Maximum Efficiency Drives of Synchronous Reluctance Motors by a Novel Loss Minimization Controller With Inductance Estimator

This paper presents a method to maximize the driving efficiency of synchronous reluctance motors (SynRMs) having cross-magnetic saturation effects. A novel loss minimization controller that generates the optimum current vector is proposed. In the proposed controller, either an off- or online inductance estimator can be adopted. In both cases, the proposed controller can determine the optimum current vector quickly and automatically, and is capable of both maximizing the driving efficiency and also realizing high-precision torque control. In addition, when the proposed controller with the online inductance estimator is employed, a troublesome offline inductance measurement test is omissible. The validity of the proposed method is verified from simulation and experimental results on a 1.1-kW flux-barrier-type SynRM.