Analysis of direct torque control method of five-phase permanent magnet synchronous motor in electric vehicles

One of the important reasons of global warming and enviromental pollution is internal combustion vehicles. Because of this reason, battery electric and hybrid electric vehicles are replacing conventional vehicles. Especially, battery electric vehicles have various advantages such as zero emission, high efficiency, and less noise operation. The major factors that affect the performance of vehicle include types of electric motor and the control method in battery electric vehicles. For this reason, the electric motors used for propulsion system should be able to satisfy high efficiency and fault-tolerant capability, high power density and dynamic torque response. Nowadays with the development of technology, due to high efficiency and power density, five-phase permanent magnet synchronous motors are very good candidate for electric vehicles. Besides, multi-phase motor possess many advantages over the traditional three-phase motor such as increasing fault-tolerant and reducing ripple of torque. In addition, the direct torque control method possesses fast torque response and increasing number and types of space voltage vectors due to multi-phase permits better flexibility and finer adjustment of torque. In this thesis, vehicle technologies and models, widely used driving cycles, general structure of electric propulsion system in battery electric vehicles, five-phase permanent magnet synchronous motor and direct torque control method are examined. Simulation studies were carried out in Matlab/Simulink program. In this simulation, the performance of direct torque control of five-phase permanent magnet synchronous motor is examined. The modelling of electric propulsion system realized. Thus, the vehicle is examined under Worldwide Harmonised Light Vehicle Test Cycle, which is provide much more accurate and realistic fuel consumption and emissions. It was realized to increasing the torque response in the transient state and reducing the ripples of torque in the steady state improves of vehicle performance with the proposed control method. Besides, it was recovered the waste energy through regenerative braking, it was ensured to determine the actual energy consumption with realistic driving cycle.