An Inductance Tracking Based Sensorless Method for Detecting the Rotor Position of Switched Reluctance Motor

Switched reluctance motors are expected to be good candidates in machine drives due to their simple structure. Detection of SRM rotor position is mandatory to effectively control the motion of the motor and commutate the rotor current correctly. However, the detection of the rotor position is done by either adding extra sensors or complicated mathematical calculations that need powerful computers that afford the huge calculation burden. In spite of many methods proposed to eliminate the rotor position sensor, which is needed to commutate the current correctly, research effort is still needed to improve the machine performance. This paper presents a sensorless method for the detection of rotor position method. The proposed method is based on measuring the current of some unexcited rotor phases. This is translated into better reliability due to the reduced number of measuring devices. Moreover, the proposed technique is independent of motor parameters and at the same time it is formed from simple calculations which renders its application to wide range of SRM achieving a more compact and cost-effective drive. The performance of the proposed technique is assessed by means of offline simulations as well as experimental prototypes. The simulation as well as experimental results proves the accuracy of the proposed detection technique.