JP6737017B2 - Control device, control method, and control program - Google Patents

Description

The present invention relates to a control device, a control method, and a control program.

In order to reduce the cost of a motor control device such as a permanent magnet synchronous motor, so-called sensorless vector control has been put into practical use, which realizes rotation control without providing a position detector for detecting the magnetic pole position of the rotor ( For example, Non-Patent Document 1 and Patent Document 1). In the sensorless vector control, the magnetic pole position and speed of the rotor are calculated from information such as the terminal voltage and current of the electric motor, and the electric current is controlled based on these to control the electric motor.

Further, it has been proposed to perform so-called current pull-in control instead of sensorless vector control during low speed rotation (for example, Patent Documents 2 and 3). In these current pull-in controls, the electric motor is controlled by keeping the amplitude of the current constant and controlling the angular velocity of the current to a speed command value to pull the rotor into the rotating magnetic field of the current.
[Non-Patent Document 1] Takashi Aihara, Akio Toba, Takao Yanase, Akihide Mashimo, and Kenji Endo "Sensorless Torque Control of Salient-Pole Synchronous Motor at Zero-Speed Operation" IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 14, NO.1 , JANUARY 1999
[Patent Document 1] Japanese Patent No. 3411878 [Patent Document 2] Japanese Patent Laid-Open No. 2001-190093 [Patent Document 3] Japanese Patent No. 5277724

It is desired to further stabilize the switching between the current pull-in control and the sensorless vector control.

In a first aspect of the present invention, a speed estimation unit that calculates a speed estimation value of a rotor included in an electric motor, a rotation control unit that controls rotation of the rotor, and a rotation speed of the rotor are equal to or lower than a first reference speed. And the rotation control unit operates in the first control mode in which the rotation control unit controls the rotation of the rotor so that the estimated speed value approaches the speed command value. In response to the detection of the speed reduction state, the rotation control unit is switched to the operation in the second control mode in which the rotation command value is used to control the rotation of the rotor without using the speed estimation value, and the electric motor is switched. There is provided a control device including a restart unit that restarts the control device, a control method and a control program executed by the control device.

In the second aspect of the present invention, a speed estimation unit that calculates a speed estimation value of a rotor included in the electric motor, a rotation control unit that controls rotation of the rotor, and a step-out detection unit that detects a step-out of the electric motor. Then, before switching the rotation control unit to the operation in the first control mode for controlling the rotation of the rotor so that the speed estimation value approaches the speed instruction value, the speed instruction value is used without using the speed estimation value. A control device that includes a restart unit that restarts the electric motor in response to the detection of step-out in the operation in the second control mode that controls the rotation of the rotor, and the control executed by the control device. A method and control program are provided.

The above summary of the invention does not list all of the features of the present invention. A sub-combination of these feature groups can also be an invention.

1 shows a schematic configuration of a control device according to the present embodiment. The schematic operation of the control device according to the present embodiment will be described. The following shows the operation during normal speed reduction. An operation when an abnormal speed reduction state is detected is shown. The γ-axis and δ-axis used for control calculation are shown. 1 shows a control device according to the present embodiment. The relationship between the expansion induced voltage and the angle difference (magnetic pole position estimation error) is shown. The step-out detection part is shown. 1 shows an example of the configuration of a computer according to this embodiment.

Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. Further, not all of the combinations of features described in the embodiments are essential to the solving means of the invention.

[1. Schematic configuration of control device]
FIG. 1 shows a schematic configuration of a control device 1 according to this embodiment. The control device 1 controls the electric motor 9 without using the magnetic pole position detector of the rotor. Here, the electric motor 9 includes a rotor (not shown). The electric motor 9 may be, for example, a synchronous motor, and in the present embodiment, as an example, a permanent magnet synchronous motor. However, the electric motor 9 may be a synchronous reluctance motor.

The control device 1 includes a rotation control unit 2, a speed estimation unit 3, an abnormality detection unit 4, and a restart unit 5. The control device 1 may further include a mode switching unit 6.

The rotation control unit 2 controls the rotation of the rotor. For example, the rotation control unit 2 converts the electric power from the electric power source 8 (for example, a three-phase AC power supply) according to the input speed command value and supplies the electric power to the electric motor 9 to rotate the rotor. You may control.

In addition, the rotation control unit 2 controls the rotation of the electric motor 9 using a plurality of control modes including a sensorless vector control mode as an example of the first control mode and a current drawing control mode as an example of the second control mode. You can go. For example, in the sensorless vector control mode, the rotation control unit 2 controls the electric motor 9 by calculating the magnetic pole position and speed of the rotor from information such as the terminal voltage and current of the electric motor and performing current control based on these. You can do it. In the current pull-in control mode, the rotation control unit 2 controls the electric motor 9 by keeping the amplitude of the current constant and controlling the angular velocity of the current to the speed command value to pull the rotor into the rotating magnetic field of the current. You can do it.

The rotation control unit 2 may include an acceleration limiting unit 101 that limits the rate of change of the speed command value input from the outside. For example, the acceleration limiting unit 101 causes the internally held speed command value to follow the speed command value input from the outside within a range equal to or lower than a predetermined rate of change, and as the speed command value after the restriction. You may output. The rotation control unit 2 may perform the rotation control using the speed command value limited by the acceleration limiting unit 101.

The speed estimation unit 3 calculates a speed estimated value of the rotor. For example, the speed estimation unit 3 may acquire the voltage and current supplied to the electric motor 9 from the rotation control unit 2 and calculate the speed estimation value. The speed estimation unit 3 may supply the speed estimation value to the rotation control unit 2 and the mode switching unit 6.

The abnormality detection unit 4 is an example of at least one of a speed decrease detection unit and a step-out detection unit, and detects an abnormality of the electric motor 9. For example, the abnormality detection unit 4 may detect a speed reduction state and/or step out of the electric motor 9.

Here, the step-out may be, for example, a state in which the motor 9 cannot operate without the rotor being drawn into the rotating magnetic field of the current. As an example, the step-out may occur due to the rotor not being able to follow the speed command value from the acceleration limiting unit 101 due to a sudden change in load, sudden acceleration, or the like in the current drawing control. The abnormality detecting unit 4 may notify the restarting unit 5 and the mode switching unit 6 that the low speed state and/or step out has been detected.

The mode switching unit 6 switches the control mode of the rotation control unit 2. For example, the mode switching unit 6 may set the rotation control unit 2 to the current drawing control mode when the electric motor 9 is started. Further, the mode switching unit 6 may switch the rotation control unit 2 to the sensorless vector control mode in response to the speed command value output from the acceleration limiting unit 101 exceeding the third reference speed V ₃ . Further, the mode switching unit 6 causes the rotation control unit 2 to draw a current in response to the speed command value becoming equal to or lower than the second reference speed V ₂ while the rotation control unit 2 is operating in the sensorless vector control mode. You may switch to control mode. The second reference speed V ₂ may be the same speed as the third reference speed V _3, it may be a speed lower than the third reference speed V ₃ to a hysteresis.

The restart unit 5 restarts the electric motor 9 when the abnormality detecting unit 4 detects an abnormality in the electric motor 9. Restarting the electric motor 9 may be, for example, initializing the speed command value after the restriction in the acceleration restriction unit 101. As an example, the speed command value internally held by the acceleration restriction unit 101 is temporarily reset to the initial value ( It may be, for example, zero) and then increased again. When the electric motor 9 is restarted, the rotor may be once stopped or may be rotating due to inertia.

For example, the restart unit 5 restarts the electric motor 9 in response to the detection of step-out in the operation in the current drawing control mode before the rotation control unit 2 is switched to the sensorless vector control mode. Good. In addition, the restart unit 5 causes the mode switching unit 6 to control the rotation control unit 2 to the current pull-in control mode in response to the detection of the speed reduction state while the rotation control unit 2 is operating in the sensorless vector control mode. The electric motor 9 may be restarted while the operation is switched to the above operation. If the control device 1 does not include the mode switching unit 6, the restarting unit 5 may switch the rotation control unit 2 to the current drawing control mode.

According to the control device 1 described above, the rotation control unit 2 is switched to the current drawing control mode and the electric motor 9 is restarted in response to the detection of the speed reduction state while operating in the sensorless vector control mode. Therefore, the stability of the operation can be improved when the speed decreases due to a sudden change in the load.

Further, before the switching to the sensorless vector control mode, the electric motor 9 is restarted in response to the detection of the step-out in the current drawing control mode, so that the operation when the step-out occurs due to a sudden change in the load or the like is performed. The stability can be improved.

[2. Schematic operation of control device]
Subsequently, a schematic operation of the control device 1 will be described. FIG. 2 shows a schematic operation of the control device according to the present embodiment.

First, when the control device 1 is started, the electric motor 9 is started in the current drawing control mode in S1. For example, the mode switching unit 6 may set the control mode of the rotation control unit 2 to the current drawing control mode. Further, the rotation control unit 2 may start controlling the rotation of the rotor. As an example, the acceleration limiting unit 101 increases the limited speed command value from zero to a desired speed command value (for example, a speed command value input from the outside) at an acceleration equal to or lower than the reference acceleration, and the rotation control unit 2 In response to this, the electric motor 9 may be driven in the current drawing control mode. When the electric motor 9 is driven, the speed estimation unit 3 may calculate a speed estimated value of the rotor.

Next, the mode switching part 6 in S3 determines whether the speed command value from the acceleration limiting portion 101 exceeds a third reference speed V _3. Speed command value in S3 if it is determined not to exceed the third reference speed V _3; A (S3 No), the control apparatus 1 repeats the process S3. As a result, the control of the electric motor 9 in the current drawing control mode continues.

Speed command value in S3 if it is judged to have exceeded the third reference speed V _3; A (S3 Yes), the restart unit 5 at S5, determines whether desynchronization is detected by the abnormality detection unit 4 To do. When it is determined that the step-out is detected in S5 (S5; Yes), the restart unit 5 shifts the process to S1 to restart the electric motor 9. In this way, when the speed command value exceeds the third reference speed V ₃ while the rotation control unit 2 is operating in the current drawing control mode, the step-out is detected, and the electric motor 9 is restarted. To be done. Therefore, if it is assumed that the position of the rotor or the like cannot be detected even after the shift to the sensorless vector control mode due to the occurrence of step-out, the shift is not performed and the electric motor 9 is restarted. Improves stability.

The process of S5 may be performed between the processes of S1 and S3. That is, before switching the rotation control unit 2 to the operation in the sensorless vector control mode, the electric motor 9 may be restarted in response to the detection of step-out in the operation in the current drawing control mode.

When it is determined that the step-out is not detected in S5 (S5; No), the mode switching unit 6 switches the control mode of the rotation control unit 2 to the sensorless vector control mode in S7. As described above, the rotation control unit 2 is switched to the sensorless vector control mode in response to the speed command value exceeding the third reference speed V ₃ and no step-out is detected during the current drawing control mode.

Next, in S9, the mode switching unit 6 determines whether or not the speed command value from the acceleration limiting unit 101 is the second reference speed V ₂ or less. When it is determined in S9 that the speed command value is equal to or lower than the second reference speed V ₂ (S9; Yes), the mode switching unit 6 switches the control mode of the rotation control unit 2 to the current drawing control mode in S11, The control device 1 shifts the processing to S3.

Further, when it is determined in S9 that the speed command value is not equal to or less than the second reference speed V ₂ (S9; No), the restart unit 5 determines in S13 whether the speed decrease state is detected by the abnormality detection unit 4. Determine whether. For example, the abnormality detection unit 4 may detect the speed reduction state when the rotation speed of the rotor has become equal to or lower than the first reference speed V ₁ . The first reference speed V ₁ may be lower than the second reference speed V ₂ . When it is determined in S13 that the speed reduction state is not detected (S13; No), the control device 1 shifts the processing to S9. As a result, the control of the electric motor 9 in the sensorless vector control mode continues.

When it is determined in S13 that the low speed state is detected (S13; Yes), the restart unit 5 switches the control mode of the rotation control unit 2 to the current drawing control mode by the mode switching unit 6 in S15. , The process shifts to S1 to restart the electric motor 9. In this way, the rotation control unit 2 is switched to the current drawing control mode and the electric motor 9 is restarted in response to the detection of the speed reduction state while the rotation control unit 2 is operating in the sensorless vector control mode. To be done. Therefore, when it is assumed that the speed command value from the acceleration limiting unit 101 and the rotation speed of the rotor deviate due to the occurrence of the speed decrease state, and the rotor position and the like cannot be detected, the rotation control unit 2 Shifts to the current drawing control mode and the electric motor 9 is restarted, so that the operation stability is improved.

[3. Example of operation during normal speed reduction]
FIG. 3 shows the operation at the time of normal speed reduction. After the rotation control unit 2 is switched to the sensorless vector control mode (S7), if the speed command value from the acceleration limiting unit 101 is larger than the second reference speed V ₂ (S9: No), the sensorless vector control mode is used. The electric motor 9 is controlled (period T _{1 in the} figure).

Next, when the speed command value becomes equal to or lower than the second reference speed V ₂ (S9; Yes), the mode switching unit 6 switches the control mode of the rotation control unit 2 to the current drawing control mode (S11), and the current drawing control mode is set. The electric motor 9 is controlled (period T _{2 in the} figure).

In this state, the speed command value from the acceleration limiting unit 101 becomes larger than the third reference speed V ₃ (here, as an example, the same speed as the second reference speed V ₂ ) (S3: Yes), and step-out is not detected. (S5; No), the motor 9 is controlled by a sensor-less vector control mode (period _T 3 in the figure).

[4. Operation when an abnormal slowdown condition is detected]
FIG. 4 shows an operation when an abnormal speed reduction state is detected. After the rotation control unit 2 is switched to the sensorless vector control mode (S7), when it is determined that the rotation speed of the rotor is equal to or lower than the first reference speed V ₁ and the speed reduction state is detected (S13; Yes, At the timing t ₁ ) in the figure, the restart unit 5 switches the control mode of the rotation control unit 2 to the current drawing control mode by the mode switching unit 6 (S15), and the electric motor 9 is restarted in the current drawing control mode. (S1, period T ₄ in the figure).

[5. Explanation of γ-axis and δ-axis]
FIG. 5 shows the γ-axis and the δ-axis used in the control calculation described later. The permanent magnet synchronous motor can realize highly accurate torque control by performing current control according to the d-axis of the rotor (the magnetic pole direction of the rotor) and the q-axis whose phase is advanced by 90 degrees from the d-axis. is there. However, since the dq axes cannot be directly detected without the magnetic pole position detector, the control device 1 estimates the γδ axes of the orthogonal rotation coordinate system that rotates at the electrical angular velocity ω ₁ corresponding to the dq axes and controls the control. Calculate.

The dq axis and the γδ axis are defined as shown in FIG. The N-pole direction of the rotor of the permanent magnet synchronous motor is the d axis, the 90-degree advance direction from this d-axis is the q-axis, the estimated axis corresponding to the d-axis is the γ-axis, and the 90-degree advance direction from this γ-axis is the δ-axis. Define. In the figure, “ω _r ”is the electrical angular velocity of the dq axes, “ω ₁ ” is the electrical angular velocity of the γδ axes (=speed estimation value), and “θ _err ” is the angle of the γδ axes with respect to the dq axes (angle difference or magnetic pole). (Also referred to as position estimation error).

[6. Specific configuration of control device]
FIG. 6 shows the control device 1 according to the present embodiment. The control device 1 includes, in addition to the acceleration limiting unit 101 and the restarting unit 5 described above, a subtractor 103, a speed adjuster 105, a current command calculation unit 107, a current command calculation unit 109, changeover switches 111 and 113, a subtractor 115, 117, current regulator 119, voltage coordinate converter 121, PWM circuit 123, power converter 131, rectifier circuit 133, u-phase current detector 135, w-phase current detector 137, current coordinate converter 139, extended induced voltage calculation The device 141, the angle calculator 143, the speed estimator 145, the changeover switch 151, the electrical angle calculator 153, the speed decrease detector 161 and the step-out detector 163 are provided.

Among these, the acceleration limiting unit 101, the subtractor 103, the speed adjuster 105, the current command calculating unit 107, the current command calculating unit 109, the changeover switches 111 and 113, the subtractors 115 and 117, the current adjuster 119, and the voltage coordinate converter. 121, PWM circuit 123, power converter 131, rectifier circuit 133, u-phase current detector 135, w-phase current detector 137, current coordinate converter 139, electrical angle calculator 153, etc. It may be configured to control the rotation of the rotor. For example, as will be described in detail later, the rotation control unit 2 rectifies the three-phase AC voltage from the power source 8 by the rectifier circuit 133 and converts the AC voltage into a DC voltage, and the power converter 131 having a PWM inverter has a desired three-phase voltage. The electric motor 9 is driven by converting it into an AC voltage and applying it to the electric motor 9.

Further, the extended electromotive voltage calculator 141, the angle calculator 143, the speed estimator 145, the changeover switch 151, and the like may configure the speed estimator 3 described above to calculate the speed estimated value of the rotor. Further, the speed decrease detection unit 161 and the step-out detection unit 163 may configure the above-described abnormality detection unit 4 to detect the abnormality of the electric motor 9. Further, the changeover switches 111, 113, the changeover switch 151, and the like may operate as a part of the mode changeover section 6 described above to change over the control mode of the rotation control section 2. However, each configuration shown in FIG. 6 may be included in other configurations in FIG. 1, for example, the current coordinate converter 139 may be included in the speed estimation unit 3, and the changeover switch 151 may be the rotation control unit. 2 may be included.

The acceleration limiting unit 101 receives the speed command value ω ^* from the outside and calculates the speed command value ω _HLR ^* so that the rate of change thereof is limited. For example, the acceleration limiting unit 101 may calculate the speed command value ω _HLR ^* from the speed command value ω ^* so that the change rate of the speed command value ω _HLR ^* is equal to or less than the reference change rate. The acceleration limiting unit 101 may supply the speed command value ω _HLR ^* to the subtractor 103 and the “S1” terminal of the changeover switch 151.

The restart unit 5 restarts the electric motor 9 by initializing the speed command value ω _HLR ^* calculated by the acceleration limiting unit 101, that is, by setting the initial value (zero as an example). For example, the restart unit 5 may initialize the speed command value ω _HLR ^* in response to the abnormality detected by the abnormality detection unit 4.

The subtractor 103 calculates a deviation between the speed command value ω _HLR ^* and the speed estimation value (electrical angular speed) ω _rest of the γδ axis. The estimated speed value ω _rest may be supplied from a speed estimator 145 described later. The subtractor 103 may supply the calculation result to the speed adjuster 105.

The speed adjuster 105 amplifies the deviation supplied from the subtractor 103 to calculate the torque command value τ ^* of the rotor. The speed adjuster 105 may supply the torque command value τ ^* to the current command calculator 107.

The current command calculation unit 107 uses the torque command value τ ^* to calculate the γδ axis current command values i _γ ^* , i _δ ^* which are the command values of the current to be flown in the γδ axis direction. The current command calculator 107 may supply the γδ axis current command values i _γ ^* , i _δ ^* to the “S2” terminals of the changeover switches 111, 113.

The current command calculation unit 109 calculates the γδ axis current command values i _γ ^* , i _δ ^* without using the torque command value τ ^* . The current command calculation unit 109 may supply the γδ axis current command values i _γ ^* , i _δ ^* to the “S1” terminals of the changeover switches 111, 113.

The change-over switches 111 and 113 conduct either one of the “S1” terminal and the “S2” terminal to make the γδ axis current command values i _γ ^* , i _δ from one of the current command calculation units 107 and 109. ^* Is supplied to the subtracters 115 and 117. For example, the changeover switches 111 and 113 are connected to the “S1” terminal in the current pull-in control mode, and γδ from the current command calculation unit 109 that is not based on the speed estimated value (electrical angular speed) ω _rest from the speed estimator 145. The axis current command values i _γ ^* and i _δ ^* are supplied to the subtracters 115 and 117. On the other hand, in the sensorless vector control mode, the changeover switches 111 and 113 are connected to the “S2” terminal, and the current command calculation unit 107 based on the speed estimated value (electrical angular speed) ω _rest from the speed estimator 145. The γδ-axis current command values i _γ ^* , i _δ ^* are supplied to the subtracters 115 and 117. A low pass filter may be provided between the changeover switches 111 and 113 and the subtractors 115 and 117.

The subtractor 115 calculates the deviation between the γ-axis current command value i _γ ^* and the γ-axis current detection value i _γ which is the detection value of the current flowing in the γ-axis direction. The γ-axis current detection value i _γ may be supplied from the current coordinate converter 139 described later. The subtractor 115 may supply the calculation result to the current regulator 119.

The subtractor 117 calculates the deviation between the δ-axis current command value i _δ ^* and the δ-axis current detection value i _δ which is the detection value of the current flowing in the δ-axis direction. The δ-axis current detection value i _δ may be supplied from the current coordinate converter 139 described later. The subtractor 117 may supply the calculation result to the current regulator 119.

The current adjuster 119 amplifies the deviations supplied from the subtracters 115 and 117, respectively, and is a γ-axis voltage command value v _γ ^* and a δ-axis voltage command value v _δ that are command values of the voltage supplied in the γδ axis direction. Calculate ^* . The current regulator 119 may supply the γ-axis voltage command value v _γ ^* and the δ-axis voltage command value v _δ ^* to the voltage coordinate converter 121 and the extended induced voltage calculator 141.

The voltage coordinate converter 121 determines the voltage command values v _γ ^* , v _δ ^* on the γδ axis based on the value of the angle (phase) θ ₁ of the γδ axis, and the phase voltage command values v _u ^* , v _v ^{* of the} three phases ^. , V _w ^* . The angle θ ₁ may be supplied from the electrical angle calculator 153 described later. The voltage coordinate converter 121 may supply the phase voltage command values v _u ^* , v _v ^* , v _w ^* to the PWM circuit 123.

The PWM circuit 123 generates a gate signal for the power converter 131 from the phase voltage command values v _u ^* , v _v ^* , v _w ^* and the input voltage E _dc to the power converter 131. The input voltage E _dc may be supplied from the input voltage detection circuit 125 described later.

The power converter 131 has a PWM inverter and controls an internal semiconductor switching element based on a gate signal input from a PWM circuit 123 described later. As a result, the power converter 131 controls the terminal voltage of the electric motor 9 applied by the rectifier circuit 133 to the phase voltage command values v _u ^* , v _v ^* , v _w ^* .

The rectifier circuit 133 rectifies the alternating current supplied from the power source 8 as a three-phase alternating current power supply, generates a direct current voltage, and supplies the direct current voltage to the power converter 131.
The input voltage detection circuit 125 detects the input voltage E _dc from the rectifier circuit 133 to the power converter 131. The input voltage detection circuit 125 may supply the input voltage E _dc to the PWM circuit 123.

The u-phase current detector 135 and the w-phase current detector 137 detect the current values passed through the u-phase and the w-phase between the power converter 131 and the electric motor 9 as the phase current detection values i _u and i _w . .. The u-phase current detector 135 and the w-phase current detector 137 may supply the phase current detection values i _u and i _w to the current coordinate converter 139.

The current coordinate converter 139 performs coordinate conversion of the phase current detection values i _u and i _w based on the γδ axis angle θ ₁ into the γδ axis current detection values i _γ and i _δ which are the current detection values in the γδ axis direction. .. The angle θ ₁ may be supplied from the electrical angle calculator 153. The current coordinate converter 139 may supply the γδ-axis current detection values i _γ and i _δ to the subtractors 115 and 117 and the extended induced voltage calculator 141. The current coordinate converter 139 may perform the coordinate conversion using the phase current detection values of the other two phases of the u phase, the v phase, and the w phase, or the coordinate conversion using all of the three phases. You may go.

The extended electromotive force calculator 141 calculates the voltage command values v _γ ^* , v _δ ^* supplied to the electric motor 9 and the detected current values i _γ , i _δ flowing through the electric motor 9 as represented by the following equation (1). , Γ-axis expansion induced voltage calculation value e _{ex γest} and δ-axis expansion induction voltage calculation value e _{ex δest} are calculated. The extension electromotive _force calculator 141 may supply the γ-axis extension electromotive _force calculation value e _{ex γest} and the δ-axis extension electromotive _force calculation value e _exδest to the angle calculator 143 and the step-out detection unit 163. Further, the expansion induced voltage calculator 141 may supply the γ-axis expansion induced voltage calculation value e _{ex γest} to the speed decrease detection unit 161.

ここで、式中、「p」は微分演算子、「Ｌ_ｄ」はｄ軸インダクタンス、「Ｌ_ｑ」はｑ軸インダクタンス、「Ｒ_ａ」は電機子抵抗である。なお、式中のγ軸電圧指令値ｖ_γ ^＊、δ軸電圧指令値ｖ_δ ^＊の代わりにγ軸電圧ｖ_γ、δ軸電圧ｖ_δを使ってもよい。これらのγ軸電圧ｖ_γ、δ軸電圧ｖ_δは、入力電圧検出回路１２５を使って測定される電動機９の相電圧または線間電圧の値と、位置推定値θ_１とから演算することができる。

Here, “p” is a differential operator, “L _d ”is a d-axis inductance, “L _q ”is a q-axis inductance, and “R _a ”is an armature resistance. The γ-axis voltage v _γ and the δ-axis voltage v _δ may be used instead of the γ-axis voltage command value v _γ ^* and the δ-axis voltage command value v _δ ^{* in} the formula. These γ-axis voltage v _γ and δ-axis voltage v _δ can be calculated from the value of the phase voltage or line voltage of the electric motor 9 measured using the input voltage detection circuit 125 and the position estimated value θ _1. it can.

The angle calculator 143 calculates the angle δ _eexest of the extended induction voltage. The angle δ _eexest of the expansion induced voltage will be described later with reference to FIG. 7. The angle calculator 143 may supply the angle δ _eexest of the extended induction voltage to the speed estimator 145.

The speed estimator 145 calculates the estimated speed value ω _rest of the rotor from the angle δ _eexest of the extended electromotive voltage. The speed estimator 145 may supply the speed estimated value ω _rest to the subtractor 103 and the “S2” terminal of the changeover switch 151.

The changeover switch 151 makes either of the “S1” terminal and the “S2” terminal conductive so that the speed command value ω _HLR ^* from the acceleration limiting unit 101 and the speed estimation value ω _rest from the speed estimator 145 are obtained. Either one of them is supplied as the γδ axis angular velocity ω ₁ to the electrical angle calculator 153, the extended induced voltage calculator 141, and the speed decrease detector 161. For example, the changeover switch 151 is connected to the “S1” terminal in the current pull-in control mode, and the speed command value ω _HLR ^* from the acceleration limiting unit 101 is supplied to the electrical angle calculator 153, the extended induced voltage calculator 141, and the speed decrease. It is supplied to the detection unit 161. On the other hand, the change-over switch 151 is connected to the “S2” terminal in the sensorless vector control mode, and the speed estimated value ω _rest from the speed estimator 145 is transferred to the electrical angle calculator 153, the extended induced voltage calculator 141, and the speed calculator. It is supplied to the drop detection unit 161.

The electrical angle calculator 153 integrates the γδ axis angular velocity ω ₁ to calculate the γδ axis angle θ ₁ . The electrical angle calculator 153 may supply the angle θ ₁ to the current coordinate converter 139 and the voltage coordinate converter 121.

The speed decrease detector 161 detects the speed decrease state from the estimated speed value ω ₁ and the δ-axis expansion induced voltage calculation value e _{ex δest} . The speed reduction detecting unit 161 may notify the restarting unit 5 that the speed reduction state is detected.

The out-of-step detecting unit 163 detects out-of-step from the γ-axis expansion induced voltage calculated value e _exγest and the δ-axis expansion induced voltage calculated value e _exδest . The step-out detection unit 163 may notify the restart unit 5 that the step-out has been detected.

[7. Specific operation of control device]
Next, the operation of the control device 1 will be described. In the current pull-in control mode executed in S1 described above, the mode switching unit 6 sets the inputs of the changeover switch 151 and the changeover switches 111 and 113 to "S1".

Acceleration limiting unit 101 limits the speed command value omega ^* rate of change, computes a speed command value omega _HLR ^*. For example, the acceleration limiting unit 101 may increase the speed command value ω _HLR ^* from zero to the speed command value ω ^* at an acceleration not higher than the reference acceleration. Here, since the input of the changeover switch 151 is set to “S1”, the angular velocity ω _{1 of the} γδ axis is controlled to the velocity command value ω _HLR ^* . The electrical angle calculator 153 integrates the angular velocity ω ₁ of the γδ axis to calculate the angle θ _{1 of the} γδ axis.

Further, the current command calculation unit 109 connected to the input “S1” of the changeover switches 111 and 113 controls the γδ axis current command values i _γ ^* , i _δ ^{* according} to the following equation (2). That is, the current command calculation unit 109 sets the γ-axis current command value i _γ ^* to a non-zero constant value and sets the δ-axis current command value i _δ ^* to zero, thereby rotating the rotor with respect to the _γ δ-axis angle θ ₁ . The current command values i _γ ^* and i _δ ^* are output so as to match the directions of.

The current coordinate converter 139 calculates the phase current detection values i _u and i _w detected by the u-phase current detector 135 and the w-phase current detector 137, respectively, based on the γδ axis angle θ ₁ and detects the γδ axis current detection value i. _The coordinates are converted into _γ and i _δ .

The subtracter 115 calculates the deviation between the γ-axis current command value i _γ ^* and the γ-axis current detection value i _γ, and the current controller 119 amplifies this deviation to calculate the γ-axis voltage command value v _γ ^* . On the other hand, the subtracter 117 calculates the deviation between the δ-axis current command value i _δ ^* and the δ-axis current detection value i _δ, and the current controller 119 amplifies this deviation to calculate the δ-axis voltage command value v _δ ^* . To do. These voltage command values v _γ ^* , v _δ ^* are converted into phase voltage command values v _u ^* , v _v ^* , v _w ^* by the voltage coordinate converter 121 based on the angle θ ₁ of the _{γ δ} axis. The rectifier circuit 133 rectifies a three-phase AC power source as the power source 8 and supplies a DC voltage to the power converter 131.

The PWM circuit 123 generates a gate signal from the phase voltage command values v _u ^* , v _v ^* , v _w ^* and the input voltage E _dc of the power converter 131 detected by the input voltage detection circuit 125. The power converter 131 controls the internal semiconductor switching element based on the gate signal to control the terminal voltage of the electric motor 9 to the phase voltage command values v _u ^* , v _v ^* , v _w ^* . By these controls, a current vector whose amplitude is I _apull ^* and whose angular velocity is equal to the speed command value ω _HLR ^* is generated to _draw the rotor into the current vector, and the angular velocity ω _r of the rotor is the speed command value ω _HLR ^* , Consequently, the speed command value ω ^* is controlled.

Next, the operation in the sensorless vector control mode when the speed command value ω _HLR ^* exceeds the third reference speed V ₃ (S3; Yes) will be described. Note that the description will be focused on the part different from the current drawing control, and the description of the overlapping parts will be omitted.

In the sensorless vector control mode executed in S7 described above, the mode switching unit 6 sets the inputs of the changeover switch 151 and the changeover switches 111 and 113 to "S2". The subtractor 103 calculates the deviation between the speed command value ω _HLR ^* and the speed estimation value ω _rest calculated by the speed estimating unit 3 as described later, and the speed controller 105 amplifies this deviation to amplify the torque command value. Calculate τ ^* . The current command calculation unit 107 calculates the γδ axis current command values i _γ ^* , i _δ ^* based on the torque command value τ ^* under the condition that the torque/current is maximized. Since the inputs of the changeover switches 111 and 113 are set to “S2”, the output of the current command calculation unit 107 is supplied to the subtracters 115 and 117.

The operations of the subtractors 115 and 117, the current regulator 119, the current coordinate converter 139, and the voltage coordinate converter 121 are the same as those in the current pull-in control, and these commands the γδ axis currents i _γ and i _δ. The phase voltage command values v _u ^* , v _v ^* , v _w ^* are controlled so as to match the values i _γ ^* , i _δ ^* .

On the other hand, the expanded induced voltage calculator 141 stores the γδ axis voltage command values v _γ ^* , v _δ ^* , the γδ axis current detection values i _γ , i _δ and the speed estimation value ω ₁ (as an example, the speed estimation value ω _rest ). Is entered. The expansion induced voltage calculator 141 calculates the expansion induced voltage e _{ex according} to the above equation (1).

Here, the angle δ _eexest of the γδ axis expansion induced voltage is equal to the angle difference (=magnetic pole position estimation error) θ _err between the dq axis and the γδ axis. Therefore, the angle calculator 143 calculates the angle δ _eexest of the extended induced voltage by the following formula (3), and the angle δ _eexest is calculated as the magnetic pole position estimation error calculation value θ _errest as shown in the following formula (4). To do.

The speed estimator 145 calculates the speed estimation value ω _rest by the following formula (5) by the PI controller that receives the magnetic pole position estimation error calculation value θ _errest as an input. Here, in the formula, "K _Pshita" velocity estimator proportional gain, "K _{I [theta]"} is a speed estimator integral gain.

Since the input of the changeover switch 151 is set to "S2", the γδ axis angular velocity ω ₁ is controlled to the estimated velocity value ω _rest . The angular velocity ω1 is input to the electrical angle calculator 153 and the extended induced voltage calculator 141.

The electrical angle calculator 153 integrates the γδ axis angular velocity ω ₁ to calculate the magnetic pole position estimated value θ ₁ (equal to the angle of the γδ axis), as in the current drawing control.
The extended induced voltage calculator 141, the angle calculator 143, the speed estimator 145, and the electrical angle calculator 153 described above can make the angular difference θ _err between the γδ axis and the dq axes converge to zero, and thereby the magnetic pole position. It is possible to accurately estimate θ ₁ and velocity ω ₁ . As a result, the torque and speed of the electric motor 9 can be accurately controlled.

When the speed command value becomes equal to or lower than the second reference speed V ₂ in the sensorless vector control mode described above (S9; Yes), the rotation control section 2 is switched to the operation in the current drawing control mode by the mode switching section 6. .. For example, the mode switching unit 6 may set the inputs of the changeover switch 151 and the changeover switches 111 and 113 to "S1". However, this time the acceleration limiting unit 101, without the speed command value omega _HLR ^* to zero, and calculates a speed command value omega _HLR ^* limits the speed command value omega ^* rate of change.

Next, the operation in the sensorless vector control mode in the case where a speed reduction state occurs due to a sudden load change or the like will be described.
The speed decrease detection unit 161 detects the speed decrease state when the rotation speed of the rotor becomes equal to or lower than the first reference speed V ₁ . For example, the speed decrease detection unit 161 may detect the speed decrease state in response to the estimated speed value ω ₁ being equal to or less than the first reference speed V ₁ . The speed decrease detection unit 161 may set the speed decrease detection signal to “H” in response to the estimated speed value ω ₁ being equal to or less than the first reference speed V _1, and may be set to “L” otherwise.

Instead of/in addition to this, the speed reduction detecting unit 161 may detect the speed reduction state using the extended induction voltage. For example, the speed reduction detecting unit 161 may detect the speed reduction state on condition that the δ-axis expansion induced voltage calculated value e _exδest is equal to or less than the reference value. The speed decrease detection unit 161 may set the speed decrease detection signal to “H” in response to the δ-axis expansion induced voltage calculated value e _exδest being equal to or less than the first reference value, and may be set to “L” otherwise. .. In addition, the speed decrease detection unit 161 determines that the estimated speed value ω ₁ (rotor speed of the rotor) has become equal to or lower than the first reference speed V ₁ and that the δ-axis expansion induced voltage calculation value e _exδest is equal to or lower than the first reference value. The speed decrease detection signal may be switched depending on the AND condition and the OR condition.

Instead of/in addition to these, the speed reduction detecting unit 161 may detect the speed reduction state using an induced voltage calculated from a voltage supplied to the electric motor 9 and a current flowing through the electric motor 9. For example, the speed decrease detection unit 161 sets the speed decrease detection signal to “H” in response to the δ-axis induced voltage calculation value _emfδest calculated by the following equation (6) being equal to or less than the second reference value, Otherwise, it may be "L". In addition, the speed decrease detection unit 161 determines that the estimated speed value ω ₁ (rotor speed of the rotor) has become equal to or lower than the first reference speed V ₁ and that the δ-axis expansion induced voltage calculation value e _exδest is equal to or lower than the first reference value. The speed decrease detection signal may be switched depending on at least one of the above condition and the AND condition or the OR condition that the calculated δ-axis induced voltage _emfδest is equal to or less than the second reference value.

When the speed decrease detection signal becomes "H" in the sensorless vector control mode (S13; Yes), the restart unit 5 causes the mode switching unit 6 to switch the rotation control unit 2 to the operation in the current drawing control mode. At the same time, the electric motor 9 is restarted. For example, the mode switching unit 6 may set the input of the changeover switch 151 to “S1” and the input of the changeover switches 111 and 113 to “S1”. Alternatively, the restarting unit 5 may initialize the speed command value ω _HLR ^* calculated by the acceleration limiting unit 101 to zero and then increase the speed command value ω ^* at a predetermined acceleration.

Next, the operation when a step out occurs in the current pull-in control mode will be described.
The out-of-step detecting unit 163 may detect out-of- _step by using the γδ-axis expansion induced voltage calculated values e _exγest and e _exδest . The out-of-step detection unit 163 may set the out-of-step detection signal to “H” in response to the detection of out-of-step, and may otherwise set it to “L”. Details of the out-of-step detection unit 163 will be described later.

When the speed command value ω _HLR ^* from the acceleration limiting unit 101 exceeds the third reference speed V ₃ in the current pull-in control mode and the out-of-step detection signal from the out-of-step detecting unit 163 is “H” (S5; In Yes), the restart unit 5 restarts the electric motor 9. For example, the restarting unit 5 may initialize the speed command value ω _HLR ^* calculated by the acceleration limiting unit 101 to zero and then increase the speed command value ω ^* at a predetermined acceleration to the speed command value ω ^* .

[8. Explanation of extended electromotive force and angular difference (magnetic pole position estimation error)]
FIG. 7 shows the relationship between the extended induced voltage and the angular difference (magnetic pole position estimation error). The expansion induced voltage e _ex is generated in the q-axis direction that is orthogonal to the rotor. As is clear from this figure, the angle δ _eex of the extended induced voltage observed on the γδ axis is equal to the angular difference (=magnetic pole position estimation error) θ _err between the dq axis and the γδ axis. Thereby, the angle difference (=magnetic pole position estimation error) θ _err can be calculated using the above equations (3) and (4).

[9. Explanation of step-out detection section]
Next, the step-out detection unit 163 will be described. As shown in the above equation (2), when the current is controlled in the γ-axis direction in the current drawing control, the motor torque τ and the angular difference θ _err between the γδ-axis and the dq-axis are expressed by the following equation. The relationship of (7) is satisfied. In the formula, “Ψ _m ”is a permanent magnet magnetic flux.

As shown by this equation, the torque τ in the current pull-in control is generally an increasing function of the angle difference θ _err when the magnitude of the angle difference θ _err is equal to or smaller than the reference value. Can be operated stably by the current pull-in control is, the torque τ is the case of increasing function of the angular difference theta _err, angular difference theta _err is step-out becomes more than the reference angle. From this, the out-of-step detection unit 163 may detect out-of- _step by using the angle difference calculation value θ _errrestf , which is the calculation value of the angle difference θ _err , and for example, the angle difference calculation value θ _errrestf becomes equal to or greater than the reference angle. Step-out may be detected accordingly.

Further, when the speed of the rotor is low, the expansion induced voltage is small, and it is difficult to accurately detect the step-out due to the calculation error of the angle difference calculation value θ _errrestf . Therefore, the out-of-step detector 163 may detect out-of-step by using the magnitude of the extended induced voltage proportional to the speed. For example, the out-of-step detection unit 163 may detect the out-of-step according to that the vector sum e _exaestf of the extended induced voltage calculation value is equal to or lower than the reference voltage.

If the step-out continues, the angle difference θ _err repeats changing within a range of ±180°. Therefore, if the presence/absence of step-out according to the instantaneous value of the angle difference calculation value θ _errestf is output as it is, the detection result output timing Depending on the situation, it may not be possible to externally recognize that the user is out of sync. Therefore, it is preferable that the out-of-step detecting unit 163 delays and outputs a signal indicating that the out-of-step has occurred. By delaying the off timing of the output signal, the period during which the step-out state can be detected can be increased. When the signal repeatedly turns on and off, the step-out state can be surely detected by filling the off period between the on period and the off period.

FIG. 8 shows the out-of-step detection unit 163. The out-of-step detecting unit 163 has low-pass filters 1631 and 1632, an angle calculator 1633, a vector sum calculator 1634, a step-out determination device 1635, and an off delay 1637.

Low pass filter 1631 and 1632 is, the ?? axes extended induced voltage calculation value _{e exγest, e exδest} of lowpass _{e exγestf,} calculates the _{e exδestf.} The low-pass filters 1631 and 1632 may supply the low-pass components e _exγestf and e _exδestf to the angle calculator 1633 and the vector sum calculator 1634, respectively.

The angle calculator 1633 calculates the angle (phase difference) δ _eexestf of the extended induction voltage by the following formula (8). As described above with reference to FIG. 7, the angle δ _eexestf of the expansion induced voltage is equal to the angular difference θ _err between the γδ axis and the dq axes. Therefore, the angle calculator 1633 calculates the angle difference calculation value θ _errestf by the following formula (9). The angle calculator 1633 may supply the calculated angle difference value θ _errestf to the out-of-step determiner 1635.

The vector sum calculator 1634 calculates the vector sum e _exaestf of the extended electromotive _force calculation value by the following equation (10). The vector sum calculator 1634 may supply the vector sum e _examestf to the out-of-step determinator 1635.

The out-of-step determiner 1635 determines out-of-step using the vector difference e _exaestf of the angle difference calculation value θ _errestf and the extended electromotive _force calculation value. For example, the out-of-step determiner 1635 determines that the absolute value of the angle difference calculation value θ _errestf is equal to or greater than the reference angle, or that the vector sum e _exaestf of the extension electromotive voltage calculation value is equal to or less than the reference voltage. The instantaneous out-of-step detection signal may be "H", and otherwise "L". However, the out-of-step determiner 1635 may switch the instantaneous out-of-step detection signal depending on the AND conditions of the both.

The off-delay 1637 outputs a step-out detection signal obtained by off-delaying the instantaneous step-out detection signal. As a result, it is surely recognized to the outside that the user is out of step.

[10. Computer configuration]
FIG. 9 shows an example of the configuration of the computer 1900 according to this embodiment. The computer 1900 according to this embodiment functions as the control device 1.

The computer 1900 according to this embodiment is connected to the host controller 2082 by an input/output controller 2084 and a CPU peripheral unit having a CPU 2000, a RAM 2020, a graphic controller 2075, and a display device 2080 which are mutually connected by a host controller 2082. An input/output unit having a communication interface 2030, a hard disk drive 2040, and a DVD drive 2060, and a legacy input/output unit having a ROM 2010 connected to the input/output controller 2084, a flash memory drive 2050, and an input/output chip 2070. ..

The host controller 2082 connects the RAM 2020 to the CPU 2000 and the graphic controller 2075 that access the RAM 2020 at a high transfer rate. The CPU 2000 operates based on the programs stored in the ROM 2010 and the RAM 2020, and controls each part. The graphic controller 2075 acquires image data generated by the CPU 2000 or the like on a frame buffer provided in the RAM 2020 and displays it on the display device 2080. Instead of this, the graphic controller 2075 may internally include a frame buffer that stores image data generated by the CPU 2000 or the like.

The input/output controller 2084 connects the host controller 2082 to the communication interface 2030, hard disk drive 2040, and DVD drive 2060, which are relatively high-speed input/output devices. The communication interface 2030 communicates with other devices via a network by wire or wirelessly. Further, the communication interface functions as hardware that performs communication. The hard disk drive 2040 stores programs and data used by the CPU 2000 in the computer 1900. The DVD drive 2060 reads a program or data from the DVD 2095 and provides it to the hard disk drive 2040 via the RAM 2020.

Further, the ROM 2010, the flash memory drive 2050, and the input/output chip 2070, which are relatively low-speed input/output devices, are connected to the input/output controller 2084. The ROM 2010 stores a boot program executed by the computer 1900 at startup, and/or a program dependent on the hardware of the computer 1900. The flash memory drive 2050 reads a program or data from the flash memory 2090 and provides it to the hard disk drive 2040 via the RAM 2020. The input/output chip 2070 connects the flash memory drive 2050 to the input/output controller 2084, and inputs/outputs various input/output devices via, for example, a parallel port, a serial port, a keyboard port, a mouse port, or the like. Connect to controller 2084.

The program provided to the hard disk drive 2040 via the RAM 2020 is stored in a recording medium such as a flash memory 2090, a DVD 2095, or an IC card and provided by the user. The program is read from the recording medium, installed in the hard disk drive 2040 in the computer 1900 via the RAM 2020, and executed by the CPU 2000.

The program installed in the computer 1900 and causing the computer 1900 to function as at least a part of the control device 1 is at least one of a rotation control module, a speed estimation module, an abnormality detection module, a restart module, a mode switching module, and an acceleration limiting module. Equipped with. These programs or modules may cause the CPU 2000 or the like to cause the computer 1900 to function as the rotation control unit 2, the speed estimation unit 3, the abnormality detection unit 4, the restart unit 5, and the mode switching unit 6, respectively.

When the information processing described in these programs is read by the computer 1900, it causes the CPU 2000 and the like, which are concrete means in which software and the various hardware resources described above cooperate, to rotate the computer 1900. It functions as the control unit 2, the speed estimation unit 3, the abnormality detection unit 4, the restart unit 5, and the mode switching unit 6. Then, by implementing the calculation or processing of information according to the purpose of use of the computer 1900 in the present embodiment by these specific means, the specific control device 1 according to the purpose of use is constructed.

As an example, when performing communication between the computer 1900 and an external device or the like, the CPU 2000 executes the communication program loaded on the RAM 2020, and based on the processing content described in the communication program, the communication interface. It instructs the communication process to 2030. Under the control of the CPU 2000, the communication interface 2030 reads out the transmission data stored in the transmission buffer area or the like provided on the storage device such as the RAM 2020, the hard disk drive 2040, the flash memory 2090, or the DVD 2095 and transmits it to the network. Alternatively, the received data received from the network is written to the reception buffer area or the like provided on the storage device. As described above, the communication interface 2030 may transfer the transmission/reception data to/from the storage device by the DMA (Direct Memory Access) method. Instead, the CPU 2000 transfers the storage device or the communication interface 2030 of the transfer source. The transmission/reception data may be transferred by reading the data from the device and writing the data to the transfer destination communication interface 2030 or the storage device.

In addition, the CPU 2000 DMAs all or necessary portions from files or databases stored in an external storage device such as a hard disk drive 2040, a DVD drive 2060 (DVD2095), a flash memory drive 2050 (flash memory 2090). The data is read into the RAM 2020 by transfer or the like, and various processing is performed on the data in the RAM 2020. Then, the CPU 2000 writes the processed data back to the external storage device by DMA transfer or the like. In such a process, the RAM 2020 can be regarded as temporarily holding the contents of the external storage device, and thus the RAM 2020, the external storage device, and the like are collectively referred to as a memory, a storage unit, a storage device, or the like in this embodiment. For example, the storage unit of the control device 1 appropriately stores data received from and/or provided to the rotation control unit 2, the speed estimation unit 3, the abnormality detection unit 4, the restart unit 5, and the mode switching unit 6. Good.

Various information such as various programs, data, tables, and databases in the present embodiment is stored in such a storage device and is a target of information processing. Note that the CPU 2000 can also hold part of the RAM 2020 in the cache memory and read/write on the cache memory. Even in such a form, the cache memory plays a part of the function of the RAM 2020. Therefore, in the present embodiment, the cache memory is also included in the RAM 2020, the memory, and/or the storage device unless otherwise indicated. To do.

Further, the CPU 2000 performs various operations described in the present embodiment on the data read from the RAM 2020, which is designated by the instruction sequence of the program, including information processing, condition determination, information search/replacement, and the like. Process and write back to the RAM 2020. For example, when the condition determination is performed, the CPU 2000 determines whether or not the various variables shown in the present embodiment satisfy a condition of being larger, smaller, above, below, or equal to other variables or constants. If the condition is satisfied (or not satisfied), a branch is made to a different instruction sequence or a subroutine is called.

Further, the CPU 2000 can search for information stored in a file in the storage device, a database, or the like. For example, when a plurality of entries in which the attribute values of the second attribute are associated with the attribute values of the first attribute are stored in the storage device, the CPU 2000 determines that the entries of the plurality of entries are stored in the storage device. Corresponding to the first attribute satisfying a predetermined condition by searching an entry in which the attribute value of the first attribute matches the specified condition and reading the attribute value of the second attribute stored in the entry. The attribute value of the obtained second attribute can be obtained.

Further, when a plurality of elements are listed in the description of the embodiment, elements other than the listed elements may be used. For example, when it is described that “X executes Y using A, B and C”, X may execute Y using D, in addition to A, B and C.

Although the present invention has been described using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is apparent to those skilled in the art that various changes or improvements can be added to the above-described embodiment. It is apparent from the description of the scope of claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

The execution order of each process such as the operation, procedure, step, and step in the device, system, program, and method shown in the claims, the specification, and the drawings is, in particular, “before” or “prior to”. It should be noted that the output of the previous process can be realized in any order unless it is used in the subsequent process. Even if the operation flow in the claims, the description, and the drawings is described by using “first,” “next,” and the like for convenience, it means that it is essential to carry out in this order. Not a thing.

DESCRIPTION OF SYMBOLS 1 control device, 2 rotation control unit, 3 speed estimation unit, 4 abnormality detection unit, 5 restart unit, 6 mode switching unit, 8 power source, 9 electric motor, 101 acceleration limiting unit, 103 subtractor, 105 speed adjuster, 107 current command calculation unit, 109 current command calculation unit, 111 changeover switch, 113 changeover switch, 115 subtractor, 117 subtractor, 119 current adjuster, 121 voltage coordinate converter, 123 PWM circuit, 125 input voltage detection circuit, 131 Power converter, 133 rectifier circuit, 135 u-phase current detector, 137 w-phase current detector, 139 current coordinate converter, 141 extended induced voltage calculator, 143 angle calculator, 145 speed estimator, 151 changeover switch, 153 Electrical angle calculator, 161 speed decrease detector, 163 step-out detector, 1631 low-pass filter, 1632 low-pass filter, 1633 angle calculator, 1634 vector sum calculator, 1635 step-out judger, 1637 off-delay, 1900 computer, 2000 CPU, 2010 ROM, 2020 RAM, 2030 communication interface, 2040 hard disk drive, 2050 flash memory drive, 2060 DVD drive, 2070 input/output chip, 2075 graphic controller, 2080 display device, 2082 host controller, 2084 input/output controller, 2090 Flash memory, 2095 DVD

Claims (20)

A speed estimation unit for calculating a speed estimation value of the rotor provided in the electric motor,
A rotation control unit that controls the rotation of the rotor,
A speed reduction detecting unit that detects a speed reduction state in response to the rotation speed of the rotor becoming equal to or lower than a first reference speed;
In response to the speed reduction state being detected while the rotation control unit is operating in the first control mode in which the rotation of the rotor is controlled so that the speed estimation value approaches the speed command value, A restart unit that switches the rotation control unit to an operation in a second control mode that controls the rotation of the rotor using the speed command value without using the speed estimation value, and restarts the electric motor;
A control device including. The control device according to claim 1, wherein the speed reduction detecting unit detects the speed reduction state in response to the estimated speed value being equal to or lower than the first reference speed. The speed estimation unit has an extended induced voltage calculator that calculates an extended induced voltage from a voltage supplied to the electric motor and a current flowing in the electric motor,
The control device according to claim 1 or 2, wherein the speed reduction detecting unit detects the speed reduction state by using the extension induced voltage. In the control coordinate system having the axis along the target angle of the rotor, the speed decrease detection unit is such that the magnitude of the extended induction voltage in the axial direction perpendicular to the axis along the target angle is a reference value or less. The control device according to claim 3, wherein the speed reduction state is detected under the condition that the speed is reduced. The control device according to claim 1, wherein the speed decrease detecting unit detects the speed decrease state by using an induced voltage calculated from a voltage supplied to the electric motor and a current flowing through the electric motor. .. In response to the speed command value becoming equal to or lower than the second reference speed while the rotation control unit is operating in the first control mode, the rotation control unit is set to the second control speed without restarting the electric motor. The control device according to any one of claims 1 to 5, further comprising a mode switching unit that switches to an operation in two control modes. The control device according to claim 6, wherein the second reference speed is higher than the first reference speed. Further comprising a step-out detection unit for detecting the step-out of the electric motor,
The restart unit restarts the electric motor in response to the detection of the step-out in the operation in the second control mode before switching the rotation control unit to the operation in the first control mode. The control device according to any one of claims 1 to 7. A speed estimation unit for calculating a speed estimation value of the rotor provided in the electric motor,
A rotation control unit that controls the rotation of the rotor,
A step-out detection unit that detects a step-out of the electric motor,
Before switching the rotation control unit to the operation in the first control mode for controlling the rotation of the rotor so as to bring the speed estimation value closer to the speed command value, the speed command value without using the speed estimation value. A restart unit that restarts the electric motor in response to the detection of the step-out in the operation in the second control mode for controlling the rotation of the rotor using
A control device including. While the rotation control unit is operating in the second control mode, the speed control value exceeds the third reference speed, and the rotation control unit is set to the 1 further comprises a mode switching unit for switching to the operation in the control mode,
The restarting unit is responsive to the step-out being detected when the speed command value exceeds the third reference speed while the rotation control unit is operating in the second control mode, The control device according to claim 9, which restarts the electric motor. The speed estimation unit has an extended induced voltage calculator that calculates an extended induced voltage from a voltage supplied to the electric motor and a current flowing in the electric motor,
The control device according to claim 9 or 10, wherein the out-of-step detector detects the out-of-step by using the extended induced voltage. The control device according to claim 11, wherein the out-of-step detecting unit detects the out-of-step by using an angle formed by the extended induced voltage in a control coordinate system having an axis along a target angle of the rotor. The control device according to claim 12, wherein the step-out detection unit detects the step-out on the condition that an angle formed by the extended induction voltage in the control coordinate system is equal to or larger than a reference angle. 14. The step-out detection unit detects the step-out using the magnitude of the extension induced voltage in a control coordinate system having an axis along a target angle of the rotor. The control device described. The control device according to claim 14, wherein the out-of-step detection unit detects the out-of-step on the condition that the magnitude of the extended induction voltage in the control coordinate system is equal to or less than a reference value. The rotation control unit has an acceleration limiting unit that limits a rate of change of the speed command value,
The control device according to any one of claims 1 to 15, wherein the restarting unit restarts the electric motor by initializing the speed command value after being limited by the acceleration limiting unit. A speed estimation step of calculating a speed estimation value of a rotor provided in the electric motor,
A rotation control step of controlling rotation of the rotor,
A speed reduction detecting step of detecting a speed reduction state in response to the rotation speed of the rotor becoming equal to or lower than a first reference speed;
The rotation control is performed in response to the speed reduction state being detected while controlling the rotation of the rotor in the first control mode so as to bring the speed estimation value closer to the speed command value by the rotation control step. A restart step of switching the stepwise control to a second control mode of controlling the rotation of the rotor using the speed command value without using the speed estimated value and restarting the electric motor;
A control method comprising: A speed estimation step of calculating a speed estimation value of a rotor provided in the electric motor,
A rotation control step of controlling rotation of the rotor,
A step-out detection step of detecting a step-out of the electric motor;
Before switching the control by the rotation control step to the first control mode for controlling the rotation of the rotor so that the speed estimated value approaches the speed command value, the speed command value is set without using the speed estimated value. A restart step of restarting the electric motor in response to the detection of the step-out in the second control mode in which the rotation of the rotor is controlled using the
A control method comprising: Computer,
A speed estimation unit for calculating a speed estimation value of the rotor provided in the electric motor,
A rotation control unit that controls the rotation of the rotor,
A speed reduction detecting unit that detects a speed reduction state in response to the rotation speed of the rotor becoming equal to or lower than a first reference speed;
In response to the speed reduction state being detected while the rotation control unit is operating in the first control mode in which the rotation of the rotor is controlled so that the speed estimation value approaches the speed command value, The rotation control unit is caused to function as a restarting unit that restarts the electric motor by switching to an operation in a second control mode in which the rotation speed of the rotor is controlled by using the speed command value without using the speed estimation value. Control program. Computer,
A speed estimation unit for calculating a speed estimation value of the rotor provided in the electric motor,
A rotation control unit that controls the rotation of the rotor,
A step-out detection unit that detects a step-out of the electric motor,
Before switching the rotation control unit to the operation in the first control mode for controlling the rotation of the rotor so as to bring the speed estimation value closer to the speed command value, the speed command value without using the speed estimation value. A control program that functions as a restart unit that restarts the electric motor when the step-out is detected in the operation in the second control mode in which the rotation of the rotor is controlled by using the.

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