Research on the permanent magnet synchronous motor control system based on additional and sensing windings

摘要

The rotor position of permanent magnet synchronous motor is mostly detected by mechanical encoders, which increase the complexity and cost but reduce the reliability of the control system, moreover limit the applications of permanent magnet synchronous motor in certain special situations. In this paper, one method that can detects the rotor position, winding temperature and the rotor flux meanwhile through additional windings instead of changing motor structure is proposed. An additional winding is connected in the orientation opposite to that of the stator winding, and then a high-frequency current is injected into the winding to calculate the rotor position, sense the main motor winding temperature and the rotor flux by detecting the variations of the additional winding resistance and back electromagnetic force (EMF). Experimental results validate that the method is effective and feasible.