A new sensorless control for switched reluctance motor

This paper describes a new estimation method of rotor position for 3-phase SRM based on the space vector of the phase inductance at standstill and during rotating condition. The rotor position is simply obtained without magnetic characteristics of the motor and additional hardware. In this method, assuming the phase inductance waveform to be sine wave, the rotor position is obtained by computing the angle of the space vector of inductance. The space vector of inductance is calculated by the phase voltage and current. At stand still, all phase inductances are estimated by applying DC bus voltage to all phases. At low speeds, the rotor position estimation is carried out by applying DC bus voltage to the idle phases over a short time. Excited phase inductance is calculated by sum of each phase inductance. At high speeds, the inductance of the excited phase is used to estimate the rotor position. In magnetic saturation region, using simplified magnetization curves, we can obtain the rotor position without the effect of saturation. The validity of the proposed method is verified by experimental results.