JP6272508B2 - Angular error correction device and angular error correction method for position detector - Google Patents

Description

  The present invention is applied to, for example, a control device for an elevator hoisting machine, a control device for an on-vehicle motor, or a control device for a motor of a machine tool, and a position detector including a periodic error that is uniquely determined according to the rotational position of the motor. The present invention relates to an angle error correction apparatus and an angle error correction method for a position detector that correct the angle error of the position detector.

  Conventionally, an angle signal is detected from a signal detected by an angle detector, for example, a resolver, and the error waveform of the resolver is made up of a determined n-order component unique to the resolver and is reproducible. Then, the position error is calculated by referring to the detected angle signal by the angle error estimator, the speed error signal is calculated by differentiating the position error, and the speed error signal is subjected to frequency analysis by, for example, Fourier transform. The detection error for each frequency component is calculated, the calculated detection errors are combined to generate an estimated angle error signal, and the angle signal correction circuit corrects the detected angle signal using the generated estimated angle error signal. A resolver angle detection device is known (see, for example, Patent Document 1).

JP 2012-145371 A

However, the prior art has the following problems.
In the conventional resolver angle detection device, the speed detector detects the rotational speed of the motor from the angle signal detected by the angle detector, and estimates the angle error using this detected speed. Here, when the angle error is estimated using the detected speed, the angle error estimation accuracy is determined by the angle detector or the speed resolution of the speed detector. For this reason, an angle detector or a velocity detector with a low velocity resolution has a problem that a quantization error occurs and the angle error estimation accuracy cannot be sufficiently obtained.

  The present invention has been made to solve the above-described problems, and provides an angle error correction device and an angle error correction method for a position detector capable of accurately estimating and correcting an angle error. Objective.

  An angle error correction apparatus for a position detector according to the present invention detects the rotational position of an electric motor and corrects the angle error of the position detector including a periodic error that is uniquely determined according to the rotational position. An error correction device that uses a current detection unit that detects a current flowing through the motor and a rotational position of the motor to analyze the frequency of the current detected by the current detection unit and to detect the amplitude of a specific frequency component corresponding to the angle error An angle error estimator that estimates an angle error consisting of a specific frequency component as an angle error estimated value based on the amplitude calculated by the frequency analysis unit and the rotational position of the motor, and a position detector The angle error correction unit that corrects the angle error using the estimated angle error value with respect to the rotation position of the motor detected in step 1 and the rotation position of the motor whose angle error is corrected by the angle error correction unit. A speed calculation unit for calculating the rotation speed of the rotating electrical machine, a speed command value generation unit for generating a speed command value for the electric motor based on a speed command input from the outside, and a speed control gain from a predetermined value A variable gain mechanism that changes, a speed controller that generates a current command value for the motor based on a speed deviation between the speed command value and the rotation speed of the rotating electrical machine, and an operating state of the motor is an angle error estimation operation And a control state switching unit that switches between normal operation and speed control, and the speed controller has a speed higher than that when the motor operation state is normal operation when the motor operation state is angle error estimation operation. The control gain is increased.

  Also, the angle error correction method of the position detector according to the present invention detects the rotational position of the electric motor and corrects the angular error of the position detector including a periodic error uniquely determined according to the rotational position. The angle error correction method executed by the angle error correction device of the current detection step of detecting the current flowing through the motor, and using the rotational position of the motor, frequency analysis of the current detected in the current detection step, Based on the frequency analysis step that calculates the amplitude of the specific frequency component corresponding to the angle error, and the amplitude calculated in the frequency analysis step and the rotational position of the motor, the angle error consisting of the specific frequency component is estimated as the angle error estimated value. The angle error is corrected by using the angle error estimation value for the angle error estimation step and the rotational position of the motor detected by the position detector. A speed calculation step for calculating the rotation speed of the rotating electrical machine based on the rotation step of the motor in which the angle error is corrected in the positive step, the angle error correction step, and a speed for the motor based on a speed command input from the outside. A speed command value generation step for generating a command value, a control state switching step for switching whether the operation state of the motor is an angle error estimation operation or a normal operation, and a speed deviation between the speed command value and the rotation speed of the rotating electrical machine A speed control step for generating a current command value for the motor, and a control state switching step for switching whether the operation state of the motor is an angle error estimation operation or a normal operation. When the motor operating state is an angle error estimating operation, the speed control gain is set larger than when the motor operating state is a normal operation. It is intended to include Kusuru step.

According to the angle error correction device and the angle error correction method for a position detector according to the present invention, the speed command value generation unit (step) generates a speed command value for the motor based on the speed command input from the outside. The speed controller (step) generates a current command value for the electric motor based on the speed deviation between the speed command value and the rotational speed of the rotating electrical machine. The control state switching unit (step) Switches between error estimation operation and normal operation. Here, the speed controller (step) increases the speed control gain when the operation state of the motor is the angle error estimation operation than when the operation state of the motor is the normal operation.
As the speed control gain increases, the current command value increases even at the same speed deviation, so even if the current detector resolution is the same, the angle error that is the output of the angle error estimator that inputs the current The estimation accuracy of the estimated value can be improved.

It is a block diagram which shows the whole structure of the control apparatus of the electric motor containing the angle error correction apparatus of the position detector concerning this invention. It is a block diagram which shows the control apparatus of the electric motor to which the angle error correction apparatus of the position detector which concerns on Embodiment 1 of this invention was applied. It is a block diagram which shows the control apparatus of the electric motor to which the angle error correction apparatus of the position detector which concerns on Embodiment 1 of this invention was applied. It is a block diagram which shows the control apparatus of the electric motor to which the angle error correction apparatus of the position detector which concerns on Embodiment 1 of this invention was applied. It is a block diagram which shows the control apparatus of the electric motor to which the angle error correction apparatus of the position detector which concerns on Embodiment 1 of this invention was applied. It is a graph which illustrates the detection error of the position detector of the angle error correction apparatus of the position detector which concerns on Embodiment 1 of this invention. It is a block diagram which shows the angle error estimation part of the angle error correction apparatus of the position detector which concerns on Embodiment 1 of this invention. It is a block diagram which shows the speed control part of the angle error correction apparatus of the position detector which concerns on Embodiment 1 of this invention with the control state switching part. It is another block diagram which shows the whole structure of the control apparatus of the electric motor containing the angle error correction apparatus of the position detector which concerns on this invention.

  Hereinafter, preferred embodiments of an angle error correction device and an angle error correction method for a position detector according to the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals. To explain.

  In the following embodiments, based on the current amplitude, the position-dependent angle error included in the rotational position of the motor, which is the output from the position detector, is estimated and corrected. A method for improving the accuracy of angle error estimation by increasing the speed control gain of the speed controller and improving the responsiveness during the angle error estimation operation in the correction apparatus will be described.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing the overall configuration of a motor control device including an angle error correction device for a position detector according to the present invention. 2 to 5 are block diagrams showing a motor control device to which the angular error correction device for a position detector according to Embodiment 1 of the present invention is applied.

  1 to 5, the motor control device includes a speed command value generation unit 1, a speed controller 2, a current controller 3, an inverter 4, an electric motor 5, a position detector 6, a current sensor (current detection unit) 7, A speed calculation unit 8, a detection position correction unit 9, a position calculation unit 11, a coordinate converter 12, an angle error estimation unit 20, and a control state switching unit 30 are provided.

  The speed command value generation unit 1 generates and outputs a speed command value for the electric motor 5 based on a speed command input from the outside. Although not shown, the speed command value generation unit 1 may include a position control system. The present invention can be applied even when the speed command value generation unit 1 includes a position control system.

  The speed controller 2 receives the speed deviation between the speed command value from the speed command value generation unit 1 and the rotation speed of the motor 5 calculated by the speed calculation unit 8 and generates a current command value for the motor 5. Output. The control state switching unit 30 switches whether the operation state of the electric motor 5 is an angle error estimation operation or a normal operation. Detailed functions of the speed controller 2 and the control state switching unit 30 will be described later.

  The speed calculation unit 8 calculates and outputs the rotation speed of the electric motor 5 based on the position information or the angle information in which the rotation position of the electric motor 5 that is an output from the position detector 6 is corrected by the detection position correction unit 9. To do. The speed calculation unit 8 calculates the rotation speed by the time differentiation of the position or angle in the simplest manner.

  2 and 4, the speed calculation unit 8 may perform speed calculation based on the position information (for example, the number of pulses of the optical encoder) of the position detector 6, as shown in FIGS. 5, the speed calculation may be performed based on the angle information calculated by the position calculation unit 11. Further, the speed calculation unit 8 may include a configuration for measuring time.

  The current controller 3 converts the current command value from the speed controller 2 and the phase current output from the current sensor 7 shown in FIGS. 2 and 3 or the phase current shown in FIGS. The voltage command value of the electric motor 5 is generated and output using the difference from the shaft current of the electric motor 5 converted into the dq axis at

  The position calculation unit 11 calculates and outputs angle information of the electric motor 5 based on the rotational position of the electric motor 5 that is an output from the position detector 6 or the position information corrected by the detection position correction unit 9. The coordinate converter 12 converts the phase current from the current sensor 7 into coordinates suitable for control, such as an α-β axis, dq axis, or γ-δ axis, when the electric motor 5 is vector-controlled. .

  The detected position correcting unit 9 is an angle error estimating unit for angle information obtained by converting the rotational position of the electric motor 5 output from the position detector 6 or the rotational position from the position detector 6 by the position calculating unit 11. The position error or angle information after correction is output by adding or subtracting the estimated angle error value output from 20.

  The current sensor 7 measures the current of the electric motor 5. For example, when the motor 5 is a three-phase motor, a two-phase phase current is often measured, but a three-phase phase current may be measured. 1 to 5, the current sensor 7 measures the output current of the inverter 4. However, the current sensor 7 measures the bus current of the inverter 4 as in a current measurement method using a one-shunt resistor, and Each phase current may be estimated. Even in this case, the present invention is not affected at all.

  Based on the voltage command value from the current controller 3, the inverter 4 converts the voltage of a power source (not shown) into a desired variable voltage variable frequency. In this invention, like an inverter device generally sold, after converting an AC voltage to a DC voltage by a converter, a power converter that converts the DC voltage to an AC voltage by an inverter, or a matrix converter, A variable voltage variable frequency power converter including a power converter that directly converts an AC voltage into an AC variable voltage variable frequency.

  In addition, inverter 4 according to Embodiment 1 of the present invention may include a coordinate conversion function in addition to inverter 4 described above. That is, when the voltage command value is a dq-axis voltage command value, the dq-axis voltage command value is converted into a phase voltage or a line voltage, and the voltage according to the commanded voltage command value. It is expressed as an inverter 4 including a coordinate conversion function for converting to. Although not shown, the present invention can be applied even if a device or means for correcting the dead time of the inverter 4 is provided.

  The position detector 6 detects the rotational position of the electric motor 5 necessary for controlling the electric motor 5, such as an optical encoder, a magnetic encoder, or a resolver. Further, as shown in FIG. 6, the position detector 6 includes a cyclic error that is uniquely determined according to the rotational position of the electric motor 5 in the output rotational position information.

  Here, the periodic error uniquely determined according to the rotational position of the electric motor 5 is, for example, the detection error of the resolver described in paragraphs 0020 and 0021 of the above-mentioned Patent Document 1, and the missing pulse due to the slit failure in the optical encoder. It also refers to a reproducible error depending on the rotational position, such as an imbalance in the distance between pulses.

Hereinafter, the periodic error uniquely determined according to the rotational position of the electric motor 5 is expressed as an angle error θ _{err obtained} by converting the position information into an angle. The present invention can be applied when the position detector 6 includes a periodic error uniquely determined according to the rotational position of the electric motor 5 and the principal component order of the angle error θ _err is known.

The periodic angular error θ _err of the position detector 6 can be approximately expressed using a sine wave as shown in the following equation (1). In addition, since there is no essential difference between the notation by the sine wave and the notation by the cosine wave, the first embodiment of the present invention unifies the notation by the sine wave.

However, in the formula (1), θ _m represents the mechanical angle of the motor 5, A ₁ represents an error amplitude in N ₁ order order, A ₂ represents an error amplitude at the N ₂ order order, A _n is N ₁ indicates the error amplitude in the N- _th order, φ ₁ indicates a phase shift (error phase) with respect to the mechanical angle of the motor 5 in the N ₁ -order, and φ ₂ indicates the mechanical angle of the motor 5 in the N- _second order. A phase shift is indicated, and φ _n indicates a phase shift with respect to the mechanical angle of the electric motor 5 in the N _{n -th} order.

It should be noted that the spatial orders of N ₁ , N ₂ ... N _n in equation (1) do not have to be consecutive integers such as 1, 2... Nn, and are periodically determined uniquely according to the rotational position of the electric motor 5. Is the spatial order of the principal component of the error. The main component here refers to a component whose amplitude in the spatial order is larger than the amplitude of other frequencies.

Further, the expression (1) is expressed as a combination of three or more frequency components, but the frequency component of the periodic angular error θ _err may be one, two, or more components. It may be configured.

  FIG. 7 is a block diagram showing the angle error estimating unit 20 of the angle error correcting device for the position detector according to the first embodiment of the present invention. In FIG. 7, the angle error estimator 20 includes a frequency analyzer 21 and an angle error estimator 22.

  The frequency analysis unit 21 receives the phase current from the current sensor 7 and the rotational position of the electric motor 5 that is the output from the position detector 6 as input by inputting position information or angle information corrected by the detection position correction unit 9. Obtain the amplitude, or amplitude and phase, of the current at the desired frequency.

  Here, the frequency analysis unit 21 is preferably configured to obtain an amplitude and phase at a desired frequency of an input signal, such as Fourier transform, Fourier series analysis, or fast Fourier transform. A configuration may be used in which a desired frequency signal is extracted and a desired amplitude or phase of an input signal is calculated by an amplitude detection unit or a phase detection unit like a filter. Moreover, the filter used here may be an electrical filter that combines a resistor, a capacitor, a coil, or the like, or may be a process performed in a computer.

  In particular, in the first embodiment of the present invention, the configuration of the frequency analysis unit 21 is not limited as long as information proportional to the amplitude of the desired frequency or information proportional to the power of the amplitude can be detected. In FIGS. 2 and 3, the phase current is input, but as shown in FIGS. 4 and 5, the d-axis current, the q-axis current, the γ-axis current, the δ-axis current obtained by coordinate conversion of the phase current, or Either α-axis current or β-axis current may be input.

The signal having a desired frequency (specific frequency) referred to here indicates a signal having the same frequency as the main component of the angle error θ _err caused by the periodic angle error θ _err of the position detector 6. In the first embodiment of the present invention, a desired frequency is expressed as a spatial frequency, but there is no essential difference even if it is a time frequency.

  Here, the spatial frequency refers to a frequency in one rotation of the electric motor 5 in a specific section, in Embodiment 1 of the present invention. A periodic N wave signal in one rotation of the motor 5 is referred to as a spatial order N wave.

In the control device for the electric motor 5 provided with the position detector 6, since the error of the position detector 6 has a periodicity corresponding to the rotational position of the electric motor 5, the frequency analysis is preferably an analysis based on the spatial frequency. 1), the angle error θ _err is expressed by the spatial frequency, and the frequency analysis unit 21 shown in FIGS. 1 to 5 also has an input (current and angle) corresponding to the spatial frequency analysis. Yes.

  However, Embodiment 1 of the present invention can also be applied to frequency analysis based on time frequency. When performing frequency analysis based on time frequency, instead of inputting current and angle, detection speed and time measurement Frequency analysis is performed using the measurement time and current measured by the unit as inputs.

In the angle error estimator 22, the current amplitude value of a desired frequency component that is an output of the frequency analysis unit 21 and the rotational position of the electric motor 5 that is an output from the position detector 6 are corrected by the detection position correction unit 9. Using the angle information as an input, a periodic angle error θ _err uniquely determined according to the rotational position of the electric motor 5 is estimated by an estimation method described later, and the angle error estimated value is output as angle information or position information.

  2 and 4, since one of the inputs of the detection position correction unit 9 is the output signal of the position detector 6 (the rotational position of the electric motor 5), the angle error estimator 22 outputs the output signal of the position detector 6. Is output. That is, when the position detector 6 is an optical encoder, the resolution is 1024 pulses / rotation, and the estimation result of the angle error estimator 22 is 1 °, the angle error estimator 22 is 1 °. The corresponding number of pulses of 3 is output as position information.

  As shown in FIGS. 3 and 5, when one of the inputs of the detection position correction unit 9 is angle information obtained by converting the rotation position from the position detector 6 by the position calculation unit 11, an angle error The estimator 22 outputs angle information.

  As shown in the above equation (1), when there are a plurality of frequency components of the angle error, the angle error may be estimated and added sequentially with each component, or a plurality of frequency components may be estimated simultaneously. . At this time, in the case of simultaneous estimation, the estimation time can be shortened as compared with the case where the angle error is sequentially estimated for each component. Here, for simplicity, a case will be described in which the angle error is composed of only a single frequency component.

  Here, when speed feedback control is performed by the position detector 6 including a cyclic angle error uniquely determined according to the rotational position of the electric motor 5, a current pulsation or current command value including a frequency component of the same order as the angle error is obtained. It is known that pulsation occurs. Therefore, if the angle error is estimated and corrected so as to suppress the current pulsation, the angle error and the error of the rotational position of the electric motor 5 calculated using the output from the position detector 6 can be reduced.

When the position detector 6 includes a periodic error that is uniquely determined according to the rotational position of the motor 5, if the frequency analysis is performed by the frequency analysis unit 21, the motor 5 is a permanent magnet synchronous motor. in some case, the current ripple appearing in the phase current, the pole and the logarithm with P _n, when the order of the desired frequency and n _n, the P _n ± n _n next degree machine degree.

Therefore, frequency analysis of at least one of the phase currents is performed, and the P _n + N _n -order or P _n -N _n -order current error is estimated from the P _n + N _n -order or P _n -N _n -order current. do it. However, the P _n -N _n following order, when the order N _n of the desired frequency than the pole pair number P _n of the electric motor 5 is large, because it may not present a negative number, P It is desirable to analyze the frequency of _n + N _nth order current. Moreover, when performing estimation, constant torque and constant speed operation is desirable.

When either the d-axis current or the q-axis current is subjected to frequency analysis by the frequency analysis unit 21, the current pulsation component appearing on the dq axis is the same as the N _n order due to the angular error of the machine N _n order. Has a pulsating component of order. In addition, the d-axis current has a current pulsation similar to the angle error because the q-axis current, which is the torque current, wraps around due to the magnetic pole deviation caused by the angle error. Furthermore, in the q-axis current, the speed pulsation becomes the pulsation of the current command value through the speed control system. Therefore, the q-axis current becomes a current pulsation similar to the angle error that causes the speed pulsation.

Therefore, for example, the angle error estimator 22 may estimate the angle error so as to minimize the N _n -order current amplitude of the d-axis current or the q-axis current obtained by the frequency analysis in the frequency analysis unit 21. .

  In addition, when performing a frequency analysis with the current detection value of either the d-axis current or the q-axis current, or any current command value, the condition that the q-axis current that wraps around is constant, that is, the condition of constant acceleration. Estimate with. In particular, it is desirable to perform the estimation under the condition that the acceleration is zero, that is, the electric motor 5 is rotating at a constant speed.

  FIG. 8 is a block diagram showing the speed control unit of the angle error correction device for the position detector according to the first embodiment of the present invention, together with the control state switching unit. As described above, the control state switching unit 30 switches the operation state of the electric motor 5 between the angle error estimation operation and the normal operation. The angle error correction apparatus of the position detector 6 according to Embodiment 1 of the present invention estimates the angle error so that the current pulsation of the frequency component due to the angle error is minimized during the angle error estimation operation, and performs the normal operation. Sometimes the angle error is corrected using the angle error estimate. When estimation is not performed, the amplitude value of the estimated angle error is set to zero.

  In FIG. 8, the speed controller 2 has a variable gain mechanism for changing the speed control gain from a predetermined value, and the speed control gain can be changed. In the variable gain mechanism, when the control state switching unit 30 switches the operation state of the motor 5 to the angle error estimation operation, the speed control is performed as compared with the case where the operation state of the motor 5 is switched to the normal operation. Responsiveness is improved by increasing the gain.

  Here, when the case where the speed controller 2 is PID control is taken as an example, the current command value that is the output of the speed controller 2 is expressed by the following equation (2).

が一定の場合、速度制御ゲイン（速度制御ＰゲインＧｓｐ、速度制御ＩゲインＧｓｉ、速度制御ＤゲインＧｓｄの何れか１つ、またはこれらの組み合わせ）が大きいほど、電流指令値の脈動が大きくなる。According to the equation (2), if the speed detection timing, the speed deviation of the speed control system, and the calculation period of the current command value are the same, the speed detection pulsation

Is constant, the pulsation of the current command value increases as the speed control gain (one of speed control P gain Gsp, speed control I gain Gsi, speed control D gain Gsd, or a combination thereof) increases.

が同一の場合において、角度誤差推定時の電流指令値の脈動が大きくなる。このとき、電流検出値は、電流指令値に追従するように大きく脈動することになる。Further, when the speed control gain is large, the speed detection pulsation generated by the position detector 6 including an error.

, The pulsation of the current command value at the time of angle error estimation becomes large. At this time, the detected current value pulsates greatly so as to follow the current command value.

  Even if the speed control gain of the speed controller 2 is changed, the resolution itself of the current sensor 7 does not change. However, even if the magnitude of the angle error is the same, the current pulsation that appears is large, so the angle error estimation resolution determined by the resolution of the current sensor 7 according to Embodiment 1 of the present invention is relatively increased. be able to. Therefore, it is possible to improve the estimation accuracy of the angle error as compared with the case of a fixed gain.

  Here, the variable gain mechanism does not change the speed control gain in accordance with the time-varying parameter, but operates by switching to a speed control gain larger than that in the normal operation during the angle error estimation operation. At this time, the variable gain mechanism may switch the preset multiple fixed gain values, or may change the gain by changing the bit shift amount, such as a shifter. The gain may be switched by a mathematical operation such as adding a certain value.

  In the above description, the case where the speed control system is PID control has been described as an example. However, the present invention is not limited to this, and the present invention is applicable regardless of whether the speed control system is P control or PI control. Can be applied. As a result, the speed control gain can be increased to increase the current pulsation, and the angle error estimation accuracy determined by the current resolution can be improved.

  As shown in FIG. 9, the speed command value generation unit 1 sets the speed command value to the operation of the motor 5 when the control state switching unit 30 switches the operation state of the motor 5 to the angle error estimation operation. You may change from the case where a state is normal driving | operation. FIG. 9 is another block diagram showing the overall configuration of the motor control device including the angle error correction device for the position detector according to the present invention.

  Here, when the operation state of the electric motor 5 is the angle error estimation operation, the speed command value generation unit 1 changes the speed command value to a value that does not cause mechanical resonance, or the speed control system does not oscillate. The speed command may be changed to such an acceleration pattern. As a result, the speed command value can be changed to prevent mechanical resonance or oscillation from occurring.

As described above, according to the first embodiment, the speed command value generation unit generates a speed command value for the electric motor based on the speed command input from the outside, and the speed controller rotates the speed command value and the rotation speed. Based on the speed deviation from the rotation speed of the electric machine, a current command value for the motor is generated, and the control state switching unit switches whether the operation state of the motor is the angle error estimation operation or the normal operation. Here, the speed controller increases the speed control gain when the operation state of the motor is the angle error estimation operation than when the operation state of the motor is the normal operation.
As the speed control gain increases, the current command value increases even at the same speed deviation, so even if the current detector resolution is the same, the angle error that is the output of the angle error estimator that inputs the current The estimation accuracy of the estimated value can be improved.

Claims (3)

An angular error correction device for a position detector that detects a rotational position of an electric motor and corrects an angular error of the position detector including a cyclic error that is uniquely determined according to the rotational position,
A current detector for detecting a current flowing in the motor;
Using the rotational position of the electric motor, frequency analysis of the current detected by the current detection unit, a frequency analysis unit that calculates the amplitude of a specific frequency component corresponding to the angle error,
An angle error estimator that estimates the angle error composed of the specific frequency component as an angle error estimated value based on the amplitude calculated by the frequency analysis unit and the rotational position of the motor;
An angular error correction unit that corrects the angular error using the estimated angular error value with respect to the rotational position of the electric motor detected by the position detector;
Based on the rotational position of the motor the angular error in the angle error correction unit is corrected, and the speed calculator for calculating the rotational speed of the rotary electric machine,
Based on a speed command input from the outside, a speed command value generation unit that generates a speed command value for the electric motor,
A speed controller having a variable gain mechanism for switching a speed control gain, and generating a current command value for the electric motor based on a speed deviation between the speed command value and a rotation speed of the rotating electrical machine;
A control state switching unit that switches whether the operation state of the electric motor is an angle error estimation operation or a normal operation, and
The speed controller increases the speed control gain when the operation state of the motor is the angle error estimation operation than when the operation state of the motor is the normal operation. Correction device. The speed command value generation unit changes the speed command value when the operation state of the motor is the angle error estimation operation, from when the operation state of the motor is the normal operation. Angle detector for position detectors. An angle error correction method executed by an angle error correction device of a position detector that detects a rotation position of an electric motor and corrects an angle error of the position detector including a periodic error uniquely determined according to the rotation position. And
A current detection step for detecting a current flowing through the motor;
Using the rotational position of the electric motor, frequency analysis of the current detected in the current detection step, the frequency analysis step of calculating the amplitude of the specific frequency component corresponding to the angle error,
An angle error estimation step for estimating the angle error consisting of the specific frequency component as an angle error estimated value based on the amplitude calculated in the frequency analysis step and the rotational position of the motor;
An angle error correction step for correcting the angle error with respect to the rotational position of the electric motor detected by the position detector, using the angle error estimated value;
And speed calculating step based on the rotational position of the motor the angular error in the angle error correction step is corrected to calculate the rotational speed of the rotary electric machine,
Based on a speed command input from outside, a speed command value generation step for generating a speed command value for the motor;
A control state switching step for switching whether the operation state of the electric motor is an angle error estimation operation or a normal operation;
A speed control step for generating a current command value for the electric motor based on a speed deviation between the speed command value and the rotational speed of the rotating electrical machine;
A control state switching step for switching whether the operation state of the electric motor is an angle error estimation operation or a normal operation, and
The speed control step includes a step of increasing a speed control gain when the operation state of the motor is the angle error estimation operation than when the operation state of the motor is the normal operation. Angle error correction method.

Images