A novel approach to MTPA tracking control of AC drives in vehicle propulsion systems
Abstract
In today's hybrid or fully electric vehicles two types of propulsion machines can mainly be found: induction machines (IM) and interior permanent magnet synchronous machines (IPMSM). They are highly utilized and operated in magnetic saturation regions where inductance parameters change non-linearly. The energy efficiency of both drives depends strongly on the choice of reference currents within field-oriented control. The paper shows two approaches for the determination of well-adjusted current components for both machines. Firstly model-based optimization is performed. It uses machine models considering saturation and loss models including the inverter. Secondly a newly-developed online-optimization scheme based on a discrete search method is presented. Simulation results show its advantages over recently published solutions for both machine types. Finally experimental results at a drive test bench are presented. They prove the fast convergence and correct funct ion of the proposed method.
