Electric motor control method and electric motor control device

Abstract

The present invention calculates a second torque command value by using a vibration compensating torque for suppressing vibration of an electric motor rotation speed to correct a first torque command value based on required output of an electric motor, restricts the vibration compensating torque on the basis of a restriction requirement indication amount indicating a status in which the suppression of the vibration is to be restricted, sets a restriction level for determining the level of restriction that indicates the degree of restriction on the vibration compensating torque, and feeds back a torque indication amount indicating an electric motor torque to the second torque command value to calculate a voltage command value. The present invention then refers to the restriction level to determine the feedback gain of the torque indication amount.

Description

[Technical Field]

[0001] The present invention relates to an electric motor control method and an electric motor control device. [Background technology]

[0002] JP2012-75257A proposes an electric motor control method for a vehicle that performs vibration suppression control to suppress vibrations caused by the torsional vibration characteristics of the drivetrain. Furthermore, this electric motor control method employs control that limits the vibration suppression function associated with the vibration suppression control in a specific operating range of the electric motor where the abnormal noise may occur, in order to suppress abnormal noise generated in the gears of the reducer due to repeated positive and negative inversions of the torque command. Summary of the Invention

[0003] It is expected that situations will arise in which it is necessary to limit the vibration damping function that suppresses torsional vibrations in the drivetrain, depending on the operating state of the electric vehicle, the electric motor, or the control system for the electric motor, such as the occurrence of abnormal noise in the gears described above. However, limiting the vibration damping function in such situations may result in insufficient suppression of torsional vibrations in the drivetrain, which may cause discomfort to the occupants.

[0004] Therefore, an object of the present invention is to provide an electric motor control method and an electric motor control device that can suppress torsional vibrations even under limitations of the vibration suppression function that suppresses torsional vibrations in a drive transmission system.

[0005] According to one aspect of the present invention, there is provided a method for controlling an electric motor based on a first torque command value corresponding to a required output of the electric motor. The electric motor control method includes a vibration suppression step of calculating a second torque command value by correcting the first torque command value with a vibration compensation torque, a limiting step of limiting the vibration compensation torque based on a limit request suggestion amount, a limit level determination step of determining a limit level indicating the degree of limit on the vibration compensation torque, and a torque control step of calculating a voltage command value by feeding back the torque suggestion amount suggesting the electric motor torque to the second torque command value. In particular, the vibration compensation torque is a torque correction value that suppresses vibration in the electric motor rotation speed. Furthermore, the limit request suggestion amount indicates a situation in which suppression of vibration in the electric motor rotation speed should be limited. Furthermore, the voltage command value is a command value of a voltage supplied to the electric motor from a predetermined power source. Then, in the torque control step, a feedback gain of the torque suggestion amount is determined by referring to the limit level. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a block diagram illustrating the configuration of an electric motor control device that executes an electric motor control method according to each embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram illustrating the configuration of the vibration suppression control unit. [Figure 3] FIG. 3 is a diagram illustrating a dynamic system model that gives the equation of motion of a torsional vibration system. [Figure 4] FIG. 4 is a graph showing the filter characteristics of the bandpass filter H(s). [Figure 5] FIG. 5 is a block diagram illustrating the configuration of the torque control unit. [Figure 6] FIG. 6 is a block diagram illustrating the configuration of the current vector control unit. [Figure 7] FIG. 7 is a block diagram illustrating the configuration of the torque compensator. [Figure 8] FIG. 8 is a block diagram illustrating the configuration of the voltage phase control unit. [Figure 9] FIG. 9 is a block diagram illustrating the configuration of the PWM control unit. [Figure 10] FIG. 10 is a block diagram illustrating the configuration of the synchronous PWM control unit. [Figure 11] FIG. 11 is a timing chart illustrating the processes in asynchronous PWM control and synchronous PWM control. [Figure 12] FIG. 12 is a flowchart illustrating the processes in the vibration suppression control section, the torque control section, and the PWM control section. [Figure 13] FIG. 13 is a block diagram illustrating the configuration of a vibration suppression control unit according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0008] (First embodiment) Fig. 1 is a block diagram illustrating an electric motor control device 10 that executes an electric motor control method. As shown in Fig. 1, the electric motor control device 10 drives a motor 106 with power supplied from a battery 113 and controls the operating state of the motor. In particular, the electric motor control device 10 is mounted on a vehicle such as an electric vehicle or a hybrid vehicle that uses the motor 106 as a driving source.

[0009] The battery 113 is a secondary battery such as a lithium ion battery that functions as a power supply source for the motor 106 and other components of the vehicle. In this embodiment, the battery 113 is a DC power supply. In addition, in this embodiment, the voltage output by the battery 113 (hereinafter referred to as "DC voltage V dc ” is detected by the voltage sensor 112.

[0010] The motor 106 is configured, for example, by an IPM (Interior Permanent Magnet) three-phase synchronous electric motor. In particular, the motor 106 (more specifically, the rotor of the motor 106) is connected to the drive wheels via a driving force transmission system of the vehicle, such as an output shaft, gears, and drive shafts, which are not shown.

[0011] The motor control device 10 mainly includes a vibration suppression control unit 101, a torque control unit 102, a PWM (Pulse Width Modulation) control unit 103, a speed calculation unit 110, and a coordinate conversion unit 111.

[0012] The vibration suppression control unit 101 determines the first torque command value T * 1, and the mechanical angular velocity ω of the motor 106 m Based on this, a vibration suppression control calculation is performed to suppress vibrations (vibrations in the motor rotation speed) caused by the driving force transmission system, and the second torque command value T * 2 is calculated. Note that the first torque command value T * 1 is a basic torque command value determined from the required output of the motor 106. The required output of the motor 106 is determined according to the required driving force based on the operation of the vehicle by the driver (operation of the accelerator pedal) or a command from a higher-level controller (not shown) such as a predetermined automatic driving control device.

[0013] Furthermore, the vibration suppression control unit 101 outputs a limit level signal S as a flag indicating the result of the determination as to whether or not a certain limit or more is imposed on the vibration suppression control calculation. H / L Then, the vibration suppression control unit 101 generates the second torque command value T * 2 and limit level signal S H / L to the torque control unit 102. Details of the processing in the vibration suppression control unit 101 will be described later.

[0014] The torque control unit 102 outputs a DC voltage V dc , limit level signal S H / L , second torque command value T * 2. Electrical angular velocity ω of the motor 106 e , d-axis current i d , and q-axis current i q is input, and the command value of the voltage to be supplied to the motor 106 (d-axis voltage command value v * d and q-axis voltage command value v q ) is calculated. Then, the torque control unit 102 calculates the calculated d-axis voltage command value v * dand q-axis voltage command value v * q to the PWM control unit 103. Details of the processing in the torque control unit 102 will be described later.

[0015] In the following, for the sake of simplicity, the components of each parameter expressed in the dq-axis coordinate system will be represented by the symbol "x" (x = d or q) as appropriate. For example, the d-axis current i d and q-axis current i q The dq axis current i x " etc.

[0016] The PWM control unit 103 controls the DC voltage V dc , voltage command value v * x , and the electrical angle θ of the motor 106 is input to generate a drive signal D for driving the switching elements of the inverter 104. * uu ~D * wl Then, the PWM control unit 103 generates the generated drive signal D * uu ~D * wl to the inverter 104. Details of the processing in the PWM control unit 103 will be described later.

[0017] The inverter 104 includes a plurality of semiconductor switching elements and a drive circuit (not shown) for driving these switching elements. In particular, the inverter 104 receives a drive signal D * uu ~D * wl Each switching element is driven according to the DC voltage V dc is the three-phase AC voltage (v u ,v v ,v w ) and is supplied to the motor 106. That is, the motor 106 operates in response to the desired torque command value T * The motor is driven so as to output an actual torque corresponding to the torque.

[0018] The current sensor 105 detects the three-phase AC current (i u ,i v ,i w ) are configured by a plurality of individual sensors that detect each phase component of the u-phase current i u and v-phase current i v In this example, two individual sensors are used to detect the remaining w-phase current i w By using the fact that the sum of the three-phase components is 0, the u-phase current i u and v-phase current i v The current sensor 105 may be configured as individual sensors provided for all three phases. The current sensor 105 outputs the detected current value of each phase to the coordinate conversion unit 111.

[0019] The resolver 107 functions as a rotor position detector that detects the rotor position of the motor 106. In particular, the resolver 107 transmits and receives excitation / modulation signals to and from an RDIC (resolver / digital conversion circuit) 108.

[0020] Based on the excitation / modulation signal, the RDIC 108 generates an ABZ signal (digital angle information of the motor 106) consisting of up / down counter pulses A and B and an origin signal pulse Z. The RDIC 108 outputs the generated ABZ signal to an ABZ counter 109.

[0021] The ABZ counter 109 calculates the electrical angle θ based on the ABZ signal, and outputs the calculated electrical angle θ to the PWM control unit 103, the speed calculation unit 110, and the coordinate conversion unit 111.

[0022] The speed calculation unit 110 calculates the electrical angular speed ω of the motor 106 from the amount of change per time of the electrical angle θ. e and mechanical angular velocity ω m Then, the speed calculation unit 110 calculates the calculated electrical angular speed ω e is input to the torque control unit 102, and the mechanical angular velocity ω m are output to the vibration suppression control unit 101.

[0023] The coordinate conversion unit 111 converts the three-phase AC current (i u ,i v ,i w ) to the dq axis current i x Convert to.

[0024]

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[0025] That is, the dq-axis current i corresponding to the current detection value in the dq-axis coordinate system is calculated using equation (1). x Then, the coordinate conversion unit 111 converts the calculated dq-axis current i x is output to the torque control unit 102.

[0026] The motor control device 10 is realized by a computer that includes a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface) and is programmed to be able to execute the above-mentioned components. The motor control device 10 can also be configured by multiple computer hardware that executes each process in a distributed manner.

[0027] Next, I. details of the processing in the vibration suppression control unit 101, II. details of the processing in the torque control unit 102, and III. details of the processing in the PWM control unit 103 will be described.

[0028] [I. Vibration control unit 101] 2 is a block diagram illustrating the configuration of vibration suppression control unit 101. As shown in the figure, vibration suppression control unit 101 includes absolute value processing unit 201, limiter 202, mechanical angular velocity estimating unit 203, vibration torque estimating unit 204, and gain unit 205.

[0029] In particular, the mechanical angular velocity estimation unit 203, the vibration torque estimation unit 204, and the gain unit 205 mainly calculate the vibration compensation torque T fbIt functions as a configuration for obtaining the vibration compensation torque T fb is the first torque command value T * This is the torque correction value for 1. In particular, the vibration compensation torque T fb is the first torque command value T according to the required output of the motor 106. * 1, it is determined to eliminate the vibration of the motor rotation speed caused by the torsional vibration of the driving force transmission system.

[0030] More specifically, the mechanical angular velocity estimation unit 203 estimates the second torque command value T * The transfer characteristic G obtained from the vehicle transfer system model described later for the feedback value of 2 p (s) to estimate the mechanical angular velocity ω^ m Then, the vibration torque estimation unit 204 calculates the estimated mechanical angular velocity ω^ m and the mechanical angular velocity ω corresponding to the detected value described above m The deviation of the transfer characteristic G p (s) and a band-pass filter H(s) are applied to obtain the vibration torque T vib Furthermore, the gain section 205 calculates the vibration torque T vib Vibration suppression gain K fb (0≦K fb ≦1) and vibration compensation torque T fb is calculated and output to the limiter 202.

[0031] On the other hand, the absolute value processing unit 201 and the limiter 202 limit the vibration compensation torque T fb_lim It functions as a configuration for determining the limit vibration compensation torque T fb_lim is the vibration compensation torque T under the specified conditions determined in consideration of suppressing abnormal noise caused by gear backlash. fb This is the value obtained by limiting

[0032] More specifically, the absolute value processing unit 201 calculates the first torque command value T *1, and the upper and lower limit values ​​of the absolute value are set as the upper and lower limit values ​​(hereinafter, these are also collectively referred to as "upper and lower limit values") in the limiter 202. That is, in this embodiment, the first torque command value T * 1 functions as a limit request suggestion amount that indicates a situation where the suppression of torsional vibration in the driving force transmission system should be limited (particularly, a situation where abnormal noise due to gear backlash may occur). fb By performing limit processing based on the upper and lower limit values ​​defined by the absolute value processing unit 201, the limit vibration compensation torque T fb_lim Here, the first torque command value T * When 1 is 0, the upper and lower limit values ​​in the limiter 202 are both set to 0. Therefore, the limit vibration compensation torque T fb_lim Therefore, in this case, the vibration compensation torque T fb This suppresses the occurrence of abnormal gear noise and the deterioration of control stability, which are caused by the torque being output without being restricted.

[0033] Furthermore, the restriction level determination unit 206 determines the vibration compensation torque T fb and outputting a restriction level signal S containing the determined restriction level as information. H / L Generate.

[0034] More specifically, the restriction level determination unit 206 determines the first torque command value T * 1, and determines whether the limiting level is relatively high or relatively low based on a comparison between the absolute value (i.e., the upper and lower limit values ​​in the limiter 202) and a predetermined reference value. The limiting level determining unit 206 then generates a binary signal ("High" or "Low") corresponding to the relative high or low of the limiting level as the limiting level signal S H / L Generate it as:

[0035] For example, the first torque command value T * Absolute value of 1 and limit level signal S H / L The relationship can be defined as shown in Table 1 below.

[0036] [Table 1]

[0037] According to the example in Table 1, the first torque command value T * When the absolute value of 1 is less than 20N, the limit level for vibration compensation is relatively high and the limit level signal S H / L is set to High. On the other hand, the first torque command value T * When the absolute value of 1 is 20N or more, the limit level for vibration compensation is relatively low and the limit level signal S H / L is set to Low.

[0038] Next, the transfer characteristic G p (s) will be explained.

[0039] Fig. 3 is a diagram illustrating a dynamic system model that gives the equation of motion of a torsional vibration system. The parameters shown in Fig. 3 are as follows:

[0040] J m : Motor inertia J w : Inertia of the drive wheels M: Vehicle weight K D : Torsional rigidity of the drivetrain K T : Coefficient of friction between the tire and road surface N: Overall gear ratio r: tire load radius ω m : Motor mechanical angular velocity T m : Motor output shaft torque T D : Torque of the drive wheels F: Force applied to the vehicle V: Vehicle speed ω w : Angular velocity of the drive wheels

[0041] From FIG. 3, the equations of motion of the electric vehicle are expressed by the following equations (2) to (6).

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[0042] Based on the above equations of motion (2) to (6), the transfer characteristic G from the motor torque to the motor mechanical angular velocity is p (s) is expressed as the following equations (7) to (15).

[0043]

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[0044] Note that "s" in equation (7) represents the Laplace operator. Furthermore, by transforming equation (7), the following equation (16) is obtained.

[0045]

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[0046] The coefficients a'1 to a'3 and b'0 to b'2 in equation (16) are values ​​determined by the coefficients a1 to a4 and b0 to b3 defined in equations (8) to (15).

[0047] Here, the transfer characteristic G p When examining the poles and zeros of (s), they show extremely high values. This means that α and β in equation (16) show values ​​that are very close to each other. Therefore, by performing pole-zero cancellation (approximation processing with α = β) on equation (16), the transfer characteristic G p (s) can be expressed as a rational function with a quadratic numerator and a cubic denominator as shown in the following equation (17).

[0048]

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[0049] However, "ω" in equation (17)p " is the transfer characteristic G p (s) represents the torsional resonance angular frequency, and "ζ p " is the transfer characteristic G p represents the damping coefficient of (s). Furthermore, for convenience of computer processing, it is preferable to discretize (z-transform) Equation (17) using the variable z expressed by the following Equation (18). Note that "T" in Equation (18) represents the sampling time of control.

[0050]

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[0051] Next, the bandpass filter H(s) will be described. The bandpass filter H(s) is configured to have a filter characteristic that functions as a feedback element that selectively reduces torsional vibrations in the drivetrain.

[0052] 4 is a graph showing the filter characteristics of the bandpass filter H(s). In the filter characteristics shown in FIG. 4, the attenuation characteristics on the low-pass side and the high-pass side are the same, and the torsional resonance frequency f p is set to be in the center of the pass band on a logarithmic axis (log scale). By giving the band-pass filter H(s) such filter characteristics, the effect of selectively reducing torsional vibration in the drivetrain can be enhanced. More specifically, the band-pass filter H(s) can be configured by combining a first-order low-pass filter and a high-pass filter as shown in the following equation (19).

[0053]

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[0054] [II. Torque control unit 102] 5 is a block diagram illustrating the configuration of the torque control unit 102. The torque control unit 102 includes a current vector control unit 501, a voltage phase control unit 502, an output controller 503, a modulation factor calculation unit 504, and a control switching determination unit 505.

[0055] The current vector control unit 501 outputs a limit level signal S H / L , second torque command value T * 2, electrical angular velocity ω e , DC voltage V dc , and dq axis current i x is used as input, and the d-axis voltage command value v is calculated by current vector control. * di-fin and q-axis voltage command value v * qi-fin Calculate the following.

[0056] The voltage phase control unit 502 outputs a limit level signal S H / L , second torque command value T * 2, electrical angular velocity ω e , DC voltage V dc , dq-axis current i x , and modulation factor M are input, and the d-axis voltage command value v is calculated by voltage phase control. * dv-fin and q-axis voltage command value v * qv-fin Calculate the following.

[0057] The output controller 503 receives the mode selection signal S generated by the control switching decision unit 505. MO is used as input, and the dq-axis voltage command value v based on the current vector control is xi-fin and the dq-axis voltage command value v based on voltage phase control xv- * fin Either one of these is used as the final dq-axis voltage command value v * x Output as

[0058] The modulation factor calculation unit 504 calculates the DC voltage V dc and dq-axis voltage command value v * x is input, the modulation factor M is calculated based on the following equation (20), and is output to the voltage phase control unit 502 and the control switching determination unit 505.

[0059]

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[0060] The control switching determination unit 505 determines the control mode (current vector control or voltage phase control) and modulation mode to be executed based on the modulation factor M. MO For example, the control switching determination unit 505 generates the mode selection signal S according to the logic shown in Table 2 below. MO Generate.

[0061] [Table 2]

[0062] The current vector control unit 501 and the voltage phase control unit 502 will be described in further detail below.

[0063] II-1. Current vector control unit 501 6 is a block diagram illustrating the configuration of the current vector control unit 501. In FIG. 6, for the sake of simplicity, the q-axis voltage command value v * qi-fin However, the omitted part is the d-axis voltage command value v * di-fin The configuration is the same as that relating to the calculation of

[0064] As shown in the figure, the current vector control unit 501 includes a torque compensator 601 , an interference voltage calculation unit 602 , a filter unit 603 , a current command value calculation unit 604 , and a voltage command value calculation unit 605 .

[0065] The torque compensator 601 calculates the second torque command value T * The torque command value T * (hereinafter referred to as "third torque command value T * 3 ”) and outputs it to the interference voltage calculation unit 602 and the current command value calculation unit 604 .

[0066] The interference voltage calculation unit 602 calculates the third torque command value T * 3, electrical angular velocity ωe , and DC voltage V dc is used as input, and the d-axis interference voltage v is calculated by referring to a look-up interference voltage table prepared in advance. * d-dcpl and q-axis interference voltage v * q-dcpl The stored values ​​of the look-up interference voltage table are determined in advance by experiment or analysis and stored in a predetermined storage area.

[0067] The filter unit 603 filters the dq-axis interference voltage v obtained by the interference voltage calculation unit 602. * x-dcpl By applying a low-pass filter determined by the following equation (21) to the dq-axis decoupling voltage v x-dcpl-fit In the following equation (21), "τ" represents the dq-axis current i x represents the nominal response time constant of

[0068]

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[0069] The current command value calculation unit 604 calculates the third torque command value T3 * , electrical angular velocity ω e , and DC voltage V dc is input, and the d-axis current command value i is calculated by referring to a look-up current table prepared in advance. d * and q-axis current command value i q * The stored values ​​of the look-up current table are determined in advance by experiment or analysis and stored in a predetermined storage area.

[0070] The voltage command value calculation unit 605 calculates the dq-axis current command value i x * , dq-axis decoupling voltage v x-dcpl-fit , and the dq-axis current i x is used as an input, and the dq-axis voltage command value v of the current vector control is calculated based on the following equations (22) and (23). * xi-fin Ask for.

[0071]

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[0072]

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[0073] Next, the torque compensator 601 will be described in detail.

[0074] II-2. Torque Compensator 601 7 is a block diagram illustrating the configuration of the torque compensator 601. As shown in the figure, the torque compensator 601 includes a torque calculator 701, a torque compensation value calculator 702, a high gain permission determiner 703, and a gain setter 704.

[0075] The torque calculator 701 calculates the dq-axis current i x is used as input, and a torque estimation value T est The stored values ​​of the look-up torque table are determined in advance by experiment or analysis and stored in a predetermined storage area.

[0076] The torque compensation value calculation unit 702 calculates the second torque command value T * 2. Torque estimation value T est , and a gain k1, which will be described later, are input, and the torque compensation value ΔT is calculated based on the following equation (25):* Calculate the following.

[0077]

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[0078] On the other hand, the high gain permission determination unit 703 determines the second torque command value T * 2, electrical angular velocity ω e , DC voltage V dc , and the modulation factor M, the high gain permission determination unit 703 determines whether to permit or prohibit the setting of a relatively high gain k1 (hereinafter also referred to as "high gain"). Then, the high gain permission determination unit 703 outputs a high gain permission signal S as a binary signal indicating the result of the determination as to whether to permit or prohibit the setting of the high gain. HP For example, the high gain permission determination unit 703 generates the high gain permission signal S according to the logic shown in Table 3 below. HP Generate.

[0079] [Table 3]

[0080] In particular, in the example shown in Table 3, high gain setting is permitted in the overmodulation region (M>100) where the PWM waveform changes easily and sharply, and in the low torque region where there is a relatively large gain margin and room for high gain. dc or electrical angular velocity ω e If the value is outside the range guaranteed by the system, the system protection is given priority and high gain setting is not permitted.

[0081] The logic for determining whether to permit or prohibit the setting of high gain is not limited to the mode shown in Table 3. In particular, for each parameter shown in Table 3, the threshold value for distinguishing between permitting and prohibiting the setting of high gain can be set to an appropriate preferable value, taking into consideration the balance between control stability and system protection.

[0082] Next, the gain setting unit 704 sets the limit level signal SH / L and high gain enable signal S HP The gain setting unit 704 determines the value of the gain k1 used in the above equation (25) based on the above. The gain setting unit 704 determines the gain k1, for example, according to the logic shown in Table 4 below.

[0083] [Table 4]

[0084] Then, the torque compensator 601 calculates the second torque command value T * 2 is the torque compensation value ΔT * The value obtained by adding the above is the third torque command value T3 * Output as

[0085] Next, the configuration of voltage phase control unit 502 will be described.

[0086] II-3. Voltage phase control unit 502 8 is a block diagram illustrating the configuration of voltage phase control unit 502. As shown in the figure, voltage phase control unit 502 has a current command value calculation unit 801, a magnetic flux calculation unit 802, a limiter 803, a voltage phase calculation unit 804, a filter processing unit 805, a high gain permission determination unit 806, a gain setting unit 807, a torque calculation unit 808, a voltage phase command value calculation unit 809, and a vector converter 810.

[0087] The current command value calculation unit 801 calculates the second torque command value T * 2, electrical angular velocity ω e , and DC voltage V dc is input, and a lookup table similar to that used in the current command value calculation unit 604 is referenced to calculate the dq axis current command value i x * Ask for.

[0088] The magnetic flux calculation unit 802 calculates the dq-axis current command value i x * Enter the value of the magnetic flux norm φ by referring to the look-up magnetic flux table prepared in advance. 0_refThe stored values ​​in the look-up magnetic flux table are determined in advance by experiment or analysis and stored in a predetermined storage area. Then, the obtained magnetic flux norm value φ 0_ref With respect to the electrical angular velocity ω e The provisional voltage norm V is obtained by multiplying the absolute value of a ' is output to limiter 803.

[0089] The limiter 803 calculates the provisional voltage norm V based on the following equation (26): a ´ to the voltage norm command value V a * Ask for.

[0090]

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[0091] That is, the voltage norm command value V a * is the provisional voltage norm V a ´ is the voltage norm V a The fundamental component value (√6 / π V dc ) is determined as the limited value.

[0092] The voltage phase calculation unit 804 calculates the voltage norm command value V a * , electrical angular velocity ω e , and the second torque command value T * 2 is input, and the voltage phase α is calculated by referring to a lookup voltage phase table prepared in advance. ff The look-up voltage phase table is determined in advance by experiment or analysis and stored in a predetermined storage area.

[0093] On the other hand, the filter processing unit 805 calculates the second torque command value T * 2 is filtered with a first-order low-pass filter having the time constant τ to obtain the torque reference value T ref That is, the torque reference value T ref is the second torque command value T * 2 is determined as the expected nominal torque response.

[0094] The high gain permission determination unit 806 determines the torque reference value T ref , DC voltage V dc , and the modulation factor M, a high gain permission signal S indicating whether or not it is permitted to relatively increase the gain k2, which will be described later. HP The high gain enable signal S HP The logic shown in Table 3 can be applied to generate the second torque command value T * 2" to "Torque reference value T ref " can be replaced with " and the logic in Table 3 can be used.

[0095] The gain setting unit 807 outputs the limit level signal S H / L and high gain enable signal S HP The value of gain k2, which will be described later, is determined based on the above. Note that the logic shown in Table 4 can be similarly applied to determine gain k2. That is, the logic of Table 4 can be used by replacing "gain k1" in Table 4 with "gain k2."

[0096] The torque calculator 808 calculates the dq-axis current i x is input, and a look-up torque table similar to that used in the torque calculator 701 is referenced to obtain the torque estimate T est Ask for.

[0097] The voltage phase command value calculation unit 809 calculates the voltage phase α ff , torque estimate T est , and the gain k2 are input, and the voltage phase compensation value α is calculated based on the following equations (27) and (28). fb and voltage phase command value α * Calculate the following.

[0098]

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[0099] The gain k2 in equation (27) is determined so that its base value (low gain) is equal to the reciprocal of the design value of the torque feedback response time constant in voltage phase control. The gain k3 in equation (27) is a constant that indicates the sensitivity of the voltage phase α to torque. In particular, the gain k3 is determined appropriately depending on the characteristics of the motor 106.

[0100] The vector converter 810 converts the voltage norm command value V a * , voltage phase command value α * , and the voltage phase compensation value α fb is used as an input, and the dq-axis voltage command value v of the current phase control is calculated based on the following equation (29). xv- * fin Ask for.

[0101]

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[0102] [III. PWM control unit 103] 9 is a block diagram illustrating the configuration of the PWM control unit 103. As shown in the figure, the PWM control unit 103 has a coordinate conversion unit 901, an asynchronous PWM control unit 902, an asynchronous PWM signal generator 903, a vector conversion unit 904, a synchronous PWM control unit 905, a synchronous PWM signal generator 906, a modulation switching determination unit 907, and a PWM output switcher 908.

[0103] The coordinate conversion unit 901 converts the dq-axis voltage command value v input from the torque control unit 102 using the electrical angle θ. * x The three-phase voltage command value (v * u ,v * v ,v * w ) is found.

[0104]

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[0105] The asynchronous PWM control unit 902 controls the DC voltage V dc and three-phase voltage command value (v * u ,v * v ,v * w ) is used as an input, and the duty command values ​​(Duty_u, Duty_v, Duty_w) are calculated based on the following equation (31).

[0106]

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[0107] The asynchronous PWM signal generator 903 receives duty command values ​​(Duty_u, Duty_v, Duty_w) as input and generates an asynchronous drive signal D that drives each of the six elements (upper arm elements and lower arm elements for each of the three phases) of the inverter 104. * uua ~D * wla More specifically, the asynchronous PWM signal generator 903 generates a carrier triangular wave (carrier signal C a ) and the duty command value (Duty_u, Duty_v, Duty_w) of each phase to generate the asynchronous drive signal D * uua ~D * wla The asynchronous drive signal D * uua ~D * wla The first subscript "u", "v", or "w" represents each phase of UVW. The second subscript "u" or "l" represents the upper arm element ("u") or lower arm element ("l") of inverter 104. The third subscript "a" indicates that this is an asynchronous PWM signal.

[0108] On the other hand, the vector conversion unit 904 converts the dq-axis voltage command value v * x is input, and the final voltage norm command value V is calculated based on the following equation (32). *a-fin and the final voltage phase command value α * fin Ask for.

[0109]

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[0110] The synchronous PWM control unit 905 determines the final voltage norm command value V * a-fin and DC voltage V dc is used as input, and the carrier signal C used for synchronous PWM control s A comparison value Th[m] (m=1, 2, 3, . . .) to be compared with is determined.

[0111] 10 is a block diagram illustrating the configuration of the synchronous PWM control unit 905. As shown in the figure, the synchronous PWM control unit 905 has a modulation factor calculation unit 1001 and a comparison value calculation unit 1002.

[0112] The modulation factor calculation unit 1001 calculates the final voltage norm command value V * a-fin and DC voltage V dc From this, the modulation factor M is calculated based on the following equation (33).

[0113]

number

[0114] The comparison value calculation unit 1002 inputs the modulation factor M and references a prepared comparison value table to determine multiple comparison values ​​Th[m]. The comparison value table stores, as each comparison value Th[m], the ON / OFF phases of the synchronous PWM pulses determined in advance by experiment or numerical calculation based on a predetermined analysis method so as to suppress harmonic currents for each modulation factor M. The predetermined analysis method may include, for example, a selected harmonic elimination ("SHE") method, which adjusts the number of switching times to eliminate harmonics of a specific order. In particular, in this embodiment, the comparison value table stores ten comparison values ​​Th[1], Th[2], ..., Th

[10] . The number of comparison values ​​Th[n] can be adjusted as appropriate, for example, depending on the number of pulses per cycle of the desired electrical angle θ.

[0115] Returning to FIG. 9, the synchronous PWM signal generator 906 generates a final voltage phase command value α * fin , the comparison value Th[m], and the electrical angle θ are input, and the synchronous drive signal D * uus ~D * wls In particular, the synchronous PWM signal generator 906 generates the electrical angle θ and the final voltage phase command value α * fin The carrier signal C generated by combining s and the comparison value Th[m], the synchronous drive signal D * uus ~D * wls The synchronous drive signal D * uus ~D * wls The first subscript "u", "v", or "w" represents each phase of UVW. The second subscript "u" or "l" represents the upper arm element ("u") or lower arm element ("l") of inverter 104. The third subscript "s" indicates that the signal is a synchronous PWM signal.

[0116] For example, the synchronous PWM signal generator 906 generates the carrier signal C for each of the UVW phases based on the following equation (34): us,C vs ,C ws Generate.

[0117]

number

[0118] FIG. 11 is a timing chart outlining the operations in asynchronous PWM control and synchronous PWM control.

[0119] In the asynchronous PWM control shown in Figure 11(A), the carrier signal C a The frequency of the asynchronous PWM signal can be set arbitrarily, regardless of the position (electrical angle θ) and drive frequency of the motor 106. On the other hand, the arrangement interval of pulses in the asynchronous PWM signal is limited to the control period Δt. In the asynchronous PWM control, the interruption of each control calculation and the updating of each parameter according to the results of these control calculations are performed every control period Δt (carrier signal C a It is executed every 1 / 2 cycle of the

[0120] On the other hand, in the synchronous PWM control shown in FIG. 11(B), the arrangement interval of pulses in the synchronous PWM signal is almost independent of the control period Δt and can be adjusted substantially arbitrarily. Therefore, when the motor 106 is driven in the overmodulation region and the square wave region where the number of pulses is limited, there is an advantage that harmonics and ripples in the current can be easily reduced. Note that, in the synchronous PWM control, as in the asynchronous PWM control, interrupts of each control calculation and updates of each parameter according to the results of these control calculations are performed every control period Δt (carrier signal C s It is executed every 1 / 2 cycle of the

[0121] Returning to FIG. 9, the modulation switching decision unit 907 receives the modulation factor M as an input and outputs the mode selection signal S MO The modulation switching determination unit 907 selects a modulation mode in which either the synchronous PWM control or the asynchronous PWM signal should be executed, using the same logic as that used to generate the modulation mode command signal S MOD Generate.

[0122] The PWM output switch 908 receives the modulation mode command signal S MOD is used as input, and the asynchronous drive signal D * uua ~D * wla and synchronous drive signal D * uus ~D * wls Either one of these is used as the driving signal D of the switching element. * uu ~D * wl is output to the inverter 104.

[0123] FIG. 12 shows a flowchart of each process in the vibration suppression control unit 101, torque control unit 102, and PWM control unit 103 described above.

[0124] The motor control method of the present embodiment described above and the resulting effects will now be described.

[0125] In this embodiment, the first torque command value T * A motor control method for controlling a motor 106 based on the above is provided.

[0126] This motor control method includes: * 1 is the vibration compensation torque T fb The second torque command value T * 2 (particularly, a mechanical angular velocity estimation unit 203, a vibration torque estimation unit 204, and a gain unit 205), and a vibration compensation torque T fb The first torque command value T * 1), and a limiting step (particularly, an absolute value processing unit 201 and a limiter 202) for limiting the vibration compensation torque T fb The limit level (limit level signal S H / L ) and a torque suggestion amount (torque estimate value T est) as the second torque command value T * 2 and feeds back the voltage command value v * x and a torque control step (particularly, the torque compensator 601 or the voltage phase control unit 502) for calculating the above.

[0127] In particular, the vibration compensation torque T fb is a torque correction value that suppresses vibrations in the motor rotation speed (vibrations caused by torsional vibrations in the driving force transmission system). The limit request suggestion amount is a parameter that indicates the situation in which the suppression of vibrations in the motor rotation speed should be limited (such as a situation in which abnormal gear noise may occur or a situation in which system protection should be prioritized). Furthermore, the voltage command value v * x is a command value of the voltage supplied to the motor 106 from a predetermined power source (battery 113).

[0128] In the torque control process, the limit level signal S H / L The feedback gain (gain k1 or gain k2) of the torque suggestion amount is determined by referring to the above (high gain permission determination unit 703 and gain setting unit 704 in FIG. 7, or high gain permission determination unit 806 and gain setting unit 807 in FIG. 8).

[0129] As a result, in vibration suppression control that suppresses torsional vibrations in the driving force transmission system, the feedback gain of the torque suggestion amount correlated with the electric motor torque is appropriately adjusted depending on the degree of restriction on the vibration suppression function. As a result, it is possible to appropriately identify situations in which the vibration suppression function should be restricted, such as situations in which abnormal noise due to gear backlash should be suppressed, and increase the feedback gain. Therefore, even in situations in which the torsional vibration suppression function of the driving force transmission system is restricted, it is possible to reduce torque fluctuations and suppress torsional vibrations in the driving force transmission system.

[0130] Furthermore, in the torque control process (particularly, the high gain permission determination unit 806 and the gain setting unit 807), the feedback gain (gain k1 or gain k2) is determined by referring to an operating point suggestion amount that suggests the operating point of the motor 106. In particular, the operating point suggestion amount includes the motor rotation speed (mechanical angular velocity ω m or electrical angular velocity ω e ) and the motor torque (second torque command value T * 2) or 3) (see Tables 3 and 4).

[0131] This makes it possible to determine a feedback gain that takes control stability into consideration according to the operating point of the motor 106. In particular, the feedback gain can be determined so as to ensure control stability while exerting the effect of suppressing torsional vibration.

[0132] In addition, the operating point suggestion quantity includes the power supply voltage (DC voltage V dc ) voltage command value v * x (In particular, the final voltage norm command value V * a-fin The feedback gain (particularly, the gain k2) is determined by referring to the modulation factor M (equation (33)) which is determined as the ratio of

[0133] This causes the operating point of the motor 106 to change to the DC voltage V dc With respect to the voltage command value v * x Gain k2 can be set by taking into consideration whether the motor control system is in a region where torque fluctuations are likely to occur due to a large value of . Therefore, even in a motor control system that is premised on using the overmodulation region, the feedback gain can be determined so as to ensure control stability while exerting the effect of suppressing torsional vibration.

[0134] Furthermore, in the torque control process, the DC voltage V dc The feedback gain (gain k1 or gain k2) is determined by referring to the above.

[0135] This allows the DC voltage Vdc It is possible to determine an appropriate feedback gain by taking into consideration the state of the system (whether it is within the system guarantee range, etc.).

[0136] Furthermore, the above-mentioned motor control method includes: * x DC voltage V dc The power conversion process (PWM control unit 103) further includes a power conversion process that performs PWM control to convert the input voltage Vin. In this power conversion process (particularly, in the modulation switching determination unit 907), a modulation method (asynchronous PWM control or synchronous PWM control) in PWM control is selected according to the operating point (modulation factor M) of the motor 106. Then, in the torque control process, a feedback gain (particularly, gain k2) is determined according to the selected modulation method (see Tables 2 and 3).

[0137] This allows the gain k2 to be set taking into account the transition between multi-pulse drive and square wave drive, which has particularly large changes in the PWM pulse waveform in the overmodulation region. This allows for more specific control logic to be realized for determining feedback gains that can both suppress torsional vibration and ensure control stability in motor control systems that assume utilization of the overmodulation region.

[0138] Furthermore, in the vibration damping process (particularly the gain unit 205) of this embodiment, the motor rotation speed (particularly the mechanical angular velocity ω m ) with the specified damping gain K fb By applying this, the vibration compensation torque T fb In the limiting step (particularly, the limiter 202), the first torque command value T * 1 according to the vibration control gain K fb By adjusting the upper and lower limits of fb Then, in the limit level determination step (particularly, the limit level determination unit 206), the first torque command value T * 1 based on the limit level (limit level signal S H / L ) is determined (see Table 1).

[0139] This realizes a more specific control logic that enables detection of a scene in which the torsional vibration suppression effect may be insufficient and determination of an appropriate feedback gain for that scene.

[0140] Furthermore, in the torque control process of this embodiment (particularly, the voltage phase command value calculation unit 809 in FIG. 8), the estimated or detected value of the motor torque (the torque estimation value T est ) is fed back as the torque suggestion amount to obtain the voltage phase command value α * is calculated, and the voltage phase command value α * Based on the voltage command value v * x (In particular, the dq-axis voltage command value v * xv-fin ) is calculated.

[0141] This allows the limit level signal S H / L The feedback gain (particularly the gain k2) can be determined so as to achieve both of these in accordance with the limit level signal S H / L is Low, the gain k2 is lowered (set to low gain), while the limit level signal S H / L When the gain k2 is set to High, it is possible to suppress torsional vibration and ensure control stability at the same time by increasing the gain k2 (setting the gain to high) within a range that does not impair control stability.

[0142] Furthermore, in the torque control process of this embodiment (particularly, the torque compensator 601 in FIG. 7), an estimated or detected value of the motor torque (estimated torque value T est ) is fed back as the torque suggestion amount to obtain the second torque command value T * 2 is corrected to obtain the corrected second torque command value T * 2 (Third torque command value T3 * ) based on the voltage command value v * x (In particular, the dq-axis voltage command value v * xi-fin ) is calculated.

[0143] This results in a voltage command value v * x In the calculation of est Even in the case of a control method such as current vector control that does not have a configuration for feedback of the limit level signal S H / L The feedback gain (gain k1) can be determined so as to suppress torsional vibration and ensure control stability in accordance with the limit level signal S H / L is Low, the gain k1 is lowered, while the limit level signal S H / L When the gain k1 is set to High, it is possible to suppress torsional vibration and ensure control stability at the same time by increasing the gain k1 within a range that does not impair control stability.

[0144] Moreover, in this embodiment, an electric motor control device 10 suitable for executing the electric motor control method is provided.

[0145] In particular, the motor control device 10 determines the first torque command value T * 1 is the vibration compensation torque T fb The second torque command value T * 2, and a vibration compensation torque T fb The first torque command value T * 1), and a limiting unit (particularly, an absolute value processing unit 201 and a limiter 202) that limits the vibration compensation torque T fb The limit level (limit level signal S H / L ) and a torque suggestion amount (torque estimate value T est ) as the second torque command value T * 2 and feeds back the voltage command value v * x and a torque control unit (particularly, a torque compensator 601 or a voltage phase control unit 502) that calculates the above.

[0146] Then, the torque control unit 102 outputs the limit level signal SH / L The feedback gain (gain k1 or gain k2) of the torque suggestion amount is determined by referring to the above (high gain permission determination unit 703 and gain setting unit 704 in FIG. 7, or high gain permission determination unit 806 and gain setting unit 807 in FIG. 8).

[0147] (Second embodiment) The second embodiment will be described below. Elements similar to those in the first embodiment are given the same reference numerals, and their description will be omitted. In particular, the motor control method of this embodiment is realized by a vibration suppression control unit 101 different from that of the first embodiment.

[0148] 13 is a block diagram illustrating the configuration of the vibration suppression control unit 101 according to this embodiment. The vibration suppression control unit 101 of this embodiment controls the vibration compensation torque T fb The configuration for calculating the above includes a mechanical angular velocity estimation unit 1303, a vibration torque estimation unit 1304, and a gain unit 1305. Note that these functions are similar to the mechanical angular velocity estimation unit 203, the vibration torque estimation unit 204, and the gain unit 205 in the first embodiment.

[0149] In addition, the vibration suppression control unit 101 controls the vibration compensation torque T fb Limit vibration compensation torque T fb_lim Furthermore, the vibration suppression control unit 101 includes a limiter 1302 for determining the limit level signal S H / L The control gain setting unit 1301 is provided as a configuration for generating the control gain.

[0150] The functions of the mechanical angular velocity estimator 1303 and the vibration torque estimator 1304 are similar to those of the mechanical angular velocity estimator 203 and the vibration torque estimator 204 in the first embodiment. On the other hand, the gain unit 1305 in this embodiment calculates the vibration damping gain K fb Generate.

[0151] The limiter 1302 has a damping gain of K fb The limit processing is performed based on the predetermined upper and lower limits, and the limit vibration compensation torque T fb_limIn particular, in this embodiment, the upper and lower limit values ​​used in the limiting process are fixed values ​​that are appropriately determined from the viewpoint of suppressing overflows and the like in the control.

[0152] The control gain setting unit 1301 sets the first torque command value T * 1, mechanical angular velocity ω m , and DC voltage V dc is used as input, and the vibration suppression gain K fb (setting of upper and lower limits in the limiter 1302) and limit level signal S H / L In particular, the control gain setting unit 1301 generates the first torque command value T * 1 is within a predetermined range from the viewpoint of suppressing control instability due to gear backlash, the vibration suppression gain K fb The control gain setting unit 1301 corrects the mechanical angular velocity ω m In a scene where the magnitude of exceeds a predetermined range, and the output torque of the motor 106 decreases, the vibration damping gain K fb The control gain setting unit 1301 corrects the first torque command value T * 1 and / or mechanical angular velocity ω m Based on the damping gain K fb If you want to make the limit level signal S smaller than the basic value, H / L is set to High. As a result, the gain k1 used in the torque compensator 601 of the current vector control unit 501 and the gain k2 used in the voltage phase control unit 502 are set to high values, so that torsional vibration in the driving force transmission system is suitably suppressed.

[0153] On the other hand, the control gain setting unit 1301 sets the DC voltage V dc is less than the predetermined system lower limit voltage, the limit level signal S H / L is set to Low, and the vibration suppression gain K fb The system lower limit voltage is set to a value lower than the base value. dc Thus, the DC voltage V dcWhen is less than the system lower limit voltage, the vibration suppression gain K fb By reducing the limit level signal S, it is possible to suppress the deterioration of control stability caused by the abnormality of the power system. H / L By setting to Low, unnecessary vibration compensation torque T fb This will prevent situations in which restrictions are placed on the use of certain services.

[0154] That is, in this embodiment, the first torque command value T * 1 and mechanical angular velocity ω m This function functions as a limit requirement suggestion quantity that indicates the situation where the suppression of torsional vibration in the drive force transmission system should be limited (particularly in the situation where abnormal noise due to gear backlash may occur). dc However, it functions as a limit requirement suggestion quantity that indicates situations in which the suppression of torsional vibration in the drivetrain should be limited (especially situations in which system protection should be prioritized).

[0155] The control gain setting unit 1301 determines the vibration suppression gain K fb Adjustment and limit level signal S H / L Configure the settings.

[0156] [Table 5]

[0157] The motor control method of the present embodiment described above and the resulting effects will now be described.

[0158] In the vibration damping process of this embodiment, the rotation speed of the electric motor (particularly, the mechanical angular velocity ω m ) with a given damping gain K fb By applying this, the vibration compensation torque T fb In the limiting step (particularly, the control gain setting unit 1301), the mechanical angular velocity ω m , the first torque command value T * 1, and DC voltage V dc The vibration damping gain K fb By adjusting the vibration compensation torque T fbThen, in the limit level determination step (particularly, the control gain setting unit 1301), the adjusted vibration suppression gain K fb mechanical angular velocity ω m , the first torque command value T * 1, and DC voltage V dc The limit level signal S is generated based on at least one of the following: H / L The following is established.

[0159] This realizes a more specific control logic that enables detection of a scene in which the torsional vibration suppression effect may be insufficient and determination of an appropriate feedback gain for that scene.

[0160] In addition, the vibration control gain K fb By adjusting the vibration compensation torque T fb Instead of the control logic limiting fb Alternatively, a control logic may be employed that limits the upper and lower limit values ​​themselves to a predetermined base value.

[0161] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0162] Furthermore, the specific numerical values ​​shown in each table are merely examples, and the technical scope of the present invention is not limited to the specific numerical values. Furthermore, the limit request suggestion amount is not limited to the aspects described in the above embodiment, and any parameter representing the operating state of the motor 106, the state of the control system including the motor 106, and / or the running state of the vehicle equipped with the motor 106 can be used, as long as it functions to suggest a situation in which suppression of torsional vibration in the driving force transmission system should be limited. Furthermore, the operating point suggestion amount is not limited to the aspects described in the above embodiment, and any parameter capable of defining the operating point of the motor 106 can be used.

Claims

1. 1. A method for controlling an electric motor based on a first torque command value corresponding to a required output of the electric motor, comprising: a vibration suppression process of calculating a second torque command value by correcting the first torque command value with a vibration compensation torque, the vibration compensation torque being a torque correction value that suppresses vibrations in the rotation speed of the electric motor; a limiting step of limiting the vibration compensation torque based on a limit request suggestion amount, the limit request suggestion amount being a parameter indicating a situation in which suppression of vibration in the rotational speed of the electric motor should be limited; a restriction level determination step of determining a restriction level representing a degree of restriction on the vibration compensation torque based on the restriction request suggestion amount; a torque control step of calculating a voltage command value by feeding back a torque suggestion amount suggesting a motor torque to the second torque command value, the voltage command value being a command value of a voltage to be supplied from a predetermined power source to the motor, In the torque control step, determining a feedback gain of the torque suggestion amount by referring to the limit level; Electric motor control method.

2. 2. The electric motor control method according to claim 1, In the torque control step, Furthermore, the feedback gain is determined by referring to an operating point suggestion amount that suggests an operating point of the electric motor. Electric motor control method.

3. 3. The electric motor control method according to claim 2, The operating point suggestion amount includes at least one of the electric motor rotation speed and the electric motor torque. Electric motor control method.

4. 4. The electric motor control method according to claim 2 or 3, The operating point suggestion amount includes a modulation factor determined as a ratio of the voltage command value to the voltage of the power supply. Electric motor control method.

5. The electric motor control method according to any one of claims 1 to 4, In the torque control step, Furthermore, the feedback gain is determined by referring to the voltage of the power supply. Electric motor control method.

6. The electric motor control method according to any one of claims 1 to 5, a power conversion step of performing PWM control to convert the voltage of the power supply so as to satisfy the voltage command value; In the power conversion step, a modulation method in the PWM control is selected in accordance with an operating point of the electric motor; The torque control step further includes determining the feedback gain in accordance with the selected modulation method. Electric motor control method.

7. The electric motor control method according to any one of claims 1 to 6, In the vibration damping step, a predetermined vibration damping gain is applied to the electric motor rotation speed to calculate the vibration compensation torque; In the limiting step, the vibration compensation torque is limited by adjusting the vibration damping gain or upper and lower limit values ​​of the vibration damping gain in accordance with the limit request suggestion amount, In the restriction level determination step, the restriction level is determined based on the adjusted vibration damping gain or the restriction request suggestion amount to which upper and lower limit values ​​of the vibration damping gain are applied. Electric motor control method.

8. 8. The electric motor control method according to claim 7, In the limiting step, the vibration compensation torque is limited by adjusting upper and lower limit values ​​of the vibration damping gain or upper and lower limit values ​​of the vibration compensation torque in accordance with at least one of the motor rotation speed, the motor torque, and the voltage of the power supply as the limit request suggestion amount; In the restriction level determination step, the restriction level is determined based on at least one of the motor rotation speed, the motor torque, and the voltage of the power supply, to which the adjusted upper and lower limit values ​​of the vibration damping gain or the adjusted upper and lower limit values ​​of the vibration compensation torque are applied. Electric motor control method.

9. The electric motor control method according to any one of claims 1 to 8, In the torque control step, Furthermore, the estimated value or the detected value of the electric motor torque is fed back as the torque suggestion amount to calculate a voltage phase command value; calculating the voltage command value based on the voltage phase command value; Electric motor control method.

10. The electric motor control method according to any one of claims 1 to 8, In the torque control step, Furthermore, the estimated value or the detected value of the electric motor torque is fed back as the torque suggestion amount to correct the second torque command value; calculating the voltage command value based on the corrected second torque command value; Electric motor control method.

11. The motor control method according to claim 1, The limit request suggestion amount includes at least one of the motor rotation speed, the motor torque, and the voltage of the power supply. Electric motor control method.

12. An electric motor control device that controls an electric motor based on a first torque command value corresponding to a required output of the electric motor, a vibration suppression unit that calculates a second torque command value by correcting the first torque command value with a vibration compensation torque, the vibration compensation torque being a torque correction value that suppresses vibrations in the rotation speed of the electric motor; a limiting unit that limits the vibration compensation torque based on a limit request suggestion amount, the limit request suggestion amount being a parameter that suggests a situation in which suppression of vibration in the motor rotation speed should be limited; a restriction level determination unit that determines a restriction level that indicates a degree of restriction on the vibration compensation torque based on the restriction request suggestion amount; a torque control unit that calculates a voltage command value by feeding back a torque suggestion amount that suggests a motor torque to the second torque command value, and the voltage command value is a command value of a voltage to be supplied to the motor from a predetermined power source, The torque control unit determining a feedback gain of the torque suggestion amount by referring to the limit level; Electric motor control device.

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