Abstract:Studies a control strategy of SRD without position sensor and discusses its principle. With DSP as the core and three phases 12/8 SRM as the implementing object, designs software and hardware of SRD without position sensor. After the examination on the sample SRD without sensor, the results show that the sample SRD can fastly and correctly compute the rotor pisiton,especially when the motor runs at mid-speed and low-speed .