Low Pass Filter Less Sliding mode Observer using QPR Controller for PMSM fed Electric Vehicle

This paper presents an approach for sensorless speed control of Permanent Magnet Synchronous Machines (PMSMs) for Electric Vehicles (EVs) using a Sliding Mode Ob-server (SMO). In vector control, position and speed encoders are indispensable for closed-loop control. However, mechanical sensors are highly susceptible to failure and necessitate considerable space and circuitry, ultimately leading to an increase in cost. The paper proposes sensorless speed control techniques for PMSM- driven EVs. The conventional SMO suffers from challenges such as chattering and phase delay due to its discontinuous function and the inclusion of a low-pass filter (LPF). A Quasi Proportional Resonant (QPR) based observer is introduced to mitigate these issues. By appropriately selecting the resonance frequency of the QPR controller, it is possible to eliminate the sign function and LPF in the conventional SMO. In this paper, the sign function of the conventional SMO is replaced with a QPR controller-based observer to improve performance. Simulation results demonstrate the superior performance of the proposed method compared to the conventional SMO.