An adaptive predictive current controller for Electric power steering system with Permanent Magnet Synchronous Motor

Abstract

A predictive current control scheme is adopted in this paper to improve the current tracking performance of Permanent Magnet Synchronous Motor in the Electric power steering system. But the motor parameters variation can lead to a steady-state error and reduce the stability margin of the current tracking system, even destabilize the system. So this paper presents an adaptive predictive current controller for Electric power steering system with Permanent Magnet Synchronous Motor, The controller is mainly composed of a cross-coupling compensator, a predictive current controller and an adaptive parameter estimator. The coupling compensator decouples the Permanent Magnet Synchronous Motor into two parallel SISO linear systems, the predictive current controller combined a two-sample deadbeat controller with a current predictor provides robustness against the control delay, and the adaptive identifier estimate the motor parameters and update the parameters in the cross-coupling compensator and current controller. The resulting controller maintains the typical fast response of the predictive current control and a better adaptability to the parameters variation. The simulation results show the validity of the analytic approach and the efficiency of the proposed method.