Torque Observation of WRSM With Model Uncertainties for EV Applications

In this article, we propose a torque observation method based on a linear parameter varying (LPV) approach for a wound rotor synchronous machine (WRSM) used in electric vehicles (EVs), specifically for the Renault ZOE. The novelty of our approach lies in its ability to handle a wide range of uncertainties and parameter variations, such as speed fluctuations and model uncertainties in both magnetic flux and resistance. This enables more accurate and robust torque estimation, which is crucial for the demanding performance requirements of EV applications. We present a comprehensive observation methodology, which includes a state and unknown input observability study, robust LPV observer design, and a convergence analysis. The effectiveness of this approach is demonstrated through both simulations and experimental tests conducted on the BEMEVE real-power test bench. To highlight its merits, the performance of the LPV observer is compared to different types of observers.