Method and apparatus for position-sensorless motor control

Claim 2

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.

Claim 3

A position-sensorless motor control method according to claim 1 , wherein the period of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal varies at random.

Claim 4

A position-sensorless motor control method according to claim 1 , wherein the period of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal varies on the basis of a predetermined table.

Claim 5

A position-sensorless motor control method according to claim 1 , wherein: (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.

Claim 6

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.

Claim 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 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.

Claim 8

A position-sensorless motor control method according to claim 5 , wherein the amplitude of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal increases when the amplitude of said current vector increases.

Claim 9

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.

Claim 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, 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.

Claim 11

A position-sensorless motor control method according to claim 7 , wherein the sampling of said current response is carried out plural times in each half period of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal.

Claim 12

A position-sensorless motor control method according to claim 8 , wherein: (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.

Claim 13

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.

Claim 14

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.

Claim 15

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.

Claim 16

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.

Claim 17

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.

Claim 18

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.

Claim 19

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.

Claim 20

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.

Claim 21

A position-sensorless motor control apparatus according to claim 13 , wherein said superimposed wave generating section varies at random the period of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal.

Claim 22

A position-sensorless motor control apparatus according to claim 13 , wherein said superimposed wave generating section has a memory storing a predetermined table, thereby varying the period of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, on the basis of said table.

Claim 23

A position-sensorless motor control apparatus according to claim 13 , wherein: (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.

Claim 24

An electric vehicle comprising a wheel driving motor with a position-sensorless motor control apparatus according to claim 13 .

Claim 25

A fan comprising a fan driving motor with a position-sensorless motor control apparatus according to claim 13 .

Claim 26

A refrigerator comprising a compressor with a position-sensorless motor control apparatus according to claim 13 .

Claim 27

An air conditioner comprising a compressor with a position-sensorless motor control apparatus according to claim 13 .

Claim 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, 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.

Claim 29

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.

Claim 30

A position-sensorless motor control apparatus according to claim 21 , wherein said superimposed wave generating section increases the amplitude of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, when the amplitude of said current vector increases.

Claim 31

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.

Claim 32

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.

Claim 33

A position-sensorless motor control apparatus according to claim 23 , wherein said rotor-position estimating section carries out the sampling of said current response plural times in each half period of one of said rotor-position estimation current signal and said rotor-position estimation voltage signal.

Claim 34

A position-sensorless motor control apparatus according to claim 23 , wherein: (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.

Claim 35

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.

Claim 36

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.

Claim 37

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.

Claim 38

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.

Claim 39

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.

Claim 40

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.