Method, device and system for controlling PMSM (Permanent Magnet Synchronous Motor) to put into operation again at belt speed

The present invention provides a control method, apparatus and system for a permanent magnet synchronous motor with speed into the back, the back EMF is obtained by the speed of the PMSM trailer. The reaction potential and the inverter side voltage, if a voltage higher than the back EMF of the inverter side is not allowed to re-enter the PMSM belt speed, and vice versa to allow the tape speed PMSM rejoin. PMSM rejoin belt speed is about isolator contactor is closed to prohibit re-enter the belt speed is about PMSM isolator contactor is opened. Accordingly, the present invention according to the size of ωe, and height is divided into two low-speed condition is calculated rotor position angle, different conditions correspond to different angular positions of the rotor, starting from the PMSM the rotor position angle. From the system point of his comprehensive control method, rejoin the PMSM forbidden band speed of the high speed step, the high-speed range using a calculated short-circuit method rotor position angle is determined to rejoin the position low speed stage using a rotor position angle calculation INFORM method to determine weight investment position of the point.