A Novel Initial Rotor Position Estimation Method at Standstill for Doubly Salient Permanent Magnet Motor

In order to receive ground signals efficiently, doubly salient permanent magnet (DSPM) motor which is applied in communication satellites as a drive needs to be activated frequently to adjust the attitude of communication satellites. Then, the initial rotor position of the motor must be estimated accurately at standstill for producing a steady and sufficient starting torque. If the rotor rotates during the estimation process, the pointing accuracy of the satellite pointing mechanism will be affected. To solve this problem, this paper proposes a novel rotor initial position estimation scheme based on the principle that different initial rotor positions can cause the variations of stator winding inductances. The identification signals, which do not cause the rotor to rotate during the identification process, are injected into the motor windings to identify the stator inductances. Thus, the variations of the winding inductances can be detected, and the initial rotor position can be estimated accurately by these variations. The proposed method is verified through experimental platform. The experimental results show that the initial rotor position is accurately estimated, and the starting performance of the DSPM is improved.