Derating efficiency in a six-pulse controlled PMSM compared to vector control: Theoretical study and experimental validation

Abstract

Selection of the control strategy for a Permanent Magnet Synchronous Motor (PMSM) depends on its constructional aspects, specific application, and the cost of implementing such a strategy. Therefore, studying different control alternatives considering their impact on critical variables such as maximum power output and motor efficiency is of great interest. This article presents the theoretical analysis and experimental validation of a model for estimating the performance of a PMSM when controlled using two different strategies: Field-Oriented Control and Six-Pulse Control. First, the equations that model the motor losses are studied and estimated for a set of operating points, which are then compared with the experimental data obtained from real tests, evaluating the efficiency maps of the machine for the two control strategies under investigation. The model results show a good correlation when fitted with test data. Finally, a simplified approach is proposed to estimate the derating efficiency at the nominal operating point.