JP2020061917A - Control arrangement of rotary electric machine - Google Patents

Abstract

To provide a control arrangement of rotary electric machine capable of restraining temporary increase of a current flowing to a stator winding.SOLUTION: A control arrangement controls a current flowing to a stator winding on the basis of an estimated pole position, and after current control is started, determines whether or not a rotor is rotating in the inverse direction. At a timing determined that the rotor is rotating in the inverse direction, a tip position of a current vector in a dq coordinate system is assumed as a first point P1, and when an assumption is made that the estimated pole position for use in current control is inverted by 180°, after a determination is made that the rotor is rotating in the inverse direction, the final position of trajectory assumed to be drawn by the tip of the current vector is assumed as a second point P2, and out of a region surrounded by a straight passing the first and second points, and the above-mentioned trajectory, the region other than the trajectory is a regulated area. When a determination is made that the rotor is rotating in the inverse direction, the control arrangement performs current control for moving the tip of the current vector from the first point P1 to the second point P2, so that the tip of the current vector does not deviate from the regulated area.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a control device for a synchronous rotary electric machine.

  As a control device of this type, as described in Patent Document 1, a device that estimates a magnetic pole position of a rotating electric machine based on a detected value of a current flowing through a stator winding of the rotating electric machine is known. The control device controls the current flowing through the stator winding in order to rotate the rotor of the rotary electric machine in a specific direction based on the estimated magnetic pole position.

  The estimated magnetic pole position may deviate from the actual magnetic pole position by 180 °. In this case, the rotor may rotate in the direction opposite to the specific direction even though the rotor is trying to rotate in the specific direction. Therefore, the control device described in Patent Document 1 deviates the estimated magnetic pole position and the actual magnetic pole position by 180 ° based on the phase difference between the command voltage vector applied to the stator winding and the estimated magnetic pole position. It is determined that the magnetic pole position is present, and the deviation of the magnetic pole position is eliminated based on the determination result.

Japanese Patent No. 3701207

  The inventor of the present application faces a problem that when the deviation between the estimated magnetic pole position and the actual magnetic pole position is eliminated, current control becomes unstable and the current flowing through the stator winding temporarily becomes excessively large. did.

  It is a main object of the present invention to provide a control device for a rotating electric machine that can suppress a temporary increase in the current flowing through the stator winding when the deviation between the estimated magnetic pole position and the actual magnetic pole position is eliminated. .

The present invention is an estimation unit for estimating the magnetic pole position of a synchronous rotating electric machine,
A drive control unit that controls a current flowing through a stator winding of the rotating electric machine to rotate the rotor of the rotating electric machine in a specific direction based on an estimated magnetic pole position that is a magnetic pole position estimated by the estimating unit;
When the current control by the drive control unit is started, a reverse rotation determination unit that determines that the rotor is rotating in a direction opposite to the specific direction, and
A dq coordinate system is defined as a coordinate system defined by a d-axis extending through the origin in the direction of the actual magnetic pole position of the rotating electric machine and a q-axis extending through the origin in a direction orthogonal to the d-axis.
If it is assumed that the estimated magnetic pole position used in the current control of the drive control unit is inverted by 180 ° after the reverse rotation determination unit determines that the current vector is the current vector in the dq coordinate system. The first position is the start position of the trajectory assumed to be drawn by the tip of, and the last position of the trajectory is the second point,
In the dq coordinate system, when a region other than the locus is defined as a prescribed region among regions surrounded by the straight line passing through the first point and the second point and the locus,
When the reverse rotation determination unit determines that the current vector is rotating in the reverse direction, the tip of the current vector is moved from the first point to the second point so that the tip does not protrude from the specified region. Therefore, a return control unit that performs a return process for controlling a current flowing through the stator winding is provided.

  In the present invention, the reverse rotation determination unit determines that the rotor is rotating in the direction opposite to the specific direction when the current control by the drive control unit for rotating the rotor in the specific direction is started.

  After the reverse rotation determination unit determines that the estimated magnetic pole position used in the current control is inverted by 180 ° after it is determined to be rotating in the reverse direction, the tip of the current vector moves in the dq coordinate system so as to draw a predetermined locus. . When the tip of the current vector moves on this locus, the current vector temporarily becomes excessively large. Here, in the dq coordinate system, the start position of the trajectory is the first point and the final position of the trajectory is the second point. In addition, a region other than the locus is defined as a defined region among the regions surrounded by the straight line passing through the first point and the second point and the locus. In this case, it is found that a temporary increase in the current vector can be suppressed if the tip of the current vector exists in the specified region before the tip moves from the first point to the second point. Who got it.

  Therefore, according to the present invention, when the reverse rotation determination unit determines that the current vector is rotating in the opposite direction, the current vector is moved from the first point to the second point so that the current vector does not protrude from the specified region. In order to do so, a recovery process for controlling the current flowing through the stator winding is performed. Accordingly, when the deviation between the estimated magnetic pole position and the actual magnetic pole position is eliminated in order to return the rotation direction of the rotor to the specific direction, it is possible to suppress a temporary increase in the current flowing through the stator winding.

The whole block diagram of the control system of the rotary electric machine which concerns on 1st Embodiment. The block diagram which shows the process of a control apparatus. The figure which shows a dq coordinate system and a (gamma) delta coordinate system. The time chart which shows the change of the high frequency voltage for estimating a magnetic pole position. The flowchart which shows the procedure of a reverse rotation determination process. The figure which shows the voltage and current vector in case an estimation error is 0 degree. The figure which shows the voltage and current vector in case an estimation error is 180 degrees. The figure which shows the locus | trajectory of a voltage and a current vector at the time of inverting the electrical angle used for control 180 degrees. The figure which shows the locus | trajectory of a voltage and a current vector in case each 180 degrees of the electrical angle used for control and the phase of a voltage vector are inverted. The figure which shows the regulation area | region in a dq coordinate system. The figure for demonstrating the process which inverts the phase of a high frequency voltage 180 degrees. The flowchart which shows the procedure of the polarity determination process which concerns on 2nd Embodiment. The figure for demonstrating the principle of polarity determination. The flowchart which shows the procedure of a reverse rotation determination process. The flowchart which shows the procedure of the reverse rotation determination process which concerns on 3rd Embodiment. The block diagram which shows the process of the control apparatus which concerns on 4th Embodiment. The flowchart which shows the procedure of a reverse rotation determination process. The figure which shows the change aspect of a command current vector. The figure which shows the defined area | region in the dq coordinate system which concerns on other embodiment.

<First Embodiment>
Hereinafter, a first embodiment that embodies a control device according to the present invention will be described with reference to the drawings. In this embodiment, the control device is applied to a three-phase inverter connected to a three-phase rotating electric machine.

  As shown in FIG. 1, the control system includes a rotary electric machine 10 and an inverter 20. The rotary electric machine 10 is a brushless synchronous machine, and is a permanent magnet synchronous machine in the present embodiment. The rotary electric machine 10 includes a rotor 10a and U, V, W phase windings 11U, 11V, 11W which are stator windings.

  The rotary electric machine 10 constitutes, for example, a drive device including a fan or a pump, and drives the fan or the pump by rotating the rotor 10a. The fan is, for example, a radiator fan or a fan for vehicle compartment air conditioning. The pump is, for example, an oil pump or a water pump.

  The rotary electric machine 10 is connected to a battery 30 as a DC power source via an inverter 20. The inverter 20 includes a series connection body of upper arm switches SUH, SVH, SWH and lower arm switches SUL, SVL, SWL. A first end of a U-phase winding 11U of the rotary electric machine 10 is connected to a connection point of the U-phase upper and lower arm switches SUH and SUL. A first end of a V-phase winding 11V of the rotary electric machine 10 is connected to a connection point of the V-phase upper and lower arm switches SVH and SVL. The first end of the W-phase winding 11W of the rotary electric machine 10 is connected to the connection point of the W-phase upper and lower arm switches SWH and SWL. The second ends of the U, V, W phase windings 11U, 11V, 11W are connected at a neutral point. In the present embodiment, the U, V and W phase windings 11U, 11V and 11W which are inductive loads are deviated from each other by 120 ° in electrical angle.

  In this embodiment, voltage-controlled semiconductor switching elements are used as the switches SUH, SUL, SVH, SVL, SWH, and SWL, and more specifically, N-channel MOSFETs are used. Each switch SUH, SUL, SVH, SVL, SWH, SWL has parasitic diodes DUH, DUL, DVH, DVL, DWH, DWL.

  The inverter 20 includes a capacitor 21 on its input side that smoothes the input voltage of the inverter 20. The high-potential side terminal of the capacitor 21 is connected to an electric path connecting the positive terminal of the battery 30 and the drains of the upper arm switches SUH to SWH. The low-potential side terminal of the capacitor 21 is connected to an electric path that connects the negative terminal of the battery 30 and the sources of the lower arm switches SUL to SWL.

  The control system comprises a current sensor 40. The current sensor 40 detects a current for at least two phases among the phase currents flowing through the rotary electric machine 10. In the present embodiment, the current sensor 40 is assumed to detect the current for three phases. The detection value of the current sensor 40 is input to the control device 50 included in the control system.

  The control device 50 is mainly composed of a microcomputer, and performs switching operation of each switch of the inverter 20 in order to perform feedback control of the control amount of the rotary electric machine 10 to its command value. In the present embodiment, the control amount is the electrical angular velocity (rotational speed), and its command value is the command angular velocity ω *. The control device 50 performs a switching operation on each switch of the inverter 20 so that the voltage vector applied to the rotary electric machine 10 becomes a command voltage vector for controlling the electric angular velocity to the command angular velocity ω *. As a result, sinusoidal phase currents that are offset from each other by 120 degrees flow through the phase windings 11U, 11V, and 11W.

  The control device 50 performs position sensorless control and estimates the electrical angle during this control. The position sensorless control is control of the rotary electric machine 10 without using the rotation angle information of the rotary electric machine 10 detected by an angle sensor such as a hall element or a resolver.

  Incidentally, the control device 50 realizes various control functions by executing programs stored in a storage device included in the control device 50. Various functions may be realized by an electronic circuit that is hardware, or may be realized by both hardware and software.

  Subsequently, the processing of the control device 50 will be described in detail with reference to the block diagram of FIG.

  The speed deviation calculation unit 51 calculates the speed deviation Δω by subtracting the estimated angular speed ωest calculated by the speed estimation unit 61 described below from the command angular speed ω *. The estimated angular velocity ωest is an estimated value of the electrical angular velocity. The command angular velocity ω * has a positive value when rotating the rotor 10a of the rotating electric machine 10 in a specific direction (positive direction), and has a negative value when rotating the rotor 10a in a direction opposite to the specific direction.

  The speed controller 52 calculates the command torque Trq * of the rotary electric machine 10 as an operation amount for feedback-controlling the speed deviation Δω to zero. The command torque Trq * has a positive value when rotating the rotor 10a in a specific direction, and has a negative value when rotating the rotor 10a in a direction opposite to the specific direction. As the feedback control in the speed controller 52, for example, proportional integral control may be used.

  The current conversion unit 53, based on the estimated angle θest calculated by the angle estimation unit 62 described below and the phase currents IU, IV, IW detected by the current sensor 40, U, V, W in the UVW coordinate system. The phase current is converted into a γ-axis current Iγr and a δ-axis current Iδr in the γδ coordinate system. The estimated angle θest is an estimated value of the electrical angle.

  Here, the UVW coordinate system is a three-phase fixed coordinate system of the rotary electric machine 10, and the γδ coordinate system is an estimated coordinate system of a dq coordinate system which is a two-phase rotary coordinate system of the rotary electric machine 10. FIG. 3 shows a γδ coordinate system, a dq coordinate system, and an αβ coordinate system which is a two-phase fixed coordinate system. The dq coordinate system is a coordinate system defined by a d-axis extending through the origin O in the direction of the actual magnetic pole position and a q-axis extending through the origin O in a direction orthogonal to the d-axis. The γδ coordinate system is a coordinate system defined by a γ axis extending through the origin O in the direction of the estimated magnetic pole position and a δ axis extending through the origin O in a direction orthogonal to the γ axis. In FIG. 3, the angle formed by the α axis of the αβ coordinate system and the γ axis of the γδ coordinate system is shown as the estimated angle θest, and the angle formed by the α axis and the d axis of the dq coordinate system is shown as the actual electrical angle θ. , The angle between the d axis and the γ axis is shown as an estimation error Δθ. The dq coordinate system is a coordinate system that rotates at the electrical angular velocity of the rotary electric machine 10 with respect to the αβ coordinate system.

  Returning to the description of FIG. 2, the command current setting unit 54 sets the γ-axis command current Iγ * and the δ-axis command current Iδ * based on the command torque Trq *. A command current vector in the γδ coordinate system is determined by the γ-axis command current Iγ * and the δ-axis command current Iδ *. In the present embodiment, the command current setting unit 54 sets the γ-axis command current Iγ * to 0. This setting is made because the rotary electric machine 10 of the present embodiment is the SPMSM of the non-salient pole machine.

  The γ-axis deviation calculator 55a calculates the γ-axis deviation ΔIγ as a value obtained by subtracting the γ-axis current Iγr from the γ-axis command current Iγ *. The δ-axis deviation calculator 55b calculates the δ-axis deviation ΔIδ as a value obtained by subtracting the δ-axis current Iδr from the δ-axis command current Iδ *.

  The current controller 56 calculates the γ-axis voltage Vγr as an operation amount for feedback-controlling the γ-axis current Iγr to the γ-axis command current Iγ * based on the γ-axis deviation ΔIγ. Further, the current controller 56 calculates the δ-axis voltage Vδr as an operation amount for feedback-controlling the δ-axis current Iδr to the δ-axis command current Iδ * based on the δ-axis deviation ΔIδ. The command voltage vector in the γδ coordinate system is determined by the γ-axis voltage Vγr and the δ-axis voltage Vδr. As the feedback control in the current controller 56, for example, proportional-integral control may be used.

  The γ-axis superimposing unit 57a outputs the added value of the γ-axis voltage Vγr and the γ-axis high frequency voltage Vγh generated by the high frequency generating unit 58 as the γ-axis command voltage Vγ *. The δ-axis superimposing unit 57b outputs the added value of the δ-axis voltage Vδr and the δ-axis high-frequency voltage Vδh generated by the high-frequency generating unit 58 as the δ-axis command voltage Vδ *. In this embodiment, the δ-axis high frequency voltage Vδh is set to zero. Therefore, the δ-axis voltage Vδr becomes the δ-axis command voltage Vδ * as it is. In the present embodiment, the γ-axis superimposing section 57a, the δ-axis superimposing section 57b and the high frequency generating section 58 correspond to the high frequency applying section.

  The γ-axis high frequency voltage Vγh is a signal that fluctuates at an angular velocity sufficiently higher than the electrical angular velocity of the fundamental wave component of the γ-axis command voltage Vγ *. In the present embodiment, as shown in FIG. 4, the amplitude of the γ-axis high frequency voltage Vγh is Va and the cycle of the γ-axis high frequency voltage Vγh is Ts. By the way, the high frequency generation unit 58 generates the γ-axis high frequency voltage Vγh necessary for calculating the estimated angle θest not only when the rotary electric machine 10 is started but also during speed control.

  The voltage conversion unit 59 uses the γ-axis command voltage Vγ *, the δ-axis command voltage Vδ *, and the estimated angle θest to convert the γ- and δ-axis command voltages Vγ * and Vδ * in the γδ coordinate system to U, Converted to V, W phase command voltages VU, VV, VW. In the present embodiment, the U, V, W phase command voltages VU, VV, VW have waveforms in which the phases are 120 ° out of phase with each other in terms of electrical angle.

  The signal generator 60 generates each operation signal gUp to gWn based on the U, V, W phase command voltages VU, VV, VW output from the voltage converter 59. The signal generator 60 outputs the generated operation signals gUp to gWn to the switches SUp to SWn of the inverter 20. Here, the operation signal may be generated, for example, by PWM control based on the magnitude comparison of a carrier signal such as a triangular wave signal and the phase command voltages VU, VV, VW. In each phase, the operation signal on the upper arm side and the corresponding operation signal on the lower arm side are complementary signals. Therefore, the upper arm switch and the corresponding lower arm switch are alternately turned on.

  The velocity estimation unit 61 calculates the estimated angular velocity ωest based on the δ-axis current Iδr. The principle of this calculation will be described below.

  The voltage equation of the rotary electric machine that also considers the high frequency is represented by the following equation (eq1), and the voltage equation regarding the high frequency included in the following equation (eq1) is represented by the following equation (eq2).

図３に示したｄｑ座標系で表された上式（ｅｑ２）をγδ座標系における式に変換すると、下式（ｅｑ３）が導かれる。

When the above equation (eq2) represented by the dq coordinate system shown in FIG. 3 is converted into the equation in the γδ coordinate system, the following equation (eq3) is derived.

上式（ｅｑ３）を電流について解くと下式（ｅｑ４）が導かれる。

Solving the above equation (eq3) for the current leads to the following equation (eq4).

本実施形態では、電気角を推定するための外乱電圧をγ軸のみに印加する。このため、上式（ｅｑ４）において「Ｖδｈ＝０」とすると、下式（ｅｑ５）が導かれる。

In the present embodiment, the disturbance voltage for estimating the electrical angle is applied only to the γ axis. Therefore, if “Vδh = 0” in the above equation (eq4), the following equation (eq5) is derived.

上式（ｅｑ５）を推定誤差Δθについて解くと、下式（ｅｑ６）が導かれる。

By solving the above equation (eq5) for the estimation error Δθ, the following equation (eq6) is derived.

「Δθ≒０」と仮定し、γ軸高周波電圧Ｖγｈの振幅Ｖａ及び周期Ｔｓを用いると、下式（ｅｑ７）が導かれる。

Assuming “Δθ≈0” and using the amplitude Va and the cycle Ts of the γ-axis high frequency voltage Vγh, the following equation (eq7) is derived.

γ軸高周波電圧Ｖγｈを印加すると、δ軸高周波電流Ｉδｈが流れる。上式（ｅｑ７）は、周期Ｔｓにおけるδ軸高周波電流Ｉδｈの変化量ΔＩδｈにより、推定誤差Δθを算出できることを示している。

When the γ-axis high frequency voltage Vγh is applied, the δ-axis high frequency current Iδh flows. The above equation (eq7) indicates that the estimation error Δθ can be calculated from the change amount ΔIδh of the δ-axis high frequency current Iδh in the cycle Ts.

  The speed estimation unit 61 calculates the δ-axis high frequency current Iδh based on the δ-axis current Iδr. The speed estimation unit 61 may calculate the δ-axis high frequency current Iδh by applying a high-pass filter to the δ-axis current Iδr, for example. The speed estimation unit 61 calculates the estimation error Δθ based on the calculated δ-axis high frequency current Iδh and the above equation (eq7). The velocity estimation unit 61 calculates the estimated angular velocity ωest as an operation amount for feedback controlling the calculated estimation error Δθ to zero. As the feedback control in the speed estimation unit 61, for example, proportional integral control may be used.

  Incidentally, the rotary electric machine to which the angle estimation using superposition of high frequency voltage is applied is usually a salient pole machine. However, the rotary electric machine 10 of the present embodiment is a non-salient pole machine. For example, when a large current flows through each of the phase windings 11U to 11W and magnetic flux saturation occurs in the rotary electric machine 10, the d-axis inductance and the q-axis inductance of the rotary electric machine 10 become different. Therefore, even when the rotary electric machine 10 is a non-salient pole machine, it is possible to perform angle estimation using superposition of high frequency voltages.

  The angle estimation unit 62 calculates the estimated angle θest by time-integrating the estimated angular velocity ωest.

  By the way, the γ axis sometimes deviates from the d axis by 180 °. In this case, the rotor 10a rotates in the direction opposite to the specific direction, even though the rotor 10a is intended to rotate in the specific direction. In this case, the control device 50 includes a return control unit 63.

  FIG. 5 shows the procedure of the reverse rotation determination process executed by the control device 50. This processing is executed by the cooperation of the processing units shown in FIG.

  In step S10, the command torque Trq * output from the speed controller 52 is set to zero. This process is a process for reducing the generated torque of the rotary electric machine 10 to 0 until a positive determination is made in step S15. In the present embodiment, it is assumed that the calculation processing in the command current setting unit 54 and the current controller 56 is not executed so as not to generate the torque until a positive determination is made in step S15.

  In step S11, the application of the γ-axis high frequency voltage Vγh is started, and in step S12, the δ-axis high frequency current Iδh flowing with the application is started to be detected. The process of step S12 corresponds to the high frequency detection unit.

  In step S13, the calculation of the estimated angular velocity ωest by the above-described method is started based on the detected δ-axis high frequency current Iδh. In step S14, calculation of the estimated angle θest based on the calculated estimated angular velocity ωest is started.

  In step S15, it is determined whether or not the elapsed time TL after the calculation processing of the estimated angular velocity ωest has started exceeds the threshold time Tth. This process is a process for determining whether or not the estimation error Δθ has converged to 0 or a value close to 0 after the process of calculating the estimated angular velocity ωest based on the above equation (eq7) is started.

  When a negative determination is made in step S15, the process returns to step S11. On the other hand, when an affirmative decision is made in step S15, the operation proceeds to step S16, and the calculation based on the command torque Trq * is permitted. That is, the execution of the arithmetic processing in the command current setting unit 54 and the current controller 56 is permitted, and the generated torque of the rotary electric machine 10 starts to increase from 0 so that the electrical angular speed becomes the command angular speed ω *.

  In step S17, it is determined whether the absolute value of the estimated angular velocity ωest is higher than the velocity threshold ωth. This process is to improve the determination accuracy of the reverse rotation in step S18. That is, noise may be superimposed on the estimated angular velocity ωest. In this case, if the absolute value of the estimated angular velocity ωest is small, the proportion of noise in the estimated angular velocity ωest increases, and there is a concern that the determination accuracy in step S18 may decrease.

  When a negative determination is made in step S17, the process returns to step S11. On the other hand, if an affirmative decision is made in step S17, then the processing advances to step S18, in which it is decided whether or not the rotation direction of the rotor 10a is the opposite direction to the specific direction. In the present embodiment, when it is determined that the product value of the command torque Trq * and the estimated angular velocity ωest is 0 or less, it is determined that the direction is opposite. This determination method is based on that the command torque Trq * and the estimated angular velocity ωest have the same sign when the rotor 10a is rotating in a specific direction.

  If an affirmative decision is made in step S18, then the processing advances to step S19, in which it is decided that the rotor 10a is rotating in the specific direction. Then, the angle estimation unit 62 outputs the estimated angle θest calculated by the method described above to the current conversion unit 53 and the voltage conversion unit 59 as they are.

  On the other hand, when a negative determination is made in step S18, the process proceeds to step S20, and it is determined that the rotor 10a is rotating in the reverse direction. Then, the value obtained by adding 180 ° to the estimated angle θest calculated by the above-described method in the angle estimation unit 62 is output to each of the current conversion unit 53 and the voltage conversion unit 59.

  In step S21, a recovery process of inverting the phase θvt of the command voltage vector by 180 ° is performed. Specifically, the signs of the γ and δ axis voltages Vγr and Vδr output from the current controller 56 are changed in order to invert the phase θvt of the command voltage vector by 180 °. The reason why the phase θvt is inverted by 180 ° will be described below with reference to FIGS. 6 to 10.

  FIG. 6 shows the command voltage vector Vtr and the current vector Itr when the estimation error Δθ is 0. The current vector Itr is a vector determined by the γ-axis current Iγr and the δ-axis current Iδr. In FIG. 6, “ωφ” represents the induced voltage vector, “RI” represents the vector of the voltage drop due to the resistance of the stator winding, and “ωLI” represents the vector of the armature reaction.

  When the estimation error Δθ is 0 °, the dq coordinate system and the γδ coordinate system match. In this case, the tip of the command voltage vector Vtr exists in the second quadrant of the dq coordinate system, and the tip of the current vector Itr exists on the positive q axis. As a result, the rotor 10a rotates in a specific direction.

  FIG. 7 shows the command voltage vector Vtr and the current vector Itr when the estimation error Δθ is 180 °. When the estimation error Δθ is 180 °, the γ axis and the d axis are displaced by 180 °. In this case, the tip of the command voltage vector Vtr exists in the third quadrant of the dq coordinate system, and the tip of the current vector Itr exists on the negative q axis. As a result, the δ-axis command current Iδ * has a positive value, but the q-axis current has a negative value, and the rotor 10a rotates in the direction opposite to the specific direction.

  Here, as shown in FIGS. 8 to 10, the tip position of the current vector Itr in the dq coordinate system at the timing when the negative determination is made in step S18 of FIG. 5 and the rotor 10a is determined to be rotating in the opposite direction, as shown in FIGS. Let it be the first point P1.

  Further, after it is determined that the rotor 10a is rotating in the reverse direction, if it is assumed that 180 ° is added to the estimated angle θest used in the current converter 53 and the voltage converter 59 shown in FIG. 2, the dq coordinate system is assumed. The final position of the trajectory assumed to be drawn by the tip of the current vector Itr at is the second point P2. In FIGS. 8 to 10, this locus is shown by an alternate long and short dash line arrow. The second point P2 is line-symmetrical to the first point P1 with respect to the d and γ axes.

  As shown in FIG. 10, in the dq coordinate system, of the area surrounded by the straight line passing through the first point P1 and the second point P2 and the locus indicated by the alternate long and short dash line, the area other than this locus is defined area Ar. To do.

  When it is determined that the rotor 10a is rotating in the opposite direction and then 180 ° is added to the estimated angle θest, as shown in FIG. 8, the tip position of the command voltage vector Vtr changes from the third quadrant to the third quadrant in the dq coordinate system. Switch to 1 quadrant. Then, the tip of the command voltage vector Vtr moves to the second quadrant. As a result, in the dq coordinate system, the tip of the current vector Itr moves on the locus indicated by the alternate long and short dash line. In the example shown in FIG. 8, the tip of the current vector Itr moves to the second point P2 via the fourth quadrant and the first quadrant in the dq coordinate system. In the example shown in FIG. 8, the current vector Itr temporarily becomes excessively large in the first quadrant.

  Here, if the tip of the current vector Itr is present in the specified region Ar by the time the tip of the current vector Itr moves from the first point P1 to the second point P2, a temporary increase in the current vector Itr can be suppressed. The inventor of the present application paid attention.

  Therefore, when it is determined that the rotor 10a is rotating in the opposite direction, the tip of the current vector Itr is moved from the first point P1 to the second point P2 so that the tip of the current vector Itr does not protrude from the specified region Ar. In order to move the currents up to, the recovery processing for controlling the currents flowing through the phase windings 11U, 11V, 11W is performed. In the present embodiment, as the restoration process, a process of inverting the phase θvt of the command voltage vector Vtr by 180 ° is performed. According to this processing, the command voltage vector Vtr at the timing when it is determined that the rotor 10a is rotating in the reverse direction and the command voltage vector Vtr obtained by adding 180 ° to the estimated angle θest and reversing the phase θvt by 180 °. And are the same. As a result, the tip of the current vector Itr moves from the first point P1 to the second point P2 on a straight line passing through the first point P1 and the second point P2, as shown in FIG. Therefore, according to the present embodiment, when 180 ° is added to the estimated angle θest in order to return the rotation direction of the rotor 10a to the specific direction, it is possible to suppress a temporary increase in the current vector Itr.

  Returning to the explanation of FIG. 5, in the subsequent step S21, the phase of the γ-axis high-frequency voltage Vγh generated by the high-frequency generator 58 is inverted by 180 °. This is a process for preventing the pulse width of the γ-axis high frequency voltage Vγh from becoming longer than the half cycle “Ts / 2” of the γ-axis high frequency voltage Vγh, as shown in FIG. 11. Despite adding 180 ° to the estimated angle θest, unless the phase of the γ-axis high-frequency voltage Vγh is inverted by 180 °, the γ-axis high-frequency voltage Vγh is alternately switched between positive and negative every half cycle “Ts / 2”. The pulse signal cannot be output. According to the process of step S21, it is possible to suppress a decrease in the calculation accuracy of the estimated angle θest. The process of steps S18 to S21 is executed by the return control unit 63.

  By the way, when the reverse rotation determination process of FIG. 5 is completed and the startup of the rotary electric machine 10 is completed, the processes of steps S11 to S14 are repeatedly executed in a predetermined control cycle.

<Modification of First Embodiment>
The phase θvt of the command voltage vector Vtr is inverted by 180 ° on the condition that the tip of the current vector Itr does not protrude from the specified region Ar before the tip moves from the first point P1 to the second point P2. Processing different from the processing to be performed may be performed. For example, the command voltage vector Vtr may be changed stepwise (for example, two steps) so that the tip of the current vector Itr moves from the first point P1 to the second point P2. In this case, the time required to move the tip of the current vector Itr from the first point P1 to the second point P2 may be set to, for example, the mechanical time constant of the rotating electric machine 10 or a time shorter than the time constant. Good. The mechanical time constant Tm is determined by “Tm = (J × L) / (Kt × Ke)”, where inertia is J, inductance is L, torque constant is Kt, and counter electromotive force constant is Ke.

  -Instead of the process of step S18 of FIG. 5, a process of determining whether or not the sign of the estimated angular velocity ωest and the sign of the command torque Trq * are positive may be performed. If an affirmative decision is made in this process, the operation proceeds to step S19, and if a negative decision is made, the operation proceeds to step S20.

  Further, instead of the process of step S18 of FIG. 5, a process of determining whether the sign of the estimated angular velocity ωest and the sign of the δ-axis command current Iδ * are positive may be performed.

  Further, the determination as to whether or not the rotor 10a is rotating in the reverse direction may be performed by the method described in (A) to (C) below, for example.

  (A) With reference to Japanese Patent No. 3701207, it may be determined whether or not the motor is rotating in the opposite direction based on the phase difference between the command voltage vector and the estimated magnetic pole position, and Japanese Patent No. 3480572. With reference to the publication, it may be determined based on the γ-axis voltage Vγr whether or not it is rotating in the opposite direction.

  (B) When the estimated angular velocity ωest is set as the first estimated angular velocity, the second estimated angular velocity is calculated based on the voltage and current of the stator winding and the motor constant of the rotating electric machine with reference to Japanese Patent No. 3722948. Then, based on the second estimated angular velocity and the first estimated angular velocity, it may be determined whether or not it is rotating in the opposite direction.

  (C) Whether or not the rotor 10a is rotating in the reverse direction may be determined based on the order of appearance of the U, V, W phase currents IU, IV, IW. This appears in the order of the U-phase current IU, the V-phase current IV, and the W-phase current IW when not rotating in the opposite direction, while the U-phase current IU and the W-phase current IW appear when rotating in the opposite direction. , And the V-phase current IV appears in that order. Here, which phase current of the three phases has appeared may be grasped, for example, based on the detection value of the current sensor 40 from the timing when each phase current reaches a predetermined determination value.

  In the magnetic pole estimation, the δ-axis high frequency voltage Vδh may be used instead of the γ-axis high frequency voltage Vγh.

  The method for estimating the magnetic pole position (electrical angle) may be, for example, the method described in Japanese Patent No. 331472, Japanese Patent No. 3454212, or Japanese Patent No. 4735287.

<Second Embodiment>
Hereinafter, the second embodiment will be described with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, the polarity determination process shown in FIG. 12 is performed before the reverse rotation determination process.

  FIG. 12 shows the procedure of the polarity determination processing executed by the control device 50. This processing is executed by the cooperation of the processing units shown in FIG.

  In step S30, the command torque Trq * output from the speed controller 52 is set to zero. This process is a process for reducing the generated torque of the rotary electric machine 10 to 0 until the process of step S16 of FIG. 14 described later is executed. In the present embodiment, it is assumed that the calculation process in the command current setting unit 54 and the current controller 56 is not executed until the process of step S16 of FIG. 14 is executed.

  In steps S31 to S35, the same processing as that in steps S11 to S15 of FIG. 5 is performed.

  When an affirmative determination is made in step S35, it is determined in steps S36 to S38 whether the γ-axis grasped from the estimated angle θest in step S33 is the N pole or the S pole. In the present embodiment, the processing of steps S36 to S38 corresponds to the polarity determination unit. Hereinafter, the principle of this determination will be described with reference to FIG. In FIG. 13, a case where a U-phase current is passed will be described as an example.

  FIG. 13 shows a case where the d-axis faces the U-phase winding 11U side. In FIG. 13, the state A and the state B show the case where the directions in which the U-phase current IU flows are different. As shown in state A, when a positive voltage is applied to U-phase winding 11U, positive U-phase current IU flows. At this time, magnetic flux saturation occurs due to the magnetic flux on the rotor 10a side and the magnetic flux on the stator winding side strengthening each other. As a result, the inductance of the stator winding decreases, and the absolute value of the U-phase current IU increases.

  On the other hand, as shown in state B, when a negative voltage is applied to U-phase winding 11U, negative U-phase current IU flows. At this time, the magnetic flux on the rotor 10a side is weakened by the magnetic flux on the stator winding side. As a result, the inductance of the stator winding does not decrease, and the absolute value of the U-phase current IU decreases. From the above, it can be determined that, of the U-phase currents IU in which the positive voltage and the negative voltage of the same magnitude are applied to the U-phase winding 11U, the one having the larger absolute value is the N pole.

  Returning to the description of FIG. 12, in step S36, the phase current In when a positive voltage is applied to the winding and the phase current Is when a negative voltage is applied are detected in the specific phase. Then, it is determined whether or not the absolute value of the phase current In when the positive voltage is applied is larger than the absolute value of the phase current Is when the negative voltage is applied. In this embodiment, | In | = | Is | does not hold in step S36.

  When an affirmative decision is made in step S36, the operation proceeds to step S37, and it is decided that the estimated γ-axis direction is the N pole. On the other hand, when a negative determination is made in step S36, the process proceeds to step S38, and it is determined that the estimated γ-axis direction is the S pole.

  After completion of the polarity determination process shown in FIG. 12, the reverse rotation determination process shown in FIG. 14 is performed. 14, for the sake of convenience, the same processes as those shown in FIG. 5 are designated by the same reference numerals. In FIG. 14, the processes of steps S10 and S15 of FIG. 5 are not executed.

  The determination result of the polarity by the processing shown in FIG. 12 may be incorrect. Even in this case, by performing the reverse rotation determination process shown in FIG. 14 thereafter, it is possible to start the rotary electric machine 10 while preventing the rotor 10a from rotating in the reverse direction.

<Third Embodiment>
Hereinafter, the third embodiment will be described with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, the content of the reverse rotation determination process is partially changed.

  FIG. 15 shows the procedure of the reverse rotation determination process executed by the control device 50. This processing is executed by the cooperation of the processing units shown in FIG. Note that, in FIG. 15, the same processing as the processing shown in FIG. 5 above is denoted by the same reference numeral for convenience.

  After the process of step S14 is completed, the process proceeds to step S22, and the electrical angular acceleration ACC of the rotary electric machine 10 is estimated. The electrical angular acceleration ACC may be calculated, for example, by time differentiation of the estimated angular velocity ωest.

  After the completion of the process of step S16, it is determined in step S23 whether the absolute value of the estimated electrical angular acceleration ACC is higher than the acceleration threshold value Ath. This process is for improving the determination accuracy of the reverse rotation in step S24, like the process of step S17. Even if the estimated angular velocity ωest includes an error (offset error) in which the estimated angular velocity ωest deviates from the actual electrical angular velocity by a predetermined amount by using the acceleration information, the error affects the determination result in step S24. Can be suppressed.

  When a negative determination is made in step S23, the process returns to step S11. On the other hand, if an affirmative decision is made in step S23, then the processing advances to step S24, in which it is decided whether or not the multiplication value of the command torque Trq * and the electrical angular acceleration ACC is larger than zero. If an affirmative decision is made in step S24, the operation proceeds to step S19. On the other hand, if a negative decision is made in step S24, the operation proceeds to step S20.

<Modification of Third Embodiment>
Instead of the process of step S24 of FIG. 15, a process of determining whether or not the sign of the electrical angular acceleration ACC and the sign of the command torque Trq * are positive may be performed. Further, instead of the process of step S24 of FIG. 15, a process of determining whether the sign of the electrical angular acceleration ACC and the sign of the δ-axis command current Iδ * are positive may be performed.

<Fourth Embodiment>
Hereinafter, the fourth embodiment will be described with reference to the drawings, focusing on the differences from the first embodiment. In the present embodiment, as the restoration process, a process of changing the command current vector is performed instead of the process of changing the command voltage vector Vtr.

  FIG. 16 is a block diagram showing the processing of the control device 50 according to this embodiment. 16, for the sake of convenience, the same components as those shown in FIG. 2 are designated by the same reference numerals.

  In the present embodiment, even when it is determined that the rotor 10a is rotating in the opposite direction, the estimated angle θest output from the angle estimation unit 62 is not corrected and is output as it is.

  FIG. 17 shows the procedure of the reverse rotation determination process executed by the control device 50. This processing is executed by the cooperation of the processing units shown in FIG. 16 in the control device 50. Note that, in FIG. 17, the same processing as the processing shown in FIG. 5 above is denoted by the same reference numeral for convenience.

  When a negative determination is made in step S18, the process proceeds to step S25, and the sign of the δ-axis command current Iδ * set by the command current setting unit 54 is inverted. As a result, as shown in FIG. 18, the command current vector after sign reversal, which is determined by the γ-axis command current Iγ * and the δ-axis command current Iδ *, is line-symmetrical to the γ-axis with respect to the command current vector before sign reversal. Become involved.

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

<Other embodiments>
The γ-axis command current Iγ * may be set to a value other than 0 (for example, Iγ * <0). This setting is adopted, for example, when the rotating electric machine is an IPMSM which is a salient pole machine. In this case, as shown in FIG. 19, the first point P1 and the second point P2 are present at positions displaced from the γ-axis. In this case, the first point P1 and the second point P2 are in line symmetry with respect to the d and γ axes. In FIG. 19, in the dq coordinate system, of the region surrounded by the straight line passing through the first point P1 and the second point P2 and the locus indicated by the alternate long and short dash line, the specified region other than this locus is indicated by Ar. .

  The rotating electric machine is not limited to a permanent magnet field type in which a rotor has a permanent magnet, but may be a winding field type in which a rotor has a field winding through which a field current flows. .

  The switch forming the inverter is not limited to the MOSFET and may be an IGBT, for example.

  10 ... Rotating electric machine, 10a ... Rotor, 50 ... Control device, 63 ... Return control part.

Claims (13)

An estimation unit for estimating the magnetic pole position of the synchronous rotating electric machine (10);
Based on the estimated magnetic pole position which is the magnetic pole position estimated by the estimation unit, a current flowing through the stator windings (11U to 11W) of the rotary electric machine in order to rotate the rotor (10a) of the rotary electric machine in a specific direction. A drive control unit for controlling,
When the current control by the drive control unit is started, a reverse rotation determination unit that determines that the rotor is rotating in a direction opposite to the specific direction, and
A dq coordinate system is defined as a coordinate system defined by a d-axis extending through the origin in the direction of the actual magnetic pole position of the rotating electric machine and a q-axis extending through the origin in a direction orthogonal to the d-axis.
If it is assumed that the estimated magnetic pole position used in the current control of the drive control unit is inverted by 180 ° after the reverse rotation determination unit determines that the current vector is the current vector in the dq coordinate system. The start position of the trajectory assumed to be drawn by the tip of is the first point (P1), the final position of the trajectory is the second point (P2),
In the dq coordinate system, when a region other than the locus among the regions surrounded by the straight line passing through the first point and the second point and the locus is the defined region (Ar),
When the reverse rotation determination unit determines that the current vector is rotating in the reverse direction, the tip of the current vector is moved from the first point to the second point so that the tip does not protrude from the specified region. Therefore, a controller for a rotating electric machine, comprising: a return controller that performs a return process for controlling a current flowing through the stator winding. The drive control unit controls a current flowing through the stator winding based on a command voltage vector applied to the stator winding and the estimated magnetic pole position,
The rotating electric machine according to claim 1, wherein the return control unit performs, as the return process, a process of reversing each of the estimated magnetic pole position and the phase of the command voltage vector used for current control of the drive control unit by 180 °. Control device. The drive control unit controls a current flowing through the stator winding based on a command current vector flowing through the stator winding and the estimated magnetic pole position,
When the coordinate system defined by the γ-axis extending through the origin in the direction of the estimated magnetic pole position and the δ-axis extending through the origin in the direction orthogonal to the γ-axis is the γδ coordinate system, the return control is performed. The unit performs, as the restoration process, a process of changing the command current vector used in the current control of the drive control unit to a vector that is line-symmetric with respect to the γ axis in the γδ coordinate system. Control device for rotating electric machine. A high frequency applying section for applying a high frequency voltage to the stator winding;
A high-frequency detector that detects a high-frequency current flowing in the stator winding by applying the high-frequency voltage,
The estimating unit estimates the magnetic pole position of the rotating electric machine based on the high frequency current detected by the high frequency detecting unit,
The rotary electric machine control according to any one of claims 1 to 3, wherein the restoration control unit performs processing for inverting the phase of the high-frequency voltage applied to the stator winding by 180 ° in addition to the restoration processing. apparatus. A polarity determining unit for determining the polarity of the magnetic pole position of the rotating electric machine,
The control device for a rotary electric machine according to claim 1, wherein the return control unit performs the return process after the polarity is determined by the polarity determination unit.   The rotation according to any one of claims 1 to 5, wherein the reverse rotation determination unit determines that the rotation is in the reverse direction based on the estimated magnetic pole position and a current flowing through the stator winding. Electric machine control device. The estimating unit estimates an electrical angular velocity of the rotating electric machine, and estimates a magnetic pole position based on the estimated electrical angular velocity,
The control device for a rotating electric machine according to claim 6, wherein the reverse rotation determination unit determines that the motor is rotating in the reverse direction based on the estimated electrical angular velocity and the current flowing through the stator winding.   The rotation according to claim 7, wherein the reverse rotation determination unit determines that the motor is rotating in the reverse direction based on the estimated sign of the electrical angular velocity and the sign of the torque current flowing through the stator winding. Electric machine control device.   The control device for a rotating electric machine according to claim 7 or 8, wherein the reverse rotation determination unit determines that the electric motor is rotating in the reverse direction on condition that the estimated electrical angular velocity is higher than a threshold value thereof. The estimation unit estimates the electrical angular acceleration of the rotating electric machine,
The said reverse rotation determination part determines that it is rotating in the said reverse direction based on the estimated said electrical angular acceleration and the electric current which flows into the said stator winding. The control device for the rotating electric machine described.   The said reverse rotation determination part determines that it is rotating in the said reverse direction based on the code | symbol of the estimated said electrical angular acceleration and the code | symbol of the torque current which flows into the said stator winding. Control device for rotating electric machine.   The control device for a rotating electric machine according to claim 10 or 11, wherein the reverse rotation determination unit determines that the electric rotation is rotating in the reverse direction on condition that the estimated electrical angular acceleration is higher than a threshold value thereof.   The rotary electric machine according to claim 1, wherein the reverse rotation determination unit determines that the reverse rotation is performed based on an appearance order of each phase current flowing in the stator winding. Control device.

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