Control device, drive device and control method

Abstract

One embodiment of a drive device according to the present invention is a control device for controlling a motor, comprising: a temperature sensor for measuring the temperature of the motor; and a torque limiter for limiting the torque of the motor based on the temperature measured by the temperature sensor. The torque limiter applies a first torque limit when the measured temperature is above a first threshold value, wherein the first torque limit limits the torque of the motor at a limit rate represented by a linear function with a slope of a first constant relative to the measured temperature. When the measured temperature is above a second threshold value higher than the first threshold value, the torque limiter applies a second torque limit when the measured temperature is above a second threshold value higher than the first threshold value, wherein the second torque limit limits the torque of the motor at a limit rate represented by a linear function with a slope of a second constant relative to the measured temperature. When the measured temperature is above a third threshold value higher than the second threshold value, the torque limiter applies a third torque limit, wherein the third torque limit stops power supply to the motor. The first constant is greater than the second constant.

Description

Technical Field

[0001] The present invention relates to a control device, a driving device and a control method. Background Art

[0002] In recent years, the development of drive motors for electric vehicles has been booming. In such motors, excessively high motor temperatures can damage the insulation coating of the motor's coil wires. Patent Document 1 discloses a drive device that limits the motor's driving torque when the motor's temperature rises.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2007-189764 Summary of the Invention

[0006] Technical problem to be solved by the invention

[0007] In existing drive devices, the motor's driving torque is linearly controlled based on the motor's temperature. However, the temperature measurement results from the temperature sensor are output with a delay relative to actual motor temperature changes. Therefore, if the motor temperature rises rapidly, the driving torque limit may be insufficient and may fail to suppress the motor temperature rise. On the other hand, simply increasing the driving torque limit relative to the motor temperature rise to account for the temperature sensor's delay may unnecessarily restrict the motor's performance.

[0008] In view of the above circumstances, one object of the present invention is to provide a control device, a drive device, and a control method that can fully exert the performance of a motor while suppressing a temperature increase of the motor.

[0009] Technical means for solving technical problems

[0010] One embodiment of a drive device according to the present invention is a control device for controlling a motor, comprising: a temperature sensor for measuring the temperature of the motor; and a torque limiter for limiting the torque of the motor based on the temperature measured by the temperature sensor. The torque limiter performs a first torque limit when the measured temperature is above a first threshold value, wherein the first torque limit limits the torque of the motor at a limit rate represented by a linear function with a slope of a first constant relative to the measured temperature. The torque limiter performs a second torque limit when the measured temperature is above a second threshold value higher than the first threshold value, wherein the second torque limit limits the torque of the motor at a limit rate represented by a linear function with a slope of a second constant relative to the measured temperature. The third torque limit is performed when the measured temperature is above a third threshold value higher than the second threshold value, wherein the third torque limit stops power to the motor. The first constant is greater than the second constant.

[0011] Effects of the Invention

[0012] According to one aspect of the present invention, it is possible to provide a control device, a drive device, and a control method that can fully demonstrate the performance of a motor while suppressing a temperature increase of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Schematic diagram of a driving device 1 according to one embodiment.

[0014] Figure 2 This is a diagram for explaining torque limitation of a motor performed by a torque limiter according to one embodiment.

[0015] Figure 3 This is a flowchart showing the procedure of torque control in the temperature increase mode performed by the torque limiter according to one embodiment.

[0016] Figure 4 This is a flowchart showing the procedure of torque control in the high temperature mode performed by the torque limiter according to one embodiment. DETAILED DESCRIPTION

[0017] Hereinafter, embodiments to which the present invention is applied will be described in detail with reference to the accompanying drawings.

[0018] In addition, the drawings used in the following description are sometimes enlarged to show the characteristic parts for the purpose of emphasizing the characteristic parts for convenience, and the dimensional ratios of the various structural elements are not necessarily the same as the actual ones. In addition, for the same purpose, the illustration of non-characteristic parts may sometimes be omitted.

[0019] Figure 1 It is a schematic diagram of the driving device 1 of this embodiment.

[0020] The drive device 1 is mounted on a vehicle and drives the vehicle. The vehicle on which the drive device 1 is mounted is a vehicle using a motor as a power source, such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an electric vehicle (EV).

[0021] The drive device 1 of this embodiment includes a motor 2 , a control device 10 that controls the motor 2 , a battery 7 that supplies power to the motor 2 via the control device 10 , and a first cooling device (cooling device) 80 and a second cooling device (cooling device) 90 that cool the motor 2 .

[0022] The motor 2 of this embodiment is a three-phase AC motor. Furthermore, the motor 2 is an outer rotor type motor. The motor 2 has both the function of an electric motor and the function of a generator.

[0023] Motor 2 is housed in housing 1a. Motor 2 is connected to the vehicle's wheels via a transmission mechanism (not shown). Motor 2 includes a stator and a rotor that rotates relative to the stator. The stator includes coil conductors. The coil conductors are connected to inverter 3 of control device 10 and receive an AC voltage.

[0024] Motor 2 is driven by AC current supplied from inverter 3, rotating the wheels. This drives the vehicle. Motor 2 also regenerates the rotation of the wheels to generate AC current. The generated power is stored in battery 7 via inverter 3.

[0025] A temperature sensor 20 is attached to the motor 2. The temperature sensor 20 measures the temperature of the coil conductors of the motor 2. Specifically, the temperature sensor 20 measures the temperature of the motor 2. Oil O is stored within the housing 1a that houses the motor 2. Specifically, the oil O is housed within the housing 1a along with the motor 2.

[0026] The first cooling device 80 includes a water jacket 82, a cooling water path 81, and a water pump (pump) 88. The first cooling device 80 may also include a radiator (not shown) disposed in the cooling water path 81 to cool the cooling water.

[0027] The water jacket 82 surrounds the outer circumference of the housing 1a. The cooling water path 81 is a circulation path through which cooling water circulates. The cooling water path 81 is connected to the water jacket 82 and passes through the interior of the water jacket. The water pump 88 pumps the cooling water in the cooling water path 81. In other words, the water pump 88 circulates the cooling water for cooling the motor 2 through the cooling water path 81.

[0028] The first cooling device 80 cools the motor 2 in the housing 1a via the housing 1a. The first cooling device 80 of this embodiment cools the oil O in the housing 1a. Thus, the first cooling device 80 indirectly cools the motor 2 immersed in the oil O.

[0029] The second cooling device 90 includes an oil passage 91, an oil pump 98, and an oil cooler 99. Oil O circulates in the oil passage 91, which passes through the interior of the housing 1a. The oil pump 98 pumps the oil O through the oil passage 91. The oil cooler 99 cools the oil O in the oil passage 91. The second cooling device 90 cools the motor 2 by passing the oil O cooled by the oil cooler 99 through the interior of the housing 1a.

[0030] The control device 10 includes an inverter 3 , an ECU (Electronic Control Unit) 10 a , and a temperature sensor 20 .

[0031] The inverter 3 is connected to the battery 7 and the motor 2. Based on a signal from the ECU 10a, the inverter 3 converts the DC voltage supplied from the battery 7 into a three-phase AC voltage and outputs this converted three-phase AC voltage to the motor 2. This drives the motor 2 to generate the target torque TT specified by the ECU 10a. Furthermore, during regenerative braking of the vehicle, the inverter 3 converts the three-phase AC voltage generated by the motor 2 into a DC voltage and outputs it to the inverter 3.

[0032] The battery 7 is a rechargeable DC power source. The battery 7 supplies DC power to the inverter 3. The battery 7 is charged by receiving DC power output from the inverter 3 during regenerative braking of the vehicle.

[0033] The ECU 10a includes a torque limiter 11, a voltage calculator 12, and a signal converter 13. That is, the control device 10 includes the torque limiter 11, the voltage calculator 12, and the signal converter 13.

[0034] The ECU 10a is connected to the VCU (Vehicle Control Unit) 9. The VCU 9 is an external device for the drive system 1 and is mounted on the vehicle. The VCU 9 performs centralized control over all vehicle components. Based on the accelerator and brake pedal depression amounts and the vehicle's driving state, the VCU 9 calculates the target torque TT, which should be output by the motor 2.

[0035] The ECU 10 a calculates a target torque TT of the motor 2 based on information received from the VCU 9 and the temperature sensor 20 , generates a signal for obtaining the target torque TT, and outputs the signal to the inverter 3 .

[0036] The torque limiter 11 receives the measured temperature T of the motor 2 from the temperature sensor 20. The torque limiter 11 calculates the torque limit rate LR based on the measured temperature T. Furthermore, the torque limiter 11 receives the command torque RT from the VCU 9. The torque limiter 11 calculates the target torque TT of the motor 2 based on the calculated limit rate LR and the received command torque RT. The target torque TT is the torque to be output by the motor 2, taking the torque limit into account. The target torque TT is calculated by multiplying the command torque RT by the value (100% - LR) obtained by subtracting the limit rate LR from 100%.

[0037] The voltage calculation unit 12 calculates voltages to be applied to the coils of each of the U, V, and W phases of the motor 2 based on the target torque TT from the torque limiter 11 , and outputs the calculated coil voltages of each phase to the signal converter 13 .

[0038] The signal conversion unit 13 generates a signal for actually turning on / off each transistor of the inverter 3 based on the coil voltage of each phase received from the voltage calculation unit 12 , and outputs the generated signal to each transistor of the inverter 3 .

[0039] <Control method>

[0040] Next, a method for controlling torque in the torque limiter 11 of the ECU 10a will be described. To protect the motor 2, the ECU 10a reduces the target torque TT of the motor 2 via the torque limiter 11 when the temperature of the motor increases.

[0041] Figure 2 1 is a diagram for explaining the torque limitation of the motor 2 by the torque limiting unit 11. Figure 2 In FIG. 1 , the horizontal axis represents the temperature T of the motor 2 measured by the temperature sensor 20 , and the vertical axis represents the limit rate LR of the torque of the motor 2 by the torque limiter 11 .

[0042] The torque limiter 11 has a temperature increase mode, which is executed when the measured temperature T increases, and a temperature decrease mode, which is executed when the measured temperature decreases. The temperature increase mode and the temperature decrease mode transition to each other when certain conditions are met. The torque limiter 11 selects the temperature increase mode as the initial mode.

[0043] (Warming mode)

[0044] Figure 3 1 is a flowchart showing the procedure of torque control in the temperature increase mode.

[0045] In the temperature increase mode, the torque limiter 11 performs control according to, for example, steps S101 to S111 described below.

[0046] The torque limiter 11 in the temperature increase mode first acquires the measured temperature T of the motor 2 measured by the temperature sensor 20 (step S101 ).

[0047] Next, the torque limiter 11 in the temperature increase mode checks whether the temperature increase mode should be maintained (steps S102 and S103 ), and shifts to the temperature decrease mode if the temperature increase mode should not be maintained.

[0048] More specifically, first, in step S102, the torque limiter 11 determines whether the measured temperature T has decreased. Specifically, the torque limiter 11 determines whether the time-dependent change (ΔT) in the measured temperature T is negative (ΔT < 0). If the measured temperature T has decreased (step S102: Yes), the torque limiter 11 further determines in step S103 whether the temperature change (|ΔT|) is greater than or equal to the temperature constant Tb. If the temperature change is greater than or equal to the temperature constant Tb (step S103: Yes), the torque limiter 11 shifts to the temperature reduction mode (step S104). On the other hand, if the temperature change is less than the temperature constant Tb (step S103: No), the torque limiter 11 maintains the temperature increase mode even if the measured temperature T has decreased.

[0049] The torque limiter 11 in the temperature rise mode performs any one of the following controls: no torque limit (step S106), first torque limit (step S108), second torque limit (step S110), and third torque limit (step S111) according to the measured temperature T. Each control will be described in detail later.

[0050] If the measured temperature T is not decreasing (step S102: No), that is, if the measured temperature T is constant or increasing, the torque limiter 11 further determines whether the measured temperature T is less than the first threshold value T1 (step S105). If the measured temperature T is less than the first threshold value T1 (step S105: Yes), the torque limiter 11 does not perform torque limitation (step S106). Therefore, the control device 10 drives the motor 2 at the command torque RT received from the VCU 9.

[0051] If the measured temperature T is not less than the first threshold value T1 (step S105: No), that is, if the measured temperature T is greater than the first threshold value T1, the torque limiter 11 further determines whether the measured temperature T is less than the second threshold value T2 (step S107). If the measured temperature T is less than the second threshold value T2 (step S107: Yes), the torque limiter 11 performs the first torque limit (step S108).

[0052] If the measured temperature T is not less than the second threshold value T2 (step S107: No), that is, if the measured temperature T is greater than the second threshold value T2, the torque limiter 11 further determines whether the measured temperature T is less than the third threshold value T3 (step S109). If the measured temperature T is less than the third threshold value T3 (step S109: Yes), the torque limiter 11 performs the second torque limit (step S110). If the measured temperature T is not less than the third threshold value T3 (step S109: No), that is, if the measured temperature T is greater than the third threshold value T3, the torque limiter 11 performs the third torque limit (step S111).

[0053] Then, based on Figure 2 The torque limitation in the temperature rise mode will be described in detail.

[0054] The torque limiter 11 in temperature rise mode begins substantial torque limiting when the temperature reaches or exceeds a first threshold value T1. The torque limiter 11 in temperature rise mode applies the first torque limit when the measured temperature T reaches or exceeds the first threshold value T1, applies the second torque limit when the measured temperature T reaches or exceeds the second threshold value T2, and applies the third torque limit when the measured temperature T reaches or exceeds the third threshold value T3. The second threshold value T2 is a temperature higher than the first threshold value T1. The third threshold value T3 is a temperature higher than the second threshold value T2.

[0055] The first torque limit is implemented when the measured temperature T is between a first threshold value T1 and a second threshold value T2. The first torque limit is a control method that limits the torque of the motor 2 using a limit rate LR represented by a linear function with a first constant a1 as its slope relative to the measured temperature T. Here, the first constant a1 is represented by ΔLR / ΔT. When the measured temperature T increases by ΔT, the torque limiter 11 in the first torque limit increases the limit rate LR by a1 × ΔT (= ΔLR).

[0056] The second torque limitation is implemented when the measured temperature T is between the second threshold value T2 and the third threshold value T3. The second torque limitation is a control method that limits the torque of the motor 2 using a limit rate LR represented by a linear function with a second constant a2 as a slope relative to the measured temperature T. When the measured temperature T increases by ΔT, the torque limiter 11 in the second torque limitation increases the limit rate LR by a2×ΔT (=ΔLR).

[0057] Typically, when the motor 2 generates heat, the measured temperature T of the motor 2 output by the temperature sensor 20 lags behind the actual temperature of the motor 2. Therefore, if the torque of the motor 2 is limited at a limit rate LR corresponding to the measurement result, the limit rate LR becomes insufficient, and there is a possibility that the temperature rise cannot be appropriately suppressed.

[0058] In this embodiment, the first constant a1 is greater than the second constant a2. Therefore, the torque limiter 11 can rapidly increase the limit rate LR for temperature increases within the range where the measured temperature T is greater than or equal to the first threshold value T1 and less than the second threshold value T2. Consequently, even if there is a delay in the temperature T measured by the temperature sensor 20, the torque limiter 11 can easily suppress the temperature increase of the motor 2 within the range below the second threshold value T2.

[0059] Furthermore, when the measured temperature T is above the second threshold value T2, torque limitation is already applied to the drive of the motor 2, resulting in a relatively slow rate of temperature increase. Therefore, even when the limit rate LR for temperature increase is gradually increased by the second constant a2 within the range where the measured temperature T is above the second threshold value T2, the influence of the delay of the temperature sensor 20 is minimal. Furthermore, by gradually increasing the limit rate LR within the temperature range above the second threshold value T2 by the torque limiter 11, the range of measured temperature T within which the limit rate reaches 100% can be expanded to the upper side, enabling control without compromising the maximum speed characteristics even during high-speed operation of the motor 2.

[0060] The third torque limit is a control method that stops power to motor 2 and sets the drive torque of motor 2 to zero. Therefore, the torque limiter 11, which performs the third torque limit, sets the target torque TT to zero, regardless of the command torque RT received from the VCU 9, and transmits it to the voltage calculation unit 12. Furthermore, the third torque limit can be said to be a method of limiting the drive torque of motor 2 to 100%.

[0061] According to this embodiment, the torque limiter 11 stops supplying power to the motor 2 when the measured temperature T rises within a temperature range equal to or greater than the third threshold value T3, thereby eliminating the cause of heat generation in the motor 2. Therefore, the torque limiter 11 can rapidly reduce the temperature of the motor 2 within a temperature range equal to or greater than the third threshold value T3, thereby improving the reliability of the motor 2.

[0062] (Cooling mode)

[0063] Figure 4 This is a flowchart showing the procedure of torque control in the temperature drop mode.

[0064] In the temperature drop mode, the torque limiter 11 performs control according to, for example, steps S201 to S211 described below.

[0065] The torque limiter 11 in the temperature drop mode first acquires the measured temperature T of the motor 2 measured by the temperature sensor 20 (step S201 ).

[0066] Next, the torque limiter 11 in the temperature drop mode checks whether the temperature drop mode should be maintained (steps S202 and S203 ), and shifts to the temperature rise mode if the temperature drop mode should not be maintained.

[0067] More specifically, in step S202, the torque limiter 11 determines whether the measured temperature T has increased. Specifically, in step S202, the torque limiter 11 determines whether the time-dependent change (ΔT) in the measured temperature T is positive (ΔT > 0). If the measured temperature has decreased (step S202: Yes), the torque limiter 11 further determines in step S203 whether the temperature change (|ΔT|) is greater than or equal to the temperature constant Tb. If the temperature change is greater than or equal to the temperature constant Tb (step S203: Yes), the torque limiter 11 shifts to the temperature increase mode (step S204). On the other hand, if the temperature change is less than the temperature constant Tb (step S203: No), the torque limiter 11 maintains the temperature decrease mode even if the measured temperature T has increased.

[0068] The torque limiter 11 in the temperature drop mode performs one of the following controls: no torque limit (step S206), fourth torque limit (step S208), fifth torque limit (step S210), and sixth torque limit (step S211), depending on the measured temperature T. Each control will be described in detail later.

[0069] If the measured temperature T is not rising (step S202: No), that is, if the measured temperature T is constant or rising, the torque limiter 11 further determines whether the measured temperature T is less than a fourth threshold value T4 (step S205). If the measured temperature T is less than the fourth threshold value T4 (step S205: Yes), the torque limiter 11 does not perform torque limitation (step S206). Therefore, the control device 10 drives the motor 2 at the command torque RT received from the VCU 9.

[0070] If the measured temperature T is not less than the fourth threshold value T4 (step S205: No), that is, if the measured temperature T is greater than the fourth threshold value T4, the torque limiter 11 further determines whether the measured temperature T is less than the fifth threshold value T5 (step S207). If the measured temperature T is less than the fifth threshold value T5 (step S207: Yes), the torque limiter 11 performs the fourth torque limit (step S208).

[0071] If the measured temperature T is not less than the fifth threshold value T5 (step S207: No), that is, if the measured temperature T is greater than the fifth threshold value T5, the torque limiter 11 further determines whether the measured temperature T is less than the sixth threshold value T6 (step S209). If the measured temperature T is less than the sixth threshold value T6 (step S209: Yes), the torque limiter 11 applies the fifth torque limit (step S210). If the measured temperature T is not less than the sixth threshold value T6 (step S209: No), that is, if the measured temperature T is greater than the sixth threshold value T6, the torque limiter 11 applies the sixth torque limit (step S211).

[0072] Then, based on Figure 2 The torque limitation in the temperature drop mode is described in detail.

[0073] The torque limiter 11 in the temperature drop mode performs torque limitation within a range above a fourth threshold value T4. The torque limiter 11 in the temperature drop mode performs a fourth torque limitation when the measured temperature T is above the fourth threshold value T4, performs a fifth torque limitation when the measured temperature T is above the fifth threshold value T5, and performs a sixth torque limitation when the measured temperature T is above the sixth threshold value T6.

[0074] The fourth threshold value T4 is a temperature lower than the first threshold value T1. The fifth threshold value T5 is a temperature higher than the first threshold value T1 and the fourth threshold value T4, and lower than the second threshold value T2. The sixth threshold value T6 is a temperature higher than the second threshold value T2 and the fifth threshold value T5, and lower than the third threshold value T3.

[0075] The fourth torque limit is implemented when the measured temperature T is between a fourth threshold value T4 and a fifth threshold value T5. The fourth torque limit is a control method that limits the torque of the motor 2 using a limit rate LR represented by a linear function with a slope of a first constant a1 relative to the measured temperature T. The slope (ΔLR / ΔT), representing the change ΔLR in the limit rate relative to a temperature change ΔT, matches the slope of the first torque limit under the fourth torque limit.

[0076] The fifth torque limit is implemented when the measured temperature T is between a fifth threshold value T5 and a sixth threshold value T6. The fifth torque limit is a control method that limits the torque of the motor 2 using a limit rate LR represented by a linear function with a slope of a second constant a2 relative to the measured temperature T. The slope (ΔLR / ΔT), representing the change ΔLR in the limit rate relative to the temperature change ΔT, matches the slope of the fifth torque limit and the second torque limit.

[0077] The sixth torque limit, like the third torque limit, is a control method that stops power to motor 2 and sets the drive torque of motor 2 to zero. Therefore, the torque limiter 11, which performs the sixth torque limit, sets the target torque TT to zero, regardless of the command torque RT received from the VCU 9, and transmits it to the voltage calculation unit 12. Furthermore, the sixth torque limit can be said to set the limit rate of the drive torque of motor 2 to 100%.

[0078] According to this embodiment, the torque limiter 11 stops energizing the motor 2 when the measured temperature T falls within a temperature range equal to or greater than the sixth threshold value T6, thereby eliminating the cause of heat generation in the motor 2. Consequently, the temperature of the motor 2 can be rapidly reduced, thereby improving the reliability of the motor 2.

[0079] In this embodiment, the fourth threshold value T4 is a temperature lower than the first threshold value T1 by the temperature constant Tb. The fifth threshold value T5 is a temperature lower than the second threshold value T2 by the temperature constant Tb. The sixth threshold value T6 is a temperature lower than the third threshold value T3 by the temperature constant Tb. Furthermore, as described above, the slope (ΔLR / ΔT) representing the change ΔLR in the limit rate relative to the temperature change ΔT is consistent with each other under the first and fourth torque limits, and is consistent with each other under the second and fifth torque limits.

[0080] According to this embodiment, Figure 2 As shown, the torque limiter 11 in the temperature drop mode varies the limit rate LR using a function that has a temperature constant Tb offset in the negative direction relative to the temperature rise mode. In this embodiment, the torque limiter 11 in the temperature drop mode controls the hysteresis characteristic, which results in torque limiting at the same limit rate at lower temperatures than in the temperature rise mode. This allows the torque limiter 11 to apply sufficient torque limiting when the temperature drops, thereby improving the reliability of the motor 2.

[0081] Furthermore, according to this embodiment, when the temperature change is less than the temperature constant Tb, the mode is not switched from the temperature increase mode to the temperature decrease mode or vice versa. Therefore, it is possible to stably limit the torque even if the measured value changes due to temperature change errors.

[0082] In the present embodiment, the torque limiter 11 is connected to the water pump 88 of the first cooling device 80 , the oil pump 98 of the second cooling device 90 , and the oil cooler 99 .

[0083] When performing any of the first to sixth torque limits, the torque limiter 11 outputs a drive command to drive the first cooling device 80 and the second cooling device 90 for cooling the motor 2. Thus, the torque limiter 11 cools the motor 2 via the first cooling device 80, thereby promoting a temperature reduction of the motor 2.

[0084] More specifically, the torque limiter 11 uses a drive command to drive a water pump that circulates cooling water through the cooling water path 81 of the first cooling device 80. Specifically, the first cooling device 80 includes a water pump 88 that circulates cooling water for cooling the motor 2, and the cooling water circulates in response to the drive command from the torque limiter 11. Thus, the torque limiter 11 cools the motor 2 via the first cooling device 80.

[0085] Furthermore, the torque limiter 11 drives the oil cooler 99 of the second cooling device 90 in response to a drive command to cool the oil therethrough, and drives the oil pump 98 to pump the oil. Specifically, the second cooling device 90 includes the oil cooler 99 and the oil pump 98, which cool the oil O housed within the housing 1a along with the motor 2. The drive command from the torque limiter 11 cools and circulates the oil O. Thus, the torque limiter 11 cools the motor 2 via the second cooling device 90.

[0086] (Map-based control)

[0087] The torque limiter 11 can limit the torque of the motor 2 based on a map indicating the relationship between the measured temperature T of the motor 2 and the limit rate of the torque of the motor 2 .

[0088] As the map, the torque limiter 11 uses the first map shown in Table 1 when the measured temperature T rises (temperature increase mode), and uses the second map shown in Table 2 when the measured temperature T falls (temperature drop mode).

[0089] In Tables 1 and 2, each temperature is represented by the reference temperature Ts, which is the temperature measured when the limit rate is 100% in the temperature rise mode. The reference temperature Ts corresponds to the third threshold value T3 described above. The reference temperature Ts is, for example, 200°C to 250°C, which is below the heat-resistant temperature of the coil conductor of the motor 2.

[0090] [Table 1]

[0091] Heating mode

[0092] Measurement temperature T[℃] Ts-25 Ts-20 Ts-15 Ts-10 Ts-5 Ts Limit rate LR[%] 0 0 37.5 75 87.5 100

[0093] [Table 2]

[0094] Cooling mode

[0095] Measurement temperature T[℃] Ts-25 Ts-20 Ts-15 Ts-10 Ts-5 Ts Limit rate LR[%] 0 37.5 75 87.5 100 100

[0096] In both the temperature increase and temperature decrease modes, the limit rate LR is linearly controlled in the range between the measured temperatures shown in the table. Furthermore, in both the temperature increase and temperature decrease modes, the limit rate LR is set to 0% in the range below Ts-25 and to 100% in the range above Ts.

[0097] In the temperature increase mode, the first threshold value T1 corresponds to "Ts-20", the second threshold value T2 corresponds to "Ts-10", and the third threshold value T3 corresponds approximately to "Ts". In the temperature decrease mode, the fourth threshold value T4 corresponds to "Ts-25", the fifth threshold value T5 corresponds to "Ts-20", and the sixth threshold value T6 corresponds approximately to "Ts-5".

[0098] When the measured temperature T is less than "Ts-20" in the temperature rise mode, the limit rate LR is set to 0. When the measured temperature T is greater than "Ts-20" and less than "Ts-10" in the temperature rise mode, the first constant a1 is set to 7.5 (% / °C), and the limit rate LR is varied relative to the measured temperature T. Furthermore, when the measured temperature T is greater than "Ts-10" and less than "Ts" in the temperature rise mode, the second constant a2 is set to 2.5 (% / °C), and the limit rate LR is varied relative to the measured temperature T.

[0099] When the measured temperature T is less than "Ts-25" in the cooling mode, the limit rate LR is set to 0. When the measured temperature T is greater than "Ts-25" and less than "Ts-15" in the cooling mode, the first constant a1 is set to 7.5 (% / °C), and the limit rate LR is varied relative to the measured temperature T. Furthermore, when the measured temperature T is greater than "Ts-15" and less than "Ts-5" in the cooling mode, the second constant a2 is set to 2.5 (% / °C), and the limit rate LR is varied relative to the measured temperature T.

[0100] The torque limiter 11 switches between the maps used in the temperature increase mode and the temperature decrease mode. The torque limiter 11 calculates the torque limit rate based on the first map and the second map, thereby simplifying the control performed by the torque limiter 11.

[0101] (Mathematical control based on the formula)

[0102] The torque limiter 11 may also limit the torque of the motor 2 based on a mathematical formula representing the relationship between the measured temperature T of the motor 2 and the limit rate of the torque of the motor 2. In this case, the torque limiter 11 may use the following mathematical formulas for the first torque limit, the second torque limit, the third torque limit, the fourth torque limit, the fifth torque limit, and the sixth torque limit, for example.

[0103] First torque limit: limit rate LR = (first threshold value T1 - measured temperature T) × first constant a1

[0104] Second torque limit: limit rate LR = (second threshold value T2 - measured temperature T) × second constant a2 + constant b

[0105] Third torque limit: limit rate LR = 100

[0106] Fourth torque limit: Limit rate LR = (fourth threshold value T4 - measured temperature T) × first constant a1

[0107] Fifth torque limit: Limit rate LR = (fifth threshold T5 - measured temperature T) × second constant a2 + constant b

[0108] Sixth torque limit: limit rate LR = 100

[0109] In the above mathematical formula, the constant b is shown in the figure. Figure 2 The constant b represents the torque limit rate LR at the boundary temperature between the first and second torque limits (ie, the second threshold value T2), and the boundary temperature between the fourth and fifth torque limits (ie, the fifth threshold value T5).

[0110] The torque limiter 11 switches the mathematical formula to any of the above-mentioned formulas each time the first to sixth torque limits are switched according to changes in the measured temperature T. By calculating the torque limit rate based on the above-mentioned mathematical formula, the control performed by the torque limiter 11 can be simplified.

[0111] The various embodiments of the present invention have been described above, but the various structures and combinations thereof in the various embodiments are merely examples, and additions, omissions, substitutions, and other modifications to the structures may be made without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments.

[0112] Label Description

[0113] 1…Drive device, 1a…Casing, 2…Motor, 10…Control device, 11…Torque limiter, 20…Temperature sensor, 80…First cooling device (cooling device), 88…Water pump (Pump), 90…Second cooling device (cooling device), 99…Oil cooler, a1…First constant, a2…Second constant, b…Constant, LR…Limiting rate, O…Oil, T…Measured temperature, T1…First threshold value, T2…Second threshold value, T3…Third threshold value, T4…Fourth threshold value, T5…Fifth threshold value, T6…Sixth threshold value, Tb…Temperature constant.

Claims

1. A control device, A control device for controlling a motor, characterized in that: have: a temperature sensor that measures the temperature of the motor; and a torque limiting unit that limits the torque of the motor based on the temperature measured by the temperature sensor, The torque limiting portion When the measured temperature is equal to or greater than a first threshold, a first torque limit is performed, wherein the first torque limit limits the torque of the motor at a limit rate represented by a linear function having a first constant as a slope with respect to the measured temperature; performing a second torque limit when the measured temperature is equal to or higher than a second threshold value higher than the first threshold value, the second torque limit limiting the torque of the motor at a limit rate represented by a linear function with a second constant as a slope relative to the measured temperature; When the measured temperature is equal to or higher than a third threshold value that is higher than the second threshold value, a third torque limitation is performed, wherein the third torque limitation stops the energization of the motor. The first constant is greater than the second constant, The torque limiter has a temperature increase mode that is performed when the measured temperature increases, and a temperature decrease mode that is performed when the measured temperature decreases. The torque limiter in the temperature rise mode performs the first torque limit, the second torque limit, and the third torque limit. The torque limiter in the temperature drop mode When the measured temperature is equal to or greater than a fourth threshold value, a fourth torque limit is performed, wherein the fourth torque limit limits the torque of the motor at a limit rate represented by a linear function with a slope of the first constant relative to the measured temperature. performing a fifth torque limit when the measured temperature is equal to or higher than a fifth threshold value that is higher than the fourth threshold value, wherein the fifth torque limit limits the torque of the motor at a limit rate represented by a linear function having a second constant as a slope with respect to the measured temperature; When the measured temperature is equal to or higher than a sixth threshold value that is higher than the fifth threshold value, a sixth torque limitation is performed, wherein the sixth torque limitation stops energizing the motor. The fourth threshold is a temperature that is lower than the first threshold by a temperature constant. The fifth threshold is a temperature lower than the second threshold by the temperature constant, The sixth threshold value is a temperature lower than the third threshold value by the temperature constant.

2. The control device according to claim 1, wherein The torque limiter limits the torque of the motor based on a map indicating a relationship between the measured temperature and a limit rate of the torque of the motor.

3. The control device according to claim 2, wherein: The torque limiter uses a first map as the map when the measured temperature increases, and uses a second map when the measured temperature decreases.

4. The control device according to claim 1, wherein: The torque limiter limits the torque of the motor based on a mathematical expression representing a relationship between the measured temperature and a limit rate of the torque of the motor.

5. The control device according to any one of claims 1 to 4, characterized in that When the torque is limited, a drive command is outputted to drive a cooling device for cooling the motor.

6. The control device according to claim 5, wherein: The cooling device includes a water pump that circulates cooling water for cooling the motor, and the cooling water is circulated by the drive command.

7. The control device according to claim 5, wherein: The cooling device includes an oil cooler for cooling oil housed in a housing together with the motor, and the oil is cooled by the drive command.

8. A driving device, characterized in that: include: The control device according to any one of claims 1 to 7; as well as The motor.

9. A control method, A motor control method, characterized in that a first torque limit performed when a temperature of the motor measured by a temperature sensor is equal to or higher than a first threshold value, wherein the first torque limit limits the torque of the motor at a limit rate represented by a linear function having a first constant as a slope with respect to the measured temperature; performing a second torque limit when the measured temperature is equal to or higher than a second threshold value higher than the first threshold value, the second torque limit limiting the torque of the motor at a limit rate represented by a linear function having a second constant as a slope with respect to the measured temperature; When the measured temperature is equal to or higher than a third threshold value that is higher than the second threshold value, a third torque limitation is performed, wherein the third torque limitation stops the energization of the motor. The first constant is greater than the second constant, There is a temperature increase mode performed when the measured temperature increases, and a temperature decrease mode performed when the measured temperature decreases, In the temperature rising mode, the first torque limit, the second torque limit, and the third torque limit are performed. In the cooling mode, When the measured temperature is equal to or greater than a fourth threshold value, a fourth torque limit is performed, wherein the fourth torque limit limits the torque of the motor at a limit rate represented by a linear function with a slope of the first constant relative to the measured temperature. performing a fifth torque limit when the measured temperature is equal to or higher than a fifth threshold value that is higher than the fourth threshold value, the fifth torque limit limiting the torque of the motor at a limit rate represented by a linear function with a slope of the second constant relative to the measured temperature; When the measured temperature is equal to or higher than a sixth threshold value that is higher than the fifth threshold value, a sixth torque limitation is performed, wherein the sixth torque limitation stops energizing the motor. The fourth threshold is a temperature that is lower than the first threshold by a temperature constant. The fifth threshold is a temperature lower than the second threshold by the temperature constant, The sixth threshold value is a temperature lower than the third threshold value by the temperature constant.

10. The control method according to claim 9, wherein: The torque of the motor is limited based on a map indicating a relationship between the measured temperature and a limiting rate of the torque of the motor.

11. The control method according to claim 10, wherein: As the map, a first map is used when the measured temperature rises, and a second map is used when the measured temperature falls.

12. The control method according to claim 9, wherein: The torque of the motor is limited based on a mathematical expression representing a relationship between the measured temperature and a limiting rate of the torque of the motor.

13. The control method according to any one of claims 9 to 12, characterized in that: When the torque is limited, a drive command is outputted to drive a cooling device for cooling the motor.

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