Eliminating starting hesitation for reliable sensorless control of switched reluctance motors

Novel methods for rotor position estimation both at standstill and during running conditions are presented for a switched reluctance machine (SRM) starting free of position sensor and hesitation. By applying a DC pulse to the stator phase windings for a short moment (0.5 ms), the initial rotor position can be accurately detected. Combining the accurate initial rotor position with a novel rotor position estimation algorithm during running, the SRM can be started at any initial rotor position without starting hesitation. Critical issues related to optimal model selection as the virtual sensor are discussed in detail. Computer simulation and experimental results are included.