Higher Order Observer Based Sensorless Control for Position and Load Estimation of SRM Drive for EV

This paper deals with the position estimation of a switched reluctance motor (SRM) drive with a simplified sensor-less control. The electric vehicle needs reliable position estimation algorithm. The encoder increases cost and size of overall drive system and is prone to electromagnetic disturbances. Here, a third order sliding mode observer (SMO) based position estimation methodology is employed based on flux-linkage error. The rotor position, angular speed and angular acceleration are estimated from the model based observer. Estimated angular acceleration is used to estimate the load torque input for aforesaid application. The estimated position is used to generate converter gate signals. The designed observer estimates the variables over a wide range and response has less disturbance and noises at steady state. Simulated results show the quite satisfactory results when compares to position and speed measured from the motor.