SVM-DTC Permanent magnet synchronous motor driven electric vehicle with bidirectional converter

Electric Vehicle (EV) technology provides an effective solution for achieving better performance compared to conventional vehicles. This paper highlights the use of a bidirectional buck-boost converter for a Permanent Magnet Synchronous Motor (PMSM) driven EV. The bidirectional buck - boost converter interfaces the low-voltage battery with a high-voltage dc bus and maintains a bidirectional power flow. The batteries are at low voltage to obtain higher volumetric efficiencies, and the dc link is at higher voltage to have higher efficiency on the motor side. PMSMs are known as a good candidate for EV due to their superior properties such as high torque/volume ratio, power factor and high efficiency. This paper also includes Space Vector Modulation (SVM) based Direct Torque Control (DTC) which controls the PMSM to reduce the ripples in both torque and speed. A closed loop control system with a Proportional Integral (PI) controller in the speed loop has been designed to operate in constant torque and flux weakening regions. Extensive simulation work was carried out using Matlab/Simulink, and the results established shows that the performance of the controller both in transient as well as in steady state is quite satisfactory.