Using patterns of stator and rotor laminations for switched reluctance motor control

A new method for direct sensing of the rotor position in switched reluctance motor is presented in this paper. In this method a new sensing unit constructed based on the motor stator and rotor laminations, is coupled to the motor. Due to the lack of electronic components, the motor can be utilized in harsh environments such as a furnace. The sensing unit behaves like the motor itself and is immune from the motor switching noises too. Therefore it would be easier to implement sensorless control techniques on it. Two different sensorless techniques are applied to the sensing unit. In the first detection method a sine wave signal is applied to every other stator pole winding of the sensing unit and from the resulting induced signals obtained from the opposite coils, the position of the rotor is accurately determined. In the second technique a set of narrow diagnostic pulses are applied to each phase windings and the resulting voltage drops are measured on sensing resistors which are connected in series with each phase winding. The control algorithm selects the correct phase for excitation based on comparing the measured voltages. The experimental results are presented which demonstrate the robust functionality of the method.