Initial rotor position detection of PMSM at standstill without rotational transducer

This paper presents a new standstill rotor position detecting algorithm for nonsalient permanent magnet synchronous machine (PMSM) without any position sensor. By injecting high frequency current to the stator of the machine, the proposed algorithm provides the standstill rotor position with reasonable accuracy as well as the direction of magnetization. Though this paper focuses on the nonsalient PMSM, the proposed algorithm also works more effectively in the case of the salient machine such as an interior permanent magnet machine. From the experiments, the standstill rotor position is successfully detected within ±5° error in electrical degree