the temperature difference between the estimated temperature Tcal and the measured temperature Tth is equal to or less than a predetermined threshold value. Further, when the absolute value of the temperature difference exceeds a predetermined threshold, the corrected temperature calculated by correcting the estimated temperature is output.

JP 2009-210282 A

  In the case of the temperature measuring apparatus as described above, it is not considered to accurately estimate the temperature of the motor regardless of the load on the motor. For this reason, there is a possibility that a time constant delay of the measured temperature of the thermistor occurs in the high load region of the motor. For this reason, the deviation between the thermistor and the actual temperature of the motor may increase in a transient state with a high load. On the other hand, when cooling is performed by directly applying a refrigerant such as ATF (automatic transmission fluid) to the motor, it is difficult to estimate the actual temperature of the motor (particularly at a high temperature) if the thermistor is applied with the refrigerant.

  On the other hand, it is also conceivable to estimate the motor temperature using the ambient temperature around the motor circuit. However, in this case as well, the difference between the measured temperature of the thermistor and the actual temperature of the motor becomes large in a transient state of high load unless consideration is given to estimating the motor temperature with high accuracy regardless of the motor load. There is a possibility that. Further, when cooling is performed by directly applying a refrigerant to the motor, it is difficult to improve the estimation accuracy of the actual temperature of the motor.

  It is also conceivable to estimate the actual motor temperature when the motor is locked from the motor speed and the measured temperature of the thermistor attached to the motor. However, in the actual temperature estimation formula, the effect of torque is considered in the heat generation term. If not, there is room for improvement in terms of accurately estimating the actual temperature of the motor regardless of the motor load.

  An object of the present invention is to accurately estimate the actual temperature of a rotating electrical machine in a rotating electrical machine temperature estimation system regardless of the load of the rotating electrical machine and the influence of the refrigerant when the rotating electrical machine is cooled by the coolant.

A rotating electrical machine temperature estimation system according to the present invention includes a rotating electrical machine, a temperature sensor that measures the temperature of the rotating electrical machine, a torque acquisition unit that acquires torque of the rotating electrical machine, an actual temperature of the rotating electrical machine, and a measured temperature of the temperature sensor. A temperature sensor temperature correction value is obtained from the amount of change in the measured temperature of the temperature sensor and the acquired value of the torque of the rotating electrical machine so as to correct the deviation of the temperature sensor, and the measured temperature is corrected using the temperature sensor temperature correction value. And an actual temperature estimating unit for estimating the actual temperature of the rotating electrical machine. In this case, “acquiring the torque of the rotating electrical machine” includes not only acquiring the target torque of the rotating electrical machine but also acquiring the torque of the rotating electrical machine by using a torque sensor.

  The rotating electrical machine temperature estimation system according to the present invention preferably includes a cooling unit that cools the rotating electrical machine with a refrigerant, and the temperature sensor is provided in a portion to which the refrigerant of the rotating electrical machine is applied.

  In the rotating electrical machine temperature estimation system according to the present invention, preferably, map data representing a relationship between a change amount of the temperature measured by the temperature sensor and an acquired value of the torque of the rotating electrical machine and a preset temperature sensor temperature correction value. The actual temperature estimation unit estimates the actual temperature of the rotating electrical machine from the amount of change in temperature measured by the temperature sensor and the acquired value of the torque of the rotating electrical machine while referring to the map stored in the storage unit. To do.

  In the rotating electrical machine temperature estimation system according to the present invention, preferably, the actual temperature estimation unit changes the measured temperature of the temperature sensor between a normal time and a rotating electrical machine locked when the rotating electrical machine is locked when the rotating electrical machine is energized. The actual temperature of the rotating electrical machine is estimated according to different situations using different relationships of the temperature sensor temperature correction value corresponding to the amount and the acquired value of the torque of the rotating electrical machine.

  In the rotating electrical machine temperature estimation system according to the present invention, preferably, the relationship between the amount of change in the measured temperature of the temperature sensor and the acquired value of the torque of the rotating electrical machine in a normal state and a preset temperature sensor temperature correction value is obtained. Data of a normal time map that represents, and a lock time map that represents the relationship between the amount of change in the measured temperature of the temperature sensor and the acquired value of the torque of the rotating electrical machine when the rotating electrical machine is locked, and a preset temperature sensor temperature correction value The actual temperature estimation unit refers to the map stored in the storage unit, and the amount of change in the temperature measured by the temperature sensor and the rotating electric machine according to whether it is normal or when the motor is locked. The actual temperature of the rotating electrical machine is estimated from the acquired torque value.

  According to the rotating electrical machine temperature estimation system according to the present invention, the actual temperature of the rotating electrical machine can be estimated with high accuracy regardless of the load of the rotating electrical machine and the influence of the refrigerant when the rotating electrical machine is cooled by the coolant.

1 is a schematic diagram showing a configuration of a hybrid vehicle including an example of a rotating electrical machine temperature estimation system according to an embodiment of the present invention. It is a figure which shows the structure of the cooling device which cools a rotary electric machine including the rotary electric machine temperature estimation system of FIG. 1, Comprising: It is a figure containing the upper half part cross section of a rotary electric machine. FIG. 2 is a map used in the rotating electrical machine temperature estimation system of FIG. 1 and illustrating a map that defines a relationship between a measured temperature change amount and a rotating electrical machine torque and a temperature correction value at a unit time interval. In embodiment of this invention, it is a figure which shows one example of the relationship between the estimated temperature (Tcoil temperature) of a rotary electric machine, and the load factor of a rotary electric machine. In the comparative example, when the torque of the rotating electrical machine is set to a certain value, the time change of the measured temperature of the thermistor, the actual temperature of the rotating electrical machine, and the estimated temperature of the rotating electrical machine corrected using the temperature correction value It is a figure which shows an example. In the embodiment of the present invention, when the torque of the rotating electrical machine is set to a certain value, the time of the measured temperature of the thermistor, the actual temperature of the rotating electrical machine, and the estimated temperature of the rotating electrical machine corrected using the temperature correction value It is a figure which shows an example of a change. It is a map which is used in a comparative example, and shows a map which defines the relationship between the rotating electrical machine torque and the temperature correction value. It is a flowchart which shows the temperature estimation method in the rotary electric machine temperature estimation system of another example of embodiment of this invention.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. 1-4 and 5B show an example of an embodiment of the present invention. FIG. 1 is a schematic diagram showing the configuration of a hybrid vehicle including an example of a rotating electrical machine temperature estimation system according to an embodiment of the present invention.

  The rotating electrical machine temperature estimation system of the present embodiment is mounted on a hybrid vehicle and is used for limiting the output of the second motor generator when the temperature of the second motor generator, which is a rotating electrical machine, rises excessively. . In the following description, the case where the actual temperature is estimated from the measured temperature of the second motor generator will be described. However, the actual temperature can also be estimated from the measured temperature of the first motor generator with the same configuration, The actual temperatures can be estimated from the measured temperatures of the first and second motor generators. The rotating electrical machine temperature estimation system of the present invention is not limited to the one mounted on the hybrid vehicle, but the temperature of other rotating electrical machines such as a traveling motor used in an electric vehicle or a fuel cell vehicle is used. It can also be used to estimate.

  As shown in FIG. 1, the hybrid vehicle 10 is driven by the temperature estimation system 12, the engine 13, the power split mechanism 14, the wheels 18 connected to the drive shaft 16, and the engine 13, and is mainly used as a generator. And a first motor generator (MG1) 22 that is a rotating electrical machine. The temperature estimation system 12 includes a second motor generator (MG2) 24 that is a rotating electrical machine that is mainly used as a traveling motor, a thermistor 26 that is a temperature sensor that measures the temperature of the second motor generator, and a control unit (ECU). 28 and a cooling device 29 (FIG. 2) as a cooling unit. Hybrid vehicle 10 includes a battery 34, a first inverter 36 that drives first motor generator 22, and a second inverter 38 that drives second motor generator 24.

  FIG. 1 shows a case where the hybrid vehicle 10 is an FF vehicle that is a front-wheel drive vehicle with a front engine. However, the hybrid vehicle may be an FR vehicle that is a rear wheel drive vehicle with a front engine, a 4WD vehicle that is a four wheel drive vehicle, or the like.

  The power split mechanism 14 can split the power from the engine 13 into a path to the drive shaft 16 and a path to the first motor generator 22. The power split mechanism 14 is constituted by, for example, a planetary gear mechanism. For example, the rotating shaft of the first motor generator 22 is hollow, and the sun gear of the planetary gear mechanism is connected to the end of the rotating shaft. Further, the carrier connected to the planetary gear of the planetary gear mechanism is connected to the drive shaft of the engine 13 inserted through the inside of the rotation shaft of the first motor generator 22. Further, the output shaft 30 is connected to the ring gear of the planetary gear mechanism, and the rotation shaft of the second motor generator 24 is connected to the output shaft 30 directly or via a speed reducer such as another planetary gear mechanism (not shown). The output shaft 30 is connected to the drive shaft 16 connected to the wheel 18 via the speed reducer 32. The power split mechanism 14 can also be connected to the drive shaft of the engine 13 via a damper (not shown).

  The first motor generator 22 is a three-phase AC motor and can also be used as a starting motor for the engine 13. However, when the first motor generator 22 is used as a generator driven by the engine 13, the engine 13, at least a part of the torque transmitted through the carrier of the planetary gear mechanism is transmitted to the rotation shaft of the first motor generator 22 through the sun gear.

  The second motor generator 24 is a three-phase AC motor for generating the driving force of the vehicle, and can also be used as a generator, that is, for power regeneration that generates electric power by the force applied from the wheel 18 side during braking.

  The rotation of the engine 13 is extracted to the output shaft 30 side and the first motor generator 22 side via the power split mechanism 14. The electric power generated by driving the first motor generator 22 is charged in a battery 34 that is a secondary battery. Note that the configuration of the hybrid vehicle 10 is not limited to such a configuration, and various configurations may be adopted as long as the hybrid vehicle 10 has a configuration of a hybrid vehicle that is driven using at least one of an engine and a traveling motor as a drive source. it can.

  As shown in FIG. 2, the temperature estimation system 12 includes the second motor generator 24, the control unit 28, and the thermistor 26.

  Returning to FIG. 1, the inverters 36 and 38 are supplied with power from the battery 34. The drive of the first motor generator 22 is controlled by the control unit 28 via the first inverter 36. The driving of the second motor generator 24 is controlled by the control unit 28 via the second inverter 38. A DC / DC converter (not shown) is provided between the battery 34 and each of the inverters 36, 38, and the voltage of the battery 34 is boosted and then supplied to each inverter 36, 38, or the voltage supplied from the inverter 36, 38. Can be supplied to the battery 34, that is, charged.

  Each of the inverters 36 and 38 receives a control signal corresponding to a torque command value that is a target torque from the control unit 28, thereby controlling switching of a switching element such as a transistor provided in each of the inverters 36 and 38. . For example, in the first inverter 36, switching on / off is controlled by the control unit 28 based on a signal corresponding to the torque command value input from the control unit 28, and DC power input from the battery 34 side is changed to AC power. The first motor generator 22 is driven by converting and supplying it to the first motor generator 22. In addition, when the first motor generator 22 generates power as the engine 13 is driven, the first inverter 36 converts the AC voltage obtained by the power generation into a DC voltage by the first inverter 36, and then converts the AC voltage. A direct current voltage is supplied to the battery 34 directly or via a DC / DC converter to charge the battery 34.

  On the other hand, in the second inverter 38, on / off of switching is controlled by the control unit 28 based on a signal corresponding to the torque command value input from the control unit 28, and the DC power input from the battery 34 side is supplied. The second motor generator 24 is driven by converting it into AC power and supplying it to the second motor generator 24. Further, the second inverter 38 converts the AC voltage generated by the second motor generator 24 into a DC voltage during regenerative braking of the hybrid vehicle 10, and the converted DC voltage is directly or via a DC / DC converter. 34 to charge the battery 34. The regenerative braking is executed when the accelerator pedal of the vehicle is not depressed and the charge amount of the battery 34 is small, and the second motor generator 24 is set in the regenerative braking state.

  The control unit 28 includes a microcomputer having a CPU, a memory, and the like provided on the control board. For example, a motor controller called a motor ECU having an actual temperature estimation unit 40 (FIG. 2) of the second motor generator 24. And an engine controller called an engine ECU. In the illustrated example, only one control unit 28 is illustrated as the control unit 28, but the control unit 28 may be appropriately divided into a plurality of components and electrically connected to each other. . For example, the control unit 28 is divided into a part having a function of a motor controller, a part having a function of an engine controller, and an overall control part that integrally controls the whole called a hybrid ECU, and is configured to be electrically connected to each other. You can also.

  Further, the control unit 28 receives detection signals for calculating torque command values and power generation amounts of the motor generators 22 and 24 such as detection signals of an accelerator operation amount sensor (not shown) and a vehicle speed sensor (not shown).

  The control unit 28 outputs a control signal to the corresponding inverter 36 (or 38) according to the calculated torque command value, and controls the switching elements constituting the corresponding inverter 36 (or 38) according to the control signal. Then, the corresponding motor generator 22 (or 24) is driven so that torque according to the torque command value is output. Such a hybrid vehicle 10 is driven using at least one of the engine 13 and the second motor generator 24 as a drive source.

  Further, a detection signal of the thermistor 26 provided in the second motor generator 24 is also input to the control unit 28. The thermistor 26 measures the temperature of the second motor generator 24.

  FIG. 2 is a diagram showing a configuration of a cooling device 29 that cools the second motor generator 24 including the temperature estimation system 12 of FIG. 1, and includes a cross section of the upper half of the second motor generator 24.

  As shown in FIG. 2, the second motor generator 24 includes a stator 46 fixed to the inside of the case 44 and a rotor 48 disposed to face the radially inner side of the stator 46. The rotor 48 is fixed to the outer diameter side of the rotating shaft 50 that is rotatably supported by the case 44. The stator 46 includes a plurality of, for example, three-phase stator coils 54 wound around a plurality of teeth provided on the inner peripheral side of a stator core 52 made of a magnetic material. In each phase of the stator coil 54, a pair of coil ends 56 are formed by portions protruding outward from both axial ends of the stator core 52. Further, the thermistor 26 is provided so as to be attached to the coil end 56 on one side or both sides. The thermistor 26 measures the temperature of the stator coil 54. The measured value of the thermistor 26 is input to the control unit 28.

  Further, an internal refrigerant channel 58 is formed inside the case 44 of the second motor generator 24, and the internal refrigerant channel 58 is connected to an external refrigerant channel 60 provided outside the case 44. An oil pump 62 is provided in the external refrigerant flow path 60 so that oil such as ATF, which is a refrigerant accumulated in a lower portion (not shown) of the case 44 can be sucked and supplied to the internal refrigerant flow path 58. In the internal refrigerant flow path 58, oil can be ejected toward the upper side of each coil end 56 from an ejection portion that is an end portion that opens to the inner surface of the case 44. Thereby, the stator coil 54 is cooled. The cooling device 29 includes an internal refrigerant channel 58, an external refrigerant channel 60, and an oil pump 62. The cooling device 29 can be provided with a heat exchange unit such as an oil cooler to cool the oil more effectively.

  The cooling device 29 can also cool the first motor generator 22 (FIG. 1) with the same configuration. In this case, some elements of the cooling device 29 such as the external refrigerant flow path 60 can be shared by the first motor generator 22 and the second motor generator 24. The thermistor 26 is provided in a portion where oil is applied when the coil end 56 of the second motor generator 24 is used.

  Unlike the example shown in the figure, a gear constituting the power transmission device can be provided in the case of the second motor generator 24. In this case, the oil accumulated in the lower portion of the case is lifted up by the gear, It is also possible to cool the stator coil 54 by supplying oil to a refrigerant supply unit (not shown) provided on the coil and applying oil to each coil end 56 from the refrigerant supply unit. Further, the configuration of the rotating electrical machine is not limited to the configuration shown in FIG. 2, and the temperature estimation system of the present invention can be used for estimating the temperature of the rotating electrical machine having various structures.

  The control unit 28 includes a motor torque acquisition unit 64, an actual temperature estimation unit 40, a storage unit 68, and a motor control unit 70. The motor control unit 70 calculates the torque command value of the motor generator 22 (or 24) corresponding to the detection value of an appropriate sensor such as the detection signal of the accelerator operation amount sensor, and the corresponding inverter 36 according to the torque command value. The driving of the corresponding motor generator 22 (or 24) is controlled via (or 38). Further, the motor torque acquisition unit 64 acquires the torque command value of the second motor generator 24 calculated by the motor control unit 70. In addition, the storage unit 68 includes a preset amount of change in the measured temperature (T2-T1) of the thermistor 26 and a torque command value of the second motor generator 24 at a preset unit time interval (t2-t1). Map data representing the relationship with the temperature correction value ΔTn (A, B, C...) Is stored.

  Further, the actual temperature estimation unit 40 corrects, that is, reduces or eliminates the difference between the actual temperature Tcoil of the second motor generator 24 and the measured temperature Tmj of the thermistor 26, so that the unit time interval (t2- The second motor generator 24 according to the amount of change in the measured temperature (T2−T1) at t1), the torque command value that is the acquired value of the torque of the second motor generator 24, and the preset temperature correction value ΔTn. An estimated temperature Test obtained by estimating the actual temperature is obtained.

  In order to configure the control unit 28 in this way, in this embodiment, the storage unit 68 stores map data as shown in FIG. 3 as an example, and the control unit 28 stores the map data. use. FIG. 3 is a map used in the rotating electrical machine temperature estimation system of FIG. 1, and is a map that defines the relationship between the measured temperature change amount per unit time interval and the torque of the second motor generator and the temperature correction value. is there.

  That is, it corresponds to the change amount (T2-T1) of the measured temperature of the thermistor 26 at a unit time interval (t2-t1) defined in advance by experiments or the like, and the torque command value of the second motor generator 24. A map representing the relationship of the temperature correction value ΔTn as an increase is obtained, and data of this map is stored in the storage unit 68. In the following description, the same elements as those shown in FIGS. 1 and 2 are denoted by the same reference numerals. In FIG. 3, A, B, C... Representing ΔTn includes numerical values, and some of the numerical values of A, B, C... May be the same or different. Further, in this experiment, the thermistor 26 is provided in a portion to which oil is applied when the stator coil 54 constituting the second motor generator 24 is used as in the case of FIG. ΔTn is an increase in the deviation correction temperature, which is a value obtained by subtracting the measured temperature Tmj of the thermistor 26 from the actual temperature Tcoil of the coil end 56 of the second motor generator 24 at a unit time interval.

  A method of estimating the actual temperature of the second motor generator 24 using such a temperature estimation system 12 is performed as follows. First, as shown in FIG. 5B described later, when the second motor generator 24 is used, the temperature T1 of the stator coil 54 is set by the thermistor 26 at preset time intervals t1 and t2 (t1 <t2). , T2 is measured, and the amount of change (T2-T1) in the measured temperature of the thermistor 26 is obtained.

  The motor torque acquisition unit 64 acquires a torque command value RT of the second motor generator 24 at time t2. Then, the actual temperature estimation unit 40 is stored in the storage unit 68 based on the measured temperature change amount (T2-T1) of the thermistor 26 and the torque command value RT acquired by the motor torque acquisition unit 64. The temperature correction value ΔTn of the corresponding second motor generator 24 is acquired while referring to the map data shown in FIG. Further, the actual temperature estimating unit 40 corrects the measured temperature Tmj (= T2) at the time t2 with the temperature correction value ΔTn. That is, the actual temperature estimation unit 40 adds the sum of one or more temperature correction values ΔTn obtained at the current time interval and the previous time interval to the measured temperature Tmj, so that the actual temperature Tcoil of the second motor generator 24 is obtained. Estimate, ie get. Specifically, the actual temperature Tcoil is obtained by the following equation.

Tcoil = Tmj + ΣΔTn + T ′ (1)
In this case, ΣΔTn represents the sum of the temperature correction values ΔTn, and T ′ represents a divergence temperature that is the difference between the actual temperature of the second motor generator 24 and the estimated temperature at the initial measurement time. This deviation temperature T ′ can also be set as zero.

  Further, the temperature correction value corresponding to the temperature change amount and torque of the thermistor 26 not defined in the map of FIG. 3 can be calculated by linear interpolation or the like from the temperature change amount on both sides and the torque on both sides thereof. . The estimated actual temperature Tcoil of the second motor generator 24 is used for protecting the second motor generator 24. For example, FIG. 4 shows an embodiment of the present invention in which the estimated temperature (Tcoil) of the second motor generator 24 that is a rotating electrical machine and the torque command value before limitation that is the torque target value of the second motor generator 24 are after limitation. It is a figure which shows one example of the relationship with the load factor which means the ratio of the torque command value.

  In the example shown in FIG. 4, when the estimated temperature of the second motor generator 24 is lower than a certain threshold value Tk ° C., the load factor is 100%, and the torque command value of the second motor generator 24 is not limited and is set as the torque command value as it is. Then, the driving of the second motor generator 24 is controlled. On the other hand, when the estimated temperature of the second motor generator 24 is equal to or higher than the threshold Tk ° C., the load factor is gradually decreased linearly from 100% so that the torque command value of the second motor generator 24 is gradually decreased. And the driving of the second motor generator 24 is controlled by the torque command value after the limitation. Therefore, it is possible to protect the second motor generator 24 from excessive temperature rise.

  Next, the effect of this embodiment is confirmed using FIG. 5A and FIG. 5B. FIG. 5A shows a measured value of the thermistor, an actual temperature of the second motor generator, and a temperature correction value when the torque of the second motor generator, which is a rotating electrical machine, is set to a certain constant value in a comparative example different from the present invention. It is a figure which shows an example of the time change with the estimated temperature of the 2nd motor generator correct | amended using. In this comparative example, unlike the case of the present embodiment, with reference to FIG. 2, the control unit 28 represents a plurality of temperature correction values defined according to a plurality of torque command values of the second motor generator 24. From this data, a temperature correction value corresponding to the acquired torque command value is obtained. That is, in the comparative example, the temperature correction value is obtained using the map shown in FIG. The map of FIG. 6 represents the relationship between the torque command value of the second motor generator and the temperature correction value. In the comparative example using the map of FIG. 6, unlike the embodiment using the map of FIG. 3, the temperature correction value is not changed by the difference in the change amount of the measured temperature of the thermistor 26, and is constant. Other configurations are the same as those of the present embodiment. In such a comparative example, unlike the present embodiment, a plurality of temperature correction values corresponding to a plurality of changes in the measured temperature of the thermistor 26 are not defined.

  FIG. 5A shows the relationship between the estimated temperature Test of the second motor generator 24 of the comparative example and the actual temperature Tcoil. In FIG. 5A, the torque of the second motor generator 24 is constant. As can be seen from FIG. 5A, the measured temperature Tmj of the thermistor 26 gradually increases until a certain time ta, but thereafter decreases rapidly and then remains substantially constant. This is because the thermistor 26 is hardly affected by low temperature oil until the actual temperature of the second motor generator 24 reaches a certain temperature, but the effect becomes significant above a certain temperature, and the actual temperature Tcoil and the thermistor This is because the difference from the measured temperature Tmj of 26 increases. In the comparative example, since the temperature correction of the measured temperature corresponding to the temperature change amount of the thermistor 26 is not performed, the estimated temperature changes with the same tendency as the measured temperature.

  On the other hand, FIG. 5B shows the measured temperature of the thermistor 26 and the actual performance of the second motor generator 24 when the torque of the second motor generator 24, which is a rotating electrical machine, is set to a certain value in the embodiment of the present invention. It is a figure which shows an example of the time change of temperature and the estimated temperature of the 2nd motor generator 24 correct | amended using the temperature correction value. In the present embodiment, unlike the comparative example, as shown in FIG. 3, a plurality of temperature correction values ΔTn are set according to a plurality of changes in the measured temperature of the thermistor 26. In this embodiment, as in the comparative example, even when the measured temperature of the thermistor 26 changes due to the effect of oil on the thermistor 26, the estimated temperature Test can be estimated so as to substantially match the actual temperature Tcoil. it can. That is, in the present embodiment, even when the torque of the second motor generator 24 is high and the elapsed time is long, as in the measured temperature Tmj in FIG. Therefore, it is possible to determine the estimated temperature Test close to the actual temperature Tcoil by correcting the measured temperature Tmj using the map of the temperature correction value ΔTn so as to compensate for this.

  According to the rotating electrical machine temperature estimation system of this embodiment, the temperature correction value ΔTn acquired according to the torque of the second motor generator 24 and the measured temperature change amount of the thermistor 26 is used. The actual temperature is estimated as the estimated temperature. Therefore, the actual temperature of the second motor generator 24 can be estimated with high accuracy regardless of the load of the second motor generator 24 and the influence of oil when the second motor generator 24 is cooled by oil. For example, in the conventional method in which the measured temperature of the second motor generator 24 is not corrected using the temperature correction value ΔTn, the time constant of the measured value of the thermistor 26 increases as the load of the second motor generator 24, that is, the torque increases. However, in this embodiment, this time constant delay can also be corrected.

  In addition, since the parameter of the oil, which is the refrigerant, is substituted by the amount of change in the measured temperature of the thermistor 26 at unit time intervals, the parameters necessary for creating the program stored in the control unit 28 can be reduced, and the memory capacity can be reduced. Reduction can be realized and calculation error can be reduced.

  In the above description, the case where the temperature correction value ΔTn is acquired using the map has been described. However, the actual temperature estimation unit 40 corrects, that is, reduces the deviation between the actual temperature of the rotating electrical machine and the measured temperature of the temperature sensor. Alternatively, as shown in FIG. 4, the measured temperature change amount and the rotation speed are calculated using a relational expression that represents the relationship between the temperature sensor measurement temperature change amount and the torque acquisition value of the rotating electrical machine, and a preset temperature sensor temperature correction value. It is also possible to calculate the temperature correction value ΔTn from the acquired value of the torque of the electric machine, and to estimate the actual temperature of the rotating electric machine based on the calculated temperature correction value ΔTn.

  Next, FIG. 7 is a flowchart showing a temperature estimation method in a rotating electrical machine temperature estimation system of another example of the embodiment of the present invention. In the configurations of FIGS. 1 to 4 and 5B described above, the control unit 28 estimates the actual temperature of the rotating electrical machine such as the second motor generator 24 using the data of one map, but in this embodiment, The actual temperature of the rotating electrical machine is estimated using two maps, a normal time map and a lock time map. In the present embodiment, the configuration other than the control unit 28 is the same as the configuration of FIGS. 1 to 4 and FIG. 5B described above. However, it will be explained.

  In the present embodiment, the control unit 28 includes an actual temperature estimation unit 40 and a storage unit 68, and the storage unit 68 stores a “normal time map” and a “lock time map” in advance. The “normal time map” includes a torque command value that is an acquired value of the measured temperature of the thermistor 26 and a torque of the second motor generator 24 in a unit time interval at a normal time when the second motor generator 24 is not locked, This represents the relationship with the set temperature sensor temperature correction value ΔTn (A, B, C...) (See FIG. 3). On the other hand, the “locking time map” indicates the amount of change in the measured temperature of the thermistor 26 at the unit time interval and the second motor generator 24 when the second motor generator 24 is locked, that is, when the rotation is stopped in the energized state. 7 shows the relationship between the torque command value and a preset temperature sensor temperature correction value ΔTnr (Ar, Br, Cr...) (FIG. 7). That is, since the relationship between the measured temperature and the actual temperature of the rotating electrical machine greatly deviates between the normal time and the locked time, two types of maps corresponding to each are prepared, so that the second motor generator 24 according to different situations. The accuracy of estimation of the actual temperature is improved.

  The normal time map is a map similar to that in the case of the configurations shown in FIGS. 1 to 4 and FIG. 5B in the normal time when the second motor generator 24 is not locked. The lock-time map is a map similar to that in the case of the configuration shown in FIGS. 1 to 4 and FIG. 5B when the second motor generator 24 is locked in an energized state, which is obtained in advance through experiments or the like. In FIG. 7, Ar, Br, Cr... Contain numerical values, and some numerical values of Ar, Br, Cr... May be the same or different. Also in the experiment for obtaining this map, the thermistor 26 is provided in a portion to which oil is applied when the stator coil 54 of the second motor generator 24 is used.

  The actual temperature estimation unit 40 acquires the amount of change in the measured temperature of the thermistor 26 and the torque of the second motor generator 24 according to whether it is normal or when the motor is locked while referring to the map stored in the storage unit 68. The temperature correction value ΔTn (or ΔTnr) of the second motor generator 24 is acquired from the torque command value that is a value, and the measured temperature is corrected by this temperature correction value ΔTn (or ΔTnr). Estimate temperature. In other words, the actual temperature estimation unit 40 is different between the normal time and the lock time by using different relationships between the amount of change in the measured temperature of the thermistor 26 and the temperature correction value corresponding to the torque command value of the second motor generator 24. The actual temperature of the second motor generator 24 is estimated according to the situation.

  Next, a method of estimating the actual temperature of the second motor generator 24 according to this embodiment will be described using the flowchart of FIG. In step S10 (hereinafter, step S is simply referred to as S), the rotational speed of the second motor generator 24 detected by a rotational speed sensor (not shown) or the like is determined. In step S12, the second motor generator 24 is energized, and the second motor generator 24 is energized. If it is determined that the rotation speed of the motor generator 24 is not substantially 0, that is, the normal time, the process proceeds to S14. On the other hand, when it is determined in S12 that the second motor generator 24 is energized and the rotation speed of the second motor generator 24 is substantially 0, that is, when it is locked, the process proceeds to S20. In S14, the normal time map stored in the storage unit 68 is read out, and the temperature correction value is calculated from the torque command value of the second motor generator 24 and the change amount of the measured temperature of the thermistor 26 while referring to the normal time map in S16. ΔTn is acquired. Next, in S18, the measured temperature of the thermistor 26 is corrected with the temperature correction value ΔTn, and the actual actual temperature of the second motor generator 24 is estimated.

  On the other hand, in S20, the lock time map stored in the storage unit 68 is read, and in S22, referring to the lock time map, the temperature is determined from the torque command value of the second motor generator 24 and the amount of change in the measured temperature of the thermistor 26. A correction value ΔTn is acquired. Next, in S24, the measured temperature of the thermistor 26 is corrected with the temperature correction value ΔTn, and the actual temperature when the second motor generator 24 is locked is estimated.

  According to such a configuration, since the map is properly used for the normal time and the lock time, the actual temperature of the second motor generator 24 can be estimated with higher accuracy. The case where the actual temperature of the second motor generator 24 is estimated has been described above. In this embodiment, the temperature of the first motor generator 22 is also used instead of the second motor generator 24 or together with the second motor generator 24. The actual temperature of the first motor generator 22 can also be estimated using the normal time map or the lock time map. Other configurations and operations are the same as those in FIGS. 1 to 4 and 5B.

  In each of the above embodiments, the case where the torque command value of the corresponding motor generator is used as the “acquired value of torque of the rotating electrical machine” has been described. However, in the present invention, a torque sensor that measures the torque of the corresponding motor generator can be provided, and the measured value of the corresponding torque sensor can be used as the “acquired value of torque of the rotating electrical machine”.

  DESCRIPTION OF SYMBOLS 10 Hybrid vehicle, 12 Temperature estimation system, 13 Engine, 14 Power split mechanism, 16 Drive shaft, 18 Wheel, 22 1st motor generator (MG1), 24 2nd motor generator (MG2), 26 Thermistor, 28 Control part (ECU) ), 29 cooling device, 30 output shaft, 32 speed reducer, 34 battery, 36 first inverter, 38 second inverter, 40 actual temperature estimation unit, 42 cooling system, 44 case, 46 stator, 48 rotor, 50 rotating shaft, 52 Stator core, 54 Stator coil, 56 Coil end, 58 Internal refrigerant flow path, 60 External refrigerant flow path, 62 Oil pump, 64 Motor torque acquisition part, 68 Storage part, 70 Motor control part.

Claims (6)

Rotating electrical machinery,
A temperature sensor for measuring the temperature of the rotating electrical machine;
A torque acquisition unit for acquiring the torque of the rotating electrical machine;
In order to correct the deviation between the actual temperature of the rotating electrical machine and the measured temperature of the temperature sensor, the temperature sensor temperature correction value is obtained from the amount of change in the measured temperature of the temperature sensor and the acquired value of the torque of the rotating electrical machine, and the temperature sensor temperature A rotating electrical machine temperature estimation system comprising: an actual temperature estimating unit that estimates the actual temperature of the rotating electrical machine by correcting the measured temperature using a correction value . The rotating electrical machine temperature estimation system according to claim 1,
A cooling unit for cooling the rotating electrical machine with a refrigerant;
The temperature sensor is provided in a portion where the refrigerant of the rotating electrical machine is applied. In the rotating electrical machine temperature estimation system according to claim 1 or 2,
A storage unit for storing map data representing the relationship between the amount of change in temperature measured by the temperature sensor and the acquired value of the torque of the rotating electrical machine and a preset temperature sensor temperature correction value;
The actual temperature estimating unit estimates the actual temperature of the rotating electric machine from the amount of change in the temperature measured by the temperature sensor and the acquired value of the torque of the rotating electric machine while referring to the map stored in the storage unit. Temperature estimation system. The rotating electrical machine temperature estimation system according to claim 1,
The actual temperature estimator calculates the temperature sensor temperature corresponding to the amount of change in the temperature measured by the temperature sensor and the acquired value of the torque of the rotating electrical machine during normal times and when the rotating electrical machine is locked when the rotating electrical machine is energized. A rotating electrical machine temperature estimation system for estimating an actual temperature of a rotating electrical machine according to different situations using different correction value relationships. The rotating electrical machine temperature estimation system according to claim 1,
The normal time map showing the relationship between the amount of change in the measured temperature of the temperature sensor and the acquired value of the torque of the rotating electrical machine and the preset temperature sensor temperature correction value in the normal state, and the temperature sensor A storage unit for storing data of a lock time map representing a relationship between a measured temperature change amount and an acquired value of torque of the rotating electrical machine and a preset temperature sensor temperature correction value;
The actual temperature estimation unit refers to the map stored in the storage unit, and determines whether the rotating electrical machine is based on the amount of change in temperature measured by the temperature sensor and the acquired value of the torque of the rotating electrical machine, depending on whether it is normal or when the motor is locked. A rotating electrical machine temperature estimation system characterized by estimating an actual temperature. The rotating electrical machine temperature estimation system according to claim 1,
The actual temperature estimation unit calculates the temperature sensor temperature correction value from the amount of change in the temperature measured by the temperature sensor and the acquired value of the torque of the rotating electrical machine, and the relational expression representing the relationship between the temperature sensor temperature correction value, the amount of change, and the torque. And the actual temperature of the rotating electrical machine is estimated using the temperature sensor temperature correction value.

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