The initial position of the mover of a planar switched reluctance motor (PSRM) must be accurately sensed at standstill to produce sufficient and stable starting thrust. Without employing position sensors, a novel initial mover position estimation method with bipolar square-wave voltage injection is proposed in this paper, in terms of that different initial positions can cause the variations of phase inductances of the PSRM. The PSRM configuration is presented. The mathematical model is derived for estimating the initial position of the mover. The experimental setup is built and a starting test of the PSRM in free-running mode is performed. The results show that the estimation precision of the initial position is greatly improved and verify the proposed method.

Planar switched reluctance motor (PSRM)， inductance identification， initial mover position estimation， sensorless control