Speed Sensorless Control of Syn-Rel Motor With Hybrid Observer for Electric Vehicles

Improving electric vehicle (EV) propulsion system through optimizing number of sensors is an essential component of synchronous reluctance (Syn-Rel) motor drive implementation. This approach ensures stable and reliable operation of EV drive. A significant obstacle, however, is ideal operation of sensorless control across whole speed range of a vehicle. Present work introduces a hybrid observer with adaptive resonant estimator (ARE)-assisted sliding mode observer (SMO) that uses more effective active EMFs for speed control over a wide range, and employs enhanced quadrature phase-locked loop (e-QPLL) technique to estimate both drive speed and position. Compared to prior approaches, presented strategy enhances active EMF throughout whole driving range while minimizing errors in both speed and position. Enhanced speed and position estimation leads to a more robust drive response to changing speed and torque demand over complete driving range. A thorough analysis is conducted in MATLAB/Simulink. Additionally, a comprehensive evaluation of a 1.5 kW Syn-Rel motor test bench's built-in hardware, including vehicle dynamics, is provided.