Device for controlling rotary electric machine, and method for controlling rotary electric machine

Abstract

This device for controlling a rotary electric machine comprises a flag setting unit that controls the output torque of a rotary electric machine and sets the necessity of restriction of the output torque as a restriction flag, and a main control unit that controls the output torque on the basis of the restriction flag, wherein: the flag setting unit turns the restriction flag on when the temperature of the rotary electric machine exceeds a limit temperature, which is a temperature upper-limit value that is set on the basis of the rotation speed of the rotary electric machine; the flag setting unit turns the restriction flag off when the temperature of the rotary electric machine falls below a predetermined return temperature; and the main control unit controls the output to be lower when the restriction flag is on than when the restriction flag is off.

Description

Rotating electric machine control device and rotating electric machine control method

[0001] The present invention relates to a control device for a rotating electric machine and a control method for a rotating electric machine.

[0002] A rotating electric machine can convert electrical energy into rotational energy. This conversion inevitably generates losses, and large energy conversions result in large heat generation. The temperature range within which a rotating electric machine operates normally is designed in advance, and it is necessary to control the rotating electric machine so that this temperature is not exceeded. Patent Document 1 discloses a control system including a rotation speed detection means for detecting the rotation speed of a motor to be controlled, an output torque detection means for detecting the output torque of the motor, a control map that defines torque limit temperature thresholds that correspond to a combination of the rotation speed of the motor and the output torque of the motor, the torque limit temperature thresholds corresponding to the temperature of the stator or the temperature of the rotor, a threshold setting means that sets the torque limit temperature threshold in accordance with the control map based on the rotation speed detected by the rotation speed detection means and the output torque detected by the output torque detection means, a stator temperature detection means that detects the temperature of the stator, a rotor temperature detection means that detects the temperature of the rotor, and a torque limit temperature threshold set by the threshold setting means. a determining means for determining whether the temperature of the stator detected by the stator temperature detecting means is equal to or greater than the torque limit temperature threshold if the threshold value set by the threshold setting means corresponds to the temperature of the stator, and for determining whether the temperature of the rotor detected by the rotor temperature detecting means is equal to or greater than the torque limit temperature threshold if the torque limit temperature threshold value set by the threshold setting means is for the temperature of the rotor; and a motor output limiting means for limiting the output of the motor if the determining means determines that the temperature of the stator is equal to or greater than the torque limit temperature threshold or if the temperature of the rotor is equal to or greater than the torque limit temperature threshold.

[0003] Japanese Patent Application Publication No. 2008-187862

[0004] The invention described in Patent Document 1 leaves room for improvement in behavior when the operating point is changed.

[0005] A control device for a rotating electric machine according to a first aspect of the present invention is a control device for a rotating electric machine that controls the output torque of a rotating electric machine, and includes a flag setting unit that sets a restriction flag to indicate whether or not the output torque needs to be restricted, and a main control unit that controls the output torque based on the restriction flag, wherein the flag setting unit changes the restriction flag to on when the temperature of the rotating electric machine exceeds a restriction temperature, which is an upper temperature limit value set based on the rotation speed of the rotating electric machine, and the flag setting unit changes the restriction flag to off when the temperature of the rotating electric machine falls below a predetermined return temperature, and the main control unit controls the output to be smaller when the restriction flag is on than when the restriction flag is off. A control method for a rotating electric machine according to a second aspect of the present invention is a control method for a rotating electric machine in which a computer controls the output torque of the rotating electric machine, and when the temperature of the rotating electric machine exceeds a limit temperature, which is an upper temperature limit value set based on the rotation speed of the rotating electric machine, a limit flag indicating whether or not the output torque needs to be limited is changed to on, and when the temperature of the rotating electric machine falls below a predetermined recovery temperature, the limit flag is changed to off, and when the limit flag is on, the output torque is controlled to be smaller than when the limit flag is off.

[0006] According to the present invention, it is possible to suppress unintended vehicle behavior when the operating point is changed.

[0007] Configuration diagram of a vehicle equipped with the control device Configuration diagram of a rotating electric machine Hardware configuration diagram of the control device Functional configuration diagram of the control device in the first embodiment Diagram showing the relationship between the limit temperature and the return temperature Flowchart showing the processing of the flag setting unit Diagram showing an operation example of the control device Diagram showing the relationship between the limit temperature in a comparative example and the return temperature in a comparative example Diagram showing an operation example in a comparative example Functional configuration diagram of the control device in the second embodiment Diagram showing a setting screen for the return temperature

[0008] First Embodiment A first embodiment of a control device and control method for a rotating electrical machine will be described below with reference to FIGS.

[0009] FIG. 1 is a configuration diagram of a vehicle 1 equipped with a control device 100. Note that, hereinafter, a person riding in the vehicle 1 is referred to as a "user." The vehicle 1 includes an engine 2, a rotating electric machine 3, a transmission 4, a differential gear 5, wheels 6, a power conversion device 7, a battery 8, and a control device 100. The engine 2 charges the battery 8 using a generator (not shown). The battery 8 stores motive energy generated by the engine 2 as electrical energy. However, the battery 8 may be configured to be rechargeable externally. The power conversion device 7 supplies AC current to the rotating electric machine 3 using power supplied from the battery 8 based on a drive control signal output from the control device 100. The rotating electric machine 3 rotates using the power provided from the battery 8 via the power conversion device 7, and rotates the differential gear 5 via the transmission 4. The differential gear 5 transmits the power generated by the rotating electric machine 3 to the wheels 6. The control device 100 controls the rotating electric machine 3.

[0010] 2 is a configuration diagram of the rotating electric machine 3. The rotating electric machine 3 includes a rotor 12, a shaft 17 which is the rotation axis of the rotor 12, a bearing 14 which supports the shaft 17, a stator 13, a temperature sensor 15 which measures the temperature of the stator 13, and a housing 10 which stores the rotor 12, the stator 13, the temperature sensor 15, and the rotation sensor 16. The temperature sensor 15 is, for example, a thermistor. The temperature sensor 15 measures the temperature of a certain part of the stator 13, and does not measure the temperature of the stator 13 or the entire rotating electric machine 3. The rotation sensor 16 measures the rotation speed of the rotor 12.

[0011] FIG. 3 is a hardware configuration diagram of the control device 100. The control device 100 includes a CPU 41, which is a central processing unit (CCU), a storage device 42, which is a nonvolatile storage device such as a flash memory, a RAM 43, which is a readable / writable storage device, an input / output device 44, which is a user interface, and a communication device 45. The CPU 41 loads and executes programs stored in the storage device 42 into the RAM 43 to perform the various calculations described above. The control device 100 may be realized by a field programmable gate array (FPGA), which is a rewritable logic circuit, or an application specific integrated circuit (ASIC), which is an application specific integrated circuit, instead of the combination of the CPU 41, the storage device 42, and the RAM 43. Furthermore, the control device 100 may be realized by a different combination of configurations, such as a combination of the CPU 41, the storage device 42, the RAM 43, and the FPGA, instead of the combination of the CPU 41, the storage device 42, and the RAM 43.

[0012] The input / output device 44 is a direct or indirect point of contact with the user. Direct points of contact with the user include, for example, an LCD display and multiple push buttons. Indirect points of contact with the user include, for example, a communication port for transmitting and receiving signals to and from a user interface device provided in the vehicle 1, such as a touch panel instrument panel. The input / output device 44 is used for user setting of a recovery threshold, which will be described later. The communication device 45 realizes communication with other devices mounted on the vehicle 1, such as the temperature sensor 15, the rotation sensor 16, and the power conversion device 7.

[0013] 4 is a functional configuration diagram of the control device 100. The control device 100 includes a flag setting unit 110 and a main control unit 120. The control device 100 internally stores a torque limit flag 111 that indicates whether torque limiting of the rotating electrical machine 3 is required. The torque limit flag 111 takes on one of two values, on or off. The initial value of the torque limit flag 111, i.e., the value of the torque limit flag 111 immediately after the power supply to the control device 100 is turned on, is off.

[0014] The flag setting unit 110 receives the output of the rotation sensor 16 and the output of the temperature sensor 15. The main control unit 120 may also receive the depression amount of an accelerator pedal that is mounted on the vehicle 1 and operated by a user. In addition, if the vehicle 1 is equipped with an autonomous driving unit, the calculation results of the autonomous driving unit may also be input to the main control unit 120.

[0015] The flag setting unit 110 sets the torque limit flag 111 by processing described below. The main control unit 120 calculates a drive control signal 121 to be output to the power conversion device 7. The main control unit 120 refers to the torque limit flag 111 when calculating the drive control signal 121, and calculates the drive control signal 121 so that when the torque limit flag 111 is on, the torque of the rotating electric machine 3 is more limited than when the torque limit flag 111 is off.

[0016] The main control unit 120 has at least the following first and second modes. In the first mode, when the torque limit flag 111 is off, the drive control signal 121 is calculated without limiting the torque. When the torque limit flag 111 is on, the drive signal is calculated so that the torque is equal to or less than a predetermined threshold. In the second mode, when the torque limit flag 111 is off, the drive control signal 121 is calculated so that the torque is equal to or less than a predetermined first threshold. When the torque limit flag 111 is on, the drive control signal 121 is calculated so that the torque is equal to or less than a second threshold that is smaller than the first threshold. Whether the main control unit 120 operates in the first mode or the second mode may be set by a user using the input / output device 44, or may be set only by a specialist through a special operation before shipment or during inspection.

[0017] FIG. 5 illustrates the relationship between the limit temperature TH and the return temperature TL. In FIG. 5, the limit temperature TH is indicated by a straight line, and the return temperature TL is indicated by a dashed line. The horizontal axis of FIG. 5 represents the rotation speed of the rotating electric machine 3, i.e., the output of the rotation sensor 16. The vertical axis of FIG. 6 represents temperature, i.e., the limit temperature TH and the return temperature TL. The limit temperature TH decreases as the rotation speed of the rotating electric machine 3 increases. However, there are periods in which the limit temperature TH does not change even when the rotation speed of the rotating electric machine 3 increases. The relationship between the value of the limit temperature TH and the rotation speed of the rotating electric machine 3 may be expressed by a mathematical formula such as a polynomial, or may be expressed as a lookup table. The mathematical formula or lookup table indicating the value of the limit temperature TH is conceptually included in the flag setting unit 110 and is actually stored in the storage device 42. The return temperature TL is a constant value regardless of the rotation speed of the rotating electric machine 3. However, the return temperature TL is a value smaller than the limit temperature TH at the highest temperature. The value of this return temperature TL is conceptually included in the flag setting unit 110 and is actually stored in the storage device 42 .

[0018] FIG. 6 is a flowchart showing the processing of the flag setting unit 110. As described above, the flag setting unit 110 switches the torque limit flag 111 between on and off. The flag setting unit 110 executes the processing shown in FIG. 6 for each predetermined control period. First, in step S301, the flag setting unit 110 reads the rotation speed of the rotating electric machine 3 output by the rotation sensor 16. In the following step S302, the flag setting unit 110 reads the temperature of the rotating electric machine 3 output by the temperature sensor 15. In the following step S303, the flag setting unit 110 determines the state of the torque limit flag 111, in other words, whether or not the torque limit state is being established. If the flag setting unit 110 determines that the torque limit flag 111 is off, the process proceeds to step S304. If the flag setting unit 110 determines that the torque limit flag 111 is on, the process proceeds to step S307.

[0019] In step S304, the flag setting unit 110 determines the limit temperature TH corresponding to the rotation speed read in step S301. As described with reference to FIG. 5, this determination may be made by performing a predetermined calculation or by referring to a pre-created lookup table. In the following step S305, the flag setting unit 110 determines whether the temperature read in step S302 is equal to or higher than the limit temperature TH determined in step S304. If the flag setting unit 110 determines that the temperature is equal to or higher than the limit temperature TH, the process proceeds to step S306, and if the flag setting unit 110 determines that the temperature is lower than the limit threshold, the process proceeds to step S307.

[0020] In step S306, the flag setting unit 110 changes the torque limit flag 111 to ON and ends the processing shown in Fig. 6. In step S307, the flag setting unit 110 determines whether the temperature read in step S302 is equal to or lower than a predetermined return temperature TL. If the flag setting unit 110 determines that the temperature is lower than the return temperature TL, the processing proceeds to step S308, but if the flag setting unit 110 determines that the temperature is equal to or higher than the return temperature TL, the processing shown in Fig. 6 ends without changing the torque limit flag 111. In step S308, the flag setting unit 110 sets the torque limit flag 111 to OFF and ends the processing shown in Fig. 6.

[0021] FIG. 7 is a diagram showing an example of the operation of the control device 100. In FIG. 7, time passes from left to right. Four graphs are arranged vertically in FIG. 7, and from top to bottom, they show the time-series changes in the temperature of the rotating electric machine 3, the torque limit flag 111, the rotation speed of the rotating electric machine 3, and the torque of the rotating electric machine 3. These four graphs are synchronized in time. Times t0 to t6 shown at the bottom of FIG. 7 are times written for convenience of explanation. Time t35 is a time between times t3 and t4.

[0022] First, the change in the rotation speed shown in the third row will be explained. For a while after time t0, the rotation speed remains constant at a relatively high value, and at time t35, after time t3, the operating point changes and the rotation speed begins to decrease. This change in the operating point is caused, for example, by a decrease in the amount of depression of the accelerator pedal by the user. The decrease in the rotation speed continues even at time t4, and stops after time t4. From time t5 onwards, the rotation speed remains constant at a relatively low value. As explained with reference to FIG. 5, the rotation speed of the rotating electric machine 3 affects the value of the limit temperature TH.

[0023] In the graph showing temperature changes shown in the first row of Figure 7, the straight line indicates the limit temperature TH, the dashed line indicates the return temperature TL, and the dashed-dotted line indicates the temperature of the rotating electrical machine 3. The limit temperature TH remains constant until around time t3, when the rotation speed does not change. Since the limit temperature TH increases or decreases in the opposite direction to the rotation speed, it begins to rise over time after time t35. The increase in the limit temperature TH continues until after time t4, and becomes constant after time t5. The return temperature TL has no correlation with the rotation speed and is always a constant value.

[0024] The temperature of the rotating electric machine 3 exceeded the limit temperature TH at time t1, fell below the return temperature TL at time t2, exceeded the limit temperature TH at time t3, fell below the return temperature TL at time t4, exceeded the limit temperature TH at time t5, and fell below the return temperature TL at time t6. Therefore, the value of the torque limit flag 111 shown in the second row is on from time t1 to t2, off from time t2 to t3, on from time t3 to t4, off from time t4 to t5, on from time t5 to t6, and off from time t6 onwards.

[0025] The torque shown in the bottom row of Fig. 7 is limited to a low value during the time period when the torque limit flag 111 is on, and can be set to a higher value during the time period when the torque limit flag 111 is off. Therefore, the torque behaves in the opposite way to the torque limit flag 111 shown in the second row. Specifically, the torque is low from time t1 to t2, high from time t2 to t3, low from time t3 to t4, high from time t4 to t5, low from time t5 to t6, and high from time t6 onwards. In the example shown in Fig. 7, the time from time t1 to t2, the time from time t2 to t3, the time from time t3 to t4, the time from time t4 to t5, and the time from time t5 to t6 are approximately the same.

[0026] (Comparative Example) FIG. 8 is a diagram showing the relationship between the limit temperature TH and the comparative example return temperature TLz in a comparative example. FIG. 8 corresponds to FIG. 5 of the present embodiment. The characteristics of the limit temperature TH are the same as those of the present embodiment. The comparative example return temperature TLz is not constant, but decreases as the rotation speed increases. However, the limit temperature TH and the comparative example return temperature TLz may have different temperature changes with increasing rotation speed. Furthermore, the range of rotation speed in which the limit temperature TH does not change may be different from the range of rotation speed in which the comparative example return temperature TLz does not change.

[0027] FIG. 9 is a diagram showing an example of operation in a comparative example. FIG. 9 corresponds to FIG. 7 of the present embodiment. The four graphs shown in FIG. 9 are also similar to those in FIG. 7. Times t20 to t27 shown at the bottom of FIG. 9 are times listed for ease of explanation. In FIG. 9, the rotation speed remains constant at a relatively high value for a while after time t20, but after time t235, the operating point changes and the rotation speed begins to decrease. The decrease in rotation speed continues even at time t24, and after time t24, the decrease in rotation speed subsides. After time t25, the rotation speed remains constant at a relatively low value.

[0028] In the graph showing temperature change shown in the first row of FIG. 9 , the straight line indicates the limit temperature TH, the dashed line indicates the comparative example return temperature TLz, and the dashed-dotted line indicates the temperature of the rotating electric machine 3. The limit temperature TH and the comparative example return temperature TLz remain constant until time t235, when the rotation speed does not change. Since the limit temperature TH and the comparative example return temperature TLz increase and decrease in the opposite direction to the rotation speed, they increase over time after time t235. The increase in the limit temperature TH and the comparative example return temperature TLz continues until after time t24, and then becomes constant after time t25. Unlike FIG. 7 , when the rotation speed changes, the comparative example return temperature TLz also changes in the same way as the limit temperature TH.

[0029] The temperature of the rotating electric machine 3 exceeded the limit temperature TH at time t21, fell below the comparative example return temperature TLz at time t22, exceeded the limit temperature TH at time t23, fell below the comparative example return temperature TLz at time t24, exceeded the limit temperature TH at time t25, and fell below the comparative example return temperature TLz at time t26. Therefore, the value of the torque limit flag 111 shown in the second row is on from time t21 to t22, off from time t22 to t23, on from time t23 to t24, off from time t24 to t25, on from time t25 to t26, and off from time t26 onwards.

[0030] 9 is limited to a low value during the time period when the torque limit flag 111 is on, and can be set to a higher value during the time period when the torque limit flag 111 is off. Therefore, the torque behaves in the opposite way to the torque limit flag 111 shown in the second row. Specifically, the torque is low from time t21 to t22, high from time t22 to t23, low from time t23 to t24, high from time t24 to t25, low from time t25 to t26, and high from time t26 onwards.

[0031] In this comparative example, the rotation speed at time t24 is lower than at time t23, so the value of the comparative example return temperature TLz is higher than at time t23. Therefore, the period from time t23 to t24 is shorter than the periods from time t21 to t22 and from time t25 to t26. In other words, the torque restriction ends in a short time from time t23 to t24, causing the vehicle 1 to suddenly accelerate, which is a behavior unintended by the user. On the other hand, in the operation example of this embodiment shown in FIG. 7, the time period during which the torque restriction flag 111 is off does not shorten even if the operating point is changed. Therefore, it can be said that this embodiment can suppress behavior of the vehicle 1 unintended by the user.

[0032] The first embodiment described above provides the following advantageous effects. (1) The control device 100 controls at least the output torque of the rotating electric machine 3. The control device 100 includes a flag setting unit 110 that sets a torque limit flag 111 to indicate whether or not the output torque needs to be limited, and a main control unit 120 that controls the output torque based on the torque limit flag 111. The flag setting unit 110 turns the torque limit flag 111 on when the temperature of the rotating electric machine 3 exceeds a limit temperature TH, which is an upper temperature limit set based on the rotation speed of the rotating electric machine 3. The flag setting unit 110 turns the torque limit flag 111 off when the temperature of the rotating electric machine 3 falls below a predetermined return temperature TL. When the limit flag is on, the main control unit 120 controls the output to be smaller than when the torque limit flag 111 is off. Therefore, as can be seen from the operational example of this embodiment shown in FIG. 7 and the operational example of the comparative example shown in FIG. 9, the control device 100 of this embodiment can suppress unintended vehicle behavior when the operating point is changed.

[0033] (2) In the first mode, the main control unit 120 does not limit the output torque when the torque limit flag 111 is off, and limits the output torque when the torque limit flag 111 is on.

[0034] (3) In the second mode, the main control unit 120 limits the output torque to a first torque when the torque limit flag 111 is off, and limits the output torque to a second torque that is smaller than the first torque when the torque limit flag 111 is on.

[0035] (Variation 1) In the first embodiment described above, the main control unit 120 calculates the drive control signal 121 by referring to the torque limit flag 111 set by the flag setting unit 110. However, managing the flag is not an essential configuration, and the flag may be managed in another manner as long as it has the same meaning as the torque limit flag 111. For example, the flag setting unit 110 may manage the state transition by defining the rotating electric machine 3 as being in a "non-limit state" when the torque limit flag 111 is off and defining the rotating electric machine 3 as being in a "limit state" when the torque limit flag 111 is on. In this case, the main control unit 120 calculates the drive control signal 121 by referring to the state of the rotating electric machine 3.

[0036] (Variation 2) In the first embodiment described above, the vehicle 1 is described as a series hybrid vehicle, but the configuration of the vehicle 1 is not limited to this. The vehicle 1 may be a parallel or split hybrid vehicle, or may be an electric vehicle without an engine 2.

[0037] (Modification 3) In the first embodiment described above, the main control unit 120 has both the first mode and the second mode. However, the main control unit 120 may have only one of the first mode and the second mode.

[0038] - Second embodiment - A second embodiment of a control device and control method for a rotating electrical machine will be described with reference to Figures 10 and 11. In the following description, the same components as in the first embodiment will be assigned the same reference numerals, and differences will be mainly described. Points that are not particularly described are the same as in the first embodiment. This embodiment differs from the first embodiment mainly in that the user can set the return temperature TL.

[0039] Fig. 10 is a functional configuration diagram of the control device 100A in the second embodiment. Comparing Fig. 10 with Fig. 4 in the first embodiment, a return temperature setting unit 130 is added. The return temperature setting unit 130 determines the return temperature TL based on a user operation and outputs the return temperature TL to the flag setting unit 110.

[0040] FIG. 11 illustrates a setting screen 80 for the return temperature TL, operated by the user. The setting screen 80, the user interface control described below, and writing to the storage device 42 are all performed by the return temperature setting unit 130. The setting screen 80 is similar to the setting screen 80 in FIG. 5 for the first embodiment, but includes an up arrow 81, a down arrow 82, a numerical input field 83, and a setting button 84, which are not included in FIG. 5. The user can use the up arrow 81 and the down arrow 82 to increase or decrease the value of the return temperature TL in increments of a predetermined value, for example, in increments of 1. The user can also directly input a numerical value into the numerical input field 83. When the user presses the setting button 84, the set value is written to the storage device 42 as the return temperature TL. The flag setting unit 110 reads the value of the return temperature TL from the storage device 42. Therefore, when the return temperature setting unit 130 writes the value of the return temperature TL to the storage device 42, the value of the return temperature TL is indirectly passed to the flag setting unit 110.

[0041] According to the second embodiment described above, the following advantageous effects can be obtained: (4) The control device 100A includes the recovery temperature setting unit 130 that sets the recovery temperature TL based on an external command, allowing the user to set the recovery temperature TL as desired.

[0042] In the above-described embodiments and modifications, the functional block configurations are merely examples. Some functional configurations shown as separate functional blocks may be integrated, or a configuration shown in a single functional block diagram may be divided into two or more functions. Furthermore, some of the functions of each functional block may be provided by other functional blocks.

[0043] In each of the above-described embodiments and modifications, the control device 100 may be provided with an input / output interface (not shown), and a program may be loaded from another device as needed via the input / output interface and a medium available to the control device 100. Here, the medium refers to, for example, a storage medium detachable from the input / output interface, or a communication medium, i.e., a wired, wireless, or optical network, or a carrier wave or digital signal propagating through the network. Furthermore, some or all of the functions realized by the program may be realized by a hardware circuit or FPGA.

[0044] The above-described embodiments and modifications may be combined with each other. Although various embodiments and modifications have been described above, the present invention is not limited to these. Other embodiments conceivable within the scope of the technical concept of the present invention are also included within the scope of the present invention.

[0045] 1: Vehicle 3: Rotating electric machine 15: Temperature sensor 16: Rotation sensor 100, 100A: Control device 110: Flag setting unit 111: Torque limit flag 120: Main control unit TH: Limit temperature TL: Recovery temperature

Claims

1. A control device for a rotating electric machine that controls the output torque of a rotating electric machine, comprising: a flag setting unit that sets a restriction flag to indicate whether or not the output torque needs to be restricted; and a main control unit that controls the output torque based on the restriction flag, wherein the flag setting unit changes the restriction flag to on when the temperature of the rotating electric machine exceeds a restriction temperature, which is an upper temperature limit set based on the rotation speed of the rotating electric machine; the flag setting unit changes the restriction flag to off when the temperature of the rotating electric machine falls below a predetermined return temperature; and the main control unit controls the output to be smaller when the restriction flag is on compared to when the restriction flag is off.

2. A control device for a rotating electric machine as described in claim 1, wherein the main control unit does not limit the output torque when the limit flag is off, and limits the output torque when the limit flag is on.

3. A control device for a rotating electric machine as described in claim 1, wherein the main control unit limits the output torque to a first torque when the limit flag is off, and limits the output torque to a second torque smaller than the first torque when the limit flag is on.

4. A control device for a rotating electric machine according to claim 1, further comprising a return temperature setting unit which sets the return temperature based on an external command.

5. A control method for a rotating electric machine in which a computer controls the output torque of a rotating electric machine, wherein when the temperature of the rotating electric machine exceeds a limit temperature, which is an upper temperature limit value set based on the rotation speed of the rotating electric machine, a limit flag indicating whether or not the output torque needs to be limited is changed to on, and when the temperature of the rotating electric machine falls below a predetermined return temperature, the limit flag is changed to off, and when the limit flag is on, the output torque is controlled to be smaller than when the limit flag is off.

6. A control device for a rotating electric machine according to claim 1, wherein the recovery temperature is a constant value regardless of the rotation speed of the rotating electric machine.

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