Method and apparatus for position-sensorless motor control
First Claim
1. A position-sensorless motor control method comprising the steps of:
- (A) determining a target current vector of stator windings;
(B) setting one of a rotor-position estimation current signal and a rotor-position estimation voltage signal, with varying the period thereof;
(C) detecting currents flowing through said stator windings;
(D) carrying out one of (a) superimposing said rotor-position estimation current signal on a component of said target current vector in a first direction based on an estimated position (γ
-axis direction, hereafter) of a rotor, thereby obtaining a target current vector with superimposed wave, and (b) superimposing said rotor-position estimation voltage signal on a component of a target voltage vector corresponding to said target current vector in said first direction, thereby obtaining a target voltage vector with superimposed wave;
(E) supplying electric power to said stator windings through a motor driving device on the basis of one of said target current vector with superimposed wave and said target voltage vector with superimposed wave;
(F) measuring a current response to one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, from a component of a current vector in a second direction having a fixed relation with said first direction, said current vector representing said currents detected in said detecting step; and
(G) correcting said γ
-axis direction on the basis of said current response.
1 Assignment
0 Petitions
Accused Products
Abstract
A method for position-sensorless motor control is provided, wherein a rotor-position estimation current signal is superimposed on the γ-axis direction component of a target current vector representing target currents of stator windings. The period of the current signal is an even multiple of a PWM carrier period and varies at random. The amplitude of the current signal increases with the amplitudes of the target currents. An even number of samples are obtained from the δ-axis direction component of a current vector representing detected currents of the stator windings in each period of the current signal. A discrete Fourier integration of the samples determines the amplitude of a current response to the current signal in the δ-axis direction. The γ-axis direction is corrected so that the current response substantially shrinks to zero in the δ-axis direction.
-
Citations
28 Claims
-
1. A position-sensorless motor control method comprising the steps of:
-
(A) determining a target current vector of stator windings;
(B) setting one of a rotor-position estimation current signal and a rotor-position estimation voltage signal, with varying the period thereof;
(C) detecting currents flowing through said stator windings;
(D) carrying out one of (a) superimposing said rotor-position estimation current signal on a component of said target current vector in a first direction based on an estimated position (γ
-axis direction, hereafter) of a rotor, thereby obtaining a target current vector with superimposed wave, and(b) superimposing said rotor-position estimation voltage signal on a component of a target voltage vector corresponding to said target current vector in said first direction, thereby obtaining a target voltage vector with superimposed wave;
(E) supplying electric power to said stator windings through a motor driving device on the basis of one of said target current vector with superimposed wave and said target voltage vector with superimposed wave;
(F) measuring a current response to one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, from a component of a current vector in a second direction having a fixed relation with said first direction, said current vector representing said currents detected in said detecting step; and
(G) correcting said γ
-axis direction on the basis of said current response.- View Dependent Claims (2, 3, 4)
(a) said first direction is one of said γ
-axis direction and a direction substantially shifted by 90°
in terms of electric angle from said γ
-axis direction;
(b) said second direction is a direction substantially shifted by 90°
in terms of electric angle from said first direction; and
(c) said γ
-axis direction is corrected so that said current response in said second direction substantially converges to zero.
-
-
5. A position-sensorless motor control method comprising the steps of:
-
(A) determining a target current vector of stator windings;
(B) setting one of a rotor-position estimation current signal and a rotor-position estimation voltage signal, with varying the amplitude thereof;
(C) detecting currents flowing through said stator windings;
(D) carrying out one of (a) superimposing said rotor-position estimation current signal on a component of said target current vector in a first direction based on a γ
-axis direction of a rotor, thereby obtaining a target current vector with superimposed wave, and(b) superimposing said rotor-position estimation voltage signal on a component of a target voltage vector corresponding to said target current vector in said first direction, thereby obtaining a target voltage vector with superimposed wave;
(E) supplying electric power to said stator windings through a motor driving device on the basis of one of said target current vector with superimposed wave and said target voltage vector with superimposed wave;
(F) measuring a current response to one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, from a component of a current vector in a second direction having a fixed relation with said first direction, said current vector representing said currents detected in said detecting step; and
(G) correcting said γ
-axis direction on the basis of said current response.- View Dependent Claims (6)
-
-
7. A position-sensorless motor control method comprising the steps of:
-
(A) determining a target current vector of stator windings;
(B) setting one of a rotor-position estimation current signal and a rotor-position estimation voltage signal, with a predetermined period;
(C) detecting currents flowing through said stator windings;
(D) carrying out one of (a) superimposing said rotor-position estimation current signal on a component of said target current vector in a first direction based on a γ
-axis direction of a rotor, thereby obtaining a target current vector with superimposed wave, and(b) superimposing said rotor-position estimation voltage signal on a component of a target voltage vector corresponding to said target current vector in said first direction, thereby obtaining a target voltage vector with superimposed wave;
(E) supplying electric power to said stator windings through a motor driving device on the basis of one of said target current vector with superimposed wave and said target voltage vector with superimposed wave;
(F) measuring a current response to one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, from a component of a current vector in a second direction having a fixed relation with said first direction through sampling at least three times in each period of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, said current vector representing said currents detected in said detecting step; and
(G) correcting said γ
-axis direction on the basis of said current response.- View Dependent Claims (8, 9)
(A) (a) the period of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal is set to be an even multiple of a carrier period of pulse width modulation (PWM), and (b) the waveform thereof is set symmetrically with respect to the middle point between the former half and the latter half of said period;
(B) target voltages are modulated through said PWM, said target voltages represented by one of a target voltage vector corresponding to said target current vector with superimposed wave and said target voltage vector with superimposed wave, and the modulated target voltages are applied to said stator windings through said motor driving device; and
(C) said current response is measured on the basis of the symmetric waveform of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal.
-
-
10. A position-sensorless motor control method comprising the steps of:
-
(A) determining a target current vector of stator windings;
(B) setting one of a rotor-position estimation current signal and a rotor-position estimation voltage signal, wherein (a) the period thereof is an even multiple of a carrier period of PWM and (b) the waveform thereof is symmetric with respect to the middle point between the former half and the latter half of said period;
(C) detecting currents flowing through said stator windings;
(D) carrying out one of (a) superimposing said rotor-position estimation current signal on a component of said target current vector in a first direction based on a γ
-axis direction of a rotor, thereby obtaining a target current vector with superimposed wave, and(b) superimposing said rotor-position estimation voltage signal on a component of a target voltage vector corresponding to said target current vector in said first direction, thereby obtaining a target voltage vector with superimposed wave;
(E) (a) modulating target voltages through said PWM, said target voltages represented by one of a target voltage vector corresponding to said target current vector with superimposed wave and said target voltage vector with superimposed wave, and (b) applying the modulated target voltages to said stator windings through a motor driving device;
(F) measuring a current response to one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, from a component of a current vector in a second direction having a fixed relation with said first direction, on the basis of the symmetric waveform of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, said current vector representing said currents detected in said detecting step; and
(G) correcting said γ
-axis direction on the basis of said current response.
-
-
11. A position-sensorless motor control method comprising the steps of:
-
(A) determining a target current vector of stator windings;
(B) setting one of a rotor-position estimation current signal and a rotor-position estimation voltage signal, with a predetermined period;
(C) detecting currents flowing through said stator windings;
(D) carrying out one of (a) superimposing said rotor-position estimation current signal on a component of said target current vector in a first direction based on a γ
-axis direction of a rotor, thereby obtaining a target current vector with superimposed wave, and(b) superimposing said rotor-position estimation voltage signal on a component of a target voltage vector corresponding to said target current vector in said first direction, thereby obtaining a target voltage vector with superimposed wave;
(E) supplying electric power to said stator windings through a motor driving device on the basis of one of said target current vector with superimposed wave and said target voltage vector with superimposed wave;
(F) (a) multiplying a component of a current vector in a second direction orthogonal to said first direction in terms of electric angle by a signal, said current vector representing said currents detected in the detecting step, said signal having (1) a period substantially equal to the period of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, and (2) a phase substantially shifted by 90°
in terms of electric angle from one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, and(b) measuring a current response to one of said rotor-position estimation current signal and said rotor-position estimation voltage signal from the result of the multiplication; and
(G) correcting said γ
-axis direction on the basis of said current response.
-
-
12. A position-sensorless motor control method comprising the steps of:
-
(A) determining a target current vector of stator windings;
(B) setting one of a rotor-position estimation current signal and a rotor-position estimation voltage signal;
(C) detecting currents flowing through said stator windings;
(D) carrying out one of (a) superimposing said rotor-position estimation current signal on a component of said target current vector in a first direction based on a γ
-axis direction of a rotor, thereby obtaining a target current vector with superimposed wave, and(b) superimposing said rotor-position estimation voltage signal on a component of a target voltage vector corresponding to said target current vector in said first direction, thereby obtaining a target voltage vector with superimposed wave;
(E) supplying electric power to said stator windings through a motor driving device on the basis of one of said target current vector with superimposed wave and said target voltage vector with superimposed wave;
(F) measuring a current response to one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, from a component of a current vector in a second direction having a fixed relation with said first direction, said current vector representing said currents detected in said detecting step;
(G) limiting a value of said current response; and
(H) correcting said γ
-axis direction on the basis of said current response with said value limited in said limiting step.
-
-
13. A position-sensorless motor control apparatus comprising:
-
(A) a motor controlling section for determining a target current vector of stator windings;
(B) a superimposed wave generating section for setting one of a rotor-position estimation current signal and a rotor-position estimation voltage signal, with varying the period thereof;
(C) current detecting devices for detecting currents flowing through said stator windings;
(D) a current controlling section for carrying out one of (a) superimposing said rotor-position estimation current signal on a component of said target current vector in a first direction based on a γ
-axis direction of a rotor, thereby obtaining a target current vector with superimposed wave, and further calculating a corresponding target voltage vector; and
(b) a current controlling section for superimposing said rotor-position estimation voltage signal on a component of a target voltage vector corresponding to said target current vector in said first direction, thereby obtaining a target voltage vector with superimposed wave;
(E) a motor driving device for supplying electric power to said stator windings on the basis of one of said target voltage vector corresponding to said target current vector with superimposed wave and said target voltage vector with superimposed wave; and
(F) a rotor-position estimating section for (a) measuring a current response to one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, from a component of a current vector in a second direction having a fixed relation with said first direction, said current vector representing said currents detected by said current detecting devices, and (b) correcting said γ
-axis direction on the basis of said current response.- View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
(A) said current controlling section sets said first direction to be one of said γ
-axis direction and a direction substantially shifted by 90°
in terms of electric angle from said γ
-axis direction; and
(B) said rotor-position estimating section sets said second direction to be a direction substantially shifted by 90°
in terms of electric angle from said first direction, and corrects said γ
-axis direction so that said current response in said second direction substantially converges to zero.
-
-
17. An electric vehicle comprising a wheel driving motor with a position-sensorless motor control apparatus according to claim 13.
-
18. A fan comprising a fan driving motor with a position-sensorless motor control apparatus according to claim 13.
-
19. A refrigerator comprising a compressor with a position-sensorless motor control apparatus according to claim 13.
-
20. An air conditioner comprising a compressor with a position-sensorless motor control apparatus according to claim 13.
-
21. A position-sensorless motor control apparatus comprising:
-
(A) a motor controlling section for determining a target current vector of stator windings;
(B) a superimposed wave generating section for setting one of a rotor-position estimation current signal and a rotor-position estimation voltage signal, with varying the amplitude thereof;
(C) current detecting devices for detecting currents flowing through said stator windings;
(D) a current controlling section for carrying out one of (a) superimposing said rotor-position estimation current signal on a component of said target current vector in a first direction based on a γ
-axis direction of a rotor, thereby obtaining a target current vector with superimposed wave, and further calculating a corresponding target voltage vector, and(b) superimposing said rotor-position estimation voltage signal on a component of a target voltage vector corresponding to said target current vector in said first direction, thereby obtaining a target voltage vector with superimposed wave;
(E) a motor driving device for supplying electric power to said stator windings on the basis of one of said target voltage vector corresponding to said target current vector with superimposed wave and said target voltage vector with superimposed wave; and
(F) a rotor-position estimating section for (a) measuring a current response to one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, from a component of a current vector in a second direction having a fixed relation with said first direction, said current vector representing said currents detected by said current detecting devices, and (b) correcting said γ
-axis direction on the basis of said current response.- View Dependent Claims (22)
-
-
23. A position-sensorless motor control apparatus comprising:
-
(A) a motor controlling section for determining a target current vector of stator windings;
(B) a superimposed wave generating section for setting one of a rotor-position estimation current signal and a rotor-position estimation voltage signal, with a predetermined period;
(C) current detecting devices for detecting currents flowing through said stator windings;
(D) a current controlling section for carrying out one of (a) superimposing said rotor-position estimation current signal on a component of said target current vector in a first direction based on a γ
-axis direction of a rotor, thereby obtaining a target current vector with superimposed wave, and further calculating a corresponding target voltage vector, and(b) superimposing said rotor-position estimation voltage signal on a component of a target voltage vector corresponding to said target current vector in said first direction, thereby obtaining a target voltage vector with superimposed wave;
(E) a motor driving device for supplying electric power to said stator windings on the basis of one of said target voltage vector corresponding to said target current vector with superimposed wave and said target voltage vector with superimposed wave; and
(F) a rotor-position estimating section for (a) measuring a current response to one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, from a component of a current vector in a second direction having a fixed relation with said first direction through sampling at least three times in each period of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, said current vector representing said currents detected by said current detecting devices, and (b) correcting said γ
-axis direction on the basis of said current response.- View Dependent Claims (24, 25)
(A) said superimposed wave generating section sets (a) the period of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal to be an even multiple-of the carrier period of PWM, and (b) the waveform thereof to be symmetric with respect to the middle point between the former half and the latter half of said period;
(B) said motor driving device modulates target voltages through said PWM, said target voltages represented by one of said target voltage vector corresponding to said target current vector with superimposed wave and said target voltage vector with superimposed wave, and applies the modulated target voltages to said stator windings; and
(C) said rotor-position estimating section measures said current response on the basis of the symmetric waveform of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal.
-
-
26. A position-sensorless motor control apparatus comprising:
-
(A) a motor controlling section determining a target current vector of stator windings;
(B) a superimposed wave generating section for setting one of a rotor-position estimation current signal and a rotor-position estimation voltage signal, with the period thereof being an even multiple of the carrier period of PWM and the waveform thereof symmetric with respect to the middle point between the former half and the latter half of said period;
(C) current detecting devices for detecting currents flowing through said stator windings;
(D) a current controlling section for carrying out one of (a) superimposing said rotor-position estimation current signal on a component of said target current vector in a first direction based on a γ
-axis direction of a rotor, thereby obtaining a target current vector with superimposed wave, and further calculating a corresponding target voltage vector, and(b) superimposing said rotor-position estimation voltage signal on a component of a target voltage vector corresponding to said target current vector in said first direction, thereby obtaining a target voltage vector with superimposed wave;
(E) a motor driving device for modulating target voltages through said PWM, said target voltages represented by one of said target voltage vector corresponding to said target current vector with superimposed wave and said target voltage vector with superimposed wave, and applying the modulated target voltages to said stator windings; and
(F) a rotor-position estimating section for (a) measuring a current response to one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, from a component of a current vector in a second direction having a fixed relation with said first direction, on the basis of the symmetric waveform of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, said current vector representing said currents detected by said current detecting devices, and (b) correcting said γ
-axis direction on the basis of said current response.
-
-
27. A position-sensorless motor control apparatus comprising:
-
(A) a motor controlling section for determining a target current vector of stator windings;
(B) a superimposed wave generating section for setting one of a rotor-position estimation current signal and a rotor-position estimation voltage signal, with a predetermined period;
(C) current detecting devices for detecting currents flowing through said stator windings;
(D) a current controlling section for carrying out one of (a) superimposing said rotor-position estimation current signal on a component of said target current vector in a first direction based on a γ
-axis direction of a rotor, thereby obtaining a target current vector with superimposed wave, and calculating a corresponding target voltage vector, and(b) superimposing said rotor-position estimation voltage signal on a component of a target voltage vector corresponding to said target current vector in said first direction, thereby obtaining a target voltage vector with superimposed wave;
(E) a motor driving device for supplying electric power to said stator windings on the basis of one of said target voltage vector corresponding to said target current vector with superimposed wave and said target voltage vector with superimposed wave; and
(F) a rotor-position estimating section for (a) multiplying a component of a current vector in a second direction orthogonal to said first direction in terms of electric angle by a signal, said current vector representing said currents detected by said current detecting devices, said signal having (1) a period substantially equal to the period of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, and (2) a phase substantially shifted by 90°
in terms of electric angle from one of said rotor-position estimation current signal and said rotor-position estimation voltage signal,(b) measuring a current response to one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, from the result of the multiplication, and (c) correcting said γ
-axis direction on the basis of said current response.
-
-
28. A position-sensorless motor control apparatus comprising:
-
(A) a motor controlling section for determining a target current vector of stator windings;
(B) a superimposed wave generating section for setting one of a rotor-position estimation current signal and a rotor-position estimation voltage signal;
(C) current detecting devices for detecting currents flowing through said stator windings;
(D) a current controlling section for carrying out one of (a) superimposing said rotor-position estimation current signal on a component of said target current vector in a first direction based on a γ
-axis direction of a rotor, thereby obtaining a target current vector with superimposed wave, and further calculating a corresponding target voltage vector, and(b) superimposing said rotor-position estimation voltage signal on a component of a target voltage vector corresponding to said target current vector in said first direction, thereby obtaining a target voltage vector with superimposed wave;
(E) a motor driving device for supplying electric power to said stator windings on the basis of one of said target voltage vector corresponding to said target current vector with superimposed wave and said target voltages with superimposed wave; and
(F) a rotor-position estimating section having a limiter, said rotor-position estimating section for (a) measuring a current response to one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, from a component of a current vector in a second direction having a fixed relation with said first direction, (b) limiting a value of said current response using said limiter, and (c) correcting said γ
-axis direction on the basis of said current response with said value limited by said limiter.
-
Specification