Motor control device, motor module, motor control method, and motor control program

Abstract

A motor control device according to one aspect of the present disclosure comprises a reception unit, a detection unit, and a control unit. The reception unit receives a switching of a travel mode from a first mode in which overmodulation control is performed to a second mode in which non-overmodulation control is performed. The detection unit detects the speed of the motor. The control unit decreases the modulation rate of the overmodulation control so as to decelerate the speed at a predetermined reduction rate when the switching is received by the reception unit in a state in which overmodulation control is performed while the speed exceeds an upper limit speed of the second mode in the first mode, and performs non-overmodulation control by setting the modulation factor to 1 or less and starts flux weakening control when the speed is equal to or less than the upper limit speed of the second mode.

Description

Motor control device, motor module, motor control method, and motor control program

[0001] The present disclosure relates to a motor control device, a motor module, a motor control method, and a motor control program.

[0002] In a mobility product such as a motorcycle or a passenger car that is driven by a motor, there are driving modes, which are the driving modes of the motor, including modes that emphasize efficiency, such as "comfortable ride" and "efficient," and modes that do not emphasize efficiency, such as "high-torque high-speed driving." The driver selects the desired driving mode from these.

[0003] When a mode that prioritizes efficiency is selected as the driving mode, it is necessary to select a motor rotation speed that will improve efficiency. Therefore, conventionally, the rotation speed that will improve efficiency (target speed) is selected by selecting the rotation speed that will improve efficiency from a predetermined relationship between the motor rotation speed and efficiency. Related patent documents include Patent Document 1.

[0004] Japanese Patent Application Laid-Open No. 2000-236601

[0005] In an efficiency-focused mode, overmodulation control may be performed to improve the utilization rate of the voltage applied from a power source such as a battery at a target speed where efficiency is maximized. However, overmodulation control increases the harmonic components of the voltage applied to the motor, resulting in increased torque pulsation. This can lead to relatively high vibration and noise levels, potentially causing discomfort to the driver. Therefore, it is desirable to provide a mode in which overmodulation control is performed with an emphasis on efficiency, as well as a mode in which overmodulation control is not performed with an emphasis on ride comfort, and to enable switching between these modes. However, because the motor speed during overmodulation control may exceed the speed that can be output in the mode in which overmodulation control is not performed, switching from the mode in which overmodulation control is performed to the mode in which overmodulation control is not performed presents a problem: the speed may suddenly decelerate to a speed that can be output. This also applies when switching from a mode in which overmodulation control is performed in which efficiency is not emphasized, such as "high-torque high-speed driving," to a mode in which overmodulation control is not performed with an emphasis on ride comfort.

[0006] The present disclosure provides a technique capable of suppressing sudden deceleration when switching from a mode in which overmodulation control is performed to a mode in which overmodulation control is not performed.

[0007] A motor control device according to one aspect of the present disclosure includes a receiving unit, a detecting unit, and a control unit. The receiving unit receives a request to switch the driving mode from a first mode in which overmodulation control is performed to a second mode in which non-overmodulation control is performed. The detecting unit detects the motor speed. When the receiving unit receives the switch while the speed in the first mode exceeds the upper limit speed of the second mode and overmodulation control is being performed, the control unit reduces a modulation factor of the overmodulation control to decelerate the speed at a predetermined reduction rate, and when the speed falls below the upper limit speed of the second mode, reduces the modulation factor to 1 or less to switch to non-overmodulation control and initiates flux-weakening control.

[0008] According to the present disclosure, it is possible to suppress sudden deceleration when switching from a mode in which overmodulation control is performed to a mode in which overmodulation control is not performed.

[0009] FIG. 1 is a diagram illustrating an example of the configuration of a motor module according to an embodiment. FIG. 2 is a diagram illustrating running modes that can be performed in a motor control device according to an embodiment. FIG. 3 is a diagram illustrating an example of the line voltage of a motor with and without overmodulation control in a motor control device according to an embodiment. FIG. 4 is a diagram illustrating an example of the TN characteristics of a motor according to an embodiment. FIG. 5 is a block diagram illustrating an example of the configuration of a target speed selection unit according to an embodiment. FIG. 6 is a graph illustrating the relationship between the motor rotation speed and the motor energy loss and motor efficiency per unit traveling distance. FIG. 7 is a graph illustrating the motor energy loss per unit traveling distance for each search speed. FIG. 8 is a block diagram illustrating an example of the configuration of a speed range determination unit in a motor control device according to an embodiment. FIG. 9 is a graph illustrating an example of a speed threshold calculated by a speed threshold calculation unit in the speed range determination unit in a motor control device according to an embodiment. FIG. 10 is a diagram illustrating details of the processing of a speed command unit in a motor control device according to an embodiment. FIG. 11 is a diagram illustrating the processing for setting the modulation factor in the speed command unit of a motor control device according to an embodiment. FIG. 12 is a diagram illustrating a speed command value output from the speed command unit of a motor control device according to an embodiment. FIG. 13 is a diagram illustrating the positional relationship of multiple curves on a dq-axis orthogonal coordinate plane. Fig. 14 is a diagram showing the relationship between flux-weakening control and overmodulation control for each speed range by the control unit of the motor control device according to the embodiment. Fig. 15 is a diagram showing an example of current control on a dq-axis orthogonal coordinate plane when a switch in running mode from the first mode to the second mode is accepted by the accepting unit in the motor control device according to the embodiment. Fig. 16 is a diagram showing another example of the speed threshold calculated by the speed threshold calculation unit of the speed range identification unit in the motor control device according to the embodiment. Fig. 17 is a diagram showing an example of the hardware configuration of the control unit of the motor control device according to the embodiment.

[0010] Below, a detailed description will be given of a motor control device, a motor module, a motor control method, and a motor control program (hereinafter referred to as "embodiments") according to the present disclosure, with reference to the drawings. Note that the present disclosure is not limited to these embodiments. Furthermore, the embodiments can be appropriately combined as long as the processing content is not contradictory. Furthermore, the same components in the following embodiments are designated by the same reference numerals, and redundant explanations will be omitted.

[0011] 1. Motor Module> Fig. 1 is a diagram showing an example of the configuration of a motor module according to an embodiment. As shown in Fig. 1, a motor module 100 according to an embodiment includes a motor control device 1 and a motor 2 controlled by the motor control device 1.

[0012] The motor 2 is, for example, an in-vehicle traction motor such as a surface permanent magnet motor (SPM) or an interior permanent magnet motor (IPM), but is not limited to such examples.

[0013] The motor module 100 is mounted on a moving body. The moving body is, for example, a two-wheeled vehicle such as a motorcycle, but may also be a passenger car or other moving body.

[0014] A vehicle-side device 101 is provided in the preceding stage of the motor control device 1. The vehicle-side device 101 receives a user command speed ω designated by a throttle operation or the like by a user. ** and a user driving mode command designated by a predetermined switch operation by the user, etc. The user is, for example, a person riding in a moving object on which the motor module 100 is mounted.

[0015] The user driving mode command is input to the driving mode determination unit 50 of the vehicle-side device 101. The driving mode determination unit 50 determines the driving mode based on the input user driving mode command. The driving modes determined by the driving mode determination unit 50 include, for example, a mild dynamic mode, a mild economy mode, a power dynamic mode, and a power economy mode.

[0016] 2 is a diagram illustrating the driving modes that can be executed in the motor control device 1 according to the embodiment. As shown in FIG. 2, the mild dynamic mode and the power dynamic mode are executed in accordance with the user command speed ω ** The mild economy mode and the power economy mode are driving modes that follow the user command speed ω ** This is a driving mode that prioritizes efficiency over the target speed ω eco This is a driving mode that follows the target speed ω eco is, for example, a speed that reduces the motor energy loss, and will be described in detail later.

[0017] The mild dynamic mode and mild economy mode are driving modes that prioritize ride comfort and do not execute overmodulation control, while the power dynamic mode and power economy mode are driving modes that allow high-speed driving and execute overmodulation control according to the speed of the motor 2.

[0018] In the present disclosure, the modulation factor is defined as the maximum overmodulation factor (= 2√3 / π ≈ 1.10) where the peak value of the line voltage when a voltage superimposed with a third harmonic is applied is taken as the reference value (= 1.00), and the ratio of the peak value of the line voltage when a one-pulse voltage is applied while overmodulation control is being executed, ignoring voltage saturation, to the reference value. Figure 3 shows an example of the line voltage of the motor 2 with and without overmodulation control in the motor control device 1 according to the embodiment. As shown in Figure 3, when overmodulation control is performed, the fundamental wave component increases in the line voltage applied to the motor 2, making high-speed running possible, but the line voltage applied to the motor 2 becomes saturated.

[0019] As a result, when overmodulation control is performed, the line voltage is mixed with 5th and 7th harmonic components, generating harmonic current components. This increases torque ripple (6nth harmonic component: n is an integer) due to harmonic current and flux linkage, causing vibration and noise and degrading ride comfort.

[0020] When overmodulation control is not performed, as shown in Figure 3, the waveform of the line voltage applied to the motor 2 becomes a sine wave and harmonic current components are suppressed, thereby improving ride comfort compared to when overmodulation control is performed.

[0021] In this way, the mild dynamic mode provides a comfortable ride and ** The mild economy mode is a driving mode that follows the target speed ω eco The power dynamic mode is a driving mode in which high-speed driving is possible and the user command speed ω ** The power economy mode is a driving mode in which high-speed driving is possible, and the target speed ω eco This is a driving mode that follows the

[0022] The power dynamic mode and the power economy mode are examples of a first mode in which overmodulation control is performed, and hereinafter, when the power dynamic mode and the power economy mode are not individually indicated, they may be referred to as the first mode. The mild dynamic mode and the mild economy mode are examples of a second mode in which non-overmodulation control is performed, and hereinafter, when the mild dynamic mode and the mild economy mode are not individually indicated, they may be referred to as the second mode.

[0023] As described above, the driving mode determination unit 50 determines the driving mode based on the user driving mode command input by the user. For example, if the user driving mode command is a command indicating the power dynamic mode, the driving mode determination unit 50 determines the power dynamic mode as the driving mode. Also, if the user driving mode command is a command indicating the power economy mode, the driving mode determination unit 50 determines the power economy mode as the driving mode.

[0024] Furthermore, when the user's driving mode command is a command indicating the mild dynamic mode, the driving mode determination unit 50 determines the mild dynamic mode as the driving mode.Furthermore, when the user's driving mode command is a command indicating the mild economy mode, the driving mode determination unit 50 determines the mild economy mode as the driving mode.

[0025] The driving mode determined by the driving mode determination unit 50 of the vehicle-side device 101 is input to the motor control device 1. In addition, the user command speed ω ** is input to the motor control device 1 via the vehicle-side device 101.

[0026] 4 is a diagram showing an example of the TN (torque-rotation speed) characteristics of the motor 2 according to the embodiment. As shown in FIG. 4, in the first mode in which overmodulation control is performed, higher speed running is possible compared to the second mode in which overmodulation control is not performed.

[0027] In FIG. 4, the upper limit speed ω of the first mode 1_lmt is set at the intersection of the TN characteristic curve in overmodulation control and the curve showing the running resistance, and the upper limit speed ω 2_lmt is set at the intersection of the TN characteristic curve under non-overmodulation control and the curve representing the running resistance. The running resistance is the load torque of the motor 2 when the moving body is running, and increases as the rotation speed of the motor 2 increases.

[0028] The motor control device 1 is configured to control the rotation speed of the motor 2 in the first mode so that the rotation speed is equal to or lower than the upper limit speed ω of the second mode. 2_lmt When the driving mode is switched from the first mode to the second mode while overmodulation control is being performed exceeding the upper limit speed ω of the second mode, the motor control device 1 reduces the modulation rate of the overmodulation control so as to decelerate the rotation speed of the motor 2 at a predetermined reduction rate. 2_lmt or less, the modulation factor is set to 1 or less to switch to non-overmodulation control and flux-weakening control is initiated. This enables the motor control device 1 to suppress sudden deceleration when switching from a mode in which overmodulation control is performed to a mode in which overmodulation control is not performed.

[0029] Furthermore, when the motor control device 1 receives a command to switch the running mode from the first mode to the second mode while overmodulation control and flux-weakening control are being performed in the first mode, it gradually decreases the amount of flux-weakening control in the flux-weakening control and stops the flux-weakening control. The motor control device 1 then decreases the modulation factor at a predetermined rate to decelerate the rotational speed of the motor 2. This also allows the motor control device 1 to suppress sudden deceleration when switching from a mode in which overmodulation control is performed to a mode in which overmodulation control is not performed.

[0030] Furthermore, when the motor control device 1 receives a command to switch the running mode from the first mode to the second mode while overmodulation control and flux weakening control are being performed in the first mode, it reduces the amount of flux weakening in the flux weakening control, and then the motor control device 1 can reduce the modulation factor so as to decelerate the rotational speed of the motor 2 at a predetermined reduction rate while the amount of flux weakening in the flux weakening control is being reduced. This also allows the motor control device 1 to suppress sudden deceleration when switching from a mode in which overmodulation control is performed to a mode in which overmodulation control is not performed.

[0031] 2. Motor control device 1 The motor control device 1 executes motor control processes such as feedback control (F / B control) that feeds back a current value so that the current flowing through the motor 2 matches a target current, and controls the motor 2. As shown in Fig. 1 , the motor control device 1 includes a detection unit 3, a reception unit 4, a control unit 5, and a drive unit 6.

[0032] The detection unit 3 detects the rotation angle θ of the output shaft of the motor 2, and calculates the motor rotation speed ω, which is the rotation speed of the output shaft of the motor 2, based on the detected rotation angle θ. m The detection unit 3 includes, for example, a Hall sensor including a Hall element, a sensor having a magnetoresistive element, or a rotary encoder, but is not limited to these examples.

[0033] The motor rotation speed ω output by the detection unit 3 m The unit of is rad / s or rpm. The motor rotation speed ω in rad / s is m[rad / s] and the motor rotation speed ω in rpm m The relationship between the motor rotation speed ω and the rotational speed [rpm] is expressed by the following formula (1) or (2): m is an example of the speed of the motor 2.

[0034]

[0035] The receiving unit 4 receives a user command speed ω input to the motor control device 1 via the vehicle-side device 101. ** The receiving unit 4 receives the received user command velocity ω ** The control unit 5 is notified of this.

[0036] Furthermore, the reception unit 4 receives the driving mode determined by the driving mode determination unit 50. When the reception unit 4 receives the driving mode determined by the driving mode determination unit 50, the reception unit 4 notifies the control unit 5 of the driving mode determined by the driving mode determination unit 50.

[0037] The reception unit 4 also receives a command to switch to a different driving mode. For example, the reception unit 4 receives a command to switch the driving mode from a first mode in which overmodulation control is performed to a second mode in which non-overmodulation control is performed.

[0038] For example, if the previously determined driving mode was the power dynamic mode and the user driving mode command is a command indicating the mild dynamic mode, the reception unit 4 receives a command to switch from the power dynamic mode to the mild dynamic mode and outputs information indicating the mild dynamic mode to the control unit 5 as information indicating the driving mode.

[0039] In addition, if the driving mode previously determined is the power economy mode and the user driving mode command is a command indicating the mild economy mode, the reception unit 4 accepts a switch from the power economy mode to the mild economy mode and outputs information indicating the mild economy mode to the control unit 5 as information indicating the driving mode.

[0040] Note that the switching of the driving mode from the first mode to the second mode is not limited to the above-described example, and may be, for example, a switching from the power economy mode to the mild dynamic mode, or a switching from the power dynamic mode to the mild economy mode.

[0041] The control unit 5 controls the user command speed ω output from the vehicle-side device 101. ** and the running mode, and outputs the generated PWM signal to the drive unit 6. The drive unit 6 drives the motor 2 based on the PWM signal output from the control unit 5.

[0042] The control unit 5 includes a storage unit 10, a target speed selection unit 11, a speed range identification unit 12, a speed command unit 13, a speed control unit 14, a current control unit 15, subtractors 16a and 16b, a q-axis PI control unit 17a, and a d-axis PI control unit 17b. The control unit 5 also includes a coordinate conversion unit 18, a PWM signal generation unit 19, an ADC (Analog to Digital Converter) 20, and a coordinate conversion unit 21. The drive unit 6 includes an inverter circuit 23 and a current detection unit 24.

[0043] The storage unit 10 stores vehicle body information 10i, a motor control program 10p, and the like. The storage unit 10 is, for example, a flash memory, but is not limited to this example. The storage unit 10 may be built into the control unit 5 or may be externally attached.

[0044] The target speed selection unit 11 selects the target speed ω eco Calculate the calculated target speed ω eco The target speed selection unit 11 outputs the target speed ω to the speed command unit 13 based on the running mode determined by the running mode determination unit 50 and the motor rotation speed ω detected by the detection unit 3. m Based on this, the target speed ω eco Calculate.

[0045] target speed ω ecois the speed of the motor 2 that reduces the loss energy of the motor 2, for example, the speed of the motor 2 that reduces the loss energy of the motor 2 more than the speed that minimizes the pseudo motor loss energy that is determined assuming that the load torque is constant regardless of changes in speed. eco The calculation process will be described in detail later.

[0046] The speed range specification unit 12 uses the vehicle body information 10i stored in the storage unit 10 and the motor load torque τ calculated by the target speed selection unit 11. load and the motor rotation speed ω detected by the detection unit 3. m Based on this, the four speed regions Z A , Z B , Z C , Z D Current speed range Z x The motor load torque τ calculated by the target speed selection unit 11 is identified. load is information indicating the running resistance characteristics, and is information indicating the relationship between the speed and the load torque of the motor 2. load may be calculated by the speed region specifying unit 12. x The process of specifying the number will be described in detail later.

[0047] The speed command unit 13 controls the vehicle to move in response to the user command speed ω ** the driving mode determined by the driving mode determination unit 50 and the speed threshold value ω (to be described later) output from the speed range specification unit 12 a , ω b , ω c , ω d and velocity region Z x and the target speed ω output from the target speed selection unit 11. eco Based on this, the speed command value ω * Output.

[0048] The speed command unit 13 receives an acceleration limit value a as a limit value for the acceleration of the motor 2. lmt is set, and the speed command value ω * The acceleration rate and deceleration rate are the acceleration limit value a lmtThe rate is set to the rate indicated by

[0049] Therefore, the speed command unit 13 controls the motor rotation speed ω m is the upper limit speed ω of the second mode 2_lmt When the reception unit 4 receives a command to switch from the first mode to the second mode in a state where overmodulation control is being performed exceeding the speed command value ω * The deceleration rate is the acceleration limit value a lmt The rate will be as shown below.

[0050] Acceleration limit value a lmt has both positive and negative acceleration (deceleration) as set values, and can be set to, for example, +300 [rpm / s] and -400 [rpm / s]. In this case, the speed command value ω * The deceleration rate (deceleration amount per second) is limited to 400 [rpm]. lmt is a preset value, but the control unit 5 controls the acceleration limit value a lmt You can also change the

[0051] The speed command unit 13 also determines the speed range Z x and the driving mode determined by the driving mode determination unit 50, the control unit 11 determines an upper limit of the modulation rate, which is the upper limit of the modulation rate, and outputs the determined upper limit of the modulation rate to the current control unit 15.

[0052] The speed command unit 13 is x is the upper limit speed ω of the second mode 2_lmt The speed range Z described below is the speed range exceeding C ,Z D In this case, the upper limit of the modulation rate is set to 1.10, and the speed region Z x is the upper limit speed ω of the second mode 2_lmt The following speed range is the speed range Z A ,Z B If so, the upper limit of the modulation factor is determined to be 1.00. * The output process and the process of determining the upper limit of the modulation rate will be described in detail later.

[0053] The speed control unit 14 controls the speed command value ω output from the speed command unit 13. * and the motor rotation speed ω output from the detection unit 3 m Based on this, the torque command value, the target torque τ * For example, the speed control unit 14 calculates the target torque τ * is calculated using the following formula (3). p is the proportional gain, and K i is the integral gain.

[0054]

[0055] The current control unit 15 controls the target torque τ * and the speed command value ω output from the speed command unit 13 * and the modulation rate upper limit output from the speed command unit 13, the d-axis current command value Id * and the q-axis current command value Iq * The d-axis current command value Id * is the command value of the d-axis component current, and the q-axis current command value Iq * is the command value of the current value of the q-axis component.

[0056] The current control unit 15 performs overmodulation control when the upper limit of the modulation factor output from the speed command unit 13 is 1.10, and performs non-overmodulation control when the upper limit of the modulation factor output from the speed command unit 13 is 1.00. * and the modulation rate upper limit. * and the q-axis current command value Iq * is generated.

[0057] As described above, the speed command value ω * The rate of decrease is the acceleration limit value a lmt Therefore, in the first mode, the motor rotation speed ω m When the reception unit 4 receives a command to switch the traveling mode from the first mode to the second mode in a state in which the upper limit speed of the second mode is exceeded and overmodulation control is being performed, the current control unit 15 receives the acceleration limit value almt The motor rotation speed ω is reduced by the rate shown by m The modulation rate of the overmodulation control is reduced so as to slow down the

[0058] This allows the motor control device 1 to suppress sudden deceleration when switching from a mode in which overmodulation control is performed to a mode in which overmodulation control is not performed (a non-overmodulation control mode). lmt The rate indicated by is an example of a predetermined decrease rate.

[0059] The subtractor 16a subtracts the q-axis current command value Iq output from the current control unit 15. * The subtractor 16b calculates the difference between the d-axis current command value Id output from the current control unit 15 and the q-axis current value Iq output from the coordinate conversion unit 21. * and the d-axis current value Id output from the coordinate conversion unit 21.

[0060] The q-axis PI control unit 17a calculates the q-axis current command value Iq * and the q-axis current value Iq to converge to zero, and the q-axis voltage command value Vq * The d-axis PI control unit 17b calculates the d-axis current command value Id * and the d-axis current value Id, and PI (proportional integral) control is performed to converge the difference between the d-axis voltage command value Vd * Calculate.

[0061] The subtractor 16a and the q-axis PI control unit 17a, and the subtractor 16b and the d-axis PI control unit 17b each perform current feedback control, but the current control method in the control unit 5 is not limited to this. For example, they may be replaced with a configuration that performs current feedforward control, or a configuration that performs both current feedback control and current feedforward control. Note that the current feedback control may be, for example, current feedforward control using a voltage command unit that incorporates a known voltage equation.

[0062] The coordinate conversion unit 18 has a two-phase / three-phase conversion function, and converts the q-axis voltage command value Vq* and the d-axis voltage command value Vd * The voltage command value Vu * , Vv * , Vw * Convert to.

[0063] The PWM signal generator 19 converts the voltage command value Vu output from the coordinate converter 18 into * , Vv * , Vw * Based on this, a PWM control signal that turns on / off a plurality of switching elements that constitute the inverter circuit 23 is generated as a drive signal for the motor 2. The inverter circuit 23 is, for example, a three-phase full-bridge circuit that includes a plurality of switching elements.

[0064] The switching element is also called a power element, and is, for example, a metal-oxide semiconductor field-effect transistor (MOSFET) or an insulated gate bipolar transistor (IGBT), but is not limited to these examples. For example, the switching element may be a switching element formed of a silicon-based material or a switching element formed of a wide bandgap semiconductor. Wide bandgap semiconductors include, for example, silicon carbide (SiC), gallium nitride (GaN), and gallium oxide (GaO). ２ O ３ ), or diamonds.

[0065] The PWM signal generating unit 19 may be configured to be built into a motor control integrated circuit (pre-driver IC) that generates a motor drive signal and functions as a drive circuit or the like.

[0066] The inverter circuit 23 of the drive unit 6 is a motor drive circuit that generates AC power for driving the motor 2 from DC power supplied from the battery BT via a power supply relay 25. The power supply relay 25 is configured to be able to cut off the DC power from the battery BT, and is configured by, for example, a mechanical relay or a semiconductor relay.

[0067] The motor drive current supplied to the motor 2 from the inverter circuit 23 is detected by the current detection unit 24. The current detection unit 24 detects, for example, a DC current flowing through a shunt resistor for detecting the motor drive current using an amplifier circuit such as an operational amplifier, but may also be configured to detect the motor drive current using a Hall element or a magnetic resistance element. The current detection unit 24 outputs three-phase current values ​​Iu, Iv, and Iw, which are instantaneous values ​​of the detected three-phase currents.

[0068] The ADC 20 converts the three-phase current values ​​Iu, Iv, and Iw output from the current detection unit 24 from analog current values ​​to digital values. The coordinate conversion unit 21 has a three-phase / two-phase conversion function and outputs the q-axis current value Iq and the d-axis current value Id based on the rotation angle θ detected by the detection unit 3 and the three-phase current values ​​Iu, Iv, and Iw output from the ADC 20. That is, the coordinate conversion unit 21 calculates the d-axis current value Id and the q-axis current value Iq based on the actual currents of the motor 2 (the q-axis actual current and the d-axis actual current). The d-axis current value Id and the q-axis current value Iq calculated by the coordinate conversion unit 21 are input to the subtractors 16a and 16b, as described above.

[0069] <2.1. Target Speed ​​Selection Unit 11> Next, the target speed ω in the target speed selection unit 11 eco 5 is a block diagram showing an example of the configuration of the target speed selection unit 11 according to the embodiment. As shown in FIG. 5, the target speed selection unit 11 includes a search speed generation unit 30, a running resistance estimation unit 31, a modulation factor setting unit 32, a current command unit 33, an efficiency estimation unit 34, and a loss comparison unit 35.

[0070] The search speed generator 30 calculates the motor rotation speed ω output from the detector 3. m and the target speed ω fed back from the loss comparison unit 35 eco and based on the motor rotation speed ω m Nearby search speed ω m-α , ω m , ω m+α The search speed ω m-α is the motor rotation speed ω m is the motor rotation speed set lower by a predetermined value α than the search speed ω m+αis the motor rotation speed ω m The motor rotation speed is set higher by a predetermined value α than the rotation speed.

[0071] The running resistance estimation unit 31 calculates the search speed ω output from the search speed generation unit 30. m -α, ω m , ω m +α and the vehicle body information 10i stored in the storage unit 10, the search speed ω m -α, ω m , ω m + α motor load torque τ load (ω m -α), τ load (ω m ), τ load (ω m +α) and calculate the calculated search speed ω m -α, ω m , ω m + α motor load torque τ load (ω m -α), τ load (ω m ), τ load (ω m +α).

[0072] The modulation factor setting unit 32 sets the modulation factor in the current command unit 33. For example, when the driving mode determined by the driving mode determination unit 50 is the mild economy mode, the modulation factor setting unit 32 sets the upper limit of the modulation factor, which is the upper limit value of the modulation factor, to 1.00, and when the driving mode determined by the driving mode determination unit 50 is the power economy mode, the modulation factor setting unit 32 sets the upper limit of the modulation factor to 1.10. Therefore, for example, when the reception unit 4 receives a request to switch the driving mode from the mild economy mode to the power economy mode, the modulation factor increases as the upper limit of the modulation factor increases, and the voltage utilization rate increases, so that the d-axis current due to flux-weakening control is suppressed, thereby improving efficiency.

[0073] When the driving mode determined by the driving mode determination unit 50 is the mild dynamic mode or the power dynamic mode, the target speed selection unit 11 is inactive and the modulation factor setting unit 32 does not set the modulation factor.

[0074] The current command unit 33 controls the search speed ω m -α, ω m , ω m + α motor load torque τ load (ω m -α), τ load (ω m ), τ load (ω m +α) and search speed ω m -α, ω m , ω m +α, the search speed ω of motor 2 m -α, ω m , ω m + α Current value i (ω m -α), i(ω m ), i(ω m +α).

[0075] The efficiency estimation unit 34 estimates the search speed ω m -α, ω m , ω m + Efficiency η of Motor 2 for each α motor (ω m -α), η motor (ω m ), η motor (ω m The loss comparison unit 35 estimates the search speed ω estimated by the efficiency estimation unit 34. m -α, ω m , ω m + Efficiency η of Motor 2 for each α motor (ω m -α), η motor (ω m ), η motor (ω m +α) m -α, ω m , ω m The loss of the motor 2 is compared for each +α. Then, the loss comparison unit 35 selects the speed with the smallest loss as the search speed ω m -α, ω m , ω m +α to target speed ω eco When the driving mode is the mild economy mode or the power economy mode, the target speed selection unit 11 selects the target speed ω eco is output to the speed command unit 13.

[0076] An example of the vehicle body information 10i stored in the storage unit 10 is as follows: gear : Gear ratio r tire : Tire radius [m] μ: Rolling resistance coefficient m: Total vehicle weight [kg] S: Vehicle frontal projection area [m 2 ] Cd: Air resistance coefficient

[0077] The air resistance Rair [N] of a vehicle is expressed by the following formula (4): ρ in the following formula (4) is the air density [kg / m 3 ], and V is the vehicle speed [m / s].

[0078]

[0079] In addition, the rolling resistance R road [N] is expressed by the following formula (5): g in the following formula (5) is the gravitational acceleration [m / s 2 The rolling resistance coefficient μ in the following formula (5) changes depending on the condition of the road surface on which the vehicle is running, but in this embodiment, it is assumed that the vehicle runs on an asphalt pavement, and the rolling resistance coefficient μ is treated as a constant. Therefore, in this embodiment, the rolling resistance R road is a constant specific to the vehicle.

[0080]

[0081] Motor load torque τ load is generally expressed by the following equation (6): In this embodiment, it is assumed that the vehicle runs on a flat road, and gradient resistance is omitted.

[0082]

[0083] However, in this embodiment, the running resistance estimation unit 31 estimates the motor load torque τ load is calculated using the following equations (7) to (11): k2 shown in the following equation (10) is the air resistance torque coefficient [Nm (s / rad) 2 The running resistance estimation unit 31 estimates the calculated motor load torque τ load is output to the speed region specifying unit 12.

[0084]

[0085] As shown in the above equations (7) to (11), the motor load torque τ load is the rolling resistance R road The first term is proportional to the motor rotation speed ω m The first term in the above equation (7) is a constant specific to the vehicle, so the motor load torque τ load is the motor rotation speed ω m The first term of the above equation (7) is calculated in advance. In the above equations (7) to (11), the air resistance torque coefficients k2 and τ0 are constants specific to the vehicle, so these constants are also calculated in advance and stored in the vehicle body information 10i of the storage unit 10.

[0086] By the way, the motor load torque τ load may be approximated to a quadratic function of the vehicle speed V. Specifically, the following equation (12) is derived from the above equations (9) and (11), so the motor load torque τ load is expressed as the rolling resistance R road The first term in the following equation (13) is a constant specific to the vehicle, so the motor load torque τ load is approximated to a quadratic function of the vehicle speed V.

[0087]

[0088] Motor load torque τ load The formula (14) may be modified as follows: Specifically, the formula (14) below is derived from the formulas (10) and (12) above.

[0089]

[0090] Furthermore, the following formula (15) is derived from the above formulas (5) and (8).

[0091]

[0092] The following equation (16) is derived from the above equations (7), (14), and (15).

[0093]

[0094] As described above, the running resistance estimation unit 31 calculates the motor load torque τ load , the search speed ω m -α, ω m , ω m + α, and calculate the search speed ω m -α, ω m , ω m + Motor load torque τ, which is the motor load torque for each α load (ω m -α), τ load (ω m ), τ load (ω m +α).

[0095] The current command unit 33 calculates the search speed ω calculated by the running resistance estimation unit 31. m -α, ω m , ω m + α motor load torque τ load (ω m -α), τ load (ω m ), τ load (ω m +α) and search speed ω m -α, ω m , ω m +α, the search speed ω of motor 2 m -α, ω m , ω m + α, the current operating point i (ω m -α), i(ω m ), i(ω m +α).

[0096] Generally, the motor load torque τ load is proportional to the current value i of the motor 2 as shown in the following equation (17A). τ is a torque constant specific to the motor 2. In this embodiment, the search speed ω of the motor 2 is calculated using the relationship of the following equation (17B). m -α, ω m , ω m +α, which is the current value i(ω m-α), i(ω m ), i(ω m +α) is calculated using the following equations (17A) and (17B). m Motor load torque τ in the case load (ω m ) and current value i(ω m ), but a similar relationship can be seen for the search speed ω m -α, ω m Or, as in the case of the current control unit 15, the motor load torque τ load (ω m ), search speed ω m From this, the current value i(ω m ) may be calculated.

[0097]

[0098] The efficiency estimation unit 34 estimates the current value i(ω m -α), i(ω m ), i(ω m +α) based on the search speed ω m -α, ω m , ω m + Efficiency η, which is the efficiency of motor 2 for each α motor (ω m -α), η motor (ω m ), η motor (ω m +α) (0≦η motor (ω m -α), η motor (ω m ), η motor (ω m +α)≦1) Efficiency of motor 2 η motor (ω m -α), η motor (ω m ), η motor (ω m +α) are calculated using the following formula (18): AC [W] is expressed by the following formula (19): The following formula (18) is expressed by the search speed ω m The same relationship holds when the search speed is ω m-α, ω m +α. The copper loss W in the following equation (19) cu is the loss [W] generated by the resistance component of the winding, and is expressed as the iron loss W fe is the loss [W] due to the core, which is a magnetic material. Also, the copper loss W cu is the current value i(ω m ) is proportional to the square of

[0099]

[0100] τ in the above formulas (18) and (19) load (ω m )・ω m , and the copper loss W in the above formula (19) cu , iron loss W fe are expressed by the following equations (20) to (22): In the following equations (20) to (22), x and y are coordinate values ​​of Cartesian coordinates on the current dq axis plane (dq axis Cartesian coordinate plane) where the x axis is the Iq component, the y axis is the Id component, and the positive direction of the y axis is defined as the field weakening direction. ξ m is the permanent magnet coefficient, which is set to 1 for motors that include permanent magnets and 0 for motors that do not. Δη is the maximum value η of the dimensionless motor constant η. max and the minimum value η min This is the difference between

[0101]

[0102] In addition, the above W ｆｅ In the formula, K(ω) is a current-independent coefficient, the hysteresis loss coefficient is kh, and the eddy current loss coefficient is k e In this case, it can be defined as in the following equation (23).

[0103]

[0104] The loss comparison unit 35 compares the efficiency η of the motor 2 estimated by the efficiency estimation unit 34 motor (ω m -α), η motor (ω m ), η motor (ω m +α) m -α, ω m , ω m+ α, and the speed with the smallest loss is searched for as ω m -α, ω m , ω m + Select from α and target speed ω eco Output as

[0105] A general calculation method for extracting the motor rotation speed when the motor efficiency is maximized, that is, when the motor loss is minimized, will be described below.

[0106] If the motor efficiency at a certain motor rotation speed is η motor (0≦η motor ≦1), the motor loss is 1-η motor Therefore, the motor loss energy is given by the following equation (24), which is the product of the sum of the air resistance Rair [N] and rolling resistance Rroad [N] of the vehicle and the vehicle speed V.

[0107]

[0108] Then, the following equation (25) is derived from the above equation (24) using the above equations (6) and (11).

[0109]

[0110] In addition, the motor loss energy W loss is expressed by the following equation (26) based on the above equation (25), and the motor loss (1-η motor ) and the motor load torque τ load It is proportional to the product of

[0111]

[0112] And the reference speed ω m_base The motor efficiency ηequal_loss, which is a loss equivalent to the above, is expressed by the following equation (27).

[0113]

[0114] FIG. 6 shows the relationship between the motor rotation speed and the motor energy loss W per unit running distance shown in the above equation (27). loss 6 is a graph showing the relationship between the motor rotation speed ω and the motor efficiency. xMotor loss energy W loss is the minimum value of the pseudo motor loss energy calculated on the assumption that the load torque is constant even when the speed changes. As shown in Figure 6, the motor rotation speed ω x The motor loss energy W per unit travel distance is greater when the motor rotation speed ωy is calculated on the assumption that the load torque changes depending on the speed than when loss becomes smaller and reaches a minimum value, and the motor efficiency becomes larger and reaches a maximum value.

[0115] Therefore, the target speed selection unit 11 selects such a motor rotation speed ω y is the target speed ω eco The motor loss energy W per unit travel distance loss To calculate the minimum value of loss is calculated for each motor rotation speed and compared, or if the above formula (26) is differentiable with respect to the motor rotation speed, the motor rotation speed at which the first derivative of the above formula (26) becomes 0 is calculated, thereby obtaining the motor loss energy W per unit running distance. loss Determine the motor rotation speed at which the value of is minimum.

[0116] However, the motor loss energy W per unit travel distance for each motor rotation speed loss and determining the minimum value, and the motor loss energy W per unit running distance based on the first derivative of the above equation (26). loss Any method for determining the minimum value of is computationally intensive.

[0117] In this embodiment, the loss comparison unit 35 calculates the efficiency η motor (ω m -α), η motor (ω m ), η motor (ω m +α) loss By comparing these, the motor loss energy Wloss The motor rotation speed at which is minimum is extracted.

[0118] FIG. 7 shows the search speed ω m -α, ω m , ω m +α Motor loss energy W for each unit travel distance loss As shown in FIG. m -α, ω m than when the motor rotation speed ω m In the case of +α, the motor energy loss per unit travel distance is smaller. m +α is the target speed ω eco Let the search speed ω m -α, ω m , ω m +α Motor loss energy W for each unit travel distance loss The calculation of motor loss energy W loss Since the calculation load is smaller than when calculating for each motor rotation speed, the control unit 5 does not need to have high calculation performance.

[0119] The target speed ω calculated by the loss comparison unit 35 eco is output to the speed command unit 13 and is also fed back to the search speed generation unit 30. The fed back target speed ω eco is the motor rotation speed ω detected by the detection unit 3 m From the search speed ω m -α, ω m +α. In addition, immediately after the start of control, the target speed ω eco If there is no feedback of the motor rotation speed ω, the search speed generator 30 uses a predetermined initial value stored in advance in the storage unit 10 or the like as the motor rotation speed ω m By adding or subtracting from m -α, ω m Decide on +α.

[0120] The information of each of the above formulas is stored in, for example, the storage unit 10, and is read out from the storage unit 10 by the target speed selection unit 11 for use, but the target speed selection unit 11 may have the information in advance.

[0121] <2.2. Speed ​​Region Identification Unit 12> Next, the speed region Z x 8 is a block diagram showing an example of the configuration of the speed range determination unit 12 in the motor control device 1 according to the embodiment.

[0122] 8, the speed region specification unit 12 includes a speed threshold calculation unit 40 and a region specification unit 41. The speed threshold calculation unit 40 calculates the motor load torque τ load and the characteristics of the motor 2, four speed thresholds ω a , ω b , ω c , ω d The speed threshold calculation unit 40 calculates the upper limit speed ω 2_lmt 1 is an example of an upper limit speed calculation unit that calculates the upper limit speed.

[0123] The speed threshold calculation unit 40 has information indicating the TN (torque-rotation speed) characteristics of the motor 2, including information indicating the TN characteristics of the motor 2 when there is no overmodulation and no flux-weakening control, and information indicating the TN characteristics of the motor 2 when there is no overmodulation and flux-weakening control.

[0124] Furthermore, the speed threshold calculation unit 40 has information indicating the TN characteristics of the motor 2 when there is overmodulation and no flux-weakening control, and information indicating the TN characteristics of the motor 2 when there is overmodulation and flux-weakening control. The information indicating the TN characteristics of the motor 2 is stored, for example, in the storage unit 10, and the speed threshold calculation unit 40 acquires the information indicating the TN characteristics of the motor 2 from the storage unit 10, but is not limited to this example.

[0125] FIG. 9 shows the speed threshold value ω calculated by the speed threshold value calculation unit 40 of the speed range identification unit 12 in the motor control device 1 according to the embodiment. a , ω b , ω c , ω d As shown in FIG. 9, the velocity threshold ω ais the speed at the intersection of the curve showing the TN characteristics of the motor 2 without overmodulation and flux weakening control and the curve showing the running resistance characteristics.

[0126] Also, the velocity threshold ω b is the speed at the intersection of the curve showing the TN characteristics of the motor 2 when there is no overmodulation and when there is flux-weakening control and the curve showing the running resistance characteristics, as shown in Figure 9. The curve showing the TN characteristics of the motor 2 when there is no overmodulation and when there is flux-weakening control is an example of a curve showing the relationship between the speed of the motor 2 and the torque of the motor 2 in the second mode, and the curve showing the running resistance characteristics is an example of a curve showing the relationship between the speed of the motor 2 and the load torque. Speed ​​threshold ω b is the upper limit speed ω of the first mode described above. 2_lmt is.

[0127] In this way, the speed threshold calculation unit 40 calculates the speed of the motor 2 at the intersection of the curve showing the relationship between the speed of the motor 2 and the load torque and the curve showing the relationship between the speed of the motor 2 and the torque of the motor 2 in the second mode as the upper limit speed ω 2_lmt It is calculated as follows.

[0128] Also, the velocity threshold ω c is the speed at the intersection of the line showing the TN characteristics of the motor 2 with overmodulation and without flux-weakening control and the curve showing the running resistance characteristics, as shown in Figure 9. d is the speed at the intersection of the line showing the TN characteristics of the motor 2 with overmodulation and flux-weakening control and the curve showing the running resistance characteristics, as shown in Figure 9. d is the upper limit speed ω of the second mode described above. 1_lmt is.

[0129] The speed region specifying unit 12 determines the speed threshold value ω calculated by the speed threshold value calculation unit 40. a , ω b , ω c , ω d and the motor rotation speed ω output by the detection unit 3. m Based on this, the four speed regions Z shown in FIG. A , Z B , Z C , Z DCurrent speed range Z x Identify.

[0130] For example, the speed region specifying unit 12 determines ω m ≦ω a If the current speed region Z x is the speed region Z A and ω a <ω m ≦ω b If the current speed region Z x is the speed region Z B Furthermore, the speed region specifying unit 12 determines that, for example, ω b <ω ｃ ≦ω c If the current speed region Z x is the speed region Z C and ω c <ω m ≦ω d If the current speed region Z x is the speed region Z D It is determined that

[0131] 2.3 Speed ​​Command Unit 13 Next, a detailed description will be given of the processing performed by the speed command unit 13. Fig. 10 is a diagram for explaining the details of the processing performed by the speed command unit 13 in the motor control device 1 according to the embodiment.

[0132] As described above, the speed command unit 13 shown in FIG. 10 determines the speed range Z x and the driving mode determined by the driving mode determination unit 50, the control unit 50 determines an upper limit of the modulation rate, which is the upper limit of the modulation rate, and outputs the determined upper limit of the modulation rate.

[0133] 11 is a diagram for explaining the process of setting the modulation factor in the speed command unit 13 of the motor control device 1 according to the embodiment. As shown in FIG. 11, for example, the speed command unit 13 sets the modulation factor in the speed region Z x is the speed region Z A or speed region Z B and the driving mode is the mild economy mode or the mild dynamic mode, the modulation rate upper limit is set to 1.00.

[0134] As shown in FIG. 11, the speed command unit 13 determines the speed range Z x is the speed region Z C or speed region Z D and the driving mode is the mild economy mode or the mild dynamic mode, the modulation rate upper limit is set to 1.10.

[0135] As shown in FIG. 11, when the driving mode is the power economy mode or the power dynamic mode, the speed command unit 13 controls the speed range Z x Regardless of this, the upper limit of the modulation rate is set to 1.10.

[0136] As described above, the speed command unit 13 x and the velocity threshold ω a , ω b , ω c , ω d and user command speed ω ** , the driving mode, and the target speed ω eco Based on this, the speed command value ω * Output.

[0137] FIG. 12 shows the speed command value ω output from the speed command unit 13 in the motor control device 1 according to the embodiment. * As shown in FIG. 12, the speed command unit 13 controls the speed controller 10 to determine the speed within the current speed range Z x is the speed region Z A or speed region Z B and the driving mode is the mild economy mode, the target speed ω calculated by the target speed selection unit 11 with the modulation factor of 1.00 is eco The speed command value ω * In this case, the speed command value ω * is the velocity threshold ω b is the upper limit.

[0138] As shown in FIG. 12, the speed command unit 13 determines the current speed range Z x is the speed region Z A or speed region Z Band the driving mode is the mild dynamic mode, the user command speed ω ** The speed command value ω * In this case, the speed command value ω * is the velocity threshold ω b is the upper limit.

[0139] As shown in FIG. 12, the speed command unit 13 determines the current speed range Z x is the speed region Z C or speed region Z D and the driving mode is the mild economy mode or the mild dynamic mode, in principle, the speed threshold ω b The speed command value ω * Output as

[0140] However, when the driving mode is the mild economy mode, the speed command unit 13 sets the target speed ω eco is the speed threshold ω b and the target speed ω eco and the velocity threshold ω b The difference between this and the acceleration limit value a lmt If the velocity threshold ω b The speed command value ω * otherwise, the target speed ω eco Acceleration limit value a lmt The speed command value ω is the value obtained by subtracting a value proportional to * The acceleration limit value a is output. lmt The value proportional to the speed command value ω * The rate of decrease is the acceleration limit value a lmt This is the value.

[0141] Furthermore, when the driving mode is the mild dynamic mode, the speed command unit 13 controls the user command speed ω ** is the speed threshold ω b and the user command speed ω ** and the velocity threshold ω b The difference between this and the acceleration limit value a lmt If the velocity threshold ω b The speed command value ω* otherwise, the user command speed ω ** Acceleration limit value a lmt The speed command value ω is the value obtained by subtracting a value proportional to * The acceleration limit value a is output. lmt As described above, the value proportional to the speed command value ω * The rate of decrease is the acceleration limit value a lmt This is the value.

[0142] 12, when the driving mode is the power economy mode, the speed command unit 13 selects the target speed ω calculated by the target speed selection unit 11 with a modulation factor of 1.10 regardless of the current speed region indicated by the speed region information. eco The speed command value ω * Output as

[0143] As shown in FIG. 12, the speed command unit 13 determines the current speed range Z x is the speed region Z A , velocity region Z B , or velocity region Z C and the running mode is the power dynamic mode, the user command speed ω ** The speed command value ω * Output as

[0144] As shown in FIG. 12, the speed command unit 13 determines the current speed range Z x is the speed region Z D and the running mode is the power dynamic mode, the user command speed ω ** The speed command value ω * The speed command value ω * The upper limit of the velocity threshold ω d is.

[0145] <2.4. Current Control Unit 15> As described above, the current control unit 15 controls the target torque τ * and the speed command value ω output from the speed command unit 13 *and the modulation rate upper limit, the d-axis current command value Id * and the q-axis current command value Iq * Generate.

[0146] When the modulation factor upper limit output from the speed command unit 13 is "1.00", the current control unit 15 controls the d-axis current command value Id * and the q-axis current command value Iq * In the non-overmodulation control, the flux-weakening control generates the speed command value ω * The amount of flux weakening is adjusted according to the

[0147] Furthermore, when the upper limit of the modulation factor output from the speed command unit 13 is "1.10", the current control unit 15 * The d-axis current command value Id is calculated by overmodulation control according to the * and the q-axis current command value Iq * In the overmodulation control, the flux-weakening control generates the speed command value ω * The amount of flux weakening is adjusted according to the

[0148] 13 is a diagram showing the positional relationships of multiple curves on a dq-axis orthogonal coordinate plane, including a power minimization curve (MP), a constant torque curve (CT), a voltage limit ellipse (LV), and a current limit circle (LA) on the dq-axis orthogonal coordinate plane.

[0149] The power minimization curve (MP (Minimum Power) curve) is an efficiency maximization curve, and in the efficiency-oriented mode, the current control unit 15 sets the d-axis current command value Id so that the d- and q-axis currents flow on the power minimization curve in a state where there is no flux-weakening control. * and the q-axis current command value Iq * Furthermore, in the efficiency-oriented mode, the stronger the flux-weakening control, the larger the d-axis current becomes, and therefore the curve moves away from the power minimization curve on the d-q-axis orthogonal coordinate plane. The efficiency-oriented modes are the mild economy mode and power economy mode described above.

[0150] The constant torque curve (CT curve) is a curve that indicates the required torque. As the rotation of the motor 2 accelerates, air resistance and other factors increase, and the required torque also increases, so the constant torque curve moves away from the origin (0,0) on the dq-axis orthogonal coordinate plane.

[0151] The voltage limit ellipse (LV (Limited Voltage) ellipse) is an ellipse that indicates the voltage limit (upper limit) value and the maximum line voltage that can be applied. The voltage applied from the motor control device 1 to the motor 2 is controlled within the voltage limit ellipse. When the current control unit 15 switches from non-overmodulation control to overmodulation control, the voltage value that can be applied to the motor 2 increases, and the voltage limit ellipse becomes larger in the direction away from the center of the voltage limit ellipse on the d-q-axis Cartesian coordinate plane. Furthermore, as the rotation of the motor 2 accelerates, the induced voltage becomes larger and the amount of voltage that needs to be applied to the motor 2 increases, and the voltage limit ellipse becomes smaller in the d-q-axis Cartesian coordinate plane toward the center of the voltage limit ellipse.

[0152] The current limit circle (LA (Limited Ampere) circle) is a circle that indicates the limit (upper limit) value of the current. The current applied from the motor control device 1 to the motor 2 is controlled within the current limit circle.

[0153] 14 is a diagram showing the relationship between the flux-weakening control and the overmodulation control for each speed region by the control unit 5 of the motor control device 1 according to the embodiment. As shown in FIG. 14, in the current speed region Z x is the speed region Z A If the speed is in the range of 1 / 2000, the flux weakening control and the overmodulation control are not performed. x is the speed region Z B If so, the flux weakening control is performed but the overmodulation control is not performed.

[0154] Also, the current speed range Z X is the speed region Z C In this case, the flux weakening control is not performed but the overmodulation control is performed. x is the speed region Z D14, "MTPV" stands for "Maximum Torque Per Volt" and means the maximum torque per unit voltage, and "One Pulse" is a control method that outputs one pulse for half a cycle of the fundamental wave.

[0155] Next, a description will be given of the processing of the current control unit 15 when a switch of the driving mode from the first mode to the second mode is received by the reception unit 4. Fig. 15 is a diagram showing an example of current control on a dq-axis orthogonal coordinate plane when a switch of the driving mode from the first mode to the second mode is received by the reception unit 4 in the motor control device 1 according to the embodiment.

[0156] In FIG. 15, the velocity region Z x is the speed region Z D 10 is a diagram illustrating a flow of current control by the current control unit 15 when a switching of the traveling mode from the first mode to the second mode is accepted by the acceptance unit 4 in the speed region Z. x is the speed region Z D When the voltage Vcc is in the range of 0.5 V to 1 V, the overmodulation control and the flux weakening control are being performed.

[0157] Speed ​​area Z x is the speed region Z D Immediately after switching the driving mode from the first mode to the second mode in the state where the vehicle is in the speed region Z x is the speed region Z D and the target speed ω eco and the velocity threshold ω b or the user command speed ω ** and the velocity threshold ω b The difference between this and the acceleration limit value a lmt The acceleration limit value a is greater than the value proportional to lmt As described above, the value proportional to the speed command value ω * The rate of decrease is the acceleration limit value a lmt This is the value.

[0158] Therefore, the speed command unit 13 determines whether the deceleration rate is greater than the acceleration limit value a lmt The speed command value ω is reduced at a rate indicated by *The speed command unit 13 outputs the speed region Z x is the speed region Z D Therefore, the upper limit of the modulation factor is set to 1.10. lmt The rate indicated by is sometimes referred to as a predetermined deceleration rate.

[0159] In this case, the current control unit 15 receives the speed command value ω output from the speed command unit 13. * and the modulation rate upper limit (=1.10), the d-axis current command value Id * and the q-axis current command value Iq * In the overmodulation control, the flux-weakening control generates the speed command value ω * The amount of flux weakening is determined by the speed range Z. x is the speed region Z D , the modulation factor is, for example, 1.10.

[0160] The speed command value ω output from the speed command unit 13 * Since the speed command value ω decreases at a predetermined deceleration rate, the constant torque curve approaches the origin and the voltage limit ellipse becomes larger. The current command value vector follows the intersection of the constant torque curve and the voltage limit ellipse, and changes so that the d-axis current command value becomes smaller. That is, the speed command value ω * In accordance with the reduction in the modulation factor, the amount of flux weakening in the flux weakening control is reduced while the modulation factor is maintained at 1.10.

[0161] Then, the speed command value ω * decreases at a predetermined deceleration rate, and the motor rotation speed ω detected by the detection unit 3 m is the speed threshold ω c When the speed reaches the speed range Z x is the speed region Z C becomes.

[0162] After the flux-weakening amount in the flux-weakening control becomes zero, the speed command value ω *As the motor rotation speed ω decreases at a predetermined deceleration rate, the constant torque curve approaches the origin and the voltage limit ellipse becomes larger. On the other hand, the current command value vector moves away from the voltage limit ellipse and changes to follow the intersection of the constant torque curve and the power minimization curve. That is, as the motor rotation speed ω decreases at a predetermined deceleration rate, m The modulation rate in the overmodulation control decreases so that

[0163] In this way, when the reception unit 4 receives a request to switch to the second mode while overmodulation control and flux weakening control are being performed in the first mode, the control unit 5 reduces the amount of flux weakening in the flux weakening control, sets the flux weakening amount to zero to stop the flux weakening control, and then reduces the modulation rate at a predetermined rate.

[0164] Speed ​​command value ω * is further reduced at a predetermined deceleration rate, the motor rotation speed ω m The modulation rate of the overmodulation control is reduced so as to decelerate the motor rotation speed ω m is the speed threshold ω b (see (c) of FIG. 15 ), the speed command unit 13 changes the speed region Z x is the speed region Z B Therefore, the upper limit of the modulation rate is set to 1.00, and the speed command value ω * is the velocity threshold ω b The upper limit is the speed threshold ω b is the upper limit speed ω of the second mode 2_lmt is.

[0165] In this case, the voltage limit ellipse becomes smaller due to the reduction in the modulation factor upper limit, and the current command value vector moves away from the power minimization curve and changes again to follow the intersection of the constant torque curve and the voltage limit ellipse. * and the modulation rate upper limit (=1.00), the d-axis current command value Id is calculated by the flux-weakening control (see (d) of FIG. 15) under non-overmodulation control in which the modulation rate is set to 1. * and the q-axis current command value Iq *In this way, when the modulation factor is set to 1.00, the current control unit 15 switches from overmodulation control to non-overmodulation control, and therefore generates the speed command value ω * The speed threshold ω b In the non-overmodulation control, the flux-weakening control is performed to maintain the speed command value ω output from the speed command unit 13 at the same value as the speed command value ω. * The upper limit of the modulation factor is not limited to 1.00, and may be less than 1.00.

[0166] In this way, the control unit 5 determines the speed command value ω * The decrease in the motor rotation speed ω m is the upper limit speed ω 2_lmt When the motor rotation speed ω reaches ω , the speed command unit 13 makes the modulation factor equal to or less than 1.00, and switches the control in the current control unit 15 from overmodulation control to non-overmodulation control. m is the upper limit speed ω of the second mode 2_lmt When the modulation factor becomes equal to or less than 1.00, the modulation factor can be set to 1.00 or less to perform non-overmodulation control and flux-weakening control can be started.

[0167] When the modulation rate of the overmodulation control is decreased until the modulation rate reaches 1.00, the motor rotation speed ω m is the velocity ω shown in FIG. e However, the control unit 5 decelerates the motor rotation speed ω m is the upper limit speed ω of the second mode 2_lmt When the modulation factor falls below 1.00, the control unit 5 sets the modulation factor to 1.00 or less to perform non-overmodulation control and starts flux-weakening control. Therefore, the control unit 5 can suppress sudden deceleration by the above-mentioned predetermined reduction rate while quickly switching from the first mode to the second mode.

[0168] The current control unit 15 is configured to, after or before starting the non-overmodulation control and the flux-weakening control, determine the user command speed ω ** or target speed ω eco decreases, and the speed command value ω * is the upper limit speed ω of the second mode 2_lmtWhen the speed command value ω * is the speed threshold ω a If this is the case, the amount of flux weakening in the flux weakening control becomes zero (see (e) of FIG. 15).

[0169] The current control by the current control unit 15 is a <ω b <ω c <ω d is not limited to the case of ω a <ω c <ω b <ω d 16 shows the speed threshold ω calculated by the speed threshold calculation unit 40 of the speed range specification unit 12 in the motor control device 1 according to the embodiment. a , ω b , ω c , ω d 16 is a diagram showing another example of the running resistance characteristic shown in FIG. 16, in which the running resistance is lower than that shown in FIG. 9, and the speed threshold ω a , ω b , ω c , ω d is ω a <ω c <ω b <ω d are in a relationship.

[0170] In this case, the speed region Z x is the speed region Z D When the driving mode is switched from the first mode to the second mode in the state, the speed command value ω * is reduced at a predetermined deceleration rate, and the motor rotation speed ω m is the velocity threshold ω c before reaching the velocity threshold ω b That is, the velocity threshold ω b , ω c ω c <ω b Therefore, when the amount of flux weakening control is reduced, the motor rotation speed ω m is the speed threshold ω c reaches the speed region Z xis the speed region Z B becomes.

[0171] The speed command unit 13 is x is the speed region Z B Therefore, the upper limit of the modulation rate is set to 1.00, and the speed command value ω * is the velocity threshold ω b The upper limit is the speed threshold ω b is the upper limit speed ω of the second mode 2_lmt is.

[0172] In this case, the current control unit 15 receives the speed command value ω output from the speed command unit 13. * and the modulation rate upper limit (=1.00), the d-axis current command value Id * and the q-axis current command value Iq * In the non-overmodulation control, the flux-weakening control generates the speed command value ω * The upper limit of the modulation factor is not limited to 1.00, and may be less than 1.00.

[0173] In this way, the control unit 5 controls the motor rotation speed ω m is the upper limit speed ω of the second mode 2_lmt When the motor rotation speed ω becomes equal to or less than ω 1 , the control unit 5 reduces the amount of flux weakening in the flux weakening control, and before the amount of flux weakening in the flux weakening control becomes zero, sets the modulation factor to 1.00 or less to non-overmodulation control and starts flux weakening control. m is the upper limit speed ω of the second mode 2_lmt When the motor rotation speed ω m Decrease the speed to slow down.

[0174] In this case, the motor control device 1 also determines the speed threshold value ω b , ω c ω b <ω c Similarly to the case where the relationship is as follows, sudden deceleration can be suppressed by the above-mentioned predetermined decrease rate while quickly switching from the first mode to the second mode.

[0175] <3. Modification> In the above example, the search speed is set to ω m -α, ω m , ω m +α, the number of search speeds is not limited to three, and may be two, four or more. m The configuration may be such that the following is calculated:

[0176] In the first mode and the second mode, the current speed region Z x is the speed region Z C , Z D In this case, in the example described above, the upper limit of the modulation rate was set to "1.10", which is the value of "2√3 / π" with three significant digits, which is the modulation rate during one-pulse control, but a value obtained by changing the significant digits or rounding up or down, such as "1.102", may also be set. Furthermore, the upper limit of the modulation rate may be set to a modulation rate value smaller than that of one-pulse control, i.e., a value smaller than "2√3 / π".

[0177] In the above example, the running resistance estimation unit 31 calculates the motor load torque τ load , the search speed ω m -α, ω m , ω m +α, but is not limited to such an example. For example, the running resistance estimation unit 31 calculates the motor load torque τ load , the search speed V m -β, V m , V m + β, and calculate the search speed V m -β, V m , V m + τ for every β load (V m -β), τ load (V m ), τ load (V m +β) may be output.

[0178] In this case, the current command unit 33 calculates "ω m " to "V m", the current value i (V m −β), i(V m ), i(V m In addition, the efficiency estimation unit 34 calculates "ω m " to "V m " and the efficiency η motor (V m -β), η motor (V m ), η motor (V m +β). The loss comparison unit 35 calculates the search speed V m -β, V m , V m + Motor 2 efficiency η per β motor (V m -β), η motor (V m ), η motor (V m + β), the motor loss energy W per unit travel distance for each load torque loss The loss comparison unit 35 calculates the motor loss energy W loss The speed at which is minimum is the target speed V eco The speed command unit 13 outputs the target speed V eco Using the target speed V * and outputs it to the speed control unit 14 and the current command unit 33.

[0179] In the above example, the running resistance estimation unit 31 calculates the motor load torque τ using the rolling resistance coefficient μ, the vehicle total weight m, and the vehicle frontal projection area S, which are stored in advance in the storage unit 10. load However, the present invention is not limited to this example. The rolling resistance coefficient μ changes depending on the road surface condition, and the total vehicle weight m changes depending on the rider's weight, the amount of luggage carried, etc. In addition, in a motorcycle, the vehicle frontal projected area S also changes depending on the rider's physique or posture. Therefore, the running resistance estimating unit 31 calculates the motor load torque τ using the rolling resistance coefficient μ, total vehicle weight m, and vehicle frontal projected area S detected on the vehicle side. load It is also possible to calculate

[0180] In this case, the control unit 5 calculates the total vehicle weight m by adding up the weight of the occupants and luggage detected by a weight detection unit (not shown) provided in the vehicle and the weight of the vehicle body. The control unit 5 also estimates the vehicle frontal projection area S based on information about images captured by multiple imaging units arranged in front of the vehicle. For example, the control unit 5 functions as an image processing unit, and uses machine learning using a mathematical model such as a convolutional neural network (CNN) or a recurrent neural network (RNN) to estimate the road surface condition from image information about the road surface and estimate the rolling resistance coefficient μ, and the vehicle frontal projection area S based on image information about the posture of the occupants.

[0181] 4. Hardware Configuration FIG. 17 is a diagram showing an example of the hardware configuration of the control unit 5 of the motor control device 1 according to the embodiment.

[0182] 17 , the control unit 5 of the motor control device 1 has a processor 90, a memory 91, an input / output interface (I / F) 92, and a media interface (I / F) 93. The processor 90, the memory 91, the input / output interface 92, and the media interface 93 are connected by a bus 95.

[0183] The processor 90 includes, for example, one or more of a central processing unit (CPU), a micro processing unit (MPU), a graphics processing unit (GPU), and a system large scale integration (LSI). The memory 91 is a random access memory (RAM) such as a static random access memory (SRAM) or a dynamic random access memory (DRAM), or a semiconductor memory element.

[0184] The processor 90 acquires information output from devices such as the vehicle-side device 101 and the detection unit 3 via the input / output interface 92, and outputs a PWM signal for driving the motor 2. The processor 90 acquires information output from devices such as the vehicle-side device 101 and the detection unit 3 via the input / output interface 92, and outputs a PWM signal for driving the motor 2. m The processor 90 executes a detection step of detecting the speed of the motor 2 by acquiring information indicating the rotation angle θ output from the detection unit 3. m It is also possible to perform a detection step of detecting the speed of the motor 2 by calculating

[0185] The media interface 93 reads a program or data stored on a recording medium 94 and provides the read data or program (e.g., a motor control program) to the processor 90 via the memory 91. The processor 90 loads the program from the recording medium 94 onto the memory 91 via the media interface 93 and executes the loaded program. The recording medium 94 is, for example, a semiconductor memory such as a flash memory, but may also be an optical recording medium such as a DVD (Digital Versatile Disc) or a PD (Phase Change Rewritable Disc).

[0186] The processor 90 executes a program using the memory 91 or the like as a working area to realize the functions of the control unit 5. Note that the control unit 5 may be partially or entirely realized by an integrated circuit such as an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a DSP (Digital Signal Processor).

[0187] Although the embodiment of the present invention has been described above, this embodiment is presented as an example and is not intended to limit the scope of the invention. This embodiment can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims.

[0188] The present technology can be configured as follows: (1) A motor control device including: a reception unit that receives a switching of a running mode from a first mode in which overmodulation control is performed to a second mode in which non-overmodulation control is performed; a detection unit that detects a motor speed; and a control unit that, when the switching is received by the reception unit while the speed in the first mode exceeds an upper limit speed of the second mode and the overmodulation control is being performed, reduces a modulation factor of the overmodulation control to decelerate the speed at a predetermined reduction rate, and, when the speed becomes equal to or less than the upper limit speed of the second mode, reduces the modulation factor to 1 or less to switch to non-overmodulation control and start flux-weakening control. (2) The motor control device described in (1), wherein, when the switching is received by the reception unit while the overmodulation control and the flux-weakening control are being performed in the first mode, the control unit decreases an amount of flux-weakening in the flux-weakening control, stops the flux-weakening control, and then decreases the modulation factor at the predetermined reduction rate to decelerate the speed. (3) The motor control device according to (1) or (2), wherein, when the receiving unit receives the switching while the overmodulation control and the flux-weakening control are being performed in the first mode, the control unit reduces the amount of flux-weakening in the flux-weakening control and then reduces the modulation factor at the predetermined reduction rate so as to decelerate the speed from the state in which the flux-weakening control was performed. (4) The motor control device according to any one of (1) to (3), wherein the control unit includes: a speed command unit that outputs a speed command value that is a target value of the speed of the motor, and an upper limit speed calculation unit that calculates the upper limit speed, and when the receiving unit receives the switching while the speed exceeds the upper limit speed in the first mode, the speed command value reduces the speed command value to the upper limit speed. (5) The motor control device according to (4), wherein the upper limit speed calculation unit calculates the upper limit speed as the motor speed at an intersection of a curve showing the relationship between the motor speed and load torque and a curve showing the relationship between the motor speed and motor torque in the second mode.(6) The motor control device according to (4), wherein the control unit, when the speed reaches the upper limit speed due to a decrease in the speed command value, sets the modulation factor to 1 or less to switch from overmodulation control to non-overmodulation control. (7) A motor module comprising the motor control device according to any one of (1) to (6) and the motor. (8) A motor control method including: a receiving step of receiving switching of a running mode from a first mode in which overmodulation control is performed to a second mode in which non-overmodulation control is performed, a detection step of detecting the motor speed, and a control step of, when the switching is received in the receiving step while the speed in the first mode exceeds an upper limit speed of the second mode and the overmodulation control is being performed, reducing the modulation factor of the overmodulation control to decelerate the speed at a predetermined reduction rate, and when the speed becomes equal to or less than the upper limit speed of the second mode, setting the modulation factor to 1 or less to switch to non-overmodulation control and starting flux-weakening control. (9) A motor control program that causes a computer to execute the following steps: a receiving step of receiving a change in running mode from a first mode in which overmodulation control is performed to a second mode in which non-overmodulation control is performed; a detection step of detecting the motor speed; and a control step of, when the change is received in the receiving step while the speed in the first mode exceeds an upper limit speed of the second mode and the overmodulation control is being performed, reducing a modulation factor of the overmodulation control so as to decelerate the speed at a predetermined reduction rate, and, when the speed becomes equal to or less than the upper limit speed of the second mode, reducing the modulation factor to 1 or less to switch to the non-overmodulation control and start flux-weakening control.

[0189] The disclosed embodiments should be considered in all respects as illustrative and not restrictive. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

[0190] REFERENCE SIGNS LIST 1 Motor control device 2 Motor 3 Detection unit 4 Reception unit 5 Control unit 6 Drive unit 10 Memory unit 10i Vehicle body information 10p Motor control program 11 Target speed selection unit 12 Speed ​​range identification unit 13 Speed ​​command unit 14 Speed ​​control unit 15 Current control unit 16a, 16b Subtractor 17a q-axis PI control unit 17b d-axis PI control unit 18, 21 Coordinate conversion unit 19 PWM signal generation unit 20 ADC 23 Inverter circuit 24 Current detection unit 25 Power supply relay 30 Search speed generation unit 31 Running resistance estimation unit 32 Modulation factor setting unit 33 Current command unit 34 Efficiency estimation unit 35 Loss comparison unit 40 Speed ​​threshold calculation unit 41 Range identification unit 50 Running mode determination unit 100 Motor module 101 Vehicle side device

Claims

a reception unit that receives a switching of a running mode from a first mode in which overmodulation control is performed to a second mode in which non-overmodulation control is performed; a detection unit that detects the speed of the motor; a control unit that, when the switching is accepted by the accepting unit in a state where the speed in the first mode exceeds an upper limit speed of the second mode and the overmodulation control is being performed, reduces a modulation rate of the overmodulation control to decelerate the speed at a predetermined reduction rate, and, when the speed becomes equal to or less than the upper limit speed of the second mode, sets the modulation rate to 1 or less to non-overmodulation control and starts flux-weakening control. 　 The control unit 2. The motor control device according to claim 1, wherein, when the switching is accepted by the accepting unit while the overmodulation control and the flux-weakening control are being performed in the first mode, the amount of flux-weakening in the flux-weakening control is decreased until the flux-weakening control is stopped, and then the modulation rate is decreased at the predetermined decrease rate so as to decelerate the speed. 　 The control unit 2. The motor control device according to claim 1, wherein, when the switching is accepted by the accepting unit while the overmodulation control and the flux-weakening control are being performed in the first mode, the amount of flux-weakening in the flux-weakening control is gradually decreased, and then the modulation rate is decreased at the predetermined decrease rate from the state in which the flux-weakening control is being performed so as to decelerate the speed. 　 The control unit a speed command unit that outputs a speed command value that is a target value for the speed of the motor; an upper limit speed calculation unit that calculates the upper limit speed, The speed command unit 4. The motor control device according to claim 1, wherein when the switching is accepted by the acceptance unit while the speed exceeds the upper limit speed in the first mode, the speed command value is reduced to the upper limit speed. 　 The upper limit speed calculation unit 5. The motor control device according to claim 4, wherein the upper limit speed is calculated as a speed of the motor at an intersection of a curve showing the relationship between the speed of the motor and the load torque and a curve showing the relationship between the speed of the motor and the torque of the motor in the second mode. 　 The control unit 5. The motor control device according to claim 4, wherein when the speed reaches the upper limit speed due to the reduction in the speed command value, the modulation factor is set to 1 or less to switch from the overmodulation control to the non-overmodulation control. 　 A motor module comprising the motor control device according to any one of claims 1 to 3 and the motor. 　 a receiving step of receiving a change of the running mode from a first mode in which overmodulation control is performed to a second mode in which non-overmodulation control is performed; a detecting step of detecting a speed of the motor; a control step of, when the switching is accepted by the accepting step, reducing a modulation factor of the overmodulation control so as to decelerate the speed at a predetermined reduction rate, and, when the speed becomes equal to or less than the upper limit speed of the second mode, switching to non-overmodulation control and starting flux-weakening control. 　 a receiving step of receiving a change of the running mode from a first mode in which overmodulation control is performed to a second mode in which non-overmodulation control is performed; a detecting step of detecting a speed of the motor; a control step of reducing a modulation factor of the overmodulation control so as to decelerate the speed at a predetermined reduction rate when the switching is accepted by the accepting step in a state where the speed in the first mode exceeds an upper limit speed of the second mode and the overmodulation control is being performed, and, when the speed becomes equal to or less than the upper limit speed of the second mode, setting the modulation factor to 1 or less to switch to the non-overmodulation control and starting flux-weakening control.

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