The invention provides a method for detecting the initial position of a magnetic pole of a rotor of a built-in permanent magnetic
synchronous motor, belongs to the field of
motor control, and solves the problems of over-complicated
processing, easy occurrence of polarity misjudging, poor practicality and the like existing in the conventional method based on high-frequency
signal injection for detecting the initial position of the rotor. The method comprises the following steps: constantly maintaining the
stationary state of the rotor; injecting a rotating high-frequency
voltage signal into a
stator winding; detecting three-phase
stator current and converting the three-phase
stator current into two-phase static coordinates; acquiring an
error signal capable of reflecting position information of the magnetic pole of the rotor through
signal processing; adjusting the
error signal by using a PI tracker so as to acquire an initial judging value of the position of the magnetic pole of the rotor; and injecting two impulse
voltage vectors in opposite directions into the stator winding, comparing values of direct axis current components by detecting the
three phase current and converting the rotating coordinates so as to determine the polarity of the magnetic pole, and finally acquiring the initial
position angle of the magnetic pole of the rotor of the built-in permanent magnetic
synchronous motor.