Control device for rotary electric machine

Abstract

Provided is a control device for a rotary electric machine, said control device being capable of controlling the temperature of the rotary electric machine without forcibly reducing the torque of the rotary electric machine. This control device for a rotary electric machine controls, via an inverter, a rotary electric machine having armature windings of a plurality of phases, said control device comprising: a temperature detection unit that detects the temperature of the rotary electric machine; and an output control unit that calculates voltage command values of the plurality of phases to be applied to the armature windings of the plurality of phases and controls the inverter on the basis of the voltage command values of the plurality of phases, the output control unit changing, on the basis of the temperature, the maximum effective value that can be set for the voltage command values of the plurality of phases.

Description

Control device for a rotating electrical machine 【0001】 The present disclosure relates to a control device for a rotating electrical machine. 【0002】 In a rotating electrical machine for an electric vehicle such as an electric vehicle and a hybrid vehicle, a boost converter is provided between a DC power supply and an inverter in order to increase the output of the rotating electrical machine. In the technique of Patent Document 1, in a region exceeding the base rotational speed, when boosting the DC voltage to reduce the increase amount in the negative direction of the d-axis current in the field weakening control, the boost voltage is changed so that the total loss of the rotating electrical machine, the inverter, and the boost converter is minimized. 【0003】 In the technique of Patent Document 2, in order to protect the rotating electrical machine from overheating, the torque of the rotating electrical machine is suppressed according to the temperature and rotational speed of the rotating electrical machine. 【0004】 Japanese Patent Application Laid-Open No. 2005-210772, Japanese Patent Application Laid-Open No. 2000-184502 【0005】 However, in the technique of Patent Document 1, only the boost voltage is changed so that the total loss is minimized, and the boost voltage is not changed so as to lower the temperature when the temperature of the rotating electrical machine such as the armature winding of the rotating electrical machine rises. Therefore, although the total loss can be reduced, the temperature of the rotating electrical machine may rise. Therefore, when the temperature of the rotating electrical machine rises too much, it is necessary to forcibly lower the torque as in the technique of Patent Document 2. 【0006】 For example, in a rotating electrical machine for an electric vehicle, the operating range of the rotational speed and torque is wide, and in the case of climbing a slope or high-speed driving, it is necessary to output a large output for a relatively long time, and the temperature rise may become a problem. 【0007】 Therefore, an object of the present disclosure is to provide a control device for a rotating electrical machine that can control the temperature of the rotating electrical machine without forcibly reducing the torque of the rotating electrical machine. 【0008】The control device for a rotating electric machine according to the present disclosure is a control device for a rotating electric machine having multiple phase armature windings, which controls the rotating electric machine via an inverter, and comprises: a temperature detection unit for detecting the temperature of the rotating electric machine; and an output control unit for calculating multiple phase voltage command values ​​to be applied to the multiple phase armature windings and controlling the inverter based on the multiple phase voltage command values, wherein the output control unit changes the settable maximum effective value of the multiple phase voltage command values ​​based on the temperature. 【0009】 According to the control device for a rotating electric machine described herein, by changing the maximum effective value that can be set based on the temperature of the rotating electric machine, the current supplied to the armature winding can be changed without forcibly reducing the torque of the rotating electric machine, thereby appropriately changing the temperature of the rotating electric machine. For example, it is possible to suppress the rise in the temperature of the rotating electric machine. 【0010】This is a configuration diagram of the rotating electric machine and control device according to Embodiment 1. This is a schematic block diagram of the control device according to Embodiment 1. This is a hardware configuration diagram of the control device according to Embodiment 1. This is a diagram illustrating the change in the execution range of maximum torque / current control and flux weakening control due to an increase in DC voltage according to Embodiment 1. This is a diagram illustrating the continuous operation range of the reference target DC voltage and the continuous operation range of the increased target DC voltage according to Embodiment 1. This is a diagram illustrating the reduction in the negative increase in d-axis current due to an increase in DC voltage according to Embodiment 1. This is a time chart illustrating the control behavior according to Embodiment 1. This is a diagram illustrating the continuous operation range of the reference target DC voltage and the continuous operation ranges of the first and second increased target DC voltages according to Embodiment 1. This is a flowchart illustrating the processing of the output control unit according to Embodiment 1. This is a flowchart illustrating the processing of the output control unit according to Embodiment 2. This is a configuration diagram of the rotating electric machine and control device according to Embodiment 3. This is a schematic block diagram of the control device according to Embodiment 3. This is a diagram illustrating the change in the execution range of maximum torque / current control and flux weakening control due to an increase in the configurable maximum modulation rate according to Embodiment 3. This is a diagram illustrating the continuous operation range of the reference maximum modulation rate and the continuous operation range of the increased maximum modulation rate according to Embodiment 3. This is a time chart illustrating the control behavior according to Embodiment 3. This is a diagram illustrating the continuous operation region of the reference maximum modulation rate and the continuous operation regions of the first and second increasing maximum modulation rates according to Embodiment 3. This is a flowchart illustrating the processing of the output control unit according to Embodiment 3. This is a flowchart illustrating the processing of the output control unit according to Embodiment 4. 【0011】 1. Embodiment 1 The control device 30 of the rotating electric machine according to Embodiment 1 (hereinafter simply referred to as the control device 30) will be described with reference to the drawings. Figure 1 is a schematic diagram of the rotating electric machine 2 and the control device 30, etc., according to this embodiment. 【0012】1-1. Rotating Electric Machine 2 The rotating electric machine 2 is equipped with an armature winding (hereinafter simply referred to as winding). The rotating electric machine 2 comprises a stator 7 and a rotor 8 arranged radially inward of the stator 7. Multiple phase armature windings are provided on the stator 7. In this embodiment, three phase armature windings Cu, Cv, and Cw of U, V, and W phases are provided. The three phase armature windings Cu, Cv, and Cw are connected in a star configuration. The three phase armature windings may also be connected in a delta configuration. The rotating electric machine 2 is a permanent magnet type synchronous rotating electric machine, and permanent magnets are provided on the rotor 8. The rotating electric machine 2 may also be a synchronous reluctance motor in which permanent magnets are not provided on the rotor 8. 【0013】 The rotating electric machine 2 is equipped with a rotation sensor 16 that outputs an electrical signal corresponding to the rotation angle of the rotor 8. The rotation sensor 16 may be a Hall element, an encoder, or a resolver. The output signal from the rotation sensor 16 is input to the control device 30. 【0014】 The rotating electric machine 2 is equipped with a temperature sensor 19 that detects the temperature Tmp of the rotating electric machine. The output signal of the temperature sensor 19 is input to the control device 30. In this embodiment, the temperature sensor 19 detects the temperature of the armature winding. The temperature sensor 19 may also detect the temperature of parts of the rotating electric machine other than the armature winding. The control device 30 may also estimate the temperature of the armature winding based on the temperature detected values ​​of the parts of the rotating electric machine other than the armature winding. Alternatively, the temperature sensor 19 may not be provided, and the control device 30 may estimate the temperature of the rotating electric machine based on the operating state of the rotating electric machine. 【0015】 1-2. DC power supply 10, converter 18, and inverter 20 <DC power supply 10> A rechargeable energy storage device (for example, a lithium-ion battery, nickel-metal hydride battery, or electric double-layer capacitor) is used for the DC power supply 10. 【0016】 <Converter 18> The converter 18 is a DC-DC converter connected between the DC power supply 10 and the inverter 20, which converts DC power. 【0017】In this embodiment, the converter 18 has the function of a boost chopper that boosts the power supply voltage Vb of the DC power supply 10 and outputs it to the inverter 20. The converter 18 also has a buck chopper mechanism that steps down the DC voltage of the inverter 20 and outputs it to the DC power supply 10. Various known boost chopper circuits and buck chopper circuits can be used as the converter 18. The converter 18 comprises at least a reactor, a switching element, and a freewheeling diode. 【0018】 In this embodiment, the converter 18 includes a reactor L1, two switching elements Q1 and Q2, and two freewheeling diodes D1 and D2. The two switching elements Q1 and Q2 are connected in antiparallel to the freewheeling diodes D1 and D2, respectively. The two switching elements Q1 and Q2 are connected in series between the high-potential side wire 14 and the low-potential side wire 15. The reactor L1 is connected between the connection node connecting the two switching elements Q1 and Q2 and the high-potential side of the DC power supply 10. The two switching elements Q1 and Q2 are turned on and off by a control signal output from the control device 30. 【0019】 <Inverter 20> The inverter 20 is a power converter that performs power conversion between the DC power supply 10 (converter 18 in this example) and the three-phase armature windings, and has multiple switching elements. The inverter 20 has three series circuits (legs) corresponding to the armature windings of each of the three phases, in which a high-potential switching element 23H (upper arm) connected in series with a low-potential switching element 23L (lower arm) connected in series with a high-potential switching element 23H connected in series with a low-potential switching element 23L connected in series with a low-potential switching element 23L connected with a low-potential switching element 23L 【0020】Switching elements include IGBTs (Insulated Gate Bipolar Transistors) with diodes 22 connected in antiparallel, FETs (Field Effect Transistors) with diodes connected in antiparallel, MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) that function as diodes connected in antiparallel, and bipolar transistors with diodes connected in antiparallel. The gate terminal of each switching element is connected to the control device 30. Each switching element is turned on or off by a control signal output from the control device 30. 【0021】 A smoothing capacitor 12 is connected between the high-potential wire 14 and the low-potential wire 15. A voltage sensor 13 is provided to detect the DC voltage Vdc supplied from the DC power supply 10 (converter 18) to the inverter 20. The voltage sensor 13 is connected between the high-potential wire 14 and the low-potential wire 15. The output signal of the voltage sensor 13 is input to the control device 30. 【0022】 The current sensor 17 outputs an electrical signal corresponding to the current flowing through the armature winding of each phase. The current sensor 17 is provided on the wires of each phase connecting the series circuit of the switching element to the armature winding. The output signal of the current sensor 17 is input to the control device 30. The current sensor 17 may also be provided in the series circuit of each phase. 【0023】 1-3. Control Device 30 The control device 30 controls the rotating electric machine 2 via the inverter 20 and the converter 18. As shown in Figure 2, the control device 30 includes a temperature detection unit 31, a rotation detection unit 32, a voltage detection unit 33, a current detection unit 34, and an output control unit 35, etc. Each function of the control device 30 is realized by the processing circuit provided in the control device 30. Specifically, as shown in Figure 3, the control device 30 includes a processing circuit such as a CPU (Central Processing Unit) or other arithmetic processing unit 90 (computer), a storage device 91 that exchanges data with the arithmetic processing unit 90, an input circuit 92 that inputs external signals to the arithmetic processing unit 90, and an output circuit 93 that outputs signals from the arithmetic processing unit 90 to the outside. 【0024】 The arithmetic processing unit 90 may include an ASIC (Application Specific Integrated Circuit), an IC (Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), various logic circuits, and various signal processing circuits. Furthermore, multiple arithmetic processing units 90 of the same or different types may be provided, with each unit performing a portion of the processing. The storage device 91 may include a RAM (Random Access Memory) configured to read and write data from the arithmetic processing unit 90, or a ROM (Read Only Memory) configured to read data from the arithmetic processing unit 90. The input circuit 92 is connected to various sensors such as a temperature sensor 19, a voltage sensor 13, a rotation sensor 16, and a current sensor 17, and includes an A / D converter that inputs the output signals from these sensors to the arithmetic processing unit 90. The output circuit 93 is connected to electrical loads such as gate drive circuits that drive switching elements on and off, and includes drive circuits that output control signals from the arithmetic processing unit 90 to these electrical loads. 【0025】 The functions of the control device 30, such as the processing units 31 to 35 shown in Figure 2, are realized by the arithmetic processing unit 90 executing software (programs) stored in the storage device 91, such as a ROM, and cooperating with other hardware of the control device 30, such as the storage device 91, input circuit 92, and output circuit 93. The setting data, such as map data, used by each of the processing units 31 to 35 is stored in the storage device 91, such as a ROM. The functions of the control device 30 will now be described in detail. 【0026】1-3-1. Temperature Detection Unit 31 The temperature detection unit 31 detects the temperature Tmp of the rotating electric machine. In this embodiment, the temperature detection unit 31 detects the temperature Tmp of the armature winding. The temperature detection unit 31 detects the temperature Tmp of the armature winding based on the output signal of the temperature sensor 19. The temperature detection unit 31 may also estimate the temperature Tmp of the rotating electric machine based on the operating state of the rotating electric machine (for example, the current, rotational speed, torque of the armature winding). The temperature detection unit 31 may also detect the temperature Tmp of parts of the rotating electric machine other than the armature winding. 【0027】 1-3-2. Rotation Detection Unit 32 The rotation detection unit 32 detects the rotation angle θ and rotational angular velocity ω (hereinafter also referred to as rotational velocity ω) of the rotor in electrical angles. In this embodiment, the rotation detection unit 32 detects the rotation angle θ and rotational angular velocity ω of the rotor based on the output signal of the rotation sensor 16. The rotation detection unit 32 detects the rotation angle θ of the rotor's magnetic pole (N pole) with reference to the position of the U-phase armature winding. The rotation detection unit 32 may be configured to estimate the rotation angle without using a rotation sensor, based on current information obtained by superimposing harmonic components on the current command value (so-called sensorless method). 【0028】 1-3-3. Voltage Detection Unit 33 The voltage detection unit 33 detects the DC voltage Vdc supplied from the DC power supply 10 (converter 18 in this example) to the inverter 20. In this embodiment, the voltage detection unit 33 detects the DC voltage Vdc based on the output signal of the voltage sensor 13. 【0029】 1-3-4. Current Detection Unit 34 The current detection unit 34 detects the currents Iu, Iv, and Iw flowing through the three phase armature windings. Based on the output signal of the current sensor 17, the current detection unit 34 detects the current Iu flowing through the U phase armature winding, the current Iv flowing through the V phase armature winding, and the current Iw flowing through the W phase armature winding. Alternatively, the current sensor 17 may be configured to detect the armature winding currents of two phases, and the armature winding current of the remaining one phase may be calculated based on the detected values ​​of the two phase armature winding currents. For example, the current sensor 17 may detect the armature winding currents Iv and Iw of the V and W phases, and the armature winding current Iu of the U phase may be calculated by Iu = -Iv - Iw. 【0030】 1-3-5. Output Control Unit 35 The output control unit 35 calculates the three-phase voltage command values ​​Vuo, Vvo, and Vwo to be applied to the three-phase armature windings, and controls the inverter 20 based on the three-phase voltage command values ​​Vuo, Vvo, and Vwo. 【0031】 The output control unit 35 changes the configurable maximum effective value Vemax of the three-phase voltage command values ​​Vuo, Vvo, and Vwo based on the temperature Tmp of the rotating electric machine. 【0032】 With this configuration, by changing the maximum configurable effective value Vemax based on the temperature Tmp of the rotating electric machine, the current supplied to the armature winding can be changed, thereby appropriately changing the temperature Tmp of the rotating electric machine. For example, it is possible to suppress the rise in the temperature Tmp of the rotating electric machine. 【0033】 Here, the effective value Ve of the three-phase voltage command values ​​Vuo, Vvo, and Vwo is the value obtained by multiplying the square root of the three-phase voltage command values ​​Vuo, Vvo, and Vwo by a predetermined coefficient (1 / √3 in this example). The coefficient may be set to a value other than 1 / √3. 【0034】 The effective value Ve is calculated using the three-phase voltage command values ​​Vuo, Vvo, and Vwo, which are lowered by the lower potential side of the DC voltage (in this example, -Vdc / 2) and upper limited by the higher potential side of the DC voltage (in this example, +Vdc / 2). The average value of the effective value Ve over the AC period is also used. 【0035】 Alternatively, the effective value Ve of the three-phase voltage command is calculated using the following formula, with respect to the voltage command values ​​Vdo and Vqo of the d and q axes, which are obtained by representing the three-phase voltage command values ​​Vuo, Vvo, and Vwo in dq-axis rotation coordinates. 【0036】 Furthermore, as shown in the following equation, the modulation index M is the value obtained by multiplying the ratio of the effective value Ve of the three-phase voltage command value to the DC voltage Vdc by a predetermined coefficient (√3 in this example). Depending on the definition of the modulation index, the coefficient may be set to a value other than √3 (for example, √6). 【0037】When amplitude reduction modulation, as described later, is performed, if the modulation ratio M exceeds 1 / √2 (≒0.707), the amplitudes of the three-phase voltage command values ​​Vuo, Vvo, and Vwo after amplitude reduction modulation exceed the range of the DC voltage Vdc (-Vdc / 2 to +Vdc / 2), resulting in a voltage saturation state (overmodulation state). On the other hand, if amplitude reduction modulation is not performed, if the modulation ratio M exceeds √(3 / 2) / 2 (≒0.612), the amplitudes of the three-phase voltage command values ​​Vuo, Vvo, and Vwo exceed the range of the DC voltage Vdc (-Vdc / 2 to +Vdc / 2), resulting in a voltage saturation state (overmodulation state). Furthermore, regardless of whether amplitude reduction modulation is performed or not, the theoretical maximum modulation ratio Mmaxthe is √6 / π (≒0.78), where the voltage command value becomes a square wave, and is the value when so-called one-pulse control (square wave control). 【0038】 Furthermore, the maximum modulus Mmax that can be set in the control system is set to be less than or equal to the theoretical maximum modulus Mmaxthe. The maximum effective value Vemax that can be set for the three-phase voltage command value is calculated using the maximum modulus Mmax and the DC voltage Vdc by the following formula. 【0039】 In this embodiment, the output control unit 35 calculates the three-phase voltage command values ​​Vuo, Vvo, and Vwo so as to reduce the maximum torque (absolute value) of the rotating electric machine when the temperature Tmp of the rotating electric machine exceeds the upper limit temperature Tmplmt. The output control unit 35 changes the settable maximum effective value Vemax based on the temperature Tmp of the rotating electric machine, at least when the temperature Tmp of the rotating electric machine does not exceed the upper limit temperature Tmplmt. 【0040】 With this configuration, before the temperature Tmp of the rotating electric machine exceeds the upper limit temperature Tmplmt and the maximum torque of the rotating electric machine decreases, the settable maximum effective value Vemax can be appropriately changed in advance to appropriately change the temperature Tmp of the rotating electric machine, thereby suppressing the temperature Tmp of the rotating electric machine from exceeding the upper limit temperature Tmplmt and suppressing the decrease in maximum torque. 【0041】 In this embodiment, the output control unit 35 includes a current command value calculation unit 351, a voltage command value calculation unit 352, a PWM control unit 353, and a converter control unit 354. 【0042】 <Current command value calculation unit 351> The current command value calculation unit 351 calculates the d-axis current command value Ido and the q-axis current command value Iqo. Based on the output command value, the rotational speed ω, and the DC voltage Vdc, the current command value calculation unit 351 calculates the dq-axis current command values Ido and Iqo according to current vector control methods such as maximum torque / current control and field-weakening control. At each DC voltage Vdc, the dq-axis current command values Ido and Iqo are set in the region of the output command value and the rotational speed ω as shown in FIG. 4, where the effective value Ve is less than or equal to the maximum effective value Vemax that can be set. 【0043】 In this embodiment, the output command value is the torque command value. When the torque command value is set to a positive value, the rotating electrical machine performs power running, and when the torque command value is set to a negative value, the rotating electrical machine regenerates. The output command value may be other parameters such as the output power command value and the output current command value according to the system in which the rotating electrical machine 2 is used. The control command value may be calculated inside the control device 30 or transmitted from an external control device. 【0044】 The dq-axis rotating coordinate system is a rotating coordinate system composed of the d-axis defined in the magnetic flux direction of the rotor and the q-axis defined in the direction advanced by an electrical angle of π / 2 from the d-axis. 【0045】 In this embodiment, the current command value calculation unit 351 switches between and executes the basic control and the field-weakening control that increases the d-axis current Id in the negative direction more than the basic control, and calculates the voltage command values of multiple phases. In this embodiment, the basic control is the maximum torque / current control. The basic control may be the Id = 0 control or the maximum efficiency control, etc. 【0046】When the rotational speed ω is less than the base rotational speed, the current command value calculation unit 351 executes basic control, and when the rotational speed ω is greater than or equal to the base rotational speed, it executes field-weakening control. The base rotational speed is the rotational speed at which the induced voltage generated in the armature winding when executing basic control (in this example, maximum torque / current control) reaches the maximum applied voltage that can be applied to the armature winding. The maximum applied voltage that can be applied is a voltage obtained by multiplying the product of the DC voltage Vdc and the set maximum modulation ratio Mmax (the set maximum effective value Vemax) by a predetermined coefficient. By field-weakening control, the d-axis current command value Ido is increased in the negative direction to weaken the flux in the d-axis direction, reduce the induced voltage, and enable torque output. 【0047】 In maximum torque / current control, the dq-axis current command values Ido and Iqo that maximize the generated torque for the same current are calculated. In field-weakening control, the d-axis current command value Ido is increased in the negative direction more than in maximum torque / current control to weaken the flux in the d-axis direction. As shown in FIG. 6, in field-weakening control, according to the torque command value, the dq-axis current command values Ido and Iqo are moved on the voltage limit ellipse corresponding to the maximum applied voltage obtained by multiplying the product of the DC voltage Vdc and the set maximum modulation ratio Mmax (the set maximum effective value Vemax) by a predetermined coefficient. In maximum efficiency control, the dq-axis current command values Ido and Iqo that maximize the efficiency of the rotating electrical machine are calculated. In Id = 0 control, the d-axis current command value Ido is set to 0, and the q-axis current command value Iqo is changed according to the torque command value. In a surface magnet type rotating electrical machine, Id = 0 control becomes maximum torque / current control. 【0048】 In the execution region of field-weakening control, the modulation ratio M becomes the set maximum modulation ratio Mmax (M = Mmax), and in the execution region of maximum torque / current control, the modulation ratio M changes within the range from 0 to the set maximum modulation ratio Mmax (0 ≤ M ≤ Mmax). 【0049】 When amplitude reduction modulation is performed and an overmodulation state is not allowed, the set maximum modulation ratio Mmax becomes 0.707 (Mmax = 0.707), and when an overmodulation state is allowed, the set maximum modulation ratio Mmax is set to a modulation ratio within the range of 0.707 < M ≤ 0.78. 【0050】 On the other hand, if amplitude reduction modulation is not performed and an overmodulation state is not permitted, the maximum configurable modulation rate Mmax becomes 0.612 (Mmax ​​= 0.612). If an overmodulation state is permitted, the maximum configurable modulation rate Mmax is set to a modulation rate within the range of 0.612 < M ≤ 0.78. 【0051】 As shown in equation (4), even with the same configurable maximum modulation ratio Mmax, the configurable maximum effective value Vemax of the three-phase voltage command increases as the DC voltage Vdc increases. Therefore, as shown in Figure 4, as the DC voltage Vdc increases, the execution range of maximum torque / current control and flux weakening control shifts to the high rotational speed side. 【0052】 For example, the current command value calculation unit 351 uses map data, which is pre-set for each control method, that shows the relationship between the torque command value, rotational speed ω, DC voltage Vdc, and dq-axis current command values ​​Ido and Iqo, to calculate the dq-axis current command values ​​Ido and Iqo corresponding to the current torque command value, DC voltage Vdc, and rotational speed ω. Instead of the DC voltage Vdc, the settable maximum effective value Vemax, which is the product of the DC voltage Vdc and the settable maximum modulation rate Mmax, may be used. Other known calculation methods may also be used. 【0053】 <Reduction in Maximum Torque When Upper Temperature Limit Tmplmt is Exceeded> When the temperature Tmp of the rotating electric machine exceeds the preset upper temperature limit Tmplmt, the current command value calculation unit 351 limits the absolute value of the output command value (torque command value in this example) by the upper limit torque Tlmt, thereby reducing the maximum torque (absolute value) of the rotating electric machine. The upper limit torque Tlmt is the torque that can maintain the temperature Tmp of the rotating electric machine at or below the upper temperature limit Tmplmt. The upper limit torque Tlmt is preset considering the cooling performance of the rotating electric machine. 【0054】 The current command value calculation unit 351 may, when the temperature Tmp of the rotating electric machine exceeds a preset upper limit temperature Tmplmt, limit the magnitude of the current vectors of the dq axis current command values ​​Ido and Iqo by an upper limit limit current. 【0055】<Voltage Command Value Calculation Unit 352> The voltage command value calculation unit 352 calculates the three-phase voltage command values ​​Vuo, Vvo, and Vwo based on the d-axis current command value Ido and the q-axis current command value Iqo. 【0056】 In this embodiment, the voltage command value calculation unit 352 converts the three-phase current detection values ​​Iu, Iv, and Iw into d-axis current detection value Id and q-axis current detection value Iq by performing known three-phase to two-phase conversion and rotational coordinate conversion based on the rotation angle θ. 【0057】 The voltage command value calculation unit 352 performs feedback control, such as PI control, to change the d-axis voltage command value Vdo and the q-axis voltage command value Vqo so that the d-axis current detection value Id and the q-axis current detection value Iq approach the d-axis current command value Ido and the q-axis current command value Iqo, respectively. Known feedforward control may also be used. 【0058】 The voltage command value calculation unit 352 converts the d-axis voltage command value Vdo and the q-axis voltage command value Vqo into three-phase voltage command values ​​Vuo, Vvo, and Vwo by performing known fixed coordinate transformations and two-phase to three-phase transformations based on the rotation angle θ. 【0059】 For the three-phase voltage command values ​​Vuo, Vvo, and Vwo, amplitude reduction modulation may be applied by superimposing an offset voltage that reduces the amplitude of the three-phase voltage command values ​​while maintaining the line voltage. As amplitude reduction modulation, third harmonic superposition, the min-max method (pseudo-third harmonic superposition), or two-phase modulation can be used. In third harmonic superposition, a sinusoidal offset voltage with three times the rotation period of the electrical angle is superimposed on the three-phase voltage command values. In the min-max method (pseudo-third harmonic superposition), a triangular wave offset voltage with three times the rotation period of the electrical angle is superimposed on the three-phase voltage command values. In two-phase modulation, an offset voltage is superimposed on the three-phase voltage command values ​​such that the lowest potential or highest potential voltage command value matches the low potential side (in this example, -Vdc / 2) or high potential side (in this example, +Vdc / 2) of the DC voltage. For the sake of explanation, the modulated three-phase voltage command values ​​will also be simply referred to as the three-phase voltage command values. 【0060】The voltage command value calculation unit 352 limits the three-phase voltage command values ​​Vuo, Vvo, and Vwo to a lower limit by the lower potential side of the DC voltage (in this example, -Vdc / 2) and to an upper limit by the higher potential side of the DC voltage (in this example, +Vdc / 2). Even if upper and lower limits are not applied, the voltage saturation in the PWM control described later will effectively result in a state where upper and lower limits are applied. Therefore, as described above, in this disclosure, the effective value Ve of the three-phase voltage command value is assumed to be the effective value of the three-phase voltage command value in a state where the upper and lower limits of the DC voltage are applied. 【0061】 <PWM Control Unit 353> The PWM control unit 353 turns on and off a plurality of switching elements of the inverter 20 based on the three-phase voltage command values ​​Vuo, Vvo, and Vwo. The PWM control unit 353 uses known carrier comparison PWM or spatial vector PWM. 【0062】 When carrier comparison PWM is used, the PWM control unit 353 compares the carrier wave with the three-phase voltage command values ​​Vuo, Vvo, and Vwo, and turns on and off multiple switching elements based on the comparison result. The carrier wave is defined as a triangular wave that oscillates around 0 with an amplitude of half the DC voltage Vdc / 2 during the PWM period. For each phase, if the carrier wave falls below the voltage command value, the PWM control unit 353 turns on the switching signal of the high-potential side switching element to turn on the high-potential side switching element, and if the carrier wave exceeds the voltage command value, it turns off the switching signal of the high-potential side switching element to turn off the high-potential side switching element. On the other hand, the PWM control unit 353, for each phase, turns off the switching signal of the switching element on the low-potential side when the carrier wave falls below the voltage command value, and turns on the switching signal of the switching element on the low-potential side when the carrier wave exceeds the voltage command value. 【0063】Furthermore, for each phase, a short-circuit prevention period (dead time) may be provided between the on-period of the high-potential switching element and the on-period of the low-potential switching element, during which both the positive-side and low-potential switching elements are turned off. 【0064】 When spatial vector PWM is used, the PWM control unit 353 generates a voltage command vector from the three-phase voltage command values ​​Vuo, Vvo, and Vwo, determines the output time distribution of the seven basic voltage vectors in the PWM period based on the voltage command vector, and generates switching signals to turn each switching element on and off in the PWM period based on the output time distribution of the seven basic voltage vectors. 【0065】 <Converter Control Unit 354> The converter control unit 354 calculates a target DC voltage Vdco, which is the target value of the DC voltage Vdc supplied to the inverter 20, and controls the converter 18 based on the target DC voltage Vdco. 【0066】 If the target DC voltage Vdco is greater than the power supply voltage Vb of the DC power supply 10, the converter control unit 354 controls the converter 18 so that the DC voltage Vdc approaches the target DC voltage Vdco. In this embodiment, the converter control unit 354 changes the duty cycle of the control signals for each switching signal according to the PWM control method based on the DC voltage Vdc and the target DC voltage Vdco. 【0067】 When the converter control unit 354 causes the converter 18 to perform a boost operation, it alternately provides, for example, an on period in which only the high-potential switching element Q1 is turned on, and an on period in which only the low-potential switching element Q2 is turned on, and changes the ratio of the two on periods to change the boost ratio. When the converter control unit 354 causes the converter 18 to perform a step-down operation, it alternately provides, for example, an on period in which only the high-potential switching element Q1 is turned on, and an off period in which all switching elements Q1 and Q2 are turned off, and changes the ratio of the on periods to the off periods to change the step-down ratio. When the target DC voltage Vdco is less than or equal to the power supply voltage Vb, the converter control unit 354 turns off all switching elements Q1 and Q2 and connects the DC power supply 10 and the inverter 20 directly. 【0068】 <Changes in target DC voltage Vdco based on the temperature Tmp of the rotating electric machine> The converter control unit 354 changes the target DC voltage Vdco based on the temperature Tmp of the rotating electric machine, thereby changing the maximum configurable RMS value Vemax. 【0069】 With this configuration, as described above using equation (4), even with the same maximum configurable modulation ratio Mmax, the maximum configurable effective value Vemax of the three-phase voltage command increases as the DC voltage Vdc increases. Therefore, by changing the DC voltage Vdc by changing the target DC voltage Vdco based on the temperature Tmp of the rotating electric machine, the DC voltage Vdc is changed, and the maximum configurable effective value Vemax is changed, thereby changing the current flowing through the armature windings and appropriately changing the temperature Tmp of the rotating electric machine. For example, the rise in the temperature Tmp of the rotating electric machine can be suppressed. As described above, the maximum configurable modulation ratio Mmax changes depending on whether or not amplitude reduction modulation is performed and whether or not an overmodulation state is permitted. 【0070】 In this embodiment, the converter control unit 354 increases the target DC voltage Vdco from the reference target DC voltage Vdcobs when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, and increases the configurable maximum effective value Vemax from the reference maximum effective value Vemaxbs. The determination temperature Tmpth is set to a temperature lower than the upper limit temperature Tmplmt. 【0071】 With this configuration, when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, the rise in the temperature Tmp of the rotating electric machine can be suppressed by increasing the target DC voltage Vdco beyond the reference target DC voltage Vdcobs and increasing the configurable maximum effective value Vemax beyond the reference maximum effective value Vemaxbs. 【0072】 In this embodiment, when the converter control unit 354 increases the target DC voltage Vdco to a level higher than the reference target DC voltage Vdcobs when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, and performs flux weakening control, it reduces the negative increase in the d-axis current Id. 【0073】With this configuration, when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, the target DC voltage Vdco is increased. When the DC voltage Vdc increases, the negative increase in the d-axis current command value Ido, which is used to weaken the induced voltage with respect to the DC voltage Vdc, can be reduced in flux weakening control. This reduces the current flowing through the armature windings and suppresses the temperature rise of the rotating electric machine's temperature Tmp. Furthermore, if flux weakening control is performed at least before the increase in the target DC voltage Vdco, the negative increase in the d-axis current command value Ido can be reduced. 【0074】 The converter control unit 354 sets the target DC voltage Vdco to the increased target DC voltage Vdcoin when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, and sets the target DC voltage Vdco to the reference target DC voltage Vdcobs when the temperature Tmp of the rotating electric machine is less than the determination temperature Tmpth. The increased target DC voltage Vdcoin is greater than the reference target DC voltage Vdcobs. 【0075】 Furthermore, the converter control unit 354 may introduce hysteresis into the determination using the determination temperature Tmpth. That is, if the target DC voltage Vdco is set to the increased target DC voltage Vdcoin, the converter control unit 354 will reduce the target DC voltage Vdco to the reference target DC voltage Vdcobs and reduce the configurable maximum effective value Vemax to the reference maximum effective value Vemaxbs when the temperature Tmp of the rotating electric machine falls below the release determination temperature Tmpth, which is set to a temperature less than the determination temperature Tmpth. With this configuration, by introducing hysteresis into the determination, chattering can be prevented and the control behavior can be stabilized. 【0076】Figure 5 shows the operating range of torque and rotational speed in which the temperature Tmp of the rotating electric machine is continuously maintained below the upper limit temperature Tmplmt when the target DC voltage Vdco is set to the reference target DC voltage Vdcobs (hereinafter referred to as the continuous operating range of the reference target DC voltage), and the operating range of torque and rotational speed in which the temperature Tmp of the rotating electric machine is continuously maintained below the upper limit temperature Tmplmt when the target DC voltage Vdco is set to the increased target DC voltage Vdcoin (hereinafter referred to as the continuous operating range of the increased target DC voltage). The reference target DC voltage Vdcobs is set to a voltage equal to or greater than the power supply voltage Vb. 【0077】 Furthermore, the maximum operating range at each target DC voltage is wider than the continuous operating range at each target DC voltage (not shown). Also, the continuous operating range at high torque and high rotational speed at each target DC voltage generally overlaps with the operating range of flux weakening control, as shown in Figure 4. 【0078】 As shown in Figure 6, when the target DC voltage Vdcoin is set, the voltage limit ellipse expands as the DC voltage Vdc increases, and the negative increase in the d-axis current command value Ido decreases compared to when the reference target DC voltage Vdcobs is set. This reduces the current flowing through the armature windings and suppresses the temperature rise of the rotating electric machine's temperature Tmp. As a result, as shown in Figure 5, the continuous operation region extends to the high rotational speed side. 【0079】 For example, the control behavior at operating point A in Figure 5 is shown in the time chart in Figure 7. Initially, the target DC voltage Vdco is set to the reference target DC voltage Vdcobs. Flux weakening control is performed, and the modulation rate M is set to the maximum modulo modulus Mmax. As shown in equations (3) and (4), the effective value Ve of the three-phase voltage command value and the maximum effective value Vemax are values ​​corresponding to the product of the maximum modulo modulus Mmax and the reference target DC voltage Vdcobs (Mmax ​​× Vdcobs / √3). Also, because flux weakening control is performed, the d-axis current Id increases in the negative direction compared to when maximum torque / current control is performed, and the current Ia, which is the magnitude of the current vector between the d-axis current and the q-axis current, increases. 【0080】Initially, the temperature Tmp of the rotating electric machine is below the judgment temperature Tmpth. Since the operating point A is outside the continuous operation region of the reference target DC voltage that can maintain the temperature Tmp of the rotating electric machine below the upper limit temperature Tmplmt, the temperature Tmp of the rotating electric machine continues to rise, and if the reference target DC voltage Vdcobs remains set, the temperature Tmp of the rotating electric machine will exceed the upper limit temperature Tmplmt. 【0081】 At time t01, the temperature Tmp of the rotating electric machine becomes equal to or greater than the judgment temperature Tmpth, and the target DC voltage Vdco is increased from the reference target DC voltage Vdcobs to the increased target DC voltage Vdcoin. Since the operating point A is within the continuous operation region of the increased target DC voltage that can maintain the temperature Tmp of the rotating electric machine below the upper limit temperature Tmplmt, even if the increased target DC voltage Vdcoin remains set, the temperature Tmp of the rotating electric machine will not exceed the upper limit temperature Tmplmt. 【0082】 When flux weakening control is performed, the effective value Ve of the three-phase voltage command value and the settable maximum effective value Vemax increase to a value corresponding to the product of the settable maximum modulation rate Mmax and the increased target DC voltage Vdcoin (Mmax ​​× Vdcoin / √3). As the DC voltage Vdc increases, in flux weakening control, the negative increase in the d-axis current command value Ido, which weakens the induced voltage with respect to the DC voltage Vdc, decreases, and the current Ia that energizes the armature winding decreases. Therefore, the temperature rise Tmp of the rotating electric machine can be suppressed. 【0083】 <Changes in target DC voltage Vdco based on rotational speed ω> In this embodiment, the converter control unit 354 changes the target DC voltage Vdco based on the temperature Tmp and rotational speed ω of the rotating electric machine, thereby changing the maximum settable effective value Vemax. 【0084】As shown in Figure 5, when the rotational speed ω is less than or equal to the judgment speed ωth, the continuous operation range of the reference target DC voltage is wider than the continuous operation range of the increased target DC voltage at high torque. Therefore, at low rotational speeds, setting the target DC voltage Vdco to the reference target DC voltage Vdcobs can suppress the temperature rise Tmp of the rotating electric machine. In other words, at low rotational speeds, the target DC voltage Vdco should be set to the reference target DC voltage Vdcobs, and at high rotational speeds, the target DC voltage Vdco should be set to the increased target DC voltage Vdcoin. 【0085】 The converter control unit 354 increases the target DC voltage Vdco to a reference target DC voltage Vdcobs and increases the configurable maximum effective value Vemax to a reference maximum effective value Vemaxbs when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth and the rotation speed ω is equal to or greater than the determination speed ωth. 【0086】 With this configuration, when the rotational speed ω is less than or equal to the judgment speed ωth, the temperature rise of the rotating electric machine Tmp can be suppressed by setting the target DC voltage Vdco to the reference target DC voltage Vdcobs. The judgment speed ωth is set to correspond to the rotational speed boundary where the continuous operation region of the reference target DC voltage is wider than the continuous operation region of the increased target DC voltage. The judgment speed ωth may be slightly increased or decreased from the rotational speed boundary. 【0087】 Figure 8 shows the continuous operation range for each target DC voltage in which the temperature Tmp of the rotating electric machine is continuously maintained below the upper limit temperature Tmplmt, when the target DC voltage Vdco is increased in two stages from the reference target DC voltage Vdcobs to the first increased target DC voltage Vdcoin1 and the second increased target DC voltage Vdcoin2 (Vdcobs < Vdcoin1 < Vdcoin2). As the target DC voltage increases, the continuous operation range expands towards the high rotational speed side. Also, as the target DC voltage increases, the continuous operation range narrows towards the low torque side. 【0088】Therefore, when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, the converter control unit 354 may continuously or stepwise increase the target DC voltage Vdco as the rotational speed ω increases at the same torque, thereby continuously or stepwise increasing the maximum effective value Vemax of the three-phase voltage command value. 【0089】 For example, in a portion X of the continuous operation region of the first increased target DC voltage that does not overlap with the continuous operation region of the reference target DC voltage, the target DC voltage Vdco is set to the first increased target DC voltage Vdcoin1, and in a portion Y of the continuous operation region of the second increased target DC voltage that does not overlap with the continuous operation region of the first increased target DC voltage, the target DC voltage Vdco is set to the second increased target DC voltage Vdcoin2. The target DC voltage Vdco may also change continuously between the reference target DC voltage Vdcobs, the first increased target DC voltage Vdcoin1, and the second increased target DC voltage Vdcoin2, complemented by the rotational speed ω. 【0090】 Similar to Embodiment 2 described later, the converter control unit 354 may calculate the target DC voltage Vdcoin corresponding to the current torque (torque command value in this example) and current rotational speed using a preset function that sets the relationship between the torque and rotational speed ω of the rotating electric machine and the target DC voltage Vdcoin. Alternatively, the converter control unit 354 may calculate the reference target DC voltage Vdcobs corresponding to the current torque (torque command value in this example) and current rotational speed using a preset function that sets the relationship between the torque and rotational speed ω of the rotating electric machine and the reference target DC voltage Vdcobs. In other words, each set voltage may change according to the operating point of the torque and rotational speed. 【0091】 <Flowchart> The flowchart in Figure 9 will be used to explain the processing of the output control unit 35 related to setting the target DC voltage Vdco in this embodiment. The processing in the flowchart in Figure 9 is executed, for example, at predetermined calculation cycles. 【0092】 In step S11, as described above, the temperature detection unit 31 detects the temperature Tmp of the rotating electric machine, and the rotation detection unit 32 detects the rotation speed ω. 【0093】 In step S12, as described above, the converter control unit 354 determines whether the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth. If it determines that the temperature Tmpth is equal to or greater than the determination temperature Tmpth, it proceeds to step S13. If it determines that the temperature Tmpth is not equal to or greater than the determination temperature Tmpth, it proceeds to step S15. 【0094】 The converter control unit 354 may introduce hysteresis into the determination using the determination temperature Tmpth. That is, when the target DC voltage Vdco is set to the reference target DC voltage Vdcobs, the converter control unit 354 determines that the upper limit temperature Tmplmt is equal to or greater than the determination temperature Tmpth when the temperature Tmp of the rotating electric machine becomes equal to or greater than the determination temperature Tmpth. On the other hand, when the target DC voltage Vdco is set to the increased target DC voltage Vdcoin, the converter control unit 354 determines that the upper limit temperature Tmplmt is not equal to or greater than the determination temperature Tmpth when the temperature Tmp of the rotating electric machine falls below the release determination temperature Tmpthoff, which is set to a temperature below the determination temperature Tmpth. 【0095】 In step S13, as described above, the converter control unit 354 determines whether the rotational speed ω is greater than or equal to the determination speed ωth. If it determines that the rotational speed ω is greater than or equal to the determination speed ωth, it proceeds to step S14. If it determines that the rotational speed is not greater than or equal to the determination speed ωth, it proceeds to step S15. Similar to the determination using the determination temperature Tmpth, the converter control unit 354 may introduce hysteresis into the determination using the determination speed ωth. 【0096】 In step S14, the converter control unit 354 sets the target DC voltage Vdco to the increased target DC voltage Vdcoin. As described above, the converter control unit 354 may continuously or stepwise increase the increased target DC voltage Vdcoin as the rotational speed ω increases at the same torque. 【0097】 Meanwhile, in step S15, the converter control unit 354 sets the target DC voltage Vdco to the reference target DC voltage Vdcobs. 【0098】2. Embodiment 2 The rotating electric machine 2 and control device 30 according to Embodiment 2 will be described. The same components as in Embodiment 1 will not be described. The basic configuration of the rotating electric machine 2 and control device 30 according to this embodiment is the same as in Embodiment 1, but the calculation process of the target DC voltage Vdco of the converter control unit 354 differs from that of Embodiment 1. 【0099】 In this embodiment, the converter control unit 354 calculates a reference target DC voltage Vdcobs and a temperature reduction target DC voltage Vdcotmp for reducing the temperature of the rotating electric machine. 【0100】 The converter control unit 354 calculates the current torque (torque command value in this example) and the target DC voltage Vdcotmp corresponding to the current rotational speed using a pre-set setting function that defines the relationship between the torque and rotational speed ω of the rotating electric machine and the target DC voltage Vdcotmp for temperature reduction. Map data or higher-order functions (e.g., polynomials, neural networks) are used as the setting function and are pre-stored in a storage device 91 such as ROM. The converter control unit 354 calculates the current torque (torque command value in this example) and the target DC voltage Vdcobs corresponding to the current rotational speed using a pre-set setting function that defines the relationship between the torque and rotational speed ω of the rotating electric machine and the reference target DC voltage Vdcobs. 【0101】As shown in Figures 5 and 8, at high rotational speeds, increasing the target DC voltage Vdco above the reference target DC voltage Vdcobs widens the continuous operation range and allows for a greater reduction in the temperature of the rotating electric machine. At low rotational speeds and high torque, decreasing the target DC voltage Vdco to the reference target DC voltage Vdcobs widens the continuous operation range and allows for a greater reduction in the temperature of the rotating electric machine. Even in other continuous operation ranges, the target DC voltage Vdco that allows for a greater reduction in the temperature of the rotating electric machine changes depending on the rotational speed and torque. That is, the target DC voltage Vdcotmp for reducing the temperature of the rotating electric machine changes depending on the operating point of the torque and rotational speed ω. If the reference target DC voltage Vdcobs is higher than the power supply voltage Vb, the target DC voltage Vdcotmp may be set lower than the reference target DC voltage Vdcobs. 【0102】 The converter control unit 354 sets the target DC voltage Vdco to the temperature drop target DC voltage Vdcotmp when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, which is set to a temperature lower than the upper limit temperature Tmplmt. On the other hand, the converter control unit 354 sets the target DC voltage Vdco to the reference target DC voltage Vdcobs when the temperature Tmp of the rotating electric machine is less than the determination temperature Tmpth. 【0103】 <Flowchart> The process of the output control unit 35 related to setting the target DC voltage Vdco in this embodiment will be explained using the flowchart in Figure 10. The process of the flowchart in Figure 10 is executed, for example, at predetermined calculation cycles. 【0104】 In step S21, as described above, the temperature detection unit 31 detects the temperature Tmp of the rotating electric machine, and the rotation detection unit 32 detects the rotation speed ω. 【0105】In step S22, as described above, the converter control unit 354 calculates the reference target DC voltage Vdcobs and the temperature reduction target DC voltage Vdcotmp for reducing the temperature of the rotating electric machine. In this embodiment, as described above, the reference target DC voltage Vdcobs and the temperature reduction target DC voltage Vdcotmp are calculated using a setting function based on the current torque (torque command value) and the current rotational speed. 【0106】 In step S23, as described above, the converter control unit 354 determines whether the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth. If it determines that the temperature Tmpth is equal to or greater than the determination temperature Tmpth, it proceeds to step S24. If it determines that the temperature Tmpth is not equal to or greater than the determination temperature Tmpth, it proceeds to step S25. Similar to Embodiment 1, the converter control unit 354 may introduce hysteresis into the determination using the determination temperature Tmpth. 【0107】 In step S24, the converter control unit 354 sets the target DC voltage Vdco to the temperature drop target DC voltage Vdcotmp. Meanwhile, in step S25, the converter control unit 354 sets the target DC voltage Vdco to the reference target DC voltage Vdcobs. 【0108】 3. Embodiment 3 The rotating electric machine 2 and control device 30 according to Embodiment 3 will now be described. The same components as in Embodiment 1 will not be described. The basic configuration of the rotating electric machine 2 and control device 30 according to this embodiment is the same as in Embodiment 1, but the converter 18 is not provided, and the calculation processing of the output control unit 35 is different from that of Embodiment 1. 【0109】 In this embodiment, as shown in Figure 11, there is no converter 18, and the DC power supply 10 is directly connected to the inverter 20. Therefore, the DC voltage Vdc matches the power supply voltage Vb. Also, as shown in Figure 12, the output control unit 35 does not include a converter control unit 354, but includes a maximum modulation rate setting unit 355. 【0110】In this embodiment, the voltage detection unit 33 detects the DC voltage Vdc (power supply voltage Vb) supplied from the DC power supply 10 to the inverter 20. The output control unit 35 includes a current command value calculation unit 351, a voltage command value calculation unit 352, a PWM control unit 353, and a maximum modulation rate setting unit 355. 【0111】 As described in Embodiment 1, the maximum modulation rate Mmax can be changed depending on whether or not an overmodulation state is permitted and whether or not amplitude reduction modulation is performed. 【0112】 As shown in equation (4), even with the same DC voltage Vdc, the maximum effective value Vemax of the three-phase voltage command increases as the maximum configurable modulation rate Mmax increases. Therefore, as shown in Figure 13, as the maximum configurable modulation rate Mmax increases, the execution range of maximum torque / current control and flux weakening control shifts to the higher rotational speed side. 【0113】 The current command value calculation unit 351 calculates the dq-axis current command values ​​Ido and Iqo based on the output command value, rotational speed ω, and the configurable maximum modulation rate Mmax, according to a current vector control method such as maximum torque / current control and flux weakening control. For each configurable maximum modulation rate Mmax, the dq-axis current command values ​​Ido and Iqo are set to a range of output command value and rotational speed ω as shown in Figure 13, where the modulation rate M is less than or equal to the configurable maximum modulation rate Mmax. 【0114】 The current command value calculation unit 351 calculates the dq-axis current command values ​​Ido and Iqo corresponding to the current torque command value, rotational speed ω, and the configurable maximum modulation rate Mmax, using map data that has been pre-set for each control method, where the relationship between the torque command value, rotational speed ω, and configurable maximum modulation rate Mmax is also set. Instead of the configurable maximum modulation rate Mmax, the configurable maximum effective value Vemax, which is the product of the DC voltage Vdc and the configurable maximum modulation rate Mmax, may be used. Other known calculation methods may also be used. 【0115】In this embodiment, the maximum modulation rate setting unit 355 changes the maximum modulus Mmax that can be set based on the temperature Tmp of the rotating electric machine, thereby changing the maximum effective value Vemax that can be set. The configuration of the output control unit 35, other than the configuration related to the maximum effective value Vemax that can be set, is the same as in Embodiment 1, so its description is omitted. 【0116】 As explained using equation (4), the maximum configurable RMS value Vemax is proportional to the maximum configurable modulation rate Mmax and the DC voltage Vdc. Therefore, by changing the maximum configurable modulation rate Mmax instead of the DC voltage Vdc in Embodiment 1, the maximum configurable RMS value Vemax can be changed. Thus, the same effect as changing the DC voltage Vdc in Embodiment 1 can be obtained. That is, by changing the maximum configurable modulation rate Mmax based on the temperature Tmp of the rotating electric machine, the current supplied to the armature winding can be changed, and the temperature Tmp of the rotating electric machine can be appropriately changed, for example, the rise in the temperature Tmp of the rotating electric machine can be suppressed. As mentioned above, the maximum configurable modulation rate Mmax changes depending on whether or not amplitude reduction modulation is performed and whether or not an overmodulation state is permitted. 【0117】 The maximum modulation rate setting unit 355 increases the maximum modulus Mmax that can be set compared to the reference maximum modulation rate Mmaxbs when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, and increases the maximum effective value Vemax that can be set compared to the reference maximum effective value Vemaxbs. The determination temperature Tmpth is set to a temperature lower than the upper limit temperature Tmplmt. 【0118】 With this configuration, when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, the rise in the temperature Tmp of the rotating electric machine can be suppressed by increasing the configurable maximum modulation rate Mmax above the reference maximum modulation rate Mmaxbs and increasing the configurable maximum effective value Vemax above the reference maximum effective value Vemaxbs. 【0119】In this embodiment, when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, the maximum modulation rate setting unit 355 increases the settable maximum modulation rate Mmax compared to the reference maximum modulation rate Mmaxbs to perform flux weakening control, thereby reducing the negative increase in the d-axis current Id. 【0120】 With this configuration, when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, the maximum configurable modulation rate Mmax is increased, and the maximum configurable RMS value Vemax is increased. In flux weakening control, the negative increase in the d-axis current command value Ido, which weakens the induced voltage with respect to the DC voltage Vdc, can be reduced, thereby reducing the current flowing through the armature winding and suppressing the temperature rise of the rotating electric machine's temperature Tmp. Furthermore, if flux weakening control is performed at least before the increase in the maximum configurable modulation rate Mmax, the negative increase in the d-axis current command value Ido can be reduced. 【0121】 The maximum modulation rate setting unit 355 sets the maximum modulus Mmax to the increased maximum modulation rate Mmaxin when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, and sets the maximum modulus Mmax to the reference maximum modulation rate Mmaxbs when the temperature Tmp of the rotating electric machine is less than the determination temperature Tmpth. The increased maximum modulation rate Mmaxin is greater than the reference maximum modulation rate Mmaxbs. 【0122】 Furthermore, similar to Embodiment 1, the maximum modulation rate setting unit 355 may introduce hysteresis into the determination using the determination temperature Tmpth. That is, if the configurable maximum modulation rate Mmax is set to the increasing maximum modulation rate Mmaxin, the maximum modulation rate setting unit 355 will reduce the configurable maximum modulation rate Mmax to the reference maximum modulation rate Mmaxbs and reduce the configurable maximum effective value Vemax to the reference maximum effective value Vemaxbs when the temperature Tmp of the rotating electric machine falls below the release determination temperature Tmpth, which is set to a temperature less than the determination temperature Tmpth. With this configuration, by introducing hysteresis into the determination, chattering can be prevented and the control behavior can be stabilized. 【0123】<Setting the maximum modulus Mmax> For each of the reference maximum modulus Mmaxbs and the increased maximum modulus Mmaxin, the presence or absence of an overmodulation state and the presence or absence of amplitude reduction modulation are combined, and the reference maximum modulus Mmaxbs and the increased maximum modulus Mmaxin corresponding to each combination are set. The maximum modulus setting unit 355 commands the voltage command value calculation unit 352 to perform or not perform amplitude reduction modulation, and the maximum modulus setting unit 355 performs or does not perform amplitude reduction modulation. 【0124】 For example, if the reference maximum modulation rate Mmaxbs is set to 0.612, amplitude reduction modulation is not performed and an overmodulation state is not permitted. If the increased maximum modulation rate Mmaxin is set to 0.707, amplitude reduction modulation is performed and an overmodulation state is not permitted. That is, when the temperature Tmp of the rotating electric machine is less than the determination temperature Tmpth, the maximum modulation rate setting unit 355 does not cause the voltage command value calculation unit 352 to perform amplitude reduction modulation, and sets the configurable maximum modulation rate Mmax to 0.612, which is the reference maximum modulation rate Mmaxbs that does not permit an overmodulation state. On the other hand, when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, the maximum modulation rate setting unit 355 causes the voltage command value calculation unit 352 to perform amplitude reduction modulation, and sets the configurable maximum modulation rate Mmax to 0.707, which is the increased maximum modulation rate Mmaxin that does not permit an overmodulation state. 【0125】 Alternatively, the reference maximum modulation rate Mmaxbs may be set to 0.612, so amplitude reduction modulation is not performed and an overmodulation state is not permitted. The increased maximum modulation rate Mmaxin may be set to a modulation rate within the range of 0.612 < M ≤ 0.78 (for example, 0.73), so amplitude reduction modulation is not performed and an overmodulation state is permitted. That is, when the temperature Tmp of the rotating electric machine is less than the determination temperature Tmpth, the maximum modulation rate setting unit 355 does not cause the voltage command value calculation unit 352 to perform amplitude reduction modulation, and sets the configurable maximum modulation rate Mmax to 0.612, which is the reference maximum modulation rate Mmaxbs that does not permit an overmodulation state. On the other hand, when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, the maximum modulation rate setting unit 355 does not cause the voltage command value calculation unit 352 to perform amplitude reduction modulation, and sets the maximum modulation rate Mmax that can be set to 0.73, which is the increased maximum modulation rate Mmaxin that allows an overmodulation state. 【0126】 Alternatively, the reference maximum modulation rate Mmaxbs may be set to 0.707, amplitude reduction modulation may be performed, and an overmodulation state may not be permitted. The increased maximum modulation rate Mmaxin may be set to a modulation rate within the range of 0.707 < M ≤ 0.78 (for example, 0.73), amplitude reduction modulation may be performed, and an overmodulation state may be permitted. That is, when the temperature Tmp of the rotating electric machine is less than the determination temperature Tmpth, the maximum modulation rate setting unit 355 causes the voltage command value calculation unit 352 to perform amplitude reduction modulation and sets the configurable maximum modulation rate Mmax to 0.707, which is the reference maximum modulation rate Mmaxbs that does not permit an overmodulation state. On the other hand, when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, the maximum modulation rate setting unit 355 causes the voltage command value calculation unit 352 to perform amplitude reduction modulation and sets the configurable maximum modulation rate Mmax to 0.73, which is the increased maximum modulation rate Mmaxin that permits an overmodulation state. 【0127】 Figure 14 shows the operating range of torque and rotational speed in which the temperature Tmp of the rotating electric machine is continuously maintained below the upper limit temperature Tmplmt when the configurable maximum modulation rate Mmax is set to the reference maximum modulation rate Mmaxbs (hereinafter referred to as the continuous operating range of the reference maximum modulation rate), and the operating range of torque and rotational speed in which the temperature Tmp of the rotating electric machine is continuously maintained below the upper limit temperature Tmplmt when the configurable maximum modulation rate Mmax is set to the increasing maximum modulation rate Mmaxin (hereinafter referred to as the continuous operating range of the increasing maximum modulation rate). 【0128】 Furthermore, the maximum operating range at each maximum modulation rate is wider than the continuous operating range at each maximum modulation rate (not shown). Also, the continuous operating range at high torque and high rotational speed at each maximum modulation rate generally overlaps with the operating range of flux weakening control, as shown in Figure 13. 【0129】 When the increased maximum modulation rate Mmaxin is set, the negative increase in the d-axis current command value Ido is reduced compared to when the reference maximum modulation rate Mmaxbs is set. This reduces the current flowing through the armature windings and suppresses the temperature rise Tmp of the rotating electric machine. As a result, as shown in Figure 14, the continuous operation region extends to the high rotational speed side. 【0130】For example, the control behavior at operating point A in Figure 14 is shown in the time chart of Figure 15. Initially, the maximum configurable modulation rate Mmax is set to the reference maximum modulation rate Mmaxbs. When flux weakening control is performed, the modulation rate M is set to the maximum configurable modulation rate Mmax, and as shown in equations (3) and (4), the effective value Ve of the three-phase voltage command value and the maximum configurable effective value Vemax become values ​​corresponding to the product of the reference maximum modulation rate Mmaxbs and the DC voltage Vdc (Mmaxbs × Vdc / √3). Also, because flux weakening control is performed, the d-axis current Id increases in the negative direction compared to when maximum torque / current control is performed, and the current Ia, which is the magnitude of the current vector between the d-axis current and the q-axis current, increases. 【0131】 Initially, the temperature Tmp of the rotating electric machine is below the judgment temperature Tmpth. Since the operating point A is outside the continuous operation region of the reference maximum modulation rate that can maintain the temperature Tmp of the rotating electric machine below the upper limit temperature Tmplmt, the temperature Tmp of the rotating electric machine continues to rise, and if the reference maximum modulation rate Mmaxbs remains set, the temperature Tmp of the rotating electric machine will exceed the upper limit temperature Tmplmt. 【0132】 At time t11, the temperature Tmp of the rotating electric machine becomes equal to or greater than the determination temperature Tmpth, and the settable maximum modulation rate Mmax is increased from the reference maximum modulation rate Mmaxbs to the increased maximum modulation rate Mmaxin. Since the operating point A is inside the continuous operation region of the increased maximum modulation rate that can maintain the temperature Tmp of the rotating electric machine below the upper limit temperature Tmplmt, even if the increased maximum modulation rate Mmaxin is kept set, the temperature Tmp of the rotating electric machine will not exceed the upper limit temperature Tmplmt. 【0133】 When flux weakening control is performed, the effective value Ve of the three-phase voltage command value and the settable maximum effective value Vemax increase, corresponding to the multiplication of the increasing maximum modulation rate Mmaxin and the DC voltage Vdc (Mmaxin × Vdc / √3). As the effective value Ve of the three-phase voltage command value increases, in flux weakening control, the negative increase in the d-axis current command value Ido, which weakens the induced voltage with respect to the DC voltage Vdc, decreases, and the current Ia that energizes the armature winding decreases. Therefore, the temperature rise Tmp of the rotating electric machine can be suppressed. 【0134】 <Changes in the maximum modulus Mmax that can be set based on the rotational speed ω> In this embodiment, the maximum modulus setting unit 355 changes the maximum modulus Mmax that can be set based on the temperature Tmp of the rotating electric machine and the rotational speed ω, thereby changing the maximum effective value Vemax that can be set. 【0135】 As shown in Figure 14, when the rotational speed ω is less than or equal to the judgment speed ωth, the continuous operation region of the reference maximum modulation rate is wider than the continuous operation region of the increasing maximum modulation rate at high torque. Therefore, at low rotational speeds, setting the configurable maximum modulation rate Mmax to the reference maximum modulation rate Mmaxbs can suppress the temperature rise Tmp of the rotating electric machine. In other words, at low rotational speeds, it is preferable to set the configurable maximum modulation rate Mmax to the increasing maximum modulation rate Mmaxin, and at high rotational speeds, it is preferable to set the configurable maximum modulation rate Mmax to the increasing maximum modulation rate Mmaxin. 【0136】 The maximum modulation rate setting unit 355 increases the maximum modulus Mmax that can be set compared to the reference maximum modulation rate Mmaxbs when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth and the rotation speed ω is equal to or greater than the determination speed ωth, and increases the maximum effective value Vemax that can be set compared to the reference maximum effective value Vemaxbs. 【0137】 With this configuration, when the rotational speed ω is less than or equal to the determination speed ωth, the temperature rise of the rotating electric machine Tmp can be suppressed by setting the maximum configurable modulation rate Mmax to the reference maximum modulation rate Mmaxbs. The determination speed ωth is set to correspond to the rotational speed boundary where the continuous operation region of the reference maximum modulation rate is wider than the continuous operation region of the increasing maximum modulation rate. The determination speed ωth may be slightly higher or lower than the rotational speed boundary. 【0138】 Similar to Embodiment 1, the maximum modulation rate setting unit 355 may, when the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, continuously or stepwise increase the maximum modulus Mmax that can be set, as the rotational speed ω increases at the same torque, thereby continuously or stepwise increasing the maximum effective value Vemax of the three-phase voltage command value. 【0139】For example, as shown in Figure 16, as the rotational speed ω increases at the same torque, the configurable maximum modulation ratio Mmax may increase in two stages from the reference maximum modulation ratio Mmaxbs to a first increasing maximum modulation ratio Mmaxin1 and a second increasing maximum modulation ratio Mmaxin2 (Mmaxbs < Mmaxin1 < Mmaxin2). For example, Mmaxbs may be set to 0.612, Mmaxin1 to 0.707, and Mmaxin1 may be set to a modulation ratio within the range of 0.707 < M ≤ 0.78 (e.g., 0.73). Similar to Embodiment 1, the configurable maximum modulation ratio Mmax may change continuously between the reference maximum modulation ratio Mmaxbs, the first increasing maximum modulation ratio Mmaxin1, and the second increasing maximum modulation ratio Mmaxin2, complemented by the rotational speed ω. 【0140】 Similar to Embodiment 4 described later, the maximum modulation rate setting unit 355 may calculate the increased maximum modulation rate Mmaxin corresponding to the current torque (torque command value in this example) and current rotational speed using a setting function in which the relationship between the torque and rotational speed ω of the rotating electric machine and the increased maximum modulation rate Mmaxin is predetermined. Alternatively, the maximum modulation rate setting unit 355 may calculate the reference maximum modulation rate Mmaxbs corresponding to the current torque (torque command value in this example) and current rotational speed using a setting function in which the relationship between the torque and rotational speed ω of the rotating electric machine and the reference maximum modulation rate Mmaxbs is predetermined. In other words, each maximum modulation rate may change according to the operating point of the torque and rotational speed. 【0141】 <Flowchart> The process of the maximum modulation rate setting unit 355 related to setting the target DC voltage Vdco in this embodiment will be explained using the flowchart in Figure 17. The process of the flowchart in Figure 17 is executed, for example, at predetermined calculation cycles. 【0142】 In step S31, as described above, the temperature detection unit 31 detects the temperature Tmp of the rotating electric machine, and the rotation detection unit 32 detects the rotation speed ω. 【0143】In step S32, as described above, the maximum modulation rate setting unit 355 determines whether the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth. If it determines that the temperature Tmpth is equal to or greater than the determination temperature Tmpth, the unit proceeds to step S33. If it determines that the temperature Tmpth is not equal to or greater than the determination temperature Tmpth, the unit proceeds to step S35. 【0144】 The maximum modulation rate setting unit 355 may introduce hysteresis into the determination using the determination temperature Tmpth. That is, if the settable maximum modulation rate Mmax is set to the reference maximum modulation rate Mmaxbs, the maximum modulation rate setting unit 355 determines that the upper limit temperature Tmplmt is equal to or greater than the determination temperature Tmpth when the temperature Tmp of the rotating electric machine becomes equal to or greater than the determination temperature Tmpth. On the other hand, if the settable maximum modulation rate Mmax is set to the increasing maximum modulation rate Mmaxin, the maximum modulation rate setting unit 355 determines that the upper limit temperature Tmplmt is not equal to or greater than the determination temperature Tmpth when the temperature Tmp of the rotating electric machine falls below the release determination temperature Tmpthoff, which is set to a temperature less than the determination temperature Tmpth. 【0145】 In step S33, as described above, the maximum modulation rate setting unit 355 determines whether the rotational speed ω is greater than or equal to the determination speed ωth. If it determines that the rotational speed ω is greater than or equal to the determination speed ωth, it proceeds to step S34. If it determines that the rotational speed is not greater than or equal to the determination speed ωth, it proceeds to step S35. Similar to the determination using the determination temperature Tmpth, the maximum modulation rate setting unit 355 may introduce hysteresis into the determination using the determination speed ωth. 【0146】 In step S34, the maximum modulation rate setting unit 355 sets the configurable maximum modulation rate Mmax to the increased maximum modulation rate Mmaxin. As described above, the maximum modulation rate setting unit 355 may continuously or stepwise increase the increased maximum modulation rate Mmaxin as the rotational speed ω increases at the same torque. 【0147】 On the other hand, in step S35, the maximum modulation rate setting unit 355 sets the configurable maximum modulation rate Mmax to the reference maximum modulation rate Mmaxbs. 【0148】4. Embodiment 4 The rotating electric machine 2 and control device 30 according to Embodiment 4 will be described. The same components as in Embodiment 3 will not be described. The basic configuration of the rotating electric machine 2 and control device 30 according to this embodiment is the same as in Embodiment 3, but the calculation process of the maximum modulus setting unit 355 for the configurable maximum modulus Mmax differs from that of Embodiment 3. 【0149】 In this embodiment, the maximum modulation rate setting unit 355 calculates the reference maximum modulation rate Mmaxbs and the temperature reduction maximum modulation rate Mmaxtmp for reducing the temperature of the rotating electric machine. 【0150】 The maximum modulation rate setting unit 355 calculates the maximum modulation rate Mmaxtmp corresponding to the current torque (torque command value in this example) and current rotation speed using a setting function in which the relationship between the torque and rotation speed ω of the rotating electric machine and the maximum modulation rate Mmaxtmp of the temperature drop is predetermined. The setting function uses map data or a higher-order function (e.g., polynomial, neural network), and is pre-stored in a storage device 91 such as ROM. The maximum modulation rate setting unit 355 calculates the reference maximum modulation rate Mmaxbs corresponding to the current torque (torque command value in this example) and current rotation speed using a setting function in which the relationship between the torque and rotation speed ω of the rotating electric machine and the reference maximum modulation rate Mmaxbs is predetermined. 【0151】 As shown in Figures 14 and 16, at high rotational speeds, increasing the configurable maximum modulation ratio Mmax above the reference maximum modulation ratio Mmaxbs widens the continuous operation range and allows for a greater reduction in the temperature of the rotating electric machine. At low rotational speeds and high torques, decreasing the configurable maximum modulation ratio Mmax to the reference maximum modulation ratio Mmaxbs widens the continuous operation range and allows for a greater reduction in the temperature of the rotating electric machine. Even in other continuous operation ranges, the configurable maximum modulation ratio Mmax that allows for a greater reduction in the temperature of the rotating electric machine changes depending on the rotational speed and torque. That is, the maximum temperature reduction modulation ratio Mmaxtmp for reducing the temperature of the rotating electric machine changes depending on the operating point of the torque and rotational speed ω. The maximum temperature reduction modulation ratio Mmaxtmp may be lower than the reference maximum modulation ratio Mmaxbs. 【0152】 The maximum modulation rate setting unit 355 sets the maximum modulus Mmax to the temperature-decreased maximum modulation rate Mmaxtmp when the temperature Tmp of the rotating electric machine is greater than or equal to the determination temperature Tmpth, which is set to a temperature lower than the upper limit temperature Tmplmt. On the other hand, the maximum modulation rate setting unit 355 sets the maximum modulus Mmax to the reference maximum modulation rate Mmaxbs when the temperature Tmp of the rotating electric machine is less than the determination temperature Tmpth. 【0153】 <Flowchart> The flowchart in Figure 18 will be used to explain the processing of the output control unit 35 related to setting the configurable maximum modulation rate Mmax in this embodiment. The processing in the flowchart in Figure 18 is executed, for example, at predetermined calculation cycles. 【0154】 In step S41, as described above, the temperature detection unit 31 detects the temperature Tmp of the rotating electric machine, and the rotation detection unit 32 detects the rotation speed ω. 【0155】 In step S42, as described above, the maximum modulation rate setting unit 355 calculates the reference maximum modulation rate Mmaxbs and the temperature reduction maximum modulation rate Mmaxtmp for reducing the temperature of the rotating electric machine. In this embodiment, as described above, the reference maximum modulation rate Mmaxbs and the temperature reduction maximum modulation rate Mmaxtmp are calculated using a setting function based on the current torque (torque command value) and the current rotational speed. 【0156】 In step S43, as described above, the maximum modulation rate setting unit 355 determines whether the temperature Tmp of the rotating electric machine is equal to or greater than the determination temperature Tmpth, which is set to a temperature lower than the upper limit temperature Tmplmt. If it determines that the temperature is equal to or greater than the determination temperature Tmpth, the unit proceeds to step S44. If it determines that the temperature is not equal to or greater than the determination temperature Tmpth, the unit proceeds to step S45. Similar to Embodiment 1, the maximum modulation rate setting unit 355 may introduce hysteresis into the determination using the determination temperature Tmpth. 【0157】In step S44, the maximum modulation rate setting unit 355 sets the configurable maximum modulation rate Mmax to the temperature-reduced maximum modulation rate Mmaxtmp. On the other hand, in step S45, the maximum modulation rate setting unit 355 sets the configurable maximum modulation rate Mmax to the reference maximum modulation rate Mmaxbs. 【0158】 [Other Embodiments] (1) The change in the target DC voltage Vdco based on the temperature Tmp of the rotating electric machine in Embodiment 1 or 2, and the change in the configurable maximum modulation rate Mmax based on the temperature Tmp of the rotating electric machine in Embodiment 3 or 4 may be performed simultaneously. For example, in the configuration of Embodiment 1 or 2 in which the converter 18 is provided, the change in the configurable maximum modulation rate Mmax based on the temperature Tmp of the rotating electric machine in Embodiment 3 or 4 may be performed. With this configuration, the range of change in the configurable maximum effective value Vemax can be increased, and the temperature reduction effect can be increased. 【0159】 (2) In the above embodiments, the example described was that one set of three-phase armature windings and inverters 20 is provided, and the control device 30 is configured to match this one set. However, two or more sets of three-phase armature windings and inverters 20 may be provided. The control device 30 may perform the same control for each set as in the above embodiments based on the temperature Tmp of the rotating electric machine. 【0160】 While this disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but are applicable individually or in various combinations to the embodiments. Accordingly, countless variations not illustrated are envisioned within the scope of the art disclosed in this disclosure. For example, these include modifying, adding or omitting at least one component, or extracting at least one component and combining it with a component from another embodiment. 【0161】10: DC power supply, 18: Converter, 20: Inverter, 30: Control device for rotating electric machine, Mmax: Settable maximum modulation rate, Mmaxbs: Reference maximum modulation rate, Mmaxin: Increased maximum modulation rate, Mmaxtmp: Temperature drop maximum modulation rate, Tmp: Rotating electric machine temperature, Tmplmt: Upper limit temperature, Tmpth: Judgment temperature, Vdc: DC voltage, Vdco: Target DC voltage, Vdcobs: Reference target DC voltage, Vdcoin: Increased target DC voltage, Vdcotmp: Temperature drop target DC voltage, Vemax: Settable maximum RMS value, Vemaxbs: Reference maximum RMS value, ω: Rotation speed, ωth: Judgment speed

Claims

1. A control device for a rotating electric machine having multiple phase armature windings, which controls the rotating electric machine via an inverter, comprising: a temperature detection unit for detecting the temperature of the rotating electric machine; and an output control unit for calculating multiple phase voltage command values ​​to be applied to the multiple phase armature windings and controlling the inverter based on the multiple phase voltage command values, wherein the output control unit changes the settable maximum effective value of the multiple phase voltage command values ​​based on the temperature.

2. The control device for a rotating electric machine according to claim 1, wherein the output control unit increases the settable maximum effective value from a reference maximum effective value when the temperature is equal to or greater than the determination temperature.

3. The control device for a rotating electric machine according to claim 2, wherein the output control unit calculates the voltage command values ​​of the multiple phases so as to reduce the maximum torque of the rotating electric machine when the temperature exceeds the upper limit temperature, and the determination temperature is set to be less than the upper limit temperature.

4. The control device for a rotating electric machine according to any one of claims 1 to 3, wherein the output control unit switches between and executes basic control and flux weakening control which increases the d-axis current in the negative direction compared to the basic control, calculates the voltage command values ​​of the multiple phases, and when the temperature is equal to or above the determination temperature, increases the settable maximum effective value above the reference maximum effective value to reduce the amount of negative increase in the d-axis current when executing the flux weakening control.

5. A control device for a rotating electric machine according to any one of claims 1 to 4, wherein the rotating electric machine is controlled via the inverter and a converter that boosts the DC voltage supplied to the inverter from a DC power supply, the output control unit calculates a target DC voltage which is a target value of the DC voltage, controls the converter based on the target DC voltage, and changes the target DC voltage based on the temperature to change the settable maximum effective value.

6. A control device for a rotating electric machine according to any one of claims 1 to 5, wherein the modulation rate is defined as the ratio of the effective values ​​of the multiple-phase voltage command values ​​to the DC voltage supplied to the inverter, multiplied by a preset coefficient, and the output control unit changes the settable maximum modulation rate based on the temperature, thereby changing the settable maximum effective value.

7. The control device for a rotating electric machine according to claim 2, wherein the output control unit provides hysteresis to the determination using the determination temperature.

8. The control device for a rotating electric machine according to claim 5, wherein the output control unit calculates a reference target DC voltage and a temperature reduction target DC voltage for reducing the temperature, sets the target DC voltage to the temperature reduction target DC voltage when the temperature is equal to or greater than the determination temperature, and sets the target DC voltage to the reference target DC voltage when the temperature is less than the determination temperature.

9. The control device for a rotating electric machine according to claim 8, wherein the output control unit calculates the target DC voltage for temperature reduction corresponding to the current torque and current rotation speed using a preset function that sets the relationship between the torque and rotation speed of the rotating electric machine and the target DC voltage for temperature reduction.

10. The control device for a rotating electric machine according to claim 6, wherein the output control unit calculates a reference maximum effective value and a maximum effective value for temperature reduction to lower the temperature, sets the configurable maximum modulation rate to the maximum effective value for temperature reduction when the temperature is equal to or greater than the determination temperature, and sets the configurable maximum modulation rate to the reference maximum effective value when the temperature is less than the determination temperature.

11. The control device for a rotating electric machine according to claim 10, wherein the output control unit calculates the maximum effective temperature drop corresponding to the current torque and current rotation speed using a preset function that sets the relationship between the torque and rotation speed of the rotating electric machine and the maximum effective temperature drop.

12. The control device for a rotating electric machine according to any one of claims 1 to 11, wherein the output control unit changes the settable maximum effective value based on the temperature and the rotational speed of the rotating electric machine.

13. The control device for a rotating electric machine according to claim 12, wherein the output control unit increases the settable maximum effective value from a reference maximum effective value when the temperature is equal to or equal to a determination temperature, and increases the settable maximum effective value continuously or in steps as the rotational speed increases at the same torque when the temperature is equal to or equal to a determination temperature.

14. The control device for a rotating electric machine according to claim 12 or 13, wherein the output control unit increases the settable maximum effective value from a reference maximum effective value when the temperature is equal to or greater than the determination temperature and the rotation speed is equal to or greater than the determination speed.

Images