JP2018121421A - Control apparatus of synchronous motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control apparatus of a synchronous motor capable of suppressing a fluctuation in a control amount when performing a power swing determination.SOLUTION: A control apparatus 30 comprises: a state amount calculation part that calculates a control system state amount that is a value used for controlling a control amount of a motor to its command value ω*, and is for controlling the control amount; an operation part that operates a power conversion circuit electrically connected to the motor on the basis of the state amount calculated by the state amount calculation part; a changing part that changes the state amount; and a determination part 40 that determines whether power swing occurs in the motor on the basis of a current that flows in the motor when changing the state amount.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a control device for a synchronous motor.

  As this type of control device, as seen in Patent Document 1, the synchronous motor is stepped out based on the q-axis current component flowing in the synchronous motor when the operation frequency command that is the command value is changed. What determines whether or not there is known.

JP 2006-149122 A

  Since the control device described in Patent Document 1 changes the operation frequency command for step-out determination, there may be a problem that the rotational speed of the synchronous motor varies greatly. Note that even if a control amount other than the operating frequency is used as the control amount of the synchronous motor, the problem that the control amount varies greatly as the command value of the control amount is changed for step-out determination is the same. Can occur.

  The main object of the present invention is to provide a control device for a synchronous motor that can suppress fluctuations in a control amount when performing step-out determination.

  The present invention is applied to a system including a synchronous motor (10) and a power conversion circuit (20) electrically connected to the synchronous motor, and controls the control amount of the synchronous motor to its command value. And a state quantity calculation unit (30b; 30p; 30d; 30u; 31a) that calculates a state quantity of a control system that controls the control quantity, and the state calculated by the state quantity calculation unit Based on the amount, an operation unit (30q, 30r) for operating the power conversion circuit, and a change unit (30k, 41; 30t, 42; 30e, 43) for changing the state amount calculated by the state amount calculation unit. 30w, 44; 31c, 45) and whether or not the synchronous motor has stepped out based on the current flowing through the synchronous motor when the state quantity is changed by the changing unit. Comprises determining unit to (40), the.

  In order to control the control amount of the synchronous motor to the command value, the present invention includes a state amount calculation unit and an operation unit. Here, when the state quantity calculated by the state quantity calculation unit is changed, the change mode of the current flowing through the motor differs depending on whether or not the motor has stepped out. For this reason, the current flowing through the motor when the state quantity is changed can be used to determine whether or not step-out has occurred. Therefore, the present invention includes a change unit and a determination unit. Thereby, it can be determined whether a step-out has occurred.

  Furthermore, in the present invention, a state quantity is used instead of a command value as a parameter to be changed for step-out determination. For this reason, the fluctuation | variation of the controlled variable of a motor can be suppressed compared with the structure which changes a command value for a step-out determination.

1 is an overall configuration diagram of a motor control system according to a first embodiment. The block diagram which shows each process which a control apparatus performs. The figure which shows (alpha) (beta) coordinate system, (gamma) delta coordinate system, MY coordinate system, etc. FIG. The figure which shows the relationship between the presence or absence of a step-out, and the voltage and current vector in a dq coordinate system. The figure which shows the relationship between the presence or absence of a step-out, and the voltage and current vector in a γδ coordinate system. The time chart which shows the superimposition aspect of amplitude disturbance value VZ. The flowchart which shows the procedure of step-out determination processing. The figure which shows an example of the setting method of the threshold value for step-out determination. The flowchart which shows the procedure of the step-out determination process which concerns on 2nd Embodiment. The block diagram which shows each process which the control apparatus which concerns on 3rd Embodiment performs. The figure which shows the relationship between the presence or absence of a step-out, and the voltage and current vector in a dq coordinate system. The figure which shows the relationship between the presence or absence of a step-out, and the voltage and current vector in a γδ coordinate system. The figure which shows an example of the setting method of the threshold value for step-out determination. The time chart which shows transition of the rotational speed and phase current of a motor. The block diagram which shows each process which the control apparatus which concerns on 4th Embodiment performs. The time chart which shows an example of a step-out determination process. The block diagram which shows each process which the control apparatus which concerns on 5th Embodiment performs. The block diagram which shows each process which the control apparatus which concerns on 6th Embodiment performs. The flowchart which shows the procedure of the step-out determination process which concerns on 7th Embodiment. The flowchart which shows the procedure of the step-out determination process which concerns on 8th Embodiment. The flowchart which shows the procedure of the step-out determination process which concerns on 9th Embodiment. The figure which shows the setting method of a determination threshold value. The figure explaining the step-out determination process which concerns on other embodiment. The figure explaining the step-out determination process which concerns on other embodiment. The figure explaining the step-out determination process which concerns on other embodiment. The figure explaining the step-out determination process which concerns on other embodiment. The figure explaining the step-out determination process which concerns on other embodiment.

(First embodiment)
Hereinafter, a first embodiment of a control device according to the present invention will be described with reference to the drawings. In the present embodiment, the synchronous motor to be controlled by the control device is used as, for example, an in-vehicle electric fan motor.

  As shown in FIG. 1, the control system includes a motor 10, an inverter 20 as a power conversion circuit, and a control device 30 that controls the motor 10. As the motor 10, for example, an SPMSM that is a non-salient pole machine or an IPMSM that is a salient pole machine may be used.

  The motor 10 is connected to a battery 21 as a DC power source via an inverter 20. A smoothing capacitor 22 is provided between the battery 21 and the inverter 20.

  The inverter 20 includes three series-connected bodies of upper arm switches Sup, Svp, Swp and lower arm switches Sun, Svn, Swn. A first end of the U-phase winding of the motor 10 is connected to a connection point between the U-phase upper and lower arm switches Sup and Sun. A first end of the V-phase winding of the motor 10 is connected to a connection point between the V-phase upper and lower arm switches Svp and Svn. A first end of the W-phase winding of the motor 10 is connected to a connection point between the W-phase upper and lower arm switches Swp and Swn. The second ends of the U, V, and W phase windings are connected at a neutral point.

  In this embodiment, a voltage-controlled semiconductor switching element is used as each switch Sup, Sun, Svp, Svn, Swp, Swn, and more specifically, an IGBT is used. Each freewheel diode Dup, Dun, Dvp, Dvn, Dwp, Dwn is connected in antiparallel to each switch Sup, Sun, Svp, Svn, Swp, Swn. The switches Sup, Sun, Svp, Svn, Swp, and Swn are not limited to IGBTs, and for example, N-channel MOSFETs may be used.

  The control system includes a phase current detection unit 23 and a voltage detection unit 24. The phase current detection unit 23 detects a current for at least two phases among the phase currents flowing through the motor 10. The voltage detection unit 24 detects the DC voltage output from the battery 21 as the power supply voltage VINV of the inverter 20.

  The control device 30 is mainly composed of a microcomputer, and operates the inverter 20 to control the control amount of the motor 10 to the command value. In the present embodiment, the control amount is the rotational speed, and the command value of the control amount is the speed command value ω *.

  The control device 30 controls each of the switches Sup, Sun, Svp, Svn, Swp, and Swn constituting the inverter 20 based on the detection values of the various detectors to turn on and off the switches Sup, Sun, Svp, Svn, Swp, and Swn. , Gwp, gwn. The control device 30 outputs the generated operation signals gup, gun, gvp, gvn, gwp, gwn to each drive circuit Dr corresponding to each switch. Here, the upper arm side operation signals gup, gvp, gwp and the corresponding lower arm side operation signals gun, gvn, gwn are complementary to each other. That is, the upper arm switch and the corresponding lower arm switch are alternately turned on.

  Next, the rotational speed control of the motor 10 executed by the control device 30 will be described with reference to FIG. FIG. 2 is a block diagram showing a control system for controlling the electrical angular speed of the motor 10 to the speed command value ω *. The rotational speed control according to the present embodiment is position sensorless control that does not use a detection value of an angle detector such as a resolver that directly detects an electrical angle.

  The two-phase conversion unit 30a uses the U-phase currents IU and V in the three-phase fixed coordinate system based on the phase current detected by the phase current detection unit 23 and the electrical angle θv calculated by the phase calculation unit 30p described later. The phase current IV and the W phase current IW are converted into a γ-axis current Iγr and a δ-axis current Iδr in the γδ coordinate system. The electrical angle θv is an angle formed by the α axis and the γ axis of the αβ coordinate system, which is the two-phase fixed coordinate system of the motor 10, as shown in FIG. The δ axis is a coordinate axis extending from the origin O in the direction of the voltage vector Vr applied from the inverter 20 to the motor 10, and the γ axis is a coordinate axis extending from the origin O in a direction orthogonal to the δ axis. The γ axis is an estimated axis of the d axis that extends in the magnetic pole direction of the motor 10. In the present embodiment, the α axis and the U axis of the three-phase fixed coordinate system are matched.

  Returning to the description of FIG. 2, the amplitude FF control unit 30b sets an amplitude command value V * that is a command value of the magnitude of the voltage vector Vr based on the speed command value ω *. Note that the amplitude command value V * may be set based on map information in which the speed command value ω * and the amplitude command value V * are related and the amplitude command value V * is defined, for example. In the present embodiment, the amplitude FF control unit 30b corresponds to a “state quantity calculation unit”.

  Based on the γ-axis current Iγr and the δ-axis current Iδr converted by the two-phase conversion unit 30a, the current amplitude calculation unit 30c calculates a current amplitude Iamp that is a magnitude of a current vector flowing through the motor 10. The γ-axis component of the current amplitude Iamp is the γ-axis current Iγr, and the δ-axis component of the current amplitude Iamp is the δ-axis current Iδr.

  The γ-axis command current calculation unit 30d calculates the γ-axis command current Iγ * based on the speed command value ω * and the current amplitude Iamp calculated by the current amplitude calculation unit 30c. Note that the γ-axis command current Iγ * may be calculated based on map information in which the γ-axis command current Iγ * is defined in association with the speed command value ω * and the current amplitude Iamp, for example.

  The current deviation calculator 30e calculates the γ-axis current deviation ΔIγ by subtracting the γ-axis current Iγr from the γ-axis command current Iγ * calculated by the γ-axis command current calculator 30d.

  The amplitude FB control unit 30f calculates the first amplitude correction value ΔV1 as an operation amount for performing feedback control of the γ-axis current deviation ΔIγ to 0. Note that the feedback control used in the amplitude FB control unit 30f may be proportional integral control, for example.

  The amplitude adding unit 30g adds the first amplitude correction value ΔV1 calculated by the amplitude FB control unit 30f to the amplitude command value V * set by the amplitude FF control unit 30b and outputs the result.

  The voltage gain multiplication unit 30h calculates the second amplitude correction value ΔV2 based on the δ-axis current Iδr and the voltage gain Kvm (> 0). Specifically, the voltage gain multiplication unit 30h calculates the second amplitude correction value ΔV2 by multiplying the change amount of the δ-axis current Iδr by the voltage gain Kvm. The second amplitude correction value ΔV2 is calculated in order to increase the stability of the rotational speed control with respect to the load fluctuation of the motor 10. The change amount of the δ-axis current Iδr is a high-frequency component of the δ-axis current Iδr. The voltage gain multiplication unit 30h may calculate the amount of change in the δ-axis current Iδr by performing high-frequency extraction processing such as high-pass filter processing on the δ-axis current Iδr, for example.

  The amplitude correction unit 30j calculates the corrected amplitude command value Vm by adding the second amplitude correction value ΔV2 calculated by the voltage gain multiplication unit 30h to the output value “V * + ΔV1” of the amplitude addition unit 30g.

  The amplitude disturbance superimposing unit 30k adds an amplitude disturbance value VZ output from the amplitude disturbance unit 41 described later to the corrected amplitude command value Vm calculated by the amplitude correcting unit 30j and outputs the result.

  The speed gain multiplication unit 30m calculates a speed correction value Δω based on the δ-axis current Iδr and the speed gain Kω (> 0). Specifically, the speed gain multiplication unit 30m calculates the speed correction value Δω by multiplying the change amount of the δ-axis current Iδr by the speed gain Kω. Note that the amount of change in the δ-axis current is a high-frequency component of the δ-axis current Iδr. The speed gain multiplication unit 30m may calculate the amount of change in the δ-axis current Iδr by performing high-frequency extraction processing such as high-pass filter processing on the δ-axis current Iδr, for example.

  The speed correction unit 30n calculates the corrected speed value ωc by subtracting the speed correction value Δω calculated by the speed gain multiplication unit 30m from the speed command value ω *.

  The phase calculating unit 30p calculates the electrical angle θv based on the corrected speed value ωc calculated by the speed correcting unit 30n. The phase calculation unit 30p only needs to be configured by an integrator, for example.

  The three-phase conversion unit 30q is configured to output the U, V, and W-phase command voltages in the three-phase fixed coordinate system based on the output value “Vm + VZ” of the amplitude disturbance superimposing unit 30k and the electrical angle θv calculated by the phase calculation unit 30p. VU, VV, and VW are calculated. These command voltages VU, VV, and VW are sinusoidal signals whose phases are shifted from each other by 120 ° in electrical angle. Note that the three-phase conversion unit 30q can grasp the value obtained by adding 90 degrees to the electrical angle θv as the voltage phase that is the phase of the voltage vector Vr.

  Based on the U, V, and W phase command voltages VU, VV, and VW calculated by the three-phase conversion unit 30q and the power supply voltage VINV detected by the voltage detection unit 24, the PWM modulator 30r , Gun, gvp, gvn, gwp, gwn are generated and output to each drive circuit Dr. Specifically, for example, the PWM modulator 30r performs PWM control based on a magnitude comparison between a signal obtained by standardizing U, V, and W phase command voltages VU, VV, and VW with a power supply voltage VINV and a carrier signal such as a triangular wave signal. Thus, the operation signals gup, gun, gvp, gvn, gwp, and gwn may be generated. Incidentally, in the present embodiment, the three-phase conversion unit 30q and the PWM modulator 30r correspond to an “operation unit”.

  The λ setting unit 30s sets the specified angle λ. As shown in FIG. 3B, the specified angle λ is γ and δ axes in the γδ coordinate system when the γ and δ axis currents flowing through the motor 10 change minutely as the speed command value ω * changes slightly. It is defined as the angle formed between the current change vector ΔIr drawn as a current locus and extending from the origin O and the δ axis. In particular, in the present embodiment, the angle formed between the axis passing through the point P1 where the magnitude of the current change vector ΔIr is the maximum in the locus of the γ and δ axis currents and the origin O and the δ axis is defined as the specified angle λ. Yes. In the column of current behavior in FIG. 3B, γ and δ-axis current minute change amounts ΔIγ and ΔIδ when the speed command value ω * slightly changes are shown. Also, the locus of γ and δ-axis currents in the range indicated by the alternate long and short dash line in the column of current behavior in FIG. 3B is shown in the column of the locus of current change vector in FIG.

  As shown in FIGS. 3A and 3B, a coordinate axis deviated from the δ axis by a specified angle λ is defined as the Y axis, and a coordinate axis extending in a direction orthogonal to the Y axis is defined as the M axis.

  The specified angle λ depends on the rotational speed. This is because the specified angle λ is expressed by the following equation (eq1).

上式（ｅｑ１）において、Ｒはモータ１０の巻線抵抗を示し、Ｌはモータ１０の巻線インダクタンスを示し、ωはモータ１０の電気角速度を示す。λ設定部３０ｓは、速度指令値ω＊が低いほど、規定角λを大きく設定する。本実施形態において、λ設定部３０ｓは、０度から９０度までの電気角範囲内において規定角λを設定する。

In the above equation (eq1), R represents the winding resistance of the motor 10, L represents the winding inductance of the motor 10, and ω represents the electrical angular velocity of the motor 10. The λ setting unit 30s sets the specified angle λ larger as the speed command value ω * is lower. In the present embodiment, the λ setting unit 30s sets the specified angle λ within an electrical angle range from 0 degrees to 90 degrees.

  Returning to the description of FIG. 2, the control device 30 includes a determination unit 40 and an amplitude disturbance unit 41. The determination unit 40 performs a step-out determination process for determining whether or not the motor 10 has stepped out. In this embodiment, the step-out is a state in which the rotation of the rotor constituting the motor 10 is stopped and the estimated rotational position (estimated electrical angle) of the motor 10 and the true rotational position (true electrical angle) are shifted. That means. The determination unit 40 instructs the amplitude disturbance unit 41 to output the amplitude disturbance value VZ in order to temporarily change the corrected amplitude command value Vm for the step-out determination. In the present embodiment, the amplitude disturbance unit 41 and the amplitude disturbance superimposing unit 30k correspond to a “change unit”.

  Hereinafter, the step-out determination method according to the present embodiment will be described with reference to FIGS. 4 and 5. 4 shows a voltage vector in the dq axis coordinate system and a current vector flowing through the motor 10, and FIG. 5 shows a voltage vector and a current vector in the γδ coordinate system. 4 and 5, Vm1 represents a voltage vector before superimposing the amplitude disturbance value VZ, and I1 represents a current vector before superimposing the amplitude disturbance value VZ. 4 and 5, Vm2 indicates a voltage vector after the amplitude disturbance value VZ is superimposed, and I2 indicates a current vector after the amplitude disturbance value VZ is superimposed. In the examples shown in FIGS. 4 and 5, the torque acting on the motor 10 is constant.

  As shown in FIG. 4A, in a normal state where no step-out occurs, when the amplitude disturbance value VZ is added to the corrected amplitude command value Vm, the voltage vector moves from Vm1 to Vm2 in the retarded direction. . In this case, the current vector moves in a retarded direction from I1 to I2 along the constant torque line, and the current amplitude of the current vector increases. In the present embodiment, the vector moving in the retard direction means that the vector moves clockwise in the coordinate system, and the vector moves in the advance direction means that the vector moves counterclockwise in the coordinate system. Means that.

  When the voltage vector moves from Vm1 to Vm2 under normal conditions, the Y-axis current, which is the Y-axis component of the current vector, changes in the Y-axis negative direction and the Y-axis current decreases as shown in FIG. . In FIG. 5A, the amount of change in the Y-axis current is indicated by ΔIY.

  On the other hand, when the step-out occurs, the equivalent circuit of the motor 10 is an RL series circuit. In addition, since the rotor is completely stopped, as shown in FIG. 4B, the voltage vector and the current vector are always on the dq coordinate system with the voltage vector advanced by a certain angle with respect to the current vector. It will continue to rotate. When step-out occurs, even if the amplitude disturbance value VZ is superimposed, each of the voltage vector and the current vector only extends on the extension line. For this reason, as shown in FIG. 5B, the Y-axis current changes in the Y-axis positive direction, and the Y-axis current increases.

  Thus, the change direction of the Y-axis current when the amplitude disturbance value VZ is superimposed on the corrected amplitude command value Vm changes between normal and step-out. Therefore, based on this change direction, it can be determined whether or not the motor 10 has stepped out.

  In the present embodiment, as shown in FIG. 6, the amplitude disturbance unit 41 gradually increases the amplitude disturbance value VZ from 0 toward the maximum value Vmax and outputs the value to the amplitude disturbance superimposing unit 30k. In FIG. 6, MODE0 indicates a state in which the amplitude disturbance value VZ is 0, MODE1 indicates a state in which the amplitude disturbance value VZ is gradually increasing, and MODE2 indicates that the amplitude disturbance value VZ has a maximum value Vmax. It shows the state.

  FIG. 7 shows the procedure of the step-out determination process executed by the determination unit 40. This process is repeatedly executed at predetermined intervals, for example.

  In this series of processing, first, in step S10, it is determined whether or not the output mode of the amplitude disturbance value VZ from the amplitude disturbance unit 41 is MODE0.

  If it is determined in step S10 that it is MODE0, the process proceeds to step S11, and the current Y-axis current IYr is based on the specified angle λ set by the λ setting unit 30s and the γ and δ-axis currents Iγr and Iδr. Is calculated. The calculated Y-axis current IYr is held as the Y-axis initial value IYb.

  On the other hand, if it is determined in step S10 that it is not MODE0, the process proceeds to step S12, and it is determined whether or not the output mode of the amplitude disturbance value VZ from the amplitude disturbance unit 41 is MODE1.

  If it is determined in step S12 that it is MODE1, the process proceeds to step S13, and the current Y-axis current IYr is based on the specified angle λ set by the λ setting unit 30s and the γ and δ-axis currents Iγr and Iδr. Is calculated. Then, the Y-axis current change amount ΔIY is calculated by subtracting the Y-axis initial value IYb from the calculated Y-axis current IYr.

  If a negative determination is made in step S12, it is determined that it is MODE2, and the process proceeds to step S14. In step S14, it is determined whether or not the state where the Y-axis current change amount ΔIY calculated in step S13 is equal to or greater than the Y-axis threshold value ΔYth is continued for a predetermined time Tα. As shown in FIG. 8, the Y-axis threshold value ΔYth is set to a value that can determine whether or not the motor 10 has stepped out. FIG. 8 is a diagram showing the results of examining the presence or absence of step-out at each rotation speed and each torque of the motor 10.

  If a negative determination is made in step S14, it is determined that the motor 10 has not stepped out. On the other hand, if an affirmative determination is made in step S14, the process proceeds to step S15, and it is determined that the motor 10 has stepped out. Then, in order to stop the operation of the motor 10, the operation of the inverter 20 is stopped to stop energization of the motor 10.

  Incidentally, if it is determined that the state in which the Y-axis current change amount ΔIY is equal to or greater than the Y-axis threshold value ΔYth has been continued for a predetermined time Tα while the mode is being set to MODE1 without waiting for MODE2. It may be determined that a tone has occurred.

  Moreover, the superimposition timing of the amplitude disturbance value VZ may be once or a plurality of times. Further, the superimposition timing of the amplitude disturbance value VZ may be periodic or aperiodic.

  According to the embodiment described in detail above, the following effects can be obtained.

  The amplitude disturbance value VZ is superimposed on the voltage amplitude which is the magnitude of the voltage vector Vr. According to this configuration, fluctuations in the rotational speed of the motor 10 can be suppressed compared to a configuration in which disturbance is superimposed on the speed command value ω *.

  The determination unit 40 performs a step-out determination process using the fact that the change direction of the Y-axis current IYr differs when the amplitude disturbance value VZ is superimposed depending on whether the step-out has occurred or not. Since it is only necessary to determine that the change direction is different, it is possible to easily and accurately determine whether or not a step-out has occurred.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment. In the present embodiment, it is determined whether or not a step-out has occurred using the Y-axis current IYr instead of the Y-axis current change amount ΔIY.

  FIG. 9 shows a procedure of the step-out determination process according to the present embodiment. This process is repeatedly executed by the determination unit 40 at predetermined intervals, for example.

  In this series of processes, first, in step S20, it is determined whether or not the output mode of the amplitude disturbance value VZ from the amplitude disturbance unit 41 is MODE0.

  If it is determined in step S20 that the mode is MODE0, the series of processes is temporarily terminated. On the other hand, if it is determined in step S20 that it is MODE1 or MODE2, the process proceeds to step S21. In step S21, the current Y-axis current IYr is calculated based on the specified angle λ set by the λ setting unit 30s and the γ and δ-axis currents Iγr and Iδr. Then, it is determined whether or not the state where the calculated Y-axis current IYr is equal to or greater than the current threshold value IYth is continued for a predetermined time Tα. As shown in FIG. 5, the Y-axis current changes in the Y-axis negative direction and the Y-axis current decreases during normal operation, while the Y-axis current decreases in the Y-axis positive direction during step-out. It changes and the Y-axis current increases. Using this fact, in step S21, it is determined whether or not step-out has occurred.

  The current threshold value IYth is set to a value that can determine whether or not the motor 10 has stepped out. The current threshold value IYth may be a fixed value, or may be variably set based on the Y-axis current IYr calculated when MODE0 is set. When a variably set configuration is used, for example, the current threshold IYth may be set larger as the Y-axis current IYr calculated when MODE0 is set.

  If a negative determination is made in step S21, it is determined that no step-out has occurred. On the other hand, when an affirmative determination is made in step S21, the process proceeds to step S15 and it is determined that a step-out has occurred.

  According to the present embodiment described above, the same effects as those of the first embodiment can be obtained.

(Third embodiment)
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the first embodiment. In the present embodiment, as shown in FIG. 10, the phase disturbance value θZ is superimposed on the electrical angle θv calculated by the phase calculation unit 30p for step-out determination. In FIG. 10, the same components as those shown in FIG. 2 are given the same reference numerals for the sake of convenience.

  The phase disturbance superimposing unit 30t adds the phase disturbance value θZ output from the phase disturbance unit 42 to the electrical angle θv calculated by the phase calculating unit 30p, and outputs the result. In the present embodiment, the phase calculation unit 30p corresponds to a “state quantity calculation unit”.

  Incidentally, in the present embodiment, the three-phase conversion unit 30q is based on the output value “θv + θZ” of the phase disturbance superimposing unit 30t and the corrected amplitude command value Vm output from the amplitude correcting unit 30j. Command voltages VU, VV, and VW are calculated. Further, the two-phase conversion unit 30a is based on the phase current detected by the phase current detection unit 23 and the output value “θv + θZ” of the phase disturbance superimposing unit 30t, and U, V, W phase currents IU, IV, IW. Is converted into γ and δ-axis currents Iγr and Iδr.

  The determination unit 40 instructs the phase disturbance unit 42 to output the phase disturbance value θZ in order to temporarily change the voltage phase for the step-out determination. In the present embodiment, the phase disturbance unit 42 and the phase disturbance superimposing unit 30t correspond to a “change unit”.

  Hereinafter, the step-out determination method according to the present embodiment will be described with reference to FIGS. 11 and 12. 11 and 12 correspond to FIGS. 4 and 5 above.

  As shown in FIG. 11A, in a normal state where no step-out occurs, when the phase disturbance value θZ is added to the electrical angle θv, the voltage vector moves from Vm1 to Vm2 in the retard direction. In this case, the current vector moves in a retarded direction from I1 to I2 along the constant torque line, and the current amplitude of the current vector increases. When the voltage vector moves from Vm1 to Vm2 under normal conditions, the Y-axis current changes in the Y-axis negative direction and the Y-axis current decreases as shown in FIG.

  On the other hand, when the step-out occurs, as shown in FIG. 11B, the voltage vector and the current vector are on the dq coordinate system with the voltage vector advanced by a certain angle with respect to the current vector. Will always continue to rotate. When step-out occurs, even if the phase disturbance value θZ is superimposed, the rotation of the rotor is stopped, so that the voltage vector and the current vector do not change as shown in FIG. . For this reason, the Y-axis current does not change before and after the phase disturbance value θZ is superimposed.

  Thus, when the phase disturbance value θZ is superimposed on the electrical angle θv, the Y-axis current changes during normal operation, but the Y-axis current does not change during step-out. For this reason, it is possible to determine whether or not the motor 10 has stepped out based on the Y-axis current.

  In the present embodiment, the phase disturbance unit 42 gradually increases the phase disturbance value θZ from 0 to its maximum value θmax and outputs the phase disturbance value θZ to the phase disturbance superimposing unit 30t, as in the method shown in FIG. . In the present embodiment, MODE0 indicates a state where the phase disturbance value θZ is 0, MODE1 indicates a state where the phase disturbance value θZ is gradually increasing, and MODE2 indicates that the phase disturbance value θZ is the maximum value θmax. The state that has been done.

  The determination unit 40 performs a step-out determination process. In the step-out determination process according to this embodiment, in the process shown in FIG. 7, the process in step S14 is such that the state where the Y-axis current change amount ΔIY is equal to or greater than the threshold value ΔK is continued for a predetermined time Tα. It has been replaced with the process of determining whether or not. As shown in FIG. 13, the threshold value ΔK is set to a value that can determine whether or not the motor 10 has stepped out. FIG. 13 is a diagram showing the results of examining the presence or absence of step-out at each rotation speed and each torque of the motor 10.

  Incidentally, the threshold value ΔK may be a fixed value or a variably set value. Here, when the threshold value ΔK is variably set, for example, it may be variably set based on the rotation speed of the motor 10.

  FIG. 14 shows changes in the Y-axis current IYr and the phase current of the motor 10 when the phase disturbance value θZ is superimposed.

  As shown in FIG. 14A, in the normal state, when the phase disturbance value θZ is superimposed, the phase currents IU, IV, IW change. For this reason, the Y-axis current IYr becomes equal to or greater than the threshold value ΔK. On the other hand, as shown in FIG. 14B, at the time of step-out, the phase currents IU, IV, IW do not change even when the phase disturbance value θZ is superimposed. For this reason, the Y-axis current IYr is less than the threshold value ΔK.

  According to the present embodiment described above, the same effects as those of the first embodiment can be obtained.

(Fourth embodiment)
Hereinafter, the fourth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment. In the present embodiment, as shown in FIG. 15, the disturbance superimposition target for step-out determination is changed to the γ-axis command current Iγ *. In FIG. 15, the same components as those shown in FIG. 2 are given the same reference numerals for the sake of convenience.

  The current deviation calculation unit 30e adds the γ-axis command disturbance value IγZ output from the command value disturbance unit 43 to the γ-axis command current Iγ *. The current deviation calculation unit 30e calculates the γ-axis current deviation ΔIγ by subtracting the γ-axis current Iγr from the added value of the γ-axis command current Iγ * and the γ-axis command disturbance value IγZ.

  In the present embodiment, the three-phase conversion unit 30q is based on the electrical angle θv output from the phase calculation unit 30p and the corrected amplitude command value Vm output from the amplitude correction unit 30j. Command voltages VU, VV, and VW are calculated. In the present embodiment, the γ-axis command current calculation unit 30d corresponds to a “state quantity calculation unit”.

  The determination unit 40 instructs the command value disturbance unit 43 to output the γ-axis command disturbance value IγZ so as to temporarily change the γ-axis command current Iγ * for the step-out determination. In the present embodiment, the command value disturbance unit 43 and the current deviation calculation unit 30e correspond to a “change unit”.

  In the present embodiment, the command value disturbance unit 43 gradually increases the γ-axis command disturbance value IγZ from 0 toward its maximum value γmax, similarly to the method shown in FIG. Output to. In this embodiment, MODE0 indicates a state where the γ-axis command disturbance value IγZ is 0, MODE1 indicates a state where the γ-axis command disturbance value IγZ is gradually increasing, and MODE2 indicates a γ-axis command disturbance value. The state where IγZ is set to the maximum value γmax is shown.

  In the present embodiment, the determination unit 40 performs a step-out determination process similar to the process shown in FIG. Hereinafter, this process will be described with reference to FIG.

  FIG. 16A shows each waveform at normal time when no step-out occurs. In the illustrated example, at time t1, the mode is switched from MODE0 to MODE1, and the γ-axis command disturbance value IγZ starts to increase gradually. As the γ-axis command disturbance value IγZ gradually increases, the Y-axis current IYr decreases.

  Thereafter, at time t2, the mode is switched from MODE1 to MODE2. Here, the determination unit 40 determines that the Y-axis current change amount ΔIY, which is a value obtained by subtracting the Y-axis initial value IYb from the Y-axis current IYr, is less than the Y-axis threshold value ΔYth. For this reason, the determination unit 40 does not determine that a step-out has occurred.

  FIG. 16 (a) shows that MODE3 is executed at times t3 to t4 after MODE2. MODE3 indicates a state where the γ-axis command disturbance value IγZ gradually decreases from the maximum value γmax toward 0.

  Next, FIG. 16B shows each waveform when a step-out occurs. In the illustrated example, at time t1, the mode is switched from MODE0 to MODE1, and the γ-axis command disturbance value IγZ starts to increase gradually. However, since step-out has occurred, the Y-axis current IYr increases as the γ-axis command disturbance value IγZ gradually increases.

  Thereafter, at time t2, the mode is switched from MODE1 to MODE2. Thereafter, the determination unit 40 determines that the state where the Y-axis current change amount ΔIY is equal to or greater than the Y-axis threshold value ΔYth continues for a predetermined time Tα. For this reason, the determination unit 40 determines that a step-out has occurred, and the operation of the motor 10 is stopped.

  According to the present embodiment described above, the same effects as those of the first embodiment can be obtained.

(Fifth embodiment)
Hereinafter, the fifth embodiment will be described with reference to the drawings with a focus on differences from the fourth embodiment. In the present embodiment, as shown in FIG. 17, a Y-axis command current IY * is set instead of the γ-axis command current Iγ *. Then, the disturbance superimposition target for step-out determination is changed from the γ-axis command current Iγ * to the Y-axis command current IY *. In FIG. 17, the same components as those shown in FIG. 15 are given the same reference numerals for the sake of convenience.

  The Y-axis command current calculation unit 30u sets the Y-axis command current IY * based on the speed command value ω * and the current amplitude Iamp calculated by the current amplitude calculation unit 30c. The Y-axis command current IY * may be calculated based on map information in which the Y-axis command current IY * is defined in relation to the speed command value ω * and the current amplitude Iamp, for example. In the present embodiment, the Y-axis command current calculation unit 30u corresponds to a “state quantity calculation unit”.

  The Y-axis current calculation unit 30v calculates the Y-axis current IYr based on the specified angle λ, the γ-axis current Iγr, and the δ-axis current Iδr set by the λ setting unit 30s.

  The Y-axis current deviation calculation unit 30w adds the Y-axis command disturbance value IYZ output from the command value disturbance unit 44 to the Y-axis command current IY *. The Y-axis current deviation calculation unit 30w calculates the Y-axis current deviation ΔIYa by subtracting the Y-axis current IYr from the added value of the Y-axis command current IY * and the Y-axis command disturbance value IYZ.

  The amplitude FB control unit 30x calculates a first amplitude correction value ΔV1 as an operation amount for performing feedback control of the Y-axis current deviation ΔIYa to zero. Note that the feedback control used in the amplitude FB control unit 30x may be proportional integral control, for example.

  The determination unit 40 instructs the command value disturbance unit 44 to output the Y-axis command disturbance value IYZ so as to temporarily change the Y-axis command current IY * for the step-out determination. In the present embodiment, the command value disturbance unit 44 and the Y-axis current deviation calculation unit 30w correspond to a “change unit”.

  In the present embodiment, the command value disturbance unit 44 gradually increases the Y-axis command disturbance value IYZ from 0 toward the maximum value Ymax in the same manner as the method shown in FIG. 6, and calculates the Y-axis current deviation. Output to the unit 30w. In the present embodiment, MODE0 indicates a state in which the Y-axis command disturbance value IYZ is 0, MODE1 indicates a state in which the Y-axis command disturbance value IYZ gradually increases toward the maximum value Ymax, and MODE2 indicates , Y-axis command disturbance value IYZ is the maximum value Ymax, and MODE3 indicates a state where Y-axis command disturbance value IYZ is gradually decreasing toward zero.

  In the present embodiment, the determination unit 40 performs a step-out determination process for determining the presence or absence of step-out based on the γ-axis current Iγr in MODE2. That is, at the normal time when no step-out occurs, the γ-axis current Iγr increases as the Y-axis command disturbance value IYZ is superimposed. On the other hand, when the step-out occurs, the γ-axis current Iγr increases with the superposition of the Y-axis command disturbance value IYZ, and the increase amount is larger than the increase amount at the normal time. Therefore, the γ-axis current Iγr can be used as a parameter for determining whether or not step-out has occurred. For example, the determination unit 40 may determine that a step-out has occurred when it is determined that the γ-axis current Iγr is equal to or greater than a predetermined threshold.

  According to this embodiment described above, the same effect as that of the fourth embodiment can be obtained.

(Sixth embodiment)
Hereinafter, the sixth embodiment will be described with reference to the drawings with a focus on differences from the fourth embodiment. In the present embodiment, as shown in FIG. 18, a command value θa * of the power factor angle is set instead of the γ-axis command current Iγ *. In the present embodiment, the power factor angle is an angle formed by a voltage vector and a current vector. Then, the disturbance superimposition target for step-out determination is changed from the γ-axis command current Iγ * to the command value θa * of the power factor angle. In FIG. 18, the same components as those shown in FIG. 15 are given the same reference numerals for the sake of convenience.

  The command value calculator 31a calculates a power factor angle command value θa * based on the speed command value ω * and the current amplitude Iamp calculated by the current amplitude calculator 30c. The command value θa * may be calculated based on, for example, map information in which the power factor angle command value θa * is defined in relation to the speed command value ω * and the current amplitude Iamp. In the present embodiment, the command value calculation unit 31a corresponds to a “state quantity calculation unit”.

  The power factor angle calculator 31 b calculates the power factor angle θar based on the electrical angle θv calculated by the phase calculator 30 p and the phase current detected by the phase current detector 23.

  The angle deviation calculating unit 31c adds the angle command disturbance value θaZ output from the command value disturbance unit 45 to the command value θa * of the power factor angle. The angle deviation calculation unit 31c calculates the angle deviation Δθ by subtracting the power factor angle θar from the addition value of the power factor angle command value θa * and the angle command disturbance value θaZ.

  The amplitude FB control unit 31d calculates a first amplitude correction value ΔV1 as an operation amount for performing feedback control of the angle deviation Δθ to zero. Note that the feedback control used in the amplitude FB control unit 31d may be proportional integral control, for example.

  The determination unit 40 instructs the command value disturbance unit 45 to output the angle command disturbance value θaZ so as to temporarily change the command value θa * of the power factor angle for the step-out determination. In the present embodiment, the command value disturbance unit 45 and the angle deviation calculation unit 31c correspond to a “change unit”.

  In the present embodiment, the command value disturbance unit 45 gradually increases the angle command disturbance value θaZ from 0 toward its maximum value θmax, and sends it to the angle deviation calculation unit 31c, similarly to the method shown in FIG. Output. In the present embodiment, MODE0 indicates a state where the angle command disturbance value θaZ is 0, MODE1 indicates a state where the angle command disturbance value θaZ gradually increases toward the maximum value θmax, and MODE2 indicates an angle. The command disturbance value θaZ indicates the maximum value θmax, and MODE3 indicates the state where the angle command disturbance value θaZ gradually decreases toward zero.

  In the present embodiment, the determination unit 40 performs a step-out determination process by the method shown in FIG.

  According to this embodiment described above, the same effect as that of the fourth embodiment can be obtained.

(Seventh embodiment)
Hereinafter, the seventh embodiment will be described with reference to the drawings with a focus on differences from the first embodiment. In the present embodiment, the determination unit 40 invalidates the out-of-step determination when it is determined that the predetermined condition is satisfied even if it is determined that the out-of-step occurs in the motor 10. .

  FIG. 19 shows a step-out determination process according to the present embodiment. This process is repeatedly executed at predetermined intervals, for example. In FIG. 19, the same steps as those shown in FIG. 7 are given the same step numbers for the sake of convenience.

  After completion of the process of step S15, the process proceeds to step S30, where the change amount ΔNm of the rotational speed of the motor 10 is equal to or greater than the predetermined speed change amount ΔNth, and the rotational speed Nmr of the motor 10 is equal to or greater than the predetermined speed Nmth. The logical sum of the conditions, the condition that the current change amount ΔIm flowing through the motor 10 is equal to or greater than the predetermined current change amount ΔIth, and the condition that the torque change amount ΔTr of the motor 10 is equal to or greater than the predetermined torque change amount ΔTth is true. It is determined whether or not.

  The rotational speed Nmr may be calculated based on, for example, the speed command value ω *, and the current change amount ΔIm may be calculated based on, for example, the detection value of the phase current detector 23, and the torque change amount ΔTr. May be calculated based on the detection value of the phase current detection unit 23 and the speed command value ω *, for example. Here, as the current change amount ΔIm, for example, a change amount of the δ-axis current may be used.

  If a negative determination is made in step S30, the step-out determination in step S15 is treated as valid. Therefore, the operation of the motor 10 is stopped thereafter. On the other hand, if a positive determination is made in step S30, the process proceeds to step S31, and the step-out determination in step S15 is invalidated. For this reason, the operation of the motor 10 is continued.

  In the present embodiment described above, even if it is determined that a step-out has occurred, the determination result is invalidated. That is, if the operation state of the motor 10 changes during the execution of the step-out determination process, the current flowing through the motor 10 may fluctuate, and the step-out determination accuracy may decrease. In this case, it is possible to prevent the operation of the motor 10 from being erroneously stopped by invalidating the determination result.

(Eighth embodiment)
Hereinafter, the eighth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment. In the present embodiment, the determination unit 40 prohibits execution of the step-out determination process when it is determined that a predetermined condition is satisfied.

  FIG. 20 shows a procedure of the step-out determination process according to this embodiment. This process is repeatedly executed at predetermined intervals, for example. In FIG. 20, the same steps as those shown in FIG. 7 are given the same step numbers for the sake of convenience.

  In this series of processing, first, in step S40, the condition that the amount of change ΔNm in the rotational speed of the motor 10 is equal to or greater than the predetermined amount of change ΔNth, the condition that the rotational speed Nmr of the motor 10 is equal to or greater than the predetermined speed Nmth, Whether the logical sum of the condition that the current change amount ΔIm flowing through the motor 10 is equal to or greater than the predetermined current change amount ΔIth and the condition that the torque change amount ΔTr of the motor 10 is equal to or greater than the predetermined torque change amount ΔTth is true. Determine whether.

  If a negative determination is made in step S40, execution of the step-out determination process is permitted, and the process proceeds to step S10. On the other hand, if a positive determination is made in step S40, the process proceeds to step S41, and execution of the step-out determination process is prohibited.

  According to the present embodiment described above, the step-out determination process is prohibited in a situation where the step-out determination accuracy decreases. For this reason, it is possible to reduce the processing load of the control device 30 while suppressing erroneous determination that the step-out has occurred although no step-out has occurred.

(Ninth embodiment)
Hereinafter, the ninth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment. In the present embodiment, the determination unit 40 performs a step-out determination process based on the voltage amplitude described in JP 2010-213518 A prior to the step-out determination process described in the first embodiment.

  FIG. 21 shows a step-out determination process according to the present embodiment. This process is repeatedly executed at predetermined intervals, for example. In FIG. 21, the same steps as those shown in FIG. 7 are given the same step numbers for the sake of convenience.

  In this series of processing, first, in step S50, a corrected amplitude command value Vm is acquired. Then, it is determined whether or not the acquired corrected amplitude command value Vm is equal to or less than the determination threshold value Vjth. This process is a process for determining whether or not a step-out has occurred. In the present embodiment, as indicated by a solid line in FIG. 22, the determination threshold value Vjth is set larger as the speed command value ω * is higher.

  If a negative determination is made in step S50, it is determined that a step-out has not occurred, and this series of processes is temporarily terminated. On the other hand, if an affirmative determination is made in step S50, the process proceeds to step S51, where it is determined that a step-out has occurred. Then, it progresses to step S10. And when the process of step S11, S13 is completed, it transfers to step S10. In the present embodiment, the processes in steps S50 and S51 correspond to a “first determination unit”.

  If a positive determination is made in step S14, the process proceeds to step S52, and the determination result in step S51 is maintained. Therefore, the operation of the motor 10 is stopped thereafter. In the present embodiment, the processes in steps S10 to S14 correspond to a “second determination unit”.

  On the other hand, if a negative determination is made in step S14, the process proceeds to step S53, and the determination result in step S51 is canceled. For this reason, the operation of the motor 10 is continued.

  In step S53, as shown by a broken line in FIG. 22, a process for reducing the determination threshold value Vjth is performed. Thereby, when the process of step S50 is performed after that, the lowered determination threshold value Vjth is used. In the present embodiment, the process of step S53 corresponds to a “threshold reduction unit”.

  In the present embodiment, step-out determination processing in step S50 is first performed. This is because the process of step S50 does not superimpose disturbance, so that the efficiency of the motor 10 is not lowered compared to the step-out determination process of steps S10 to S14 where the disturbance is superimposed. However, in the process of step S50, the out-of-step determination accuracy tends to decrease in the low rotation region of the motor 10. This is because the difference between the normal correction amplitude command value Vm and the step-out correction amplitude command value Vm tends to be small in the low rotation region. On the other hand, the out-of-step determination process in steps S10 to S14 is a process in which disturbance is superimposed, and therefore, the out-of-step determination accuracy is higher than that in step S50.

  Therefore, in this embodiment, even when it is determined that step out has occurred in the process of step S50, step out occurs when it is determined in step S14 that no step out has occurred. And the determination threshold value Vjth is lowered. For this reason, the step-out determination accuracy by the process of step S50 in the low rotation region can be increased thereafter.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  In the first embodiment, the Y-axis current IYr is used as a parameter for step-out determination, but the present invention is not limited to this. For example, as shown in FIGS. 23A to 23E, the M-axis current IMr and δ-axis current Iδr, which are the M-axis components of the current vector, the phase current flowing through the motor 10, and the α-axis component of the current vector, α The axis current Iα, the β-axis current Iβ that is the β-axis component of the current vector, or the current amplitude Iamp may be used as a determination parameter. These parameters increase with the superposition of the amplitude disturbance value VZ under normal conditions. On the other hand, at the time of step-out, these parameters increase with the superposition of the amplitude disturbance value VZ, and the increase amount is larger than the increase amount at the normal time. For this reason, the determination part 40 should just perform a step-out determination process by the method similar to the determination method demonstrated in the said 5th Embodiment. Note that the M-axis current IMr may be calculated based on the specified angle λ and the γ and δ-axis currents Iγr and Iδr.

  In the third embodiment, the Y-axis current IYr is used as a step-out determination parameter, but the present invention is not limited to this. For example, as shown in FIGS. 24A to 24E, the M-axis current IMr, the δ-axis current Iδr, the phase current flowing through the motor 10, the α-axis current Iα, the β-axis current Iβ, or the current amplitude Iamp is for determination. It may be used as a parameter. These parameters increase with the superposition of the phase disturbance value θZ under normal conditions. On the other hand, these parameters do not change during step-out even when the phase disturbance value θZ is superimposed. For this reason, the determination part 40 should just perform a step-out determination process by the method similar to the determination method demonstrated in the said 3rd Embodiment.

  In the fourth embodiment, the Y-axis current IYr is used as a parameter for step-out determination, but the present invention is not limited to this. For example, as shown in FIGS. 25A to 25E, the M-axis current IMr, the δ-axis current Iδr, the phase current flowing through the motor 10, the α-axis current Iα, the β-axis current Iβ, or the current amplitude Iamp is for determination. It may be used as a parameter. Under normal conditions, these parameters increase with the superposition of the γ-axis command disturbance value IγZ. On the other hand, at the time of step-out, these parameters increase with the superposition of the γ-axis command disturbance value IγZ, and the increase amount is larger than the increase amount at the normal time. For this reason, the determination part 40 should just perform a step-out determination process by the method similar to the determination method demonstrated in the said 5th Embodiment.

  In the fifth embodiment, the γ-axis current Iγr is used as a parameter for step-out determination, but the present invention is not limited to this. For example, as shown in FIGS. 26A to 26E, the M-axis current IMr, the δ-axis current Iδr, the phase current flowing through the motor 10, the α-axis current Iα, the β-axis current Iβ, or the current amplitude Iamp is for determination. It may be used as a parameter. These parameters increase with the superposition of the Y-axis command disturbance value IYZ under normal conditions. On the other hand, at the time of step-out, these parameters increase with the superposition of the Y-axis command disturbance value IYZ, and the increase amount is larger than the increase amount at the normal time. For this reason, the determination part 40 should just perform a step-out determination process by the method similar to the determination method demonstrated in the said 5th Embodiment.

  In the fifth embodiment, the disturbance superimposition target is the Y-axis command current IY *, but is not limited thereto. For example, as shown in FIG. 2 of the first embodiment, the disturbance superimposition target may be the corrected amplitude command value Vm. In this case, as shown in FIGS. 26 (f) to (k), as parameters for step-out determination, the γ-axis current Iγr, the M-axis current IMr, the δ-axis current Iδr, the phase current flowing through the motor 10, and the α-axis current Iα, β-axis current Iβ, or current amplitude Iamp may be used. These parameters increase with the superposition of the amplitude disturbance value VZ under normal conditions. On the other hand, at the time of step-out, these parameters increase with the superposition of the amplitude disturbance value VZ, and the increase amount is larger than the increase amount at the normal time. For this reason, the determination part 40 should just perform a step-out determination process by the method similar to the determination method demonstrated in the said 5th Embodiment.

  In the fifth embodiment, the disturbance superimposition target may be the electrical angle θv as shown in FIG. 10 of the third embodiment. In this case, as shown in FIGS. 26 (l) to (q), as parameters for step-out determination, the γ-axis current Iγr, the M-axis current IMr, the δ-axis current Iδr, the phase current flowing through the motor 10, and the α-axis current Iα, β-axis current Iβ, or current amplitude Iamp may be used. These parameters increase with the superposition of the phase disturbance value θZ under normal conditions. On the other hand, these parameters do not change during step-out even if the phase disturbance value θZ is superimposed. For this reason, the determination part 40 should just perform a step-out determination process by the method similar to the determination method demonstrated in the said 3rd Embodiment.

  In the sixth embodiment, the Y-axis current IYr is used as a parameter for step-out determination, but the present invention is not limited to this. For example, as shown in FIGS. 27A to 27F, an M-axis current IMr, a γ-axis current Iγr, a δ-axis current Iδr, a phase current flowing through the motor 10, an α-axis current Iα, a β-axis current Iβ, or a current The amplitude Iamp may be used as a determination parameter. These parameters increase with the superposition of the angle command disturbance value θaZ under normal conditions. On the other hand, at the time of step-out, these parameters increase with the superposition of the angle command disturbance value θaZ, and the increase amount is larger than the increase amount at the normal time. For this reason, the determination part 40 should just perform a step-out determination process by the method similar to the determination method demonstrated in the said 5th Embodiment.

  In the sixth embodiment, the disturbance superimposition target is the command value θa * for the power factor angle, but the present invention is not limited to this. For example, as shown in FIG. 2 of the first embodiment, the disturbance superimposition target may be the corrected amplitude command value Vm. In this case, for example, as shown in FIG. 27G, a Y-axis current IYr may be used as a parameter for step-out determination. Further, for example, as shown in FIGS. 27 (h) to 27 (m), as parameters for step-out determination, an M-axis current IMr, a γ-axis current Iγr, a δ-axis current Iδr, a phase current flowing through the motor 10, and an α-axis current Iα, β-axis current Iβ, or current amplitude Iamp may be used. In this case, the determination unit 40 may perform the step-out determination process by the same method as the determination method described in the fifth embodiment.

  In the sixth embodiment, the disturbance superimposition target may be the electrical angle θv as shown in FIG. 10 of the third embodiment. In this case, as shown in FIGS. 27 (n) to 27 (t), the parameters for determining the step-out include the Y-axis current IYr, the M-axis current IMr, the γ-axis current Iγr, the δ-axis current Iδr, and the phase flowing through the motor 10. A current, an α-axis current Iα, a β-axis current Iβ, or a current amplitude Iamp may be used. In this case, the determination unit 40 may perform the step-out determination process by a method similar to the determination method described in the third embodiment.

  In the first embodiment, the average value of the plurality of Y-axis currents IYr calculated when MODE0 is set may be held as the Y-axis initial value IYb.

  In FIG. 6 of the first embodiment, MODE 1 may be eliminated, and the amplitude disturbance value VZ may be changed stepwise from 0 to the maximum value Vmax. Note that the disturbances in the embodiments other than the first embodiment may be changed stepwise.

  The process in step S14 shown in FIG. 7 may be replaced with a process for determining whether or not the Y-axis current change amount ΔIY is equal to or greater than the Y-axis threshold value ΔYth. Further, the process of step S21 illustrated in FIG. 9 may be replaced with a process of determining whether or not the Y-axis current IYr is equal to or greater than the current threshold value IYth.

  In the first embodiment, a value obtained by performing high-frequency extraction processing such as high-pass filter processing on the Y-axis current IYr may be used as a parameter used for step-out determination.

  The Y-axis threshold value ΔYth shown in FIG. 7 of the first embodiment or the current threshold value IYth shown in FIG. 9 of the second embodiment is variably set based on the operating state other than the rotational speed of the motor 10. Also good. Here, examples of the operation state other than the rotation speed include the torque of the motor 10 and the temperature of the motor 10.

  The four conditions in step S30 of FIG. 19 in the seventh embodiment are the condition that the change amount ΔNm of the rotation speed of the motor 10 is equal to or greater than the predetermined change amount ΔNth, and the rotation speed Nmr of the motor 10 is the predetermined speed Nmth. Of the above conditions, the condition that the current change amount ΔIm flowing through the motor 10 is equal to or greater than the predetermined current change amount ΔIth, and the condition that the torque change amount ΔTr of the motor 10 is equal to or greater than the predetermined torque change amount ΔTth. , And may be reduced to at least one condition. The same applies to step S40 in FIG. 20 of the eighth embodiment.

  In the configuration shown in FIG. 2 of the first embodiment, the speed correction unit 30n and the speed gain multiplication unit 30m are not essential. Further, in the configuration shown in FIG. 2, the amplitude correction unit 30j and the voltage gain multiplication unit 30h are not essential.

  -You may remove the voltage detection part 24 from the structure shown in FIG. 1 of the said 1st Embodiment. This configuration is employed when, for example, the amount of change in the output voltage of the battery 21 is small and the power supply voltage VINV is set to a fixed value.

  The control amount of the motor is not limited to the rotation speed, and may be torque, for example.

  -The motor is not limited to a three-phase motor but may be other than a three-phase motor. Further, the motor is not limited to an auxiliary motor such as an electric fan, but may be a motor as an in-vehicle main machine mounted on an electric vehicle or a hybrid vehicle, for example.

  DESCRIPTION OF SYMBOLS 10 ... Motor, 20 ... Inverter, 30 ... Control apparatus.

Claims (17)

Applied to a system comprising a synchronous motor (10) and a power conversion circuit (20) electrically connected to the synchronous motor;
A state quantity calculation unit (30b; 30p; 30d; 30u; 31a) which is a value used to control the control amount of the synchronous motor to its command value and calculates a state quantity of a control system which controls the control amount. )When,
An operation unit (30q, 30r) for operating the power conversion circuit based on the state quantity calculated by the state quantity calculation unit;
A changing unit (30k, 41; 30t, 42; 30e, 43; 30w, 44; 31c, 45) for changing the state quantity calculated by the state quantity calculating unit;
A determination unit (40) that determines whether or not a step-out has occurred in the synchronous motor based on a current flowing through the synchronous motor when the state quantity is changed by the changing unit. Control device.   The state quantity calculation unit (30b; 30p) is an operation quantity for controlling the control quantity to the command value as the state quantity, and is a voltage amplitude that is a magnitude of a voltage vector applied to the synchronous motor. The synchronous motor control device according to claim 1, wherein   The state quantity calculation unit (30t, 42) is an operation quantity for controlling the control quantity to the command value as the state quantity, and a voltage phase which is a phase of a voltage vector applied to the synchronous motor, The synchronous motor control device according to claim 1, wherein the correlation value of the voltage phase is calculated.   The determination unit includes a current amplitude which is a magnitude of a current vector flowing through the synchronous motor, a phase current flowing through the synchronous motor, a current in a rotating coordinate system flowing through the synchronous motor, or a current in a fixed coordinate system flowing through the synchronous motor. 4. The synchronous motor control device according to claim 2, wherein whether or not the step-out has occurred is determined based on the control. A coordinate axis extending in the direction of the voltage vector is defined as a δ axis, a coordinate axis extending in a direction orthogonal to the δ axis is defined as a γ axis, a coordinate axis deviating from the δ axis by a specified angle (λ) is defined as a Y axis, and Y A coordinate axis extending in a direction perpendicular to the axis is defined as the M axis,
The determination unit includes a Y-axis component of a current flowing through the synchronous motor, an M-axis component of a current flowing through the synchronous motor, a γ-axis component of a current flowing through the synchronous motor, or a δ-axis component of a current flowing through the synchronous motor. The synchronous motor control device according to claim 4, wherein it is used as a current in the rotating coordinate system to determine whether or not the step-out occurs. The determination unit determines whether or not the step-out has occurred using the Y-axis component of the current flowing through the synchronous motor or the M-axis component of the current flowing through the synchronous motor as a current in the rotating coordinate system. ,
6. The synchronous motor control device according to claim 5, wherein the specified angle is set within a range of 0 degrees to 90 degrees.   The synchronous motor control device according to claim 1, wherein the changing unit changes the state quantity stepwise or gradually.   The synchronous motor control device according to any one of claims 1 to 7, wherein the determination unit determines whether or not the step-out occurs based on a high-frequency component of a current flowing through the synchronous motor.   When the determination unit determines that the difference between the state quantity before changing the state quantity by the changing unit and the state quantity after changing the state quantity by the changing unit is greater than or equal to a threshold value The control device for a synchronous motor according to claim 1, wherein it is determined that the step-out has occurred.   The determination unit is in a state where a difference between the state quantity before changing the state quantity by the changing unit and the state quantity after changing the state quantity by the changing unit is equal to or greater than the threshold value. The synchronous motor control device according to claim 9, wherein it is determined that the step-out has occurred when it is determined that has been continued for a predetermined time.   The said determination part determines that the said step-out has arisen, when it determines with the said state quantity after changing the said state quantity by the said change part being more than a threshold value. The control apparatus of the synchronous motor of the term.   The determination unit determines that the step-out has occurred when it is determined that the state in which the state amount after the state unit is changed by the changing unit is equal to or greater than the threshold has continued for a predetermined time. The synchronous motor control device according to claim 11.   The synchronous motor control device according to claim 11 or 12, wherein the determination unit variably sets the threshold based on the state quantity before the change unit changes the state quantity.   The synchronous motor control device according to any one of claims 9 to 13, wherein the determination unit variably sets the threshold value based on an operation state of the synchronous motor.   The determination unit includes a condition that a change amount of the rotational speed of the synchronous motor is equal to or greater than a predetermined speed change amount, a condition that the rotational speed is equal to or greater than a predetermined speed, and a change amount of a current flowing through the synchronous motor is predetermined. The step-out is performed on condition that at least one of a condition that the current change amount is equal to or greater than a condition and a condition that the torque change amount of the synchronous motor is equal to or greater than a predetermined torque change amount is satisfied. The synchronous motor control device according to any one of claims 1 to 14, wherein the determination result is invalidated.   The determination unit includes a condition that a change amount of the rotational speed of the synchronous motor is equal to or greater than a predetermined speed change amount, a condition that the rotational speed is equal to or greater than a predetermined speed, and a change amount of a current flowing through the synchronous motor is predetermined. The step-out is performed on condition that at least one of a condition that the current change amount is equal to or greater than a condition and a condition that the torque change amount of the synchronous motor is equal to or greater than a predetermined torque change amount is satisfied. The synchronous motor control device according to any one of claims 1 to 14, wherein determination of whether or not it has occurred is prohibited. The determination unit is a second determination unit,
Prior to the determination of step-out by the second determination unit, a first determination that determines that the step-out has occurred when a voltage amplitude that is a magnitude of a voltage vector applied to the synchronous motor is equal to or less than a determination threshold value. Part (S50, S51),
After determining that the step-out has occurred by the first determination unit, if the second determination unit determines that the step-out has not occurred, a threshold value reduction unit that decreases the determination threshold value (S53) The control apparatus of the synchronous motor of any one of Claims 1-16 provided with these.

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