Optimal Torque Control of the Externally Excited Synchronous Machine

Abstract

The basic function of any type of electric machine used in automotive powertrain is to propel the automobile in motor mode or to recharge the high-voltage battery in generator mode. The torque control of electric machine in motor and generator modes, using more efficient high-voltage battery, is a goal for the automotive industry. A good choice for Electric Vehicles (EVs), due to many advantages, is the Externally Excited Synchronous Machine (EESM). In this paper, a new optimal torque control algorithm for EESMs that aims at optimum torque control in the entire operating range based on a dual-rate sampling solution is presented. In order to test the developed algorithm a dynamic model of EESM is designed based on mathematical equations. The model is validated against the data obtained on a system testbench. The simulated results obtained with the proposed control strategy are compared with the ones obtained with the classical PID approach and the results show improved performances.