Permanent magnet blushless direct current motor ( pmbldcm ) has been paid more attention in the past two decades by researchers in the motor and control system fields because of its excellent performance , for example , small cubage , great power density and high efficiency 永磁无刷直流电动机体积小，功率密度高，控制性能好，效率很高，在工业、车辆、家电、计算机及军事等诸多领域得到广泛应用，尤其在电动车应用领域倍受青睐，是当前电动车电动机研发的热点。
