Motor control method and motor control device

Abstract

The second torque command value is calculated by correcting a first torque command value based on the motor's requested output using a vibration compensation torque for suppressing vibrations in the motor's rotational speed. The vibration compensation torque is limited based on a limit request indication amount indicating a situation where vibration suppression should be limited. A limit level is set to determine the degree of limitation of the vibration compensation torque. The torque indication amount indicating the motor torque is fed back to the second torque command value to calculate the voltage command value. Furthermore, the feedback gain of the torque indication amount is determined with reference to the limit level.

Description

Technical Field

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

[0002] JP2012-75257A proposes a motor control method for a vehicle that performs vibration reduction control to suppress vibrations caused by the torsional vibration characteristics of the drive transmission system. Based on the concept of suppressing abnormal noise generated by the gears of the speed reducer by repeatedly reversing the positive and negative directions of the torque command, this motor control method employs control to limit the vibration reduction function involved in the vibration reduction control within a specific motor operating range where this abnormal noise is likely to occur. Summary of the Invention

[0003] It is conceivable that situations arise where, depending on the operating state of the electric vehicle, the motor, or the motor's control system, the vibration damping function needed to suppress torsional vibrations in the drive transmission system should be limited, such as the occurrence of the aforementioned abnormal gear noise. However, limiting the vibration damping function in such situations would not fully suppress the torsional vibrations in the drive transmission system, potentially causing discomfort to the occupants.

[0004] Therefore, an object of the present invention is to provide a motor control method and a motor control device capable of suppressing torsional vibration even under the limitation of the vibration reduction function for suppressing torsional vibration of a drive transmission system.

[0005] According to one embodiment of the present invention, a motor control method is provided for controlling a motor based on a first torque command value corresponding to a requested output of the motor. The motor control method includes the following steps: a vibration reduction step for calculating a second torque command value by correcting the first torque command value using a vibration compensation torque; a limiting step for limiting the vibration compensation torque based on a limit request indication amount; a limit level determination step for determining a limit level indicating the degree of limitation of the vibration compensation torque; and a torque control step for calculating a voltage command value by feeding back a torque indication amount indicating the motor torque to the second torque command value. Specifically, the vibration compensation torque is a torque correction value for vibrations in the motor speed. Furthermore, the limit request indication amount indicates a condition in which the suppression of vibrations in the motor speed should be limited. Furthermore, the voltage command value is a command value for the voltage supplied to the motor from a predetermined power supply. Furthermore, in the torque control step, a feedback gain for the torque indication amount is determined with reference to the limit level. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 This is a block diagram illustrating the configuration of a motor control device that executes the motor control method according to each embodiment of the present invention.

[0007] Figure 2This is a block diagram illustrating the configuration of a vibration suppression control unit.

[0008] Figure 3 This diagram explains a mechanical system model that expresses the equation of motion of a torsional vibration system.

[0009] Figure 4 It is a graph showing the filtering characteristics of the bandpass filter H(s).

[0010] Figure 5 This is a block diagram illustrating the configuration of a torque control unit.

[0011] Figure 6 This is a block diagram illustrating the configuration of a current vector control unit.

[0012] Figure 7 This is a block diagram illustrating the structure of a torque compensator.

[0013] Figure 8 This is a block diagram illustrating the configuration of a voltage phase control unit.

[0014] Figure 9 This is a block diagram illustrating the configuration of a PWM control unit.

[0015] Figure 10 This is a block diagram illustrating the configuration of a synchronous PWM control unit.

[0016] Figure 11 This is a timing chart explaining the processing of asynchronous PWM control and synchronous PWM control.

[0017] Figure 12 This is a flowchart for explaining each process of the vibration reduction control unit, the torque control unit, and the PWM control unit.

[0018] Figure 13 This is a block diagram illustrating the configuration of a vibration damping control unit according to another embodiment. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0020] (First embodiment)

[0021] Figure 1 1 is a block diagram illustrating a motor control device 10 for executing a motor control method. Figure 1 As shown, motor control device 10 drives motor 106 and controls its operating state using power supplied from battery 113. Specifically, motor control device 10 is mounted on a vehicle such as an electric vehicle or a hybrid vehicle that uses motor 106 as a driving source for traveling.

[0022] The battery 113 is a secondary battery such as a lithium ion battery that functions as a source of power for the motor 106 and other parts of the vehicle. In this embodiment, the battery 113 is a DC power supply. In this embodiment, the voltage output by the battery 113 (hereinafter also referred to as "DC voltage V dc ”) is detected by the voltage sensor 112.

[0023] Motor 106 is, for example, an IPM (Interior Permanent Magnet) three-phase synchronous motor. Specifically, motor 106 (more specifically, its rotor) is connected to drive wheels via a vehicle drive force transmission system including an output shaft, gears, and a drive shaft (not shown).

[0024] The motor control device 10 mainly includes a vibration reduction 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 .

[0025] The vibration reduction control unit 101 is based on the first torque command value T ＊ 1, and the mechanical angular velocity ω of the motor 106 m The second torque command value T is obtained by executing a vibration reduction control calculation for suppressing vibration (motor speed vibration) caused by the driving force transmission system. ＊ 2. In addition, the first torque command value T ＊ Reference numeral 1 denotes a basic torque command value defined by a requested output for motor 106. The requested output for motor 106 is defined by a driver's vehicle operation (operation of the accelerator pedal) or a requested driving force based on a command from a higher-level controller (not shown), such as a predetermined automatic driving control device.

[0026] Furthermore, the vibration suppression control unit 101 generates a limit level signal S as a flag indicating a result of determination as to whether or not a certain level of limitation is imposed on the vibration suppression control operation. H / L Then, the vibration reduction control unit 101 sets the second torque command value T ＊ 2 and the limit level signal S H / L The output is to the torque control unit 102. Note that the details of the processing of the vibration reduction control unit 101 will be described later.

[0027] The torque control unit 102 controls the DC voltage V dc , limit level signal S H / L , the second torque command value T ＊ 2. Electrical angular velocity ω of motor 106 e , d-axis current i dAnd the q-axis current i q As input, the command value of the voltage to be supplied to the motor 106 (d-axis voltage command value v ＊ d And the q-axis voltage command value v q ) is calculated. Then, the torque control unit 102 calculates the d-axis voltage command value v ＊ d And the q-axis voltage command value v ＊ q The torque control unit 102 outputs the torque to the PWM control unit 103. The details of the process performed by the torque control unit 102 will be described later.

[0028] In order to simplify the description below, the symbol "x" (x = d or q) is used to represent the components of each parameter expressed in the dq axis coordinate system. For example, the d axis current i d And the q-axis current i q It is recorded as "dq axis current i x "wait.

[0029] The PWM control unit 103 converts the DC voltage V dc , voltage command value v ＊ x and the electrical angle θ of the motor 106 as inputs, and generates a drive signal D for driving the switching element of the inverter 104. ＊ uu ~D ＊ wl Then, the PWM control unit 103 generates the driving signal D ＊ uu ~D ＊ wl The output is to the inverter 104. Note that the details of the processing of the PWM control unit 103 will be described later.

[0030] The inverter 104 includes a plurality of semiconductor switching elements and a driving circuit (not shown) for driving these switching elements. ＊ uu ~D ＊ wl And each switching element is driven. As a result, the DC voltage V dc is converted into three-phase AC voltage (v u 、v v 、v w ) and supplied to the motor 106. That is, to match the desired torque command value T ＊ The motor 106 is driven in a manner corresponding to the actual torque output.

[0031] The current sensor 105 is connected to the three-phase AC current (i u 、i v 、i w ) is composed of multiple individual sensors that detect each phase component. Figure 1 The figure shows the detection of phase current i by u u And the v-phase current i v An example of a current sensor 105 composed of two separate sensors. In this case, the sum of the three-phase components can be used to obtain the current sensor 105 according to the u-phase current i u And the v-phase current i v And determine the remaining w-phase current i w Alternatively, the current sensor 105 may be formed of 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 .

[0032] The resolver 107 functions as a rotor position detector for detecting the rotor position of the motor 106. Specifically, the resolver 107 transmits and receives excitation / modulation signals to and from an RDIC (resolver / digital conversion circuit) 108.

[0033] Based on the excitation / modulation signal, the RDIC 108 generates an ABZ signal (digital angle information of the motor 106 ) composed of up and down counter pulses A and B and an origin signal pulse Z. The RDIC 108 outputs the generated ABZ signal to the ABZ counter 109 .

[0034] 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 .

[0035] The speed calculation unit 110 calculates the electrical angular velocity ω of the motor 106 based on the amount of change per unit time of the electrical angle θ. e and the mechanical angular velocity ω m Then, the speed calculation unit 110 calculates the electrical angular velocity ω e Output to the torque control unit 102, the mechanical angular velocity ω m Output to the vibration reduction control unit 101 .

[0036] The coordinate conversion unit 111 converts the three-phase AC current (i u 、i v 、i w ) is transformed into dq axis current i x .

[0037] [Mathematical formula 1]

[0038]

[0039] That is, the dq axis current i corresponding to the current detection value in the dq axis coordinate system is determined according to equation (1). x Then, the coordinate conversion unit 111 converts the obtained dq axis current i x Output to the torque control unit 102.

[0040] The motor control device 10 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 implemented using a computer programmed to execute the aforementioned components. Alternatively, the motor control device 10 may be configured using multiple computer hardware components that execute various processes in a distributed manner.

[0041] Next, I. Details of the processing of the vibration reduction control unit 101 , II. Details of the processing of the torque control unit 102 , and III. Details of the processing of the PWM control unit 103 will be described respectively.

[0042] [I. Vibration Damping Control Unit 101]

[0043] Figure 2 1 is a block diagram illustrating the configuration of the vibration suppression control unit 101. As shown in the figure, the vibration suppression control unit 101 includes an absolute value processing unit 201, a limiter 202, a mechanical angular velocity estimation unit 203, a vibration torque estimation unit 204, and a gain unit 205.

[0044] In particular, the mechanical angular velocity estimation unit 203, the vibration torque estimation unit 204, and the gain unit 205 are mainly used to determine the vibration compensation torque T fb In addition, the vibration compensation torque T fb The first torque command value T ＊ Specifically, the first torque instruction value T corresponding to the requested output of the motor 106 is used. ＊ 1 The vibration compensation torque T is specified by removing the vibration of the motor speed caused by the torsional vibration of the driving force transmission system. fb .

[0045] More specifically, the mechanical angular velocity estimating unit 203 calculates the second torque command value T ＊ 2, and the transfer characteristic G obtained from the vehicle transfer system model described later is applied. p (s) and calculate the estimated mechanical angular velocity ω m Then, the vibration torque estimation unit 204 uses the estimated mechanical angular velocity ω m The mechanical angular velocity ω corresponding to the detection value mentioned abovem The deviation is taken as input and the transfer characteristic G is applied. p (s) and the transfer function composed of the bandpass filter H(s) to obtain the vibration torque T vib Furthermore, the gain unit 205 generates the vibration torque T vib Apply vibration reduction gain K fb (0≤K fb ≤1) and calculate the vibration compensation torque T fb And output to the limiter 202.

[0046] On the other hand, the absolute value processing unit 201 and the limiter 202 are used to limit the vibration compensation torque T fb_lim In addition, the vibration compensation torque T is limited. fb_lim The vibration compensation torque T is limited under the prescribed conditions that take into account the suppression of abnormal noise caused by gear backlash. fb The value obtained.

[0047] More specifically, the absolute value processing unit 201 processes the first torque command value T ＊ 1 is processed as an absolute value, and the upper limit and lower limit of the absolute value are respectively defined as the upper limit and lower limit of the limiter 202 (hereinafter, also collectively referred to as "upper and lower limits"). That is, in this embodiment, the first torque command value T ＊ 1 acts as a limit request notification amount to notify that the torsional vibration of the driving force transmission system should be limited (especially when there is a possibility of abnormal noise due to backlash of the gear). fb The limited vibration compensation torque T is obtained by performing a limit process based on the upper and lower limit values ​​specified by the absolute value processing unit 201. fb_lim Here, in the first torque command value T ＊ When 1 is 0, both the upper limit and the lower limit of the limiter 202 are set to 0. Therefore, the vibration compensation torque T is limited. fb_lim Therefore, in this case, the vibration compensation torque T can be suppressed. fb Direct output causes abnormal gear noise and a decrease in control stability.

[0048] Then, the limit level determination unit 206 determines that the limit level indicates that the vibration compensation torque T fb The slice level signal S including the determined slice level as information is generated. H / L .

[0049] More specifically, the limit level determination unit 206 refers to the first torque command value T ＊1, and based on the comparison between the absolute value (i.e., the upper and lower limits of the limiter 202) and the predetermined reference value, the slice level determination unit 206 determines whether the slice level is relatively high or relatively low. The slice level determination unit 206 generates a binary signal ("High" or "Low") corresponding to the relative high and low of the slice level as the slice level signal S H / L .

[0050] For example, the first torque command value T can be specified as shown in Table 1 below: ＊ The absolute value of 1 and the limit level signal S H / L relationship.

[0051] [Table 1]

[0052] <![CDATA[|T1 ＊ |[Nm]]]> Limit level signal <20 High ≥20 LOW

[0053] According to the example in Table 1, the first torque command value T ＊ When the absolute value of 1 is less than 20N, the slice level signal S is set to a relatively high value as the slice level for vibration compensation. H / L On the other hand, at the first torque command value T ＊ When the absolute value of 1 is greater than or equal to 20N, the slice level signal S is set to a relatively low value as the slice level for vibration compensation. H / L Set to Low.

[0054] Next, the transfer characteristic G p (s) for explanation.

[0055] Figure 3 This is a diagram that explains the mechanical system model that gives the equation of motion of the torsional vibration system. Figure 3 The parameters shown are as follows.

[0056] J m : Motor inertia moment

[0057] J w : Moment of inertia of the driving wheel

[0058] M: Vehicle weight

[0059] K D : Torsional rigidity of the drive system

[0060] K T : The coefficient of friction between the tire and the road

[0061] N: total transmission ratio

[0062] r: tire load radius

[0063] ω m : Motor mechanical angular velocity

[0064] T m : Motor output shaft torque

[0065] T D : Torque of the driving wheel

[0066] F: force applied to the vehicle

[0067] V: vehicle speed

[0068] ω w : angular velocity of the driving wheel

[0069] according to Figure 3 The equations of motion of an electric vehicle are expressed by the following equations (2) to (6).

[0070] [Mathematical formula 2]

[0071]

[0072]

[0073]

[0074]

[0075] F=K T ·(r·ω m -v)…(6)

[0076] Based on the above motion equations (2) to (6), the transfer characteristic G from motor torque to motor mechanical angular velocity is p (s) is shown in the following equations (7) to (15).

[0077] [Mathematical formula 3]

[0078]

[0079] a4=2J m J w M··(8)

[0080] a3=J m (2J w +Mr 2 )K T ··(9)

[0081] a2=(J m +2J w / N 2 )MK D ···(10)

[0082] a1=(J m+2J w / N 2 +Mr 2 / N 2 )K D K T ···(11)

[0083] b3=2J w M···(12)

[0084] b2=(2J w +Mr 2 )K T ···(13)

[0085] b1=MK D ···(14)

[0086] b0=K D K T ···(15)

[0087] In addition, "s" in equation (7) represents the Laplace operator. Furthermore, if equation (7) is modified, the following equation (16) can be obtained.

[0088] [Formula 4]

[0089]

[0090] In addition, the coefficients a′1 to a′3 and b′0 to b′2 in the formula (16) are values ​​specified by the coefficients a1 to a4 and b0 to b3 specified in the formulas (8) to (15).

[0091] Here, if we study the transfer characteristic G p (s) has extreme values ​​and zero values, which means that α and β in equation (16) are extremely close. Therefore, by performing extreme value and zero value cancellation (approximation processing such that α = β) on equation (16), the transfer characteristic G can be expressed as a rational function with a numerator of quadratic and a denominator of cubic as shown in the following equation (17): p (s).

[0092] [Formula 5]

[0093]

[0094] Among them, “ω” in formula (17) p " represents the transfer characteristic G p (s) is the torsional resonance angular frequency, “ζ p " represents the transfer characteristic G p(s) is the attenuation coefficient. In addition, considering the convenience of computer processing, it is preferred to discretize (z-transform) equation (17) using the variable z represented by the following equation (18). In addition, "T" in equation (18) represents the sampling time of the control.

[0095] [Formula 6]

[0096]

[0097] 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 attenuates torsional vibrations of the drive system.

[0098] Figure 4 It is a graph showing the filtering characteristics of the bandpass filter H(s). Figure 4 The filter characteristics shown are set so that the attenuation characteristics of the low-pass side and the high-pass side are consistent with each other, and the torsional resonance frequency f of the drive system is p On a logarithmic axis (logarithmic scale), it is located in the center of the passband. Giving the bandpass filter H(s) this filtering characteristic can enhance the effectiveness of selectively reducing the torsional vibration of the drive system. More specifically, the bandpass filter H(s) can be constructed by combining a primary lowpass filter and a highpass filter as shown in the following equation (19).

[0099] [Formula 7]

[0100]

[0101] [II. Torque Control Unit 102]

[0102] Figure 5 1 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 .

[0103] The current vector control unit 501 limits the level signal S H / L , the second torque command value T ＊ 2. Electrical angular velocity ω e 、DC voltage V dc and the dq axis current i x As input, the d-axis voltage command value v is controlled by current vector control. ＊ di-fin And the q-axis voltage command value v ＊ qi-fin Perform calculations.

[0104] The voltage phase control unit 502 limits the level signal S H / L , the second torque command value T ＊ 2. Electrical angular velocity ω e 、DC voltage V dc , dq axis current i x and modulation rate M as input, and the d-axis voltage command value v is controlled by voltage phase control. ＊ dv-fin And the q-axis voltage command value v ＊ qv-fin Perform calculations.

[0105] The output controller 503 outputs the mode selection signal S generated by the control switching determination unit 505. MO As input, the dq axis voltage command value v based on current vector control is xi-fin And the dq axis voltage command value v based on voltage phase control xv- ＊ fin Any one of the following is used as the final dq axis voltage command value v ＊ x And output.

[0106] The modulation rate calculation unit 504 converts the DC voltage V dc And the dq axis voltage command value v ＊ x The modulation factor M is calculated based on the following equation (20) as input and output to the voltage phase control unit 502 and the control switching determination unit 505 .

[0107] [Formula 8]

[0108]

[0109] The control switching determination unit 505 generates a mode selection signal S that specifies the control mode (current vector control or voltage phase control) to be executed and the modulation mode based on the modulation rate 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 .

[0110] [Table 2]

[0111]

[0112] Next, the current vector control unit 501 and the voltage phase control unit 502 will be described in more detail.

[0113] II-1. Current Vector Control Unit 501

[0114] Figure 6This is a block diagram illustrating the structure of the current vector control unit 501. Figure 6 In order to simplify the drawing, the q-axis voltage command value v is omitted. ＊ qi-fin However, the omitted part is related to the d-axis voltage command value v ＊ di-fin The operations involved are the same structure.

[0115] 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 .

[0116] The torque compensator 601 obtains the second torque command value T by the processing described later. ＊ 2 Torque command value T for compensation ＊ (hereinafter also referred to as "third torque command value T ＊ 3”), and output to the interference voltage calculation unit 602 and the current command value calculation unit 604.

[0117] The interference voltage calculation unit 602 calculates the third torque command value T ＊ 3. Electrical angular velocity ω e and DC voltage V dc As input, the d-axis interference voltage v is obtained by referring to the pre-prepared query interference voltage table ＊ d-dcpl and the q-axis interference voltage v ＊ q-dcpl In addition, the stored value of the interferometer is determined in advance through experiments or analysis and stored in a predetermined storage area.

[0118] The filter unit 603 is used to filter the dq-axis interference voltage v obtained by the interference voltage calculation unit 602. ＊ x-dcpl Applying the low-pass filter defined by the following equation (21), the dq-axis non-interference voltage v is obtained. x-dcpl-fit In addition, “τ” in the following equation (21) represents the dq axis current i x The canonical response time constant.

[0119] [Formula 9]

[0120]

[0121] The current command value calculation unit 604 calculates the third torque command value T3 ＊ , electrical angular velocity ω e and DC voltage V dcAs input, the d-axis current command value i is obtained by referring to the pre-prepared query current table. d ＊ And the q-axis current command value i q ＊ In addition, the storage value of the query ammeter is determined in advance through experiments or analysis and stored in a predetermined storage area.

[0122] The voltage command value calculation unit 605 calculates the dq axis current command value i x ＊ , dq axis non-interference voltage v x-dcp1-fit And the dq axis current i equivalent to the detection value x As input, the dq axis voltage command value v for current vector control is obtained based on the following equations (22) and (23): ＊ xi-fin .

[0123] [Formula 10]

[0124]

[0125] V * xi_fin =v xi_pi +v x_dcpl_fit ···(twenty three)

[0126] In addition, the “k px " represents the proportional gain, "k ix ” represents the integral gain. In addition, “v xi-pi " is the basic dq axis control voltage without considering the interference voltage component. And the proportional gain k px and the integral gain k ix For example, it is defined by the following formula (24).

[0127] [Mathematical formula 11]

[0128]

[0129] In addition, the “L x ” represents the self-inductance of each axis component, “R” represents the winding resistance, and “τ” represents the dq axis current i x The canonical response time constant.

[0130] Next, the details of the torque compensator 601 will be described.

[0131] II-2. Torque compensator 601

[0132] Figure 71 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 determination unit 703, and a gain setting unit 704.

[0133] The torque calculator 701 converts the dq axis current i x As input, the torque estimated value T is obtained by referring to the pre-prepared lookup torque table. est In addition, the storage values ​​of the lookup torque table are determined in advance through experiments or analysis and stored in a predetermined storage area.

[0134] The torque compensation value calculation unit 702 calculates the second torque instruction value T ＊ 2. Torque estimation value T est , and the gain k1 described later are used as inputs, and the torque compensation value ΔT is calculated based on the following equation (25): ＊ Perform calculations.

[0135] [Mathematical formula 12]

[0136]

[0137] 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 The high gain permission determination unit 703 determines whether to allow or not allow the setting of a relatively high gain k1 (hereinafter also referred to as "high gain") and the modulation rate M. Furthermore, the high gain permission determination unit 703 generates a high gain permission signal S as a binary signal indicating the determination result of whether to allow or not allow 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 .

[0138] [Table 3]

[0139]

[0140] In particular, in the example shown in Table 3, in the overmodulation region (M>100) where the PWM waveform changes easily become rapid, and in the low torque region where the gain margin is relatively large and there is room for high gain, a high gain setting is permitted. dc Or the electrical angular velocity ω e When the system is outside the guaranteed range, system protection is prioritized and high gain settings are not permitted.

[0141] Furthermore, the logic for determining whether to allow or not to allow high-gain setting is not limited to that shown in Table 3. In particular, with respect to each parameter shown in Table 3, the thresholds for distinguishing between allowance and disallowance of high-gain setting can be appropriately set to preferred values, taking into account the balance between control stability and system protection.

[0142] Next, the gain setting unit 704 sets the gain based on the slice level signal S H / L and the high gain permission signal S HP The value of the gain k1 used in the above equation (25) is determined. The gain setting unit 704 determines the gain k1 according to the logic shown in Table 4 below, for example.

[0143] [Table 4]

[0144]

[0145] Furthermore, the torque compensator 601 adjusts the second torque command value T ＊ 2 plus the torque compensation value ΔT ＊ The obtained value is taken as the third torque command value T3 ＊ And output.

[0146] Next, the configuration of the voltage phase control unit 502 will be described.

[0147] II-3. Voltage Phase Control Unit 502

[0148] Figure 8 This is a block diagram illustrating the configuration of voltage phase control unit 502. As shown, voltage phase control unit 502 includes 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 calculator 808, a voltage phase command value calculation unit 809, and a vector converter 810.

[0149] 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 The dq axis current command value i is obtained by referring to the same lookup table as that used in the current command value calculation unit 604 as an input. x ＊ .

[0150] The magnetic flux calculation unit 802 calculates the dq axis current command value i x ＊ As input, the flux norm value φ is obtained by referring to the pre-prepared lookup flux table 0_refIn addition, the storage value of the magnetic flux table is determined in advance by experiments or analysis and stored in a predetermined storage area. 0_ref Multiply by the electrical angular velocity ω e The absolute value of the provisional voltage norm V a ’ is output to the limiter 803.

[0151] The limiter 803 is based on the following equation (26) and is determined according to the provisional voltage norm V a ' and find the voltage norm command value V a ＊ .

[0152] [Mathematical formula 13]

[0153]

[0154] That is, the voltage norm command value V a ＊ Specified as a voltage norm V equivalent to rectangular wave drive a The fundamental wave component value (√6 / π·V dc ) limits the provisional voltage norm V a ′’s value.

[0155] The voltage phase calculation unit 804 converts the voltage norm command value V a ＊ , electrical angular velocity ω e and the second torque command value T ＊ 2 as input, and refer to the pre-prepared query voltage phase table to find the voltage phase α ff In addition, the lookup voltage phase table is defined in advance through experiments or analysis and stored in a predetermined storage area.

[0156] On the other hand, the filtering unit 805 processes the second torque command value T ＊ 2 Apply a primary low-pass filter with the above time constant τ to obtain the torque reference value T ref That is, the torque reference value T ref The second torque command value T ＊ 2 and the assumed standard torque response.

[0157] The high gain permission determination unit 806 is based on the torque reference value T ref 、DC voltage V dc and the modulation rate M to generate a high gain permission signal S HP , the high gain permission signal S HP Indicates the decision of whether to allow or not to allow the gain k2 described later to be set relatively high. HP, the logic shown in Table 3 can be applied in the same way. That is, the "second torque command value T ＊ 2” is replaced by “torque reference value T ref ” and use the logic of Table 3.

[0158] The gain setting unit 807 is based on the slice level signal S H / L and the high gain permission signal S HP The value of the gain k2 described later is determined. In addition, the logic shown in Table 4 can be similarly applied to determine the gain k2. That is, the "gain k1" in Table 4 can be replaced with "gain k2" and the logic of Table 4 can be used.

[0159] The torque calculator 808 converts the dq axis current i x As input, the torque estimation value T is obtained by referring to the same lookup torque table used in the torque calculator 701. est .

[0160] The voltage phase command value calculation unit 809 calculates the voltage phase α ff , torque estimated value T est And gain k2 as input, and the voltage phase compensation value α is calculated based on the following equations (27) and (28): fb And the voltage phase command value α ＊ Perform calculations.

[0161] [Mathematical formula 14]

[0162]

[0163] α * =α ff +α fb …···(28)

[0164] Furthermore, gain k2 in equation (27) is defined so that its base value (low gain) matches the inverse of the design value of the torque feedback response time constant in voltage phase control. Gain k3 in equation (27) is a constant indicating the sensitivity of voltage phase α to torque. Gain k3 is appropriately defined based on the characteristics of motor 106.

[0165] 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 As input, the dq axis voltage command value v for current phase control is obtained based on the following equation (29): xv- ＊ fin .

[0166] [Mathematical formula 15]

[0167]

[0168] [III. PWM Control Unit 103]

[0169] Figure 9 This is a block diagram illustrating the configuration of the PWM control unit 103. As shown, the PWM control unit 103 includes 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 switch 908.

[0170] The coordinate conversion unit 901 converts the dq axis voltage command value v input from the torque control unit 102 into the dq axis voltage command value v using the electrical angle θ. ＊ x Perform coordinate transformation based on the following equation (30) to obtain the three-phase voltage command value (v ＊ u 、v ＊ v 、v ＊ w ).

[0171] [Mathematical formula 16]

[0172]

[0173] The asynchronous PWM control unit 902 controls the DC voltage V dc And the three-phase voltage command value (v ＊ u 、v ＊ v 、v ＊ w ) as input, and the duty cycle command value (Duty_u, Duty_v, Duty_w) is calculated based on the following formula (31).

[0174] [Mathematical formula 17]

[0175]

[0176] The asynchronous PWM signal generator 903 receives the duty cycle command values ​​(Duty_u, Duty_v, Duty_w) as input and generates asynchronous drive signals D for driving the six elements (upper arm elements and lower arm elements of each of the three phases) of the inverter 104. ＊ uua ~D ＊ wlaMore specifically, the asynchronous PWM signal generator 903 generates a triangular wave of a carrier wave (carrier signal C a ) and the duty ratio command value (Duty_u, Duty_v, Duty_w) of each phase to generate an asynchronous drive signal D ＊ uua ~D ＊ wla In addition, the asynchronous drive signal D ＊ uua ~D ＊ wla The first subscripts "u," "v," and "w" represent the respective phases of UV and W. Furthermore, the second subscripts "u" and "l" represent the upper arm element ("u") or the lower arm element ("l") of inverter 104. The third subscript "a" indicates an asynchronous PWM signal.

[0177] On the other hand, the vector conversion unit 904 converts the dq axis voltage command value v ＊ x As input, the final voltage norm command value V is obtained based on the following formula (32): ＊ a-fin And the final voltage phase command value α ＊ fin .

[0178] [Mathematical formula 18]

[0179]

[0180] The synchronous PWM control unit 905 sets the final voltage norm command value V ＊ a-fin and DC voltage V dc As input, it is specified that the carrier signal C used in synchronous PWM control s Comparison value Th[m] (m=1, 2, 3...)

[0181] Figure 10 100 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 includes a modulation rate calculation unit 1001 and a comparison value calculation unit 1002.

[0182] The modulation rate calculation unit 1001 calculates the final voltage norm command value V ＊ a-fin and DC voltage V dc The modulation rate M is calculated based on the following formula (33).

[0183] [Mathematical formula 19]

[0184]

[0185] The comparison value calculation unit 1002 takes the modulation rate M as input and obtains a plurality of comparison values ​​Th[m] with reference to a comparison value table prepared in advance. In addition, the comparison value table stores, as each comparison value Th[m], the ON / OFF phase of the synchronous PWM pulse obtained in advance by experiments or numerical calculations based on a prescribed analytical method in order to suppress high modulation current for each modulation rate M. In addition, as a prescribed analytical method, for example, a specific high modulation wave elimination method ("SHE": Selected Harmonic Elimination) that adjusts the number of switching times to eliminate a specific number of high modulation waves can be cited. In particular, in this embodiment, 10 comparison values ​​Th[1], Th[2]...Th

[10] are stored in the comparison value table. In addition, the number of comparison values ​​Th[n] can be appropriately adjusted according to, for example, the number of pulses per cycle of the desired electrical angle θ.

[0186] Back to Figure 9 The synchronous PWM signal generator 906 sets the final voltage phase command value α ＊ fin , the comparison value Th[m] and the electrical angle θ are used as input to generate the synchronous drive signal D ＊ uus ~D ＊ wls Specifically, the synchronous PWM signal generator 906 synthesizes the electrical angle θ and the final voltage phase command value α ＊ fin The generated carrier signal C s The synchronous drive signal D is generated by comparing and matching the comparison value Th[m]. ＊ uus ~D ＊ wls In addition, the synchronous drive signal D ＊ uus ~D ＊ wls The first subscripts "u," "v," and "w" represent the respective phases of UV and W. Furthermore, the second subscripts "u" and "l" represent the upper arm element ("u") or the lower arm element ("l") of inverter 104. The third subscript "s" represents the synchronized PWM signal.

[0187] For example, the synchronous PWM signal generator 906 generates carrier signals C for each phase of UVW based on the following equation (34): us 、C vs 、C ws .

[0188] [Mathematical formula 20]

[0189]

[0190] Figure 11 This is a timing chart schematically illustrating the operations of each of the asynchronous PWM control and the synchronous PWM control.

[0191] exist Figure 11 In the asynchronous PWM control shown in (A), the carrier signal C can be arbitrarily set regardless of the position (electrical angle θ) of the motor 106 and the drive frequency. a On the other hand, the configuration interval of the pulse of the asynchronous PWM signal is limited to the control period Δt. In addition, in the asynchronous PWM control, in each control period Δt (carrier signal C a Each 1 / 2 cycle) executes the interruption of each control operation and the update of each parameter corresponding to the result of the above control operation.

[0192] On the other hand, Figure 11 In the synchronous PWM control shown in (B), the interval between the pulses of the synchronous PWM signal can be adjusted substantially arbitrarily, regardless of the control period Δt. Therefore, there is an advantage in that when the motor 106 is driven in the overmodulation region and the rectangular wave region where the number of pulses is limited, it is easy to reduce the high modulation wave and ripple of the current. In addition, in the synchronous PWM control, as in the asynchronous PWM control, the carrier signal C s Each 1 / 2 cycle) executes the interruption of each control operation and the update of each parameter corresponding to the result of the above control operation.

[0193] Back to Figure 9 The modulation switching determination unit 907 takes the modulation rate M as input and selects the mode signal S according to the mode selection signal S shown in Table 2. MO The modulation mode in which either synchronous PWM control or asynchronous PWM signal should be executed is selected by the same logic as that of the generation of the modulation mode. Furthermore, the modulation switching determination unit 907 generates a modulation mode instruction signal S for instructing execution of the selected modulation mode. MOD .

[0194] The PWM output switch 908 modulates the mode instruction signal S MOD As input, the asynchronous drive signal D ＊ uua ~D ＊ wla And the synchronous driving signal D ＊ uus ~D ＊ wls Any one of the above is used as the driving signal D of the switching element ＊ uu ~D ＊wl And output to the inverter 104.

[0195] In addition, Figure 12 Flowcharts showing the respective processes of the vibration reduction control unit 101 , the torque control unit 102 , and the PWM control unit 103 are shown in FIG.

[0196] The motor control method according to the present embodiment described above and its effects will be described.

[0197] In this embodiment, a first torque command value T is provided based on a requested output of the electric motor (motor 106). ＊ 1 and a motor control method for controlling the motor 106.

[0198] The motor control method includes the following steps: using the vibration compensation torque T fb The first torque command value T ＊ 1 is corrected and the second torque command value T ＊ 2 vibration reduction process (particularly the mechanical angular velocity estimation unit 203, the vibration torque estimation unit 204 and the gain unit 205); based on the limit request prompt amount (the first torque command value T ＊ 1) The vibration compensation torque T fb The limiting process (particularly the absolute value processing unit 201 and the limiter 202) performs limiting; the determination indicates that the vibration compensation torque T fb The limit level of the limit degree (limit level signal S H / L ) of the limit level determination process (particularly the limit level determination unit 206); and the torque prompt amount (torque estimation value T est ) is fed back to the second torque command value T ＊ 2 And the voltage command value v ＊ x A torque control process (particularly the torque compensator 601 or the voltage phase control unit 502) for performing calculations.

[0199] In particular, the vibration compensation torque T fb The torque correction value is used to suppress the vibration of the motor speed (vibration caused by the torsional vibration of the driving force transmission system). In addition, the limit request prompt amount is a parameter that prompts the situation where the suppression of the vibration of the motor speed should be limited (such as the situation where abnormal noise of the gear may occur or the situation where the system protection should be given priority). In addition, the voltage command value v ＊ x It is a command value of the voltage supplied from a predetermined power source (battery 113 ) to the motor 106 .

[0200] Furthermore, in the torque control process, the limit level signal S is referred to.H / L The feedback gain (gain k1 or gain k2) that determines the torque prompt amount ( Figure 7 The high gain permission determination unit 703 and the gain setting unit 704, or Figure 8 high gain permission determination unit 806 and gain setting unit 807).

[0201] Thus, during vibration reduction control to suppress torsional vibration in the drive force transmission system, the feedback gain of the torque feedback amount associated with the motor torque is appropriately adjusted according to the degree of limitation of the vibration suppression function. Therefore, for example, it is possible to appropriately determine when the vibration suppression function should be limited, such as when suppressing abnormal noise caused by gear backlash, and increase the feedback gain accordingly. Consequently, even when the torsional vibration suppression function of the drive force transmission system is limited, torque fluctuations can be reduced to suppress the torsional vibration of the drive force transmission system.

[0202] In addition, 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 the operating point indication amount indicating the operating point of the motor 106. In particular, the operating point indication amount includes the motor speed (mechanical angular velocity ω m Or the electrical angular velocity ω e ) and the motor torque (the second torque command value T ＊ 2) (see Table 3 and Table 4).

[0203] This allows the feedback gain to be determined in consideration of control stability according to the operating point of the motor 106. In particular, the feedback gain can be determined so as to exert the effect of suppressing torsional vibration and ensure control stability.

[0204] In addition, regarding the operating point indication amount, refer to the voltage command value v ＊ x (Especially the final voltage norm command value V ＊ a-fin ) with respect to the power supply voltage (DC voltage V dc ) ratio, determines the feedback gain (especially the gain k2).

[0205] Therefore, it can be considered whether the operating point of the motor 106 belongs to the voltage command value v ＊ x Relative to DC voltage V dcTherefore, even in a motor control system based on the use of the overmodulation region, the feedback gain can be set so as to exert the torsional vibration suppression effect and ensure control stability.

[0206] Furthermore, in the torque control process, the DC voltage V dc The feedback gain (gain k1 or gain k2) is determined.

[0207] Therefore, in addition to the operating point of the motor 106, the DC voltage V dc Based on the status of the system (whether it is within the guaranteed range of the system, etc.), an appropriate feedback gain is specified.

[0208] Furthermore, the motor control method further includes executing the voltage command value v ＊ x Convert DC voltage V dc The PWM control power conversion process (PWM control unit 103) is performed. In this power conversion process (particularly the modulation switching determination unit 907), the PWM control modulation method (asynchronous PWM control or synchronous PWM control) is selected based on the operating point (modulation factor M) of the motor 106. Furthermore, in the torque control process, the feedback gain (particularly the gain k2) is determined based on the selected modulation method (see Tables 2 and 3).

[0209] Thus, in the overmodulation region, gain k2 can be set, particularly taking into account the transition between multi-pulse driving and rectangular wave driving, in which the PWM pulse waveform varies significantly. Consequently, in a motor control system based on flexible utilization of the overmodulation region, more specific control logic is implemented for defining a feedback gain that achieves a balance between suppressing torsional vibration and ensuring control stability.

[0210] Furthermore, in the vibration reduction step (particularly the gain unit 205) of this embodiment, the motor speed (particularly the mechanical angular velocity ω m ) Apply the specified vibration reduction gain K fb The vibration compensation torque T fb In addition, in the limiting process (particularly the limiter 202), the first torque instruction value T is calculated based on the limiting request indication amount. ＊ 1 pair of vibration reduction gain K fb The upper and lower limits of the vibration compensation torque T are adjusted to limit fb Furthermore, in the limit level determination step (particularly the limit level determination unit 206), the first torque command value T is set based on the first torque command value T to which the adjusted upper and lower limits are assigned. ＊ 1 and specifies the limit level (limit level signal SH / L )(See Table 1).

[0211] This realizes a more specific control logic capable of detecting a situation where the torsional vibration suppression effect may be insufficient and determining an appropriate feedback gain in that situation.

[0212] Furthermore, in the torque control process of this embodiment (especially Figure 8 The estimated value or detected value of the motor torque (torque estimated value T est ) is fed back as the torque prompt value, and the voltage phase command value α ＊ Calculation is performed based on the voltage phase command value α ＊ For the voltage command value v ＊ x (especially the dq axis voltage command value v ＊ xv-fin ) to perform the operation.

[0213] Therefore, in voltage phase control, which is generally difficult to achieve both control stability and high-response feedback gain setting compared to current vector control, the limit level signal S can be used to control the voltage phase. H / L The feedback gain (particularly the gain k2) is determined in a manner taking the above factors into consideration. More specifically, when the limit level signal S H / L When the gain is low, the gain k2 is reduced (set to low gain). On the other hand, when the limit level signal S H / L When High, by increasing the gain k2 (setting it to a high gain) within a range that does not impair the control stability, it is possible to achieve both suppression of torsional vibration and assurance of control stability.

[0214] In addition, in the torque control process of this embodiment (especially Figure 7 In the torque compensator 601), the estimated value or detected value of the motor torque (torque estimated value T est ) is fed back as the torque prompt value, and the second torque command value T ＊ 2 is corrected, and based on the corrected second torque command value T ＊ 2 (Third torque command value T3 ＊ ) and the voltage command value v ＊ x (especially the dq axis voltage command value v ＊ xi-fin ) to perform the operation.

[0215] Therefore, even if there is no voltage command value v ＊ x The torque estimated value T is directly used in the calculation of estThe current vector control and other control methods of the feedback structure can also be controlled according to the limit level signal S H / L The feedback gain (gain k1) is determined so as to achieve both suppression of torsional vibration and assurance of control stability. More specifically, when the slice level signal S H / L When the gain k1 is low, the limit level signal S is set to H / L When High, by increasing the gain k1 within a range that does not impair the control stability, it is possible to achieve both suppression of torsional vibration and assurance of control stability.

[0216] Furthermore, in the present embodiment, a motor control device 10 suitable for executing the above-described motor control method is provided.

[0217] In particular, the motor control device 10 includes a vibration reduction unit (particularly a mechanical angular velocity estimation unit 203, a vibration torque estimation unit 204, and a gain unit 205) that uses the vibration compensation torque T fb The first torque command value T ＊ 1 is corrected and the second torque command value T ＊ 2 performs calculation; a limiting unit (particularly an absolute value processing unit 201 and a limiter 202), which is based on the limit request prompt amount (the first torque command value T ＊ 1) Limit the vibration compensation torque T fb Limit level determination unit 206, which determines that the vibration compensation torque T fb The limit level of the limit degree (limit level signal S H / L ) and a torque control unit (particularly the torque compensator 601 or the voltage phase control unit 502), which prompts the torque prompt amount of the motor torque (torque estimated value T est ) is fed back to the second torque command value T ＊ 2 And the voltage command value v ＊ x Perform calculations.

[0218] Furthermore, the torque control unit 102 refers to the limit level signal S H / L The feedback gain (gain k1 or gain k2) that determines the torque prompt amount ( Figure 7 The high gain permission determination unit 703 and the gain setting unit 704, or Figure 8 high gain permission determination unit 806 and gain setting unit 807).

[0219] (Second embodiment)

[0220] The second embodiment will be described below. Elements identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted. In particular, the motor control method of this embodiment is implemented by a vibration reduction control unit 101 that is different from that of the first embodiment.

[0221] Figure 13 This is a block diagram for explaining the configuration of the vibration reduction control unit 101 according to the present embodiment. fb The vibration reduction control unit 101 of this embodiment includes a mechanical angular velocity estimation unit 1303, a vibration torque estimation unit 1304, and a gain unit 1305. The functions are the same as those of the mechanical angular velocity estimation unit 203, the vibration torque estimation unit 204, and the gain unit 205 of the first embodiment.

[0222] In addition, as the vibration compensation torque T fb The vibration compensation torque T is limited. fb_lim The vibration reduction control unit 101 includes a limiter 1302. In addition, the limiter level signal S is generated. H / L The vibration reduction control unit 101 has a control gain setting unit 1301.

[0223] The functions of the mechanical angular velocity estimation unit 1303 and the vibration torque estimation unit 1304 are the same as those of the mechanical angular velocity estimation unit 203 and the vibration torque estimation unit 204 of the first embodiment, respectively. On the other hand, the gain unit 1305 of this embodiment generates a vibration reduction gain K as a variable value corresponding to the instruction from the control gain setting unit 1301. fb .

[0224] The limiter 1302 is for the vibration reduction gain K fb The limiting process based on the specified upper limit and lower limit is performed to obtain the limited vibration compensation torque T fb_lim In particular, in the present embodiment, fixed values ​​appropriately defined from the perspective of suppressing overload or the like during control are employed as the upper limit value and the lower limit value used for the restriction process.

[0225] The control gain setting unit 1301 sets the first torque command value T ＊ 1. Mechanical angular velocity ω m and DC voltage V dc The vibration reduction gain K is used as input fb The adjustment (setting of the upper and lower limits of the limiter 1302) and the limit level signal S H / L In particular, when the first torque command value T ＊ 1 If the vibration reduction gain K is within a predetermined range from the viewpoint of suppressing the control instability caused by the backlash of the gear, the control gain setting unit 1301 sets the vibration reduction gain Kfb Correction is made so that it becomes smaller than the basic value. In addition, the control gain setting unit 1301 is corrected by the mechanical angular velocity ω. m When the magnitude of exceeds the prescribed range and the output torque of the motor 106 is reduced, the vibration reduction gain K fb The control gain setting unit 1301 is corrected so that it becomes smaller than the basic value. ＊ 1 and / or mechanical angular velocity ω m So the vibration reduction gain K fb When the level signal S is less than the basic value, the level signal S H / L 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, thereby appropriately suppressing the torsional vibration of the driving force transmission system.

[0226] On the other hand, the control gain setting unit 1301 controls the DC voltage V dc When the voltage is less than the specified lower limit of the system, the level signal S H / L Set to Low and make the vibration reduction gain K fb In addition, from the perspective of determining whether an abnormality in the power system such as power supply abnormality occurs, the system lower limit voltage is the DC voltage V dc Thus, when the DC voltage V dc When the voltage is less than the lower limit of the system, reduce the vibration reduction gain K fb , thereby suppressing the decline in control stability caused by the abnormality of the above-mentioned power system. On the other hand, by limiting the level signal S H / L Set to Low to suppress unnecessary limitation of the vibration compensation torque T fb situation.

[0227] That is, in this embodiment, the first torque command value T ＊ 1 and the mechanical angular velocity ω m It functions as a limit request notification amount to notify that the torsional vibration suppression of the driving force transmission system should be limited (especially when abnormal noise may be generated due to backlash of the gear). dc The limit request notification amount functions as a notification indicating a situation in which the suppression of torsional vibration of the driving force transmission system should be limited (particularly, a situation in which system protection should be prioritized).

[0228] The control gain setting unit 1301 determines the vibration reduction gain K according to the logic shown in Table 5, for example. fb Adjustment and limiting level signal S H / L settings.

[0229] [Table 5]

[0230]

[0231] The motor control method according to the present embodiment described above and its effects will be described.

[0232] In the vibration reduction process of this embodiment, the motor speed (especially the mechanical angular velocity ω) is m ) Apply the specified vibration reduction gain K fb The vibration compensation torque T fb In addition, in the restriction process (particularly the control gain setting unit 1301), the mechanical angular velocity ω is calculated based on the restriction request amount. m , first torque command value T ＊ 1 and DC voltage V dc At least one of the vibration reduction gain K fb Adjustment is performed to thereby adjust the vibration compensation torque T fb Furthermore, in the limit level determination process (particularly the control gain setting unit 1301), based on the vibration reduction gain K after adjustment, fb The mechanical angular velocity ω m , first torque command value T ＊ 1 and DC voltage V dc At least one of the following is used to define the limit level signal S H / L .

[0233] This realizes a more specific control logic capable of detecting a situation where the torsional vibration suppression effect may be insufficient and determining an appropriate feedback gain in that situation.

[0234] In addition, the vibration reduction gain K can be adjusted instead. fb The vibration compensation torque T is limited fb The control logic is to limit the vibration compensation torque T relative to the specified basic value. fb The control logic of the upper and lower limits itself.

[0235] While the embodiments of the present invention have been described above, the above embodiments merely illustrate a part of application examples of the present invention, and the technical scope of the present invention is not intended to be limited to the specific configurations of the above embodiments.

[0236] The specific numerical values ​​shown in each table are for illustrative purposes only and do not restrict the technical scope of the present invention to specific numerical values. Furthermore, the limitation request indication amount is not limited to the method described in the above embodiment. Any parameter representing the operating state of motor 106, the state of the control system including motor 106, and / or the driving state of the vehicle equipped with motor 106, etc., may be used, as long as it can provide a function of indicating a situation in which torsional vibration suppression of the drive force transmission system should be limited. Furthermore, the operating point indication amount is not limited to the method described in the above embodiment; any parameter capable of specifying the operating point of motor 106 may be used.

Claims

1. A method for controlling a motor, comprising controlling the motor based on a first torque command value corresponding to a requested output of the motor, wherein: The motor control method comprises the following steps: a vibration reduction step of calculating a second torque command value by correcting the first torque command value using a vibration compensation torque that is a torque correction value for suppressing vibration of the motor speed; a limiting step of limiting the vibration compensation torque based on a limit request indication amount, the limit request indication amount being a parameter indicating a situation in which the vibration suppression of the motor speed should be limited; a limit level determining step of determining a limit level indicating a degree of limitation on the vibration compensation torque; and The torque control step feeds back a torque indication amount indicating the motor torque to the second torque instruction value to calculate a voltage instruction value, the voltage instruction value being an instruction value of a voltage supplied from a predetermined power source to the motor. In the torque control process, The feedback gain of the torque prompt amount is determined with reference to the limit level, In the vibration reduction step, the vibration compensation torque is calculated by applying a predetermined vibration reduction gain to the motor speed. In the limiting step, the vibration compensation torque is limited by adjusting the vibration reduction gain or upper and lower limit values ​​of the vibration reduction gain according to the limit request indication amount. In the limit level determination step, the limit level is determined based on the limit request presentation amount to which the adjusted vibration reduction gain or upper and lower limit values ​​of the vibration reduction gain are assigned. The limit level includes two levels: high and low.

2. The motor control method according to claim 1, wherein: In the torque control process, The feedback gain is determined by referring to an operating point indication amount indicating the operating point of the electric motor.

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

4. The motor control method according to claim 2 or 3, wherein: The operating point presentation amount includes a modulation rate defined as a ratio of the voltage command value to the voltage of the power supply.

5. The motor control method according to any one of claims 1 to 3, wherein: In the torque control process, The feedback gain is further determined with reference to the voltage of the power supply.

6. The motor control method according to any one of claims 1 to 3, wherein: The motor control method further includes a power conversion step of executing 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 of the PWM control is selected according to the operating point of the motor. In the torque control step, the feedback gain is further determined according to the selected modulation method.

7. The motor control method according to claim 1, wherein: In the limiting step, the vibration compensation torque is limited by adjusting upper and lower limits of the vibration reduction gain or upper and lower limits of the vibration compensation torque based on at least one of the motor speed, the motor torque, and the power supply voltage as the limitation request indication amount. In the limit level determination step, the limit level is defined based on at least one of the motor speed, the motor torque, and the power supply voltage to which the adjusted upper and lower limits of the vibration reduction gain or the upper and lower limits of the vibration compensation torque are assigned.

8. The motor control method according to any one of claims 1 to 3, wherein: In the torque control process, Furthermore, the estimated value or detected value of the motor torque is fed back as the torque prompt amount to calculate the voltage phase command value. The voltage command value is calculated based on the voltage phase command value.

9. The motor control method according to any one of claims 1 to 3, wherein: In the torque control process, Furthermore, the estimated value or the detected value of the motor torque is fed back as the torque presentation amount to correct the second torque command value. The voltage command value is calculated based on the corrected second torque command value.

10. A motor control device for controlling a motor based on a first torque command value corresponding to a requested output of the motor, wherein: The motor control device comprises: a vibration reduction unit that calculates a second torque command value by correcting the first torque command value using a vibration compensation torque that is a torque correction value for suppressing vibration in the motor rotation speed; a limiting unit that limits the vibration compensation torque based on a limit request indication amount, the limit request indication amount being a parameter indicating a situation in which the vibration suppression of the motor rotation speed should be limited; a limit level determination unit that determines a limit level indicating a degree of limitation on the vibration compensation torque; as well as a torque control unit that feeds back a torque indication amount indicating the motor torque to the second torque instruction value and calculates a voltage instruction value, the voltage instruction value being an instruction value of a voltage supplied from a predetermined power source to the motor; The torque control unit determines the feedback gain of the torque warning amount with reference to the limit level. The vibration reduction unit calculates the vibration compensation torque by applying a predetermined vibration reduction gain to the motor rotation speed. The limiting unit limits the vibration compensation torque by adjusting the vibration reduction gain or upper and lower limit values ​​of the vibration reduction gain according to the limitation request presentation amount. The limit level determination unit defines the limit level based on the limit request presentation amount to which the adjusted vibration reduction gain or upper and lower limit values ​​of the vibration reduction gain are assigned. The limit level includes two levels: high and low.

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