Magnetic pole position estimating method and control apparatus for synchronous motor

Claim 2

A magnetic pole position estimating method for a synchronous motor, comprising the steps of: superposing a high-frequency voltage having a different frequency from a driving frequency on an exciting component of a voltage command value for controlling the synchronous motor, thereby generating an electrical saliency on an impedance in a high-frequency region; estimating a position of a magnetic pole based on the saliency so as to be a first magnetic pole position; multiplying a torque component of a current command value by a proportional constant, thereby calculating an internal phase angle compensating angle; and subtracting the calculated internal phase angle compensating angle from the first magnetic pole position, thereby setting a second magnetic pole position.

Claim 3

A magnetic pole position estimating method for a synchronous motor, comprising the steps of: superposing a high-frequency current having a different frequency from a driving frequency on an exciting component of a current command value for controlling the synchronous motor, thereby generating an electrical saliency on an impedance in a high-frequency region; estimating a position of a magnetic pole based on the saliency so as to be a first magnetic pole position; multiplying a torque component of a current command value by a proportional constant, thereby calculating an internal phase angle compensating angle; and subtracting the calculated internal phase angle compensating angle from the first magnetic pole position, thereby setting a second magnetic pole position.

Claim 4

A magnetic pole position estimating method for a synchronous motor, comprising the steps of: superposing a high-frequency current having a different frequency from a driving frequency on an exciting component of a current command value for controlling the synchronous motor, thereby generating an electrical saliency on an impedance in a high-frequency region; estimating a position of a magnetic pole based on the saliency so as to be a first magnetic pole position; multiplying a torque component of a current command value by a proportional constant, thereby calculating an internal phase angle compensating angle; and subtracting the calculated internal phase angle compensating angle from the first magnetic pole position, thereby setting a second magnetic pole position.

Claim 5

A control apparatus for a synchronous motor which separates a current value of the synchronous motor into a magnetic flux component and a torque component based on an estimated value of a position of a magnetic pole and independently controls the respective current values, thereby controlling the synchronous motor, comprising: a high-frequency voltage generator for superposing a high-frequency voltage on a voltage command value of a control axis (a γ-axis) of the synchronous motor; a coordinate transformer for transforming a phase of the current value of the synchronous motor into a position having an electrical angle of 45 degrees with the control axis interposed therebetween; a high-frequency component extractor for extracting a signal having the same frequency component as a frequency component of the high-frequency voltage superposed by the high-frequency generator from an output current of the coordinate transformer; a high-frequency impedance estimator for estimating a high-frequency impedance on two points which are advanced and delayed from the control axis by the electrical angle of 45 degrees based on a current extracted by the high-frequency component extractor and the high-frequency voltage respectively and for estimating a deviation between the impedances on the two points; a first magnetic pole position estimator for estimating, as a first magnetic pole position, such a magnetic pole position that the deviation between the two high-frequency impedances is zero; and a second magnetic pole position estimator for multiplying a torque component of a current command value by a proportional constant to calculate an internal phase angle compensating angle and for subtracting the calculated internal phase angle compensating angle from the first magnetic pole position to set a second magnetic pole position.

Claim 6

A control apparatus for a synchronous motor which separates a current value of the synchronous motor into a magnetic flux component and a torque component based on an estimated value of a position of a magnetic pole and independently controls the respective current values, thereby controlling the synchronous motor, comprising: a high-frequency voltage generator for superposing a high-frequency voltage on a voltage command value of a control axis (a γ-axis) of the synchronous motor; a coordinate transformer for transforming a phase of the current value of the synchronous motor into a position having an electrical angle of 45 degrees with the control axis interposed therebetween; a high-frequency component extractor for extracting a signal having the same frequency component as a frequency component of the high-frequency voltage superposed by the high-frequency generator from an output current of the coordinate transformer; a high-frequency impedance estimator for estimating a high-frequency impedance on two points which are advanced and delayed from the control axis by the electrical angle of 45 degrees based on a current extracted by the high-frequency component extractor and the high-frequency voltage respectively and for estimating a deviation between the impedances on the two points; a first magnetic pole position estimator for estimating, as a first magnetic pole position, such a magnetic pole position that the deviation between the two high-frequency impedances is zero; and a second magnetic pole position estimator for multiplying a torque component of a current command value by a proportional constant to calculate an internal phase angle compensating angle and for subtracting the calculated internal phase angle compensating angle from the first magnetic pole position to set a second magnetic pole position.

Claim 7

A control apparatus for a synchronous motor which separates a current value of the synchronous motor into a magnetic flux component and a torque component based on an estimated value of a position of a magnetic pole and independently controls the respective current values, thereby controlling the synchronous motor, comprising: a high-frequency current generator for superposing a high-frequency current on a current command value of a control axis (a γ-axis) of the synchronous motor; a coordinate transformer for transforming a phase of a voltage value of the synchronous motor into a position having an electrical angle of 45 degrees with the control axis interposed therebetween; a high-frequency component extractor for extracting a signal having the same frequency component as a frequency component of the high-frequency current superposed by the high-frequency generator from an output voltage of the coordinate transformer; a high-frequency impedance estimator for estimating a high-frequency impedance on two points which are advanced and delayed from the control axis by the electrical angle of 45 degrees based on a voltage extracted by the high-frequency component extractor and the high-frequency current respectively and for estimating a deviation between the impedances on the two points; a first magnetic pole position estimator for estimating, as a first magnetic pole position, such a magnetic pole position that the deviation between the two high-frequency impedances is zero; and a second magnetic pole position estimator for multiplying a torque component of a current command value by a proportional constant to calculate an internal phase angle compensating angle and for subtracting the calculated internal phase angle compensating angle from the first magnetic pole position to set a second magnetic pole position.

Claim 8

A control apparatus for a synchronous motor which separates a current value of the synchronous motor into a magnetic flux component and a torque component based on an estimated value of a position of a magnetic pole and independently controls the respective current values, thereby controlling the synchronous motor, comprising: a high-frequency current generator for superposing a high-frequency current on a current command value of a control axis (a γ-axis) of the synchronous motor; a coordinate transformer for transforming a phase of a voltage value of the synchronous motor into a position having an electrical angle of 45 degrees with the control axis interposed therebetween; a high-frequency component extractor for extracting a signal having the same frequency component as a frequency component of the high-frequency current superposed by the high-frequency generator from an output voltage of the coordinate transformer; a high-frequency impedance estimator for estimating a high-frequency impedance on two points which are advanced and delayed from the control axis by the electrical angle of 45 degrees based on a voltage extracted by the high-frequency component extractor and the high-frequency current respectively and for estimating a deviation between the impedances on the two points; a first magnetic pole position estimator for estimating, as a first magnetic pole position, such a magnetic pole position that the deviation between the two high-frequency impedances is zero; and a second magnetic pole position estimator for multiplying a torque component of a current command value by a proportional constant to calculate an internal phase angle compensating angle and for subtracting the calculated internal phase angle compensating angle from the first magnetic pole position to set a second magnetic pole position.