Position detection strategy of permanent magnet synchronous motor at standstill using transient finite element analysis

The sensorless control of permanent magnet synchronous motor (PMSM) at standstill and low speed is very difficult to implement. A methodology to design and optimize the position detection strategy of PMSM using transient finite element analysis (FEA) of magnetic field is presented. It addresses those effects arising both from iron core saturation and the transient characteristics of signals. A combined inductance which is sensitive to the rotor position throughout the complete cycle is proposed for the realization of position detection. The advantage of the proposed novel algorithm is that the rotor's position at low speeds down to standstill can be detected easily. A two-phase PMSM with salient structure is used as an example to demonstrate the method.