The invention discloses a d-axis
positive direction determination method of a
permanent magnet synchronous motor, comprising the steps that firstly a pulsating
high frequency current injecting methodis adopted to establish a rotor
closed loop system, and the d-axis
voltage response is obtained; secondly, the amplitudes of the d-axis
voltage response (1) are recorded when the injection current
signal phase is pai / 2, 3pai / 2; the value of the two amplitudes are compared, and the d-axis
positive direction is determined, and the compensation value of the d-axis
positive direction after determination can be obtained. The rotor synchronization rotating coordinates q-axis current can be set as 0, and the d-axis current is injected with a pulsating
high frequency sinusoidal
signal, and the rotor
closed loop system can be established, and the d-axis
voltage response of the rotor synchronization rotating coordinates can be extracted. The invention is advantageous in that during the process of determining the d-shaft positive direction, the injected current is always the sine
high frequency signal, and signals of other types like positive and negative pulse are not required to be injected, and
estimation process can be simplified; motor running cannot be affected; the structure is simple, reliability is high, operation complexity can be reduced, and the process of estimating the initial position can be simplified.