Rotor Position Detection of Switched Reluctance MotorsViaTransient Voltage Suppressor Circuits

This paper presents a newsensorless rotor position detection for a Three-phase single switch SR motor with regeneration capability at standstill mode. The proposed method is based on the dependency of phase current waveform at turn off time to rotor position angle. It is shown that the combination of a motor with single switch per phase converter and a transient voltage suppressor (TVS) circuit define a resonant circuit. It means, the resonance frequency of the circuit depends on the rotor position. In this method, the rotor position is achieved by inspecting of regeneration current results of applied high frequency and low level diagnostic pulses to the motor phases at the beginning step. To obtain the rotor position of switched reluctance motors (SRMs) by meaning of the overlap of rising voltage measurements. During this interval, rotor position is detected by exchanging energy between the phase and source repeatedly in one cycle of a phase current. The resulting current magnitudes are measured and compared to detect the rotor position. The new configuration enables the motor for self-starting without any other mechanism or starting device. The prototype controller was simulated, fabricated, and tested in laboratory and experimental results of the proposed SRM drive system are presented.