METHOD AND APPARATUS FOR ON-LINE ESTIMATION OF INITIAL POSITION OF SURFACE PERMANENT MAGNET ELECTRIC MACHINE

The present invention relates to a method and apparatus for on-line estimation of an initial position of a surface permanent magnet electric machine in a stationary state or at a first speed. The method (100) for on-line estimation of an initial position of a surface permanent magnet electric machine in a stationary state or at a first speed comprises: injecting (110) a high-frequency pulsating voltage signal; acquiring (120) a d-axis high-frequency current signal responding to the high-frequency pulsating voltage signal; and estimating (130) an initial position of the surface permanent magnet electric machine on the basis of a second harmonic of the d-axis high- frequency current signal. According to the present invention, the apparatus (200) for on-line estimation of an initial position of a surface permanent magnet electric machine in a stationary state or at a first speed is also provided, the apparatus comprising a voltage injection unit (210) configured to inject a high-frequency pulsating voltage signal, a current acquisition unit (220) configured to acquire a d- axis high-frequency current signal responding to the high-frequency pulsating voltage signal, and an analysis unit (230) configured to analyse a second harmonic of the d- axis high-frequency current signal so as to estimate an initial position of the surface permanent magnet electric machine. (Figure 1)