JP2014017924A - Motor control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor control device capable of controlling stable current vector in accordance with external environment change in weak field and transition with simple composition without requiring supplementary external equipment.SOLUTION: A motor control device 100 that controls torque and speed of a motor 2 containing a rotor having saliency includes: a gate signal conversion 60 that calculates duty ratio Dby PWM control outputting to an inverter 3; duty ratio D; and a q axis restriction controller 70 that controls a q axis current limit value iqon the basis of a comparison result (counter value D) with a duty ratio reference value D.

Description

  The present invention relates to a motor control device, and more particularly to a motor control device that controls torque and speed of a motor.

  Conventionally, motor control devices that control the torque and speed of a motor are known (see, for example, Non-Patent Documents 1 to 3 and Patent Document 1).

  Non-Patent Documents 1 to 3 and Patent Document 1 disclose a current vector control technique in which maximum torque control and field-weakening control are switched in order to control motor output with high efficiency.

  As shown in FIG. 11, the maximum torque control is a control that performs current vector control on a maximum torque control line MT that can maximize the motor-generated torque with respect to the same current. Since the induced voltage of the motor increases as the speed increases, the maximum voltage that can be applied to the motor is reached and the speed cannot be increased under the maximum torque control. The upper limit of the voltage is shown in FIG. 11 as a voltage limit line VL, and the voltage limit line VL drops downward in FIG. 11 as the motor speed increases. The field weakening control is a control that increases the negative d-axis current (field weakening current), decreases the armature linkage magnetic flux by the reaction magnetic flux, and suppresses the rise of the induced voltage, thereby expanding the upper speed limit. For this reason, in the maximum torque control, the current limit (current upper limit that can be supplied to the motor) indicated by the current limit circle CL in FIG. 11 until the voltage limit line VL descends and reaches the coordinates of the current vector (point Pc). ) Only need to be considered. On the other hand, in the field weakening control, the voltage limit line VL decreases as the motor speed (induced voltage) increases. Therefore, in addition to the current limit (current limit circle CL), the voltage limit (voltage limit line VL) is further taken into consideration. It is necessary to determine the current vector command value.

  While the technique disclosed in Non-Patent Document 1 discloses a method for determining a current vector command value in the maximum torque control and field weakening control, complicated calculation is required to calculate the current vector command value in field weakening control. Therefore, the influence of fluctuations in various parameters of the motor is also great. On the other hand, in Non-Patent Document 2, by using the power supply voltage (voltage loop) supplied to the PWM inverter acquired by the voltage sensor, the upper limit value of the q-axis current in the current vector is controlled, so in the field weakening control. A configuration for reducing the calculation load is disclosed. Non-Patent Document 3 formulates a method of acquiring a power supply voltage and determining a limit value of d-axis current (field weakening current) in field weakening control by mutual conversion between a current vector and a voltage vector. . In any of the techniques disclosed in Non-Patent Documents 1 to 3, when the upper limit of speed is reached during the execution of the maximum torque control (when the voltage limit line VL reaches the point Pc in FIG. 11), the voltage limit is considered. Transition to field weakening control. In the field weakening control, a current vector is determined on the voltage limit line VL. That is, in FIG. 11, a current vector is set at the intersection of the voltage limit line VL and the current limit circle CL, and the current vector becomes an arc as the voltage limit line VL descends (in the diagonally lower left direction in FIG. 11). It goes down.

  In Patent Document 1, the modulation factor is calculated from the power supply voltage of the PWM inverter acquired by the voltage sensor, and the maximum torque control and the field weakening control are switched according to the modulation factor, and the weakening is performed based on the modulation factor. A motor control device for calculating a d-axis field weakening current in field control is disclosed. In the field weakening control, the motor control device reads the d-axis current target value from the first map in which the target torque value and the d-axis current target value are associated with each other, and subtracts the field weakening current from the d-axis current target value. To calculate the d-axis current command value. The motor control device then determines the q-axis current command value corresponding to the d-axis current command value obtained by subtracting the field weakening current from the second map in which the target torque value is associated with the d-axis current and the q-axis current. Is read. The motor control device controls the inverter by using the d-axis current command value obtained by subtracting the field weakening current and the q-axis current command value read from the second map, thereby performing drive control of the motor. .

JP 2007-274843 A

Shigeo Morimoto et al., “Expansion of Operating Limits for Permanent Magnet Motor by Current Control Inverter Capacity 9” 26, NO. 5, p. 866-p. 871 Jang-Mok Kim, Seung-Ki Sul, “Speed Control of Interior Permanent Magnet Synchronous Motor Drive for the Flux Weaking Operation, ON ON, Tr. 33, NO. 1, p. 43-p. 48 Pavel Vaclavek, Petr Blaha, “Internal Permanent Magnet Synchronous Machine 7 Gender High Speed Operation Operation Singing Field Wet Singing Control”

  However, in Non-Patent Documents 1 to 3, all transition from maximum torque control to field-weakening control on the voltage limit line VL, and in the field-weakening region, a current vector at the intersection of the voltage limit line VL and the current limit circle CL. Therefore, when these control methods are applied to actual motor control, the maximum torque control is changed to the field weakening control due to various external environmental changes such as load torque fluctuations and power supply voltage changes. At the time of transition, the current vector sometimes deviated from the limit condition and became uncontrollable. Specifically, the current vector indicated by the thick line in FIG. 11 is a simulation result in consideration of the load and disturbance. The current vector deviates from the current vector command (thin line in FIG. 11) in the vicinity of the transition point Pc from the maximum torque control to the field weakening control, and deviates without making a transition to the field weakening region. Thus, in the said nonpatent literature 1-3, when it applies to actual motor control, there exists a problem that the stable current vector control in a field weakening and its transition is difficult.

  In Patent Document 1, after calculating the d-axis current command value, the q-axis current command value corresponding to the target torque value and the d-axis current command value is read using the second map. Therefore, when the target torque value increases, first, the d-axis current command value corresponding to the increased target torque value is read, and the q-axis corresponding to the increased target torque value and d-axis current command value The current command value is read from the second map. As a result, the q-axis current command value before the change of the target torque value exceeds the q-axis current command value after the change, and the current vector may deviate from the voltage limiting condition. For this reason, similarly to the non-patent documents 1 to 3, there is a problem that it is difficult to perform stable current vector control in the field-weakening region.

  In Non-Patent Documents 2 and 3 and Patent Document 1, since it is necessary to acquire a power supply voltage in order to calculate a current vector command value, a voltage is used to acquire a power supply voltage supplied to the PWM inverter. It is necessary to provide a sensor. For this reason, it is necessary to add an external device (voltage sensor) for acquiring the power supply voltage supplied to the PWM inverter separately from the motor control device, which causes a problem that the configuration becomes complicated.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to provide a simple structure that does not require the addition of an external device, and is stable in the field weakening and its transition. A motor control device capable of performing current vector control is provided.

  In order to achieve the above object, a motor control device according to one aspect of the present invention is a motor control device that controls torque and speed of a motor including a rotor having saliency, and is a duty by PWM control that is output to an inverter. Means for calculating the ratio, and q-axis limit value control means for controlling the q-axis current limit value based on a comparison result between the duty ratio and the reference value of the duty ratio.

  In the motor control device according to one aspect of the present invention, as described above, the q-axis is calculated based on the comparison result between the duty ratio by the PWM control output to the inverter and the duty ratio and the duty ratio reference value. By providing q-axis limit value control means for controlling the current limit value, current vector control in the field weakening region is performed based on the comparison result between the duty ratio of the output to the inverter and the duty ratio reference value. be able to. Specifically, for example, control can be performed so that the q-axis current command value is limited by the q-axis current limit value from the time when the duty ratio exceeds the duty ratio reference value. Since the duty ratio becomes the maximum value (= 100%) on the voltage limit line VL, by controlling the q-axis current limit value with respect to the duty ratio reference value before the duty ratio becomes the maximum value, the load fluctuation or the like Even when the external environment changes, stable current vector control can be performed. Moreover, since it is not necessary to provide an external device (voltage sensor) for acquiring the power supply voltage supplied to the inverter, current vector control can be performed with a simple configuration without providing an external device (voltage sensor).

  The motor control device according to the above aspect further includes q-axis limit responsiveness adjusting means for adjusting the responsiveness of the q-axis current limit value. If comprised in this way, the responsiveness of the q-axis current limit value can be adjusted by the q-axis limit responsiveness adjusting means so that the limit of the q-axis current command value is changed quickly or slowly. As a result, the response of limiting the q-axis current command value so that it responds to changes in the external environment of the control target due to differences in responsiveness during acceleration and deceleration, motor performance, and the size of the load connected to the motor. Therefore, more stable current vector control can be realized.

  In this case, the responsiveness of the q-axis current limit value is adjusted based on the difference between the comparison result between the duty ratio and the duty ratio reference value and the comparison result reference value. According to this configuration, the q-axis current limit value can be controlled according to the magnitude of the difference based on the difference between the comparison result of the duty ratio and the duty ratio reference value and the comparison result reference value. . Thereby, the q-axis current limit value can be controlled more easily.

  In this case, the q-axis limit responsiveness adjusting means determines the ratio of the duty ratio that is equal to or higher than the duty ratio reference value as a comparison result between the duty ratio and the duty ratio reference value, and the ratio reference value as the comparison result reference value. Is configured to adjust the responsiveness of the q-axis current limit value. With this configuration, the q-axis current limit value can be stably controlled based on the difference between the ratio at which the duty ratio is equal to or greater than the duty ratio reference value and the ratio reference value as the comparison result reference value. Can do. In other words, in the actual operating state of the motor, the duty ratio changes from moment to moment, and even when the duty ratio rises as a whole, there is a moment when the duty ratio exceeds the duty ratio reference value. There are also moments below. For this reason, by taking the ratio, it is possible to control the q-axis current limit value stably while suppressing the influence of instantaneous fluctuation of the duty ratio.

  The motor control device according to one aspect further includes a maximum torque control unit that calculates a d-axis current target value and a q-axis current target value based on the maximum torque control, and the q-axis current target value calculated by the maximum torque control unit. Is limited by the q-axis current limit value controlled by the q-axis limit value control means, the current vector command value transitions from the maximum torque control region to the field weakening region. With this configuration, when the motor speed increases during the control by the maximum torque control and the mode is changed to the field weakening control by the voltage limitation, the q-axis current target value calculated based on the maximum torque control is changed to the q-axis current. The current vector can be shifted from the maximum torque control region to the field weakening region only by being limited by the limit value. This eliminates the need to perform control such as determining whether or not to switch between maximum torque control and field weakening control, or calculating a field weakening current value separately and subtracting it from the current vector. Processing can be simplified and calculation load can be reduced.

  In this case, it further includes q-axis current limiting means for limiting the q-axis current target value in accordance with the q-axis current limit value controlled by the q-axis limit value control means. With this configuration, the current vector is easily changed from the maximum torque control region to the field weakening region only by limiting the q-axis current target value output from the maximum torque control unit by the q-axis current limiting unit. be able to. That is, when the motor speed is low, the q-axis current limit value is sufficiently large and the q-axis current target value is not limited. Therefore, the maximum torque control is performed by the q-axis current target value output from the maximum torque control means. It can be carried out. When the motor speed increases (when the voltage limit becomes stronger), the q-axis current target value is limited based on the q-axis current limit value by the q-axis current limiter, so the current vector is weakened. Transition to the field region is possible.

  In the configuration including the maximum torque control means, in the field-weakening region, from the d-axis current target value calculated by the maximum torque control means independently of the q-axis current target value limited by the q-axis current limit value, The d-axis current command value of the current vector is determined, and the q-axis current command value of the current vector is determined from the q-axis current target value limited by the q-axis current limit value. With this configuration, when performing field weakening control, the q-axis current target value calculated by the maximum torque control unit can be limited by the q-axis current limiting unit, and the q-axis current command value can be determined. The d-axis current command value of the current vector can be determined as it is from the d-axis current target value calculated by the maximum torque control means. As a result, the control process for calculating the current vector (command value) can be further simplified, and the calculation load can be further reduced.

  According to the present invention, as described above, a motor capable of performing stable current vector control that follows a field weakening and changes in the external environment at the transition thereof with a simple configuration that does not require the addition of an external device. A control device can be provided.

It is the figure which showed the whole structure of the motor apparatus provided with the motor control apparatus by 1st Embodiment of this invention. It is a control block diagram for demonstrating the structure of the motor control apparatus by 1st Embodiment of this invention. It is a figure for demonstrating the comparison result of a duty ratio and a duty ratio reference value. It is a figure for demonstrating the difference in the responsiveness of the q-axis current limiting value by a ratio reference value. It is a current vector diagram for demonstrating the current vector control of the motor control apparatus by 1st Embodiment of this invention. FIG. 6 is an enlarged view around a point P6 in FIG. 5. It is an electric current vector figure which shows the control test result by Example 1 of this invention. It is an electric current vector figure which shows the control test result by Example 2 of this invention. It is an electric current vector figure which shows the control test result by Example 3 of this invention. It is a control block diagram for demonstrating the structure of the motor control apparatus by 2nd Embodiment of this invention. It is the figure which showed the simulation result for demonstrating the current vector control by a conventional method.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

(First embodiment)
First, with reference to FIGS. 1-6, the whole structure of the motor control apparatus 100 by 1st Embodiment of this invention is demonstrated. 1st Embodiment demonstrates the example which applied this invention to the motor control apparatus 100 in the electric actuator mounted in an aircraft, for example, and the motor apparatus for general industries.

  As shown in FIG. 1, the motor control device 100 according to the first embodiment constitutes a part of a motor device (electric actuator) 1 including a motor 2, an inverter 3, a position detector 4, and the like, and controls driving of the motor 2. It has a function to perform.

The motor 2 is, for example, a synchronous motor (IPMSM: Interior Permanent Synchronous Motor) driven by a three-phase alternating current, and includes a rotor in which a permanent magnet is embedded, a stator in which an armature winding is disposed, including. The IPM motor 2 has a saliency in which the d-axis inductance and the q-axis inductance are different. The motor 2 is rotationally driven by a three-phase alternating current (iu, iv, iw) supplied from the inverter 3 and operates a load (not shown) connected to the output shaft. The position of the motor 2 is detected by the position detector 4, and the position signal P _fb is output (feedback) from the position detector 4 to the motor control device 100.

  The inverter 3 is connected to the motor control device 100 and the motor 2, converts a direct current of a power supply unit (not shown) into a three-phase alternating current, and supplies the three-phase alternating current to the motor 2. The inverter 3 is switching-controlled by a three-phase gate drive signal (Gu, Gv, Gw) of the motor control device 100, and performs motor drive by a PWM (pulse width modulation) signal. U-phase current signal iu and V-phase current signal iv output from inverter 3 are output (feedback) to motor control device 100.

Motor controller 100 generates a speed command omega _c, fed back U-phase current signals iu, based on the V-phase current signals iv and the position signal _{P fb,} 3-phase gate drive signals (Gu, Gv, Gw) and And output to the inverter 3. In the first embodiment, the motor control device 100 is configured by an FPGA (Field-Programmable Gate Array), and includes various control blocks shown in FIG.

Specifically, as shown in FIG. 2, the motor control device 100 includes a speed controller 10, a maximum torque controller 20, a current controller 30, a limiter 40, a three-phase converter 50, a gate signal. A conversion unit 60 and a q-axis limit control unit 70 are mainly included. The motor control device 100 as a whole is based on cascade control of speed feedback control using a speed signal ω _fb obtained by speed calculation of the position signal P _fb and current feedback control using a U-phase current signal iu and a V-phase current signal iv. The drive control of the motor 2 is performed. The maximum torque controller 20 and the limiter 40 correspond to “maximum torque control means” and “q-axis current limiting means” in the claims, respectively. The q-axis limit control unit 70 corresponds to “q-axis limit value control means” and “q-axis limit response adjusting means” in the claims.

Speed controller 10, a speed command omega _c, generates a current command Ia from the difference omega _err of the speed signal omega _fb, and outputs the generated current command Ia to a maximum torque controller 20. Here, as shown in FIG. 5, in the current vector diagram in which the d-axis current and the q-axis current are taken on the horizontal axis and the vertical axis, the current vector is determined by determining predetermined d-axis coordinates and q-axis coordinates. . The current command Ia of the speed controller 10 corresponds to the magnitude of the current vector, and corresponds to setting a circle whose center is the origin and whose radius corresponds to the current command Ia in FIG.

The maximum torque controller 20 calculates and outputs a maximum torque control current vector command value (d-axis current target value id _ex and q-axis current target value iq _ex ) based on the maximum torque control. Here, the maximum torque control line MT shown in FIG. 5 is a locus of a current vector that maximizes the generated torque with respect to the same current. The maximum torque controller 20 determines a point on the maximum torque control line MT shown in FIG. 5 based on the current command Ia (intersection of the circle corresponding to the magnitude of the current command Ia and the maximum torque control line MT). The d-axis current target value id _ex and the q-axis current target value iq _ex are output. As shown in FIG. 2, in the first embodiment, the d-axis current target value id _ex is directly output to the current controller 30 as the d-axis current command value id _c , and the q-axis current target value iq _ex is the limiter. 40.

The limiter 40 has a function of limiting the q-axis current target value iq _ex input from the maximum torque controller 20 according to the q-axis current limit value iq _lim controlled (set) by the q-axis limit control unit 70. . When the q-axis current target value iq _ex is smaller than the q-axis current limit value iq _lim , the q-axis current limit in the limiter 40 does not act, and the q-axis current target value iq _ex remains as it is as the q-axis current command value iq _c Is output as On the other hand, when the q-axis current target value _{iq ex} is greater than the q-axis current limit value _{iq lim} is the q-axis current limit processing in the limiter 40, the q-axis current target value _{iq ex} is the q-axis current limit value _{iq lim} After being limited, it is output as a q-axis current command value iq _c .

The current controller 30 obtains the d-axis current command value id _c from the maximum torque controller 20 and the q-axis current command value iq _c from the limiter 40, and at the same time, U-phase current signal iu and V-phase current signal iv (feedback). D-axis FB current id _fb and q-axis FB current iq _fb obtained by performing coordinate conversion on the dq-axis. Based on the d and q-axis current command values (id _c , iq _c ) and the d and q-axis FB currents (id _fb , iq _fb ), the current controller 30 d and q-axis voltage command values (Vd _c , Vq _c ) is output.

The three-phase conversion unit 50 performs coordinate conversion of the d and q-axis voltage command values (Vd _c , Vq _c ) into three-phase command values (Vu _c , Vv _c , Vw _c ), and outputs them to the gate signal conversion unit 60. To do.

The gate signal conversion unit 60 acquires the rotation angle position θ coordinate-converted from the position signal P _fb of the motor 2, and uses the vector PWM method to output the three-phase command values (Vu _c , Vv _c , Vw _c ) to the three-phase. Conversion into gate drive signals (Gu, Gv, Gw). As a result, three-phase gate drive signals (Gu, Gv, Gw) are output from the motor control device 100 to the inverter 3. Further, the gate signal converter unit 60 outputs the three-phase gate drive signal outputted by the vector PWM method (Gu, Gv, Gw) the duty ratio _{D real} q-axis limiting control unit 70 of the.

Here, in the first embodiment, the q-axis limit control unit 70 controls the q-axis current limit value iq _lim using the duty ratio D _real acquired from the gate signal conversion unit 60, and sends the q-axis current to the limiter 40. It has a function of outputting (setting) the limit value iq _lim . The q-axis limit control unit 70 mainly includes a comparator 71, a UD (up / down) counter 72, and an integrator 73.

The comparator 71 compares the duty ratio D _real with the duty ratio reference value D _crit and outputs the comparison result CR to the UD counter 72. The q-axis limit control unit 70 controls the q-axis current limit value iq _lim based on the comparison result CR. The comparison result CR is a binary signal in which an H signal is output when D _real ≧ D _crit and an L signal is output when D _real <D _crit . The duty ratio reference value D _crit is preset in the motor control device 100 and stored in the storage unit 74. As will be described later, the transition timing from the maximum torque control to the field weakening control is arbitrarily set by the duty ratio reference value D _crit . For example, the duty ratio reference value D _crit is set to about 95% with respect to the maximum duty ratio of 100%.

The UD counter 72 acquires the comparison result CR, and increments the counter value by +1 (adds) when the comparison result CR is H, and decrements the counter value by -1 when the comparison result CR is L. The counter value takes a value from 0 to 100 normalized by setting the maximum value to 100 and the minimum value to 0. Then, the UD counter 72 outputs the current counter value D _fb . The counter value D _fb corresponds to the ratio at which the duty ratio D _real is equal to or greater than the duty ratio reference value D _crit . The comparator 71 and the UD counter 72 convert the duty ratio _Dreal , which is an analog value, into a counter value _Dfb , which is a digital value, and outputs it.

Here, increase / decrease of the counter value D _fb will be described with reference to FIG. For example, when the speed of the motor 2 increases as the motor driving time elapses, the terminal voltage of the motor 2 increases due to the increase of the induced voltage (duty ratio _Dreal increases). Looking separated changes of the duty ratio at this time at a predetermined period T1 to T6, the actual value of the duty ratio D _real while variations within the scope defined by a circle in FIG. 3, continue to increase as a whole. In the period T1 and T2, since there is no the duty ratio _{D real} reaches the duty ratio reference value _{D crit,} the ratio of the H signal / L signal of the comparison result CR becomes 0/100 (subtraction only). Therefore, the counter value D _fb is 0. On the other hand, in the period T3 and T4, the duty ratio _{D real} reaches the vicinity of the duty ratio reference value _{D crit,} or the duty ratio _{D real} becomes a duty ratio reference value _{D crit} above, or below the duty ratio reference value _{D crit} repeat. At this time, since the H signal / L signal = 50/50 in the period T3 in the entire period, the count stop at the upper limit (100) or the lower limit (0), the q-axis current limit value iq _lim described later, If the change is not taken into account, the rate of increase / decrease in the counter value D _fb becomes substantially equal (no change in the counter value), and during the period T4, the H signal / L signal = 70/30. If the change of the shaft current limit value iq _lim is not taken into account, the counter value D _fb increases gently. In the periods T5 and T6, the duty ratio _Dreal completely exceeds the duty ratio reference value _Dcrit , so that H signal / L signal = _100/0 (only addition). As a result, the counter value D _fb quickly reaches the upper limit of 100, and then continues to be 100.

As shown in FIG. 2, the integrator 73 acquires and integrates the ratio difference value dR that is the difference (LRR−D _fb ) between the ratio reference value LRR and the counter value D _fb of the UD counter 72. Then, the integrator 73 outputs (sets) the obtained integrated value to the limiter 40 as the q-axis current limit value iq _lim . As the integrated value increases in the negative direction, the q-axis current limit value iq _lim decreases, and the q-axis current limit in the limiter 40 increases. Further, the larger the integrated value is in the positive direction, the larger the limit value is, and the q-axis current limit in the limiter 40 is relaxed. The ratio reference value LRR corresponds to the “comparison result reference value” in the claims.

The ratio reference value LRR is a numerical value that determines the responsiveness of increase / decrease in the q-axis current limit value iq _lim (ratio of increase / decrease in the integrator 73) and the convergence point of the counter value _Dfb , and is set in the motor control device 100 in advance. And stored in the storage unit 75. The ratio reference value LRR is set from a value of 0 <LRR <100. Since the difference between the counter value D _fb and the ratio reference value LRR is integrated and the q-axis current limit value iq _lim is changed, the counter value D _fb and the q-axis current limit value iq _lim are the ratio reference value LRR at which the difference becomes zero. Converge to the value of. Regarding the responsiveness, as shown in FIG. 4, when the ratio reference value LRR is 50, the integration value of the ratio difference value dR in the integrator 73 is increased or decreased (that is, the q-axis current limit value iq _lim is increased or decreased). It becomes the same ratio. When the ratio reference value LRR is smaller than 50, the increase / decrease of the integrated value (q-axis current limit value iq _lim ) of the ratio difference value dR becomes a larger ratio in the decreasing direction, and the ratio reference value LRR is larger than 50. In this case, the increase / decrease of the integrated value (q-axis current limit value iq _lim ) of the ratio difference value dR becomes a larger ratio in the increasing direction. To briefly show the operation of the ratio reference value LRR, it is assumed that the counter value D _fb = 100 is fixed. At this time, when the ratio reference value LRR = 50, −50 is accumulated by the integrator 73, and when the ratio reference value LRR = 25, −75 is accumulated by the integrator 73. The integrated value (q-axis current limit value iq _lim ) increases rapidly in the negative direction as the ratio reference value LRR is smaller. Therefore, the response for increasing the q-axis current limit becomes faster and the response for weakening becomes slower. On the other hand, as the ratio reference value LRR is larger, the integrated value is gradually increased in the negative direction. Therefore, the response for increasing the q-axis current limit is delayed, and the response for weakening is accelerated. In order to perform a more stable control operation, the ratio reference value LRR preferably takes a value smaller than 50. Thus, in the first embodiment, the responsiveness of the q-axis current limit is adjusted based on the ratio difference value dR that is the difference between the ratio reference value LRR and the counter value D _fb of the UD counter 72, and the limit value To control.

With the above configuration, of the output of the maximum torque controller 20, the d-axis current target value id _ex is determined independently of the q-axis current limit value iq _lim of the limiter 40, and the d-axis current command of the current vector is used as it is. The value is id _c . On the other hand, the target value (output of the limiter 40) after the q-axis current target value iq _ex is limited by the limiter 40 (q-axis current limit value iq _lim ) becomes the q-axis current command value iq _{c of} the current vector. .

Next, the current vector control of the motor control device 100 according to the first embodiment will be described with reference to FIGS. 5 and 6 schematically show the simulation results of current vector control in a constant state where the load torque does not vary. 5 and 6, a load torque line CT is a locus of a current vector for the motor 2 to output a torque equal to the load torque. The current limit circle CL is the maximum value of the current vector in the steady state, and is set based on the hardware specifications (rated current value) of the inverter 3 and the like. Current limit circle CL Current Limiting is not performed in the transient state, such as when the starter motor 2 (during acceleration), the rotational speed of the motor 2 omega reaches the vicinity of the speed command omega _c, the current vector is the current limit circle CL Limited to within. In the control block diagram of FIG. 2, this current limiting process is omitted.

Also, voltage limit lines VL (ω1), VL (ω2), and VL (ω3) indicate voltage limits due to induced voltages at the rotational speeds ω = ω1, ω2 and ω3 (ω1 <ω2 <ω3), respectively. It is a trajectory. The voltage limit line VL drops as the speed ω increases. When the voltage limit line VL reaches the position of the current vector, the duty ratio is theoretically 100%. When the current vector is set outside (upper side) of the voltage limit line VL, the maximum output voltage (duty ratio 100%) of the inverter 3 is exceeded, so that current control becomes impossible. For this reason, it is necessary to set the current vector within the limit region below the voltage limit line VL (below the voltage limit line VL) corresponding to the current speed ω following the speed change of the motor 2. Therefore, in the maximum torque control along the maximum torque control line MT, the generated torque becomes maximum at the point P1 within the current limit circle CL (steady state), and the speed ω1 becomes the speed limit (duty ratio 100%). Further, at the point P2, it becomes a limit point of constant speed rotation (speed ω2) that balances with the load torque line CT. Inside the point P2 (on the side opposite to the point P1 of the point P2 on the maximum torque control line MT in FIG. 5), the rotational speed of the motor 2 cannot be maintained. Thus, for example, when the speed command omega _c speed ω3 exceeding the speed ω2 is given, from the maximum torque region along the maximum torque control line MT, it is necessary to transition the field weakening range FW shown by hatched regions.

In the first embodiment, as the duty ratio D _real exceeds the duty ratio reference value D _crit (for example, 95%) and approaches 100%, the counter value D _fb increases, and the ratio difference value dR (LRR−D _fb ) Since it takes a negative value, the q-axis current limit value iq _lim as the output of the integrator 73 decreases (the q-axis current limit becomes stronger). Conversely, as the duty ratio D _real falls below the duty ratio reference value D _crit (for example, 95%), the counter value D _fb decreases and the ratio difference value dR (LRR−D _fb ) increases. Q-axis current limit value iq _lim increases as the output of (q-axis current limit is relaxed). Since the q-axis current limit value iq _lim is maintained when the ratio difference value dR (LRR−D _fb ) is 0, the ratio counter value D _fb is controlled to become the ratio reference value LRR, and accordingly the voltage limit line The current vector (q-axis current target value) is controlled so that the duty ratio D _real converges in the vicinity of the duty ratio reference value D _crit inside the VL (lower side in FIG. 5). Therefore, setting 95%, for example, as the duty ratio reference value D _crit is a virtual equivalent to the duty ratio reference value below the voltage limit line VL having the duty ratio of 100% (lower side in FIG. 5). This corresponds to setting the voltage limit line VLc.

Hereinafter, a case where the motor 2 is driven with the speed ω3 (voltage limit line VL (ω3)) as a target will be considered. The duty ratio reference value D _{crit is set} to 95% (voltage limit line VLc). In this case, the load torque and the generated torque of the motor 2 are balanced at the intersection P6 (convergence point) between the load torque line CT and the voltage limit line VLc, and constant speed rotation at the speed ω3 is possible. 5 and 6, the current vector (command) is a current vector determined by the d and q axis current command values (id _c and iq _c ), and the current vector (FB) is the d and q axis FB current ( id _fb , iq _fb ) is a current vector (control result).

First, at the time of starting the motor drive, maximum torque control from the origin along the maximum torque control line MT is performed based on the speed command ω _c (= ω3). Since the difference between the speed command ω _c and the speed signal ω _fb (≈0) is sufficiently large, the d and q axis current target values (id _ex , iq _ex ) of the maximum torque controller 20 are on the maximum torque control line MT. A point Pmt corresponding to the maximum value of is output. At this time, since the motor 2 is in a transient state during acceleration and the speed ω is sufficiently low, the voltage limit VL due to the induced voltage and the current limit circle CL are not a problem. Therefore, the duty ratio _{D real,} as shown in the period T1 and T2 of FIG. 3 for less than the duty ratio reference value _{D crit,} q-axis current limit value _{iq lim} from the integrator 73 has a sufficiently high value. In this case, the q-axis current target value iq _ex of the maximum torque controller 20 becomes the q-axis current command value iq _{c as} it is without being limited by the limiter 40.

When the rotational speed ω of the motor 2 increases, the voltage limit line VL decreases. As described above, when the duty ratio D _real starts to exceed the duty ratio reference value D _crit (95%), the q-axis current limit value iq _lim decreases. As a result, the restriction by the q-axis current limit value iq _lim begins to take effect at a stage earlier than the duty ratio D _real reaches 100% (the stage at which the voltage limit line VLc reaches the current vector command value). For this reason, the q-axis current target value iq _ex is limited to the q-axis current limit value iq _lim by the limiter 40. As a result, the current vector deviates from the maximum torque control line MT and follows the speed increase and decreases to the point P3. As a result, since the speed ω of the motor 2 reaches the vicinity of the target speed ω3 and gradually converges to the target speed ω3, a current limit by the current limit circle CL is added.

For this reason, when the current vector falls to the point P3, the current vector moves to the right while being limited by the q-axis current limit value iq _lim , and reaches the intersection P4 with the current limit circle CL. After point P4, voltage limit line VL (VLc) decreases as rotation speed ω increases. Accordingly, q-axis current limit value iq _lim decreases accordingly, and the current vector changes along current limit circle CL. Move to P5.

As shown in FIG. 6, in the vicinity of the point P5, when the current vector is below the voltage limit line VLc corresponding to the duty ratio reference value D _crit (95%), the duty ratio D _real is equal to the duty ratio reference value D. _The q-axis current limit value iq _lim increases below _crit . For this reason, as the q-axis current limit value iq _lim of the limiter 40 increases (limit relaxation), the q-axis current command value iq _c gradually increases as the output of the limiter 40. As a result, when the speed is lower than the target speed ω3, the current vector is set above the load torque line CT by the generated speed difference ω _err , and the speed ω increases due to the increase in the generated torque (voltage limit line). VL goes down).

On the other hand, when the current vector is above the voltage limit line VLc, the duty ratio _{D real} exceeds the duty ratio reference value _{D crit,} q-axis current limit value _{iq lim} is lowered. For this reason, the q-axis current command value iq _c as the output of the limiter 40 gradually decreases as the q-axis current limit value iq _lim of the limiter 40 decreases (limit strengthening). As a result, when the speed is higher than the target speed ω3, the current vector is set below the load torque line CT by the generated speed difference ω _err and the q-axis current limit value iq _lim, and the generated torque is reduced. The speed ω decreases (the voltage limit line VL increases). At this time, the speed of the rise and fall of the q-axis current limit value iq _lim (responsiveness) is adjusted by setting the ratio reference value LRR. As a result of a series of control operations, in the vicinity of P5, the current vector rises and falls across the load torque line CT, and gradually approaches the convergence point P6 (target speed ω3).

At the convergence point P6, the current vector is located in the vicinity of the voltage limit line VLc (ω3) corresponding to the duty ratio reference value D _crit (duty ratio 95%). At this time, the counter value D _fb becomes equal to the ratio reference value LRR, and the q-axis current limit value iq _lim converges to a substantially constant value. As a result, the current vector converges to the convergence point P6, and constant speed driving is performed at a speed ω3 that balances with the load torque line CT.

Thus, in the motor control device 100, the q-axis current limit value iq _lim is adjusted by the operation of the q-axis limit control unit 70 so that the duty ratio D _real becomes the duty ratio reference value D _crit, and the voltage limit line VL The current vector control is performed so that the duty ratio D _real converges (reaches the convergence point) in the vicinity of the duty ratio reference value D _crit .

In the first embodiment, as described above, the gate signal converter unit 60 for calculating the duty ratio _{D real,} based on the duty ratio _{D real,} comparison between the duty ratio reference value _{D crit} (counter value _{D fb)} By providing a q-axis limit control unit 70 that controls the q-axis current limit value iq _lim , weakening based on the comparison result between the duty ratio D _real of the output to the inverter 3 and the duty ratio reference value D _crit Current vector control can be performed in the field region. Specifically, when the duty ratio D _real exceeds the duty ratio reference value D _crit , control can be performed so that the q-axis current target value iq _ex is limited by the q-axis current limit value iq _lim . Since the duty ratio _{D real} on voltage limiting line VL becomes a maximum value (= 100%), the duty ratio reference value before the duty ratio _{D real} becomes a maximum value based on the counter value _{D fb D crit} (e.g. 95% ) By controlling the q-axis current limit value iq _lim , stable current vector control can be performed even when an external environment change such as load fluctuation occurs. Further, since it is not necessary to provide an external device (voltage sensor) for acquiring the power supply voltage supplied to the inverter 3, current vector control can be performed with a simple configuration without providing an external device (voltage sensor). .

In the first embodiment, as described above, the q-axis limit control unit 70 that adjusts the responsiveness of the q-axis current limit value iq _lim is provided. With this configuration, the q-axis limit control unit 70 can adjust the response of the q-axis current limit value iq _lim so that the limit of the q-axis current target value iq _ex is changed quickly or slowly. it can. As a result, the q-axis current target value iq _ex is adjusted so as to follow changes in the external environment such as the difference in responsiveness during acceleration and deceleration, the performance of the motor 2 and the size of the load connected to the motor 2. Since the limit responsiveness can be adjusted, more stable current vector control can be realized.

  As an example, in a motor with a small mechanical time constant, for example, the number of revolutions increases (decreases) quickly, and the voltage limit line VL (voltage limit line VLc) changes quickly, so that the current vector can exceed the voltage limit line VL. Increases nature. For a motor with such a small mechanical time constant, the ratio reference value LRR is set to be smaller than 50, thereby speeding up the response of the q-axis current limit and preventing the current vector from deviating from the limit. be able to. Further, even when the voltage limit line VL (voltage limit line VLc) changes due to the influence of noise, load torque fluctuation, etc., the q-axis current limit can be promptly responded to prevent the current vector from deviating from the limit. it can.

Further, in the first embodiment, as described above, the q-axis limit control unit 70 determines the comparison result (counter value D _fb ) between the duty ratio D _real and the duty ratio reference value D _crit and the ratio reference value LRR. Based on this, the responsiveness of the q-axis current limit value iq _lim is adjusted. With this configuration, when the q-axis current limit value iq _lim is controlled based on the counter value D _fb , the response of the q-axis current limit value iq _lim can be easily adjusted by adjusting the ratio reference value LRR. Can do. This makes it possible to flexibly adjust the limit responsiveness of the q-axis current target value iq _ex .

In the first embodiment, as described above, the q-axis limit control unit 70 performs the comparison between the duty ratio D _real and the duty ratio reference value D _crit (counter value D _fb ) and the ratio reference value LRR. The responsiveness of the q-axis current limit value iq _lim is adjusted based on the difference (ratio difference value dR). With this configuration, the q-axis current limit value iq _lim can be controlled according to the magnitude of the difference based on the ratio difference value dR. Thereby, the responsiveness of the q-axis current limit value iq _lim can be adjusted more easily.

In the first embodiment, as described above, the q-axis limit control unit 70 performs the ratio (counter value D _fb ) in which the duty ratio D _real is equal to or higher than the duty ratio reference value D _crit , the ratio reference value LRR, Based on the difference (ratio difference value dR), the responsiveness of the q-axis current limit value iq _lim is adjusted, and the limit value is controlled. With this configuration, the responsiveness of the q-axis current limit value iq _lim can be stably adjusted based on the ratio difference value dR. That is, as shown in FIG. 3, the duty ratio D _real the actual operating state of the motor _is changed with time, even in the course of the duty ratio D _{real rises} as a whole, the duty ratio D _{real duty} ratio reference There are also moments when the value D _crit is exceeded and other times when the value falls below the duty ratio reference value D _crit . Therefore, the ratio by suppressing the influence of instantaneous variation of the duty ratio D _real by taking the q-axis current limit value iq _lim can be stably controlled.

In the first embodiment, as described above, the maximum torque controller 20 that calculates the d-axis current target value id _ex and the q-axis current target value iq _{ex based} on the maximum torque control is provided. Then, the q-axis current target value iq _ex calculated by the maximum torque controller 20 is limited by the q-axis current limit value iq _lim controlled by the q-axis limit control unit 70, whereby the current vector command value (d-axis The motor control device 100 is configured such that the current command value id _c and the q-axis current command value iq _c ) transition from the maximum torque control region (maximum torque control line MT) to the field weakening region FW. According to this configuration, when the speed of the motor 2 increases during the control by the maximum torque control and the mode is changed to the field weakening control due to the voltage limit, the q-axis current target value iq _ex calculated based on the maximum torque control is set. The current vector can be shifted from the maximum torque control region (MT) to the field weakening region FW only by being limited by the q-axis current limit value iq _lim . This eliminates the need to perform control such as determining whether or not to switch between maximum torque control and field weakening control, or calculating a field weakening current value separately and subtracting it from the current vector. Processing can be simplified and calculation load can be reduced.

In the first embodiment, as described above, the limiter 40 that limits the q-axis current target value iq _ex according to the q-axis current limit value iq _lim controlled by the q-axis limit control unit 70 is provided. With this configuration, the current vector can be easily changed from the maximum torque control region (MT) to the field weakening region only by limiting the q-axis current target value iq _ex output from the maximum torque controller 20 by the limiter 40. Transition to FW is possible. That is, when the speed of the motor 2 is low, the q-axis current limit value iq _lim is sufficiently large, and the q-axis current target value iq _ex is not limited, so that the q-axis current output from the maximum torque controller 20 Maximum torque control can be performed by the target value iq _ex . When the speed of the motor 2 increases (when the voltage limit becomes strong), the q-axis current target value iq _ex is limited based on the q-axis current limit value iq _lim by the limiter 40, so that the current vector Can be shifted to the field weakening region FW.

In the first embodiment, as described above, in the field-weakening region, the current is calculated from the d-axis current target value id _ex calculated by the maximum torque controller 20 independently of the q-axis current command value iq _c. The vector d-axis current command value id _c is determined, and the q-axis current command value iq _c of the current vector is determined from the q-axis current target value iq _ex limited by the q-axis current limit value iq _lim . With this configuration, when the field weakening control is performed, the q-axis current target value iq _ex calculated by the maximum torque controller 20 can be limited by the limiter 40 to determine the q-axis current command value iq _c. At the same time, the d-axis current command value id _c of the current vector can be determined as it is from the d-axis current target value id _ex calculated by the maximum torque controller 20. As a result, the control process for calculating the current vector (command value) can be further simplified, and the calculation load can be further reduced.

(Example)
Next, the result of the verification test (Examples 1 to 3) performed to confirm the stability of the current vector control of the motor control device 100 according to the first embodiment will be described.

Example 1
In Figure 7, from a state of constant speed drive at a speed ω2 at the point of FIG. 5 P2 (maximum torque control region) shows the result of gradually changing the speed command omega _c. As described above, the point P2 is in a position balanced with the load torque line CT and is the limit point of the maximum torque control at the speed ω2. Note that, unlike the simulation, there is a load fluctuation in an actual test, and thus the load torque line CT has a fluctuation width.

Voltage limiting lines VL (ω11~ω17) is when the speed command omega _c increased stepwise, the voltage limit line corresponding to the respective speeds are lowered with the speed increase. In the test results shown in FIG. 7, the current vector deviates from the maximum torque control line MT as the speed increases, and moves along the load torque line CT. That is, the current vector convergence points P11 to P17 are moved along the load torque line CT due to the decrease of the q-axis current limit value iq _lim accompanying the decrease of the voltage limit line VL. Thus, even in the case of changing the speed command omega _c, changing the convergence point P11~P17 following the change of the voltage limit line VL (ω11~ω17), that has achieved a stable speed control Was confirmed.

(Example 2)
FIG. 8 shows a result of increasing the load torque stepwise from the point P21 on the maximum torque control region. The load torque lines CT21 to CT26 are load torque lines (representative values) corresponding to the respective load torques when the load torque is increased stepwise. The speed command ω _c is constant (ω 21), and the voltage limit line corresponding to the speed command ω _c is VL (ω 21). In the test result of FIG. 8, the current vector moves along the voltage limit line VL corresponding to the fluctuation of the load torque. Thus, it was confirmed that stable control is possible even with respect to changes in load torque in actual use conditions.

(Example 3)
FIG. 9 shows the result of gradually reducing the power supply voltage of the inverter 3. Even if the speed ω is constant, the voltage limit line VL (VL31 to VL36) decreases as the power supply voltage decreases. On the other hand, in the test result of FIG. 9, the current vector follows the fluctuation of the voltage limit line VL as the power supply voltage decreases, and moves along the load torque line CT (representative value). Since the current vector moves along the load torque line CT, the torque generated by the motor 2 and the load torque are in a substantially balanced state, and the speed change is suppressed. Thus, it was confirmed that stable speed control is possible even when the power supply voltage fluctuates in the actual use state.

(Second Embodiment)
Next, a motor control device 200 according to a second embodiment of the present invention will be described with reference to FIGS. 2, 3 and 10. In the second embodiment, unlike the first embodiment in which the q-axis limit control unit 70 that controls the q-axis current limit value using the comparator 71, the UD counter 72, and the ratio reference value LRR is provided, the q-axis limit A configuration in which the control unit is simplified will be described.

  As shown in FIG. 10, the q-axis limit control unit 170 of the motor control device 200 according to the second embodiment mainly includes a PI controller 171. The configuration of the motor control device 200 other than the q-axis limit control unit 170 is the same as that of the first embodiment, and the same reference numerals as those of the first embodiment are used and description thereof is omitted. The q-axis limit control unit 170 corresponds to “q-axis limit value control means” and “q-axis limit response adjusting means” in the claims.

The q-axis limit control unit 170 uses the comparator 71 and the UD counter 72 (see FIG. 2) to convert the duty ratio _Dreal , which is an analog value, into a digital value (counter value D _fb ). Differently, it is configured to handle analog values as they are. That is, the q-axis limit control unit 170 takes the difference (D _crit −D _real ) between the duty ratio D _real and the duty ratio reference value D _crit and outputs the difference to the PI controller 171. Then, outputs of P (proportional) and I (integral) control by the PI controller 171 are output (set) to the limiter 40 as the q-axis current limit value iq _lim .

As shown in the period T5 and T6 in FIG. 3, the duty ratio _{D real} with the speed increase is greater than the duty ratio reference value _{D crit,} negative difference is inputted to a PI controller 171, q-axis current limit The value iq _lim decreases. As a result, the q-axis current target value iq _ex from the maximum torque controller 20 is limited by the limiter 40.

On the other hand, as shown in the periods T1 and T2 in FIG. 3, when the duty ratio D _real falls below the duty ratio reference value D _crit due to the speed reduction, a positive difference is input to the PI controller 171 and the q-axis current The limit value iq _lim increases. Thereby, the restriction by the limiter 40 is released (relaxed), and the q-axis current target value iq _ex from the maximum torque controller 20 is output as it is as the q-axis current command value iq _c . As a result, the speed of the motor 2 increases, and the limiter 40 again works.

As a result, the operation of the PI controller 171 adjusts the q-axis current limit value iq _lim so that the duty ratio D _real becomes the duty ratio reference value D _crit, and the duty ratio D _real is set inside the voltage limit line VL. The current vector is moved to the convergence point so as to converge to the duty ratio reference value D _crit .

In the first embodiment, the difference between the counter value D _fb and the ratio reference value LRR is input to the integrator 73, so that the response of the q-axis current limit value iq _lim according to the magnitude of the ratio reference value LRR. In this second embodiment, the response of the q-axis current limit value iq _lim can also be adjusted by adjusting the gain of the PI controller 171.

In the second embodiment, as described above, the gate signal converter unit 60 for calculating the duty ratio _{D real,} using the duty ratio _{D real,} and q-axis limiting control unit 170 for controlling the q-axis current limit value _{iq lim} Since the current vector control can be performed based on the duty ratio D _real of the output to the inverter 3, an external device (voltage sensor) for acquiring the power supply voltage supplied to the inverter 3 is provided. There is no need. Then, by controlling the q-axis current limit value _{iq lim} with the duty ratio _{D real,} it is possible to apply a limitation to increase in q-axis current target value _{iq ex} maximum torque controller 20. Thereby, when the current vector is controlled in the vicinity of the voltage limit line VL, even if the d-axis current command value id _c increases, the increase in the q-axis current command value iq _c can be limited. Current vector control can be performed on the limit line VL. As described above, according to the motor control device 200 according to the second embodiment, stable current vector control can be performed without requiring addition of an external device.

Further, in the second embodiment, unlike the first embodiment, the q-axis current command value iq _c is controlled by treating the duty ratio D _real as an analog value without providing the comparator 71 and the UD counter 72. be able to. Thereby, the configuration and control processing of the motor control device 200 can be simplified.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the first and second embodiments, the example in which the control device 100 and the inverter 3 are separately provided has been shown, but the present invention is not limited to this. In this invention, it is good also as a motor control apparatus incorporating an inverter circuit.

  In the first and second embodiments, an example of performing drive control of an IPM motor (IPMSM) having an embedded magnet structure has been described, but the present invention is not limited to this. In this invention, you may comprise so that drive control of motors (salient pole machine) other than an IPM motor (IPMSM) may be performed.

  Moreover, although the example which comprised the motor control apparatus by FPGA was shown in the said 1st and 2nd embodiment, this invention is not limited to this. In the present invention, for example, a control process by the control block shown in FIG. 2 (FIG. 10) may be realized by a configuration in which a microcomputer or CPU executes a predetermined program (software).

  Moreover, although the said 1st and 2nd embodiment demonstrated the motor control apparatus which performs maximum torque control and field-weakening control, this invention is not limited to this. In the present invention, in addition to the maximum torque control and the field weakening control, a control method other than the maximum torque control and the field weakening control may be executed.

In the first embodiment, the output D _{fb of the} UD counter is set to 0 to 100 and the difference from the ratio reference value LRR is input to the integrator. However, the present invention is not limited to this. I can't. For example, the output D _{fb of the} UD counter may be set to −50 to +50, and a value obtained by multiplying this by an appropriate coefficient may be input to the integrator.

2 Motor 3 Inverter 20 Maximum torque controller (Maximum torque control means)
40 limiter (q-axis current limiting means)
60 Gate signal conversion unit 70, 170 q-axis limit control unit 70 (q-axis limit value control means, q-axis limit response adjusting means)
100 motor controller D _real duty ratio D _crit duty ratio reference value id _c d-axis current command value iq _c q-axis current command value id _ex d-axis current target value iq _ex q-axis current target value iq _lim q-axis current limit value LRR Ratio standard value (comparison result standard value)

Claims (7)

A motor controller for controlling torque and speed of a motor including a rotor having saliency,
Means for calculating a duty ratio by PWM control output to the inverter;
A motor control device comprising q-axis limit value control means for controlling a q-axis current limit value based on a comparison result between the duty ratio and a duty ratio reference value.   The motor control device according to claim 1, further comprising q-axis limit responsiveness adjusting means for adjusting responsiveness of the q-axis current limit value.   The q-axis limit responsiveness adjusting means adjusts the responsiveness of the q-axis current limit value based on a difference between the comparison result between the duty ratio and the duty ratio reference value and the comparison result reference value. The motor control device according to claim 2, which is configured.   The q-axis limit responsiveness adjusting means includes a ratio as a result of comparison between the duty ratio and the duty ratio reference value, a ratio at which the duty ratio is equal to or greater than the duty ratio reference value, and a ratio as the comparison result reference value. The motor control device according to claim 3, wherein the motor control device is configured to adjust the responsiveness of the q-axis current limit value based on a difference from the reference value. A maximum torque control means for calculating a d-axis current target value and a q-axis current target value based on the maximum torque control;
The q-axis current target value calculated by the maximum torque control means is limited by the q-axis current limit value controlled by the q-axis limit value control means, so that the current vector command value is weakened from the maximum torque control region. The motor control device according to claim 1, wherein the motor control device transitions to a magnetic region.   6. The motor control device according to claim 5, further comprising q-axis current limiting means for limiting a q-axis current target value in accordance with a q-axis current limit value controlled by the q-axis limit value control means. In the field weakening region,
A d-axis current command value of a current vector is determined from a d-axis current target value calculated by the maximum torque control means independently of the q-axis current target value limited by the q-axis current limit value;
The motor control device according to claim 5 or 6, wherein a q-axis current command value of a current vector is determined from the q-axis current target value limited by the q-axis current limit value.

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