Design and Modelling of Energy Conversion with the Two-Region Torque Control of a PMSM in an EV Powertrain

Abstract

This paper investigates the properties and design of energy conversion in an electric vehicle (EV) powertrain. Here, we combined the dynamics of vehicle motion with controlled electric propulsion, which is an EV powertrain. The control of two types of permanent magnet synchronous motors (PMSMs) was considered. An algorithm was developed for the determination of the static characteristics of two-region motor torque control. A constant torque and a constant power region were used in the powertrain of the EV. The design of the control system for the PMSM was considered in the d,q reference frame. A precise mechanical model of the EV and the determination of road loads is shown. The main results of this study were the selection of the PI controller parameters (in analytical form), which was carried out for the simplified motor model and then extended for the d,q model, and energy consumption during the WLTP standard driving cycle. The presented simulation results of the proposed control system with synchronous motors in the EV (Fisker Karma as an example) confirmed the approach taken for the selection of the controller. The presentation of the EV’s acceleration for an optimized powertrain, and hence its performance, is a novelty not found in other articles.

Keywords

• PMSM
• field weakening
• vector control
• constant torque
• control system
• two-region control of motor torque