Maximum Efficiency Per Ampere Control for Interior PMSM Using Parameter Estimation

The global shift towards energy-efficient electric vehicles (EVs) has prompted the research community to investigate efficiency improvements, enabling the increasing success of the EV industry. It is vital to utilise advancements in control to implement software updates for existing hardware, to improve the efficiency of the Interior Permanent Magnet Synchronous Motor (IPMSM) powertrain. Maximum Torque Per Ampere (MTPA) control is currently the benchmark for the EV powertrain providing the minimum copper loss per ampere. However, Maximum Efficiency Per Ampere (MEPA) considers minimisation of both copper loss and core loss of the IPMSM. Current MEPA methods are particularly parameter dependent; therefore, the implementation of parameter estimators is essential to guarantee optimal tracking of operating points to provide optimal efficiency. The proposed approach implements a gradient descent core loss resistance estimator in order to accurately determine the optimal operational point. The methodology is verified using simulations that present the results throughout the operational range.