Mathematical Modeling of PMSM for Simulation of Electric Drives and Comparison with Multi Level Inverters

Abstract

Electric Vehicles (EV) are one of the best alternatives to conventional IC engines in the present scenario due to various problems such as depletion of fossil fuels, global warming, emissions, engine efficiency etc. A smooth driving pattern by an electric vehicle is one of the most desired needs in the current automotive industry. To ensure a smooth driving pattern, the torque ripple produced by the electric motor should be at its minimum. Motors in an EV must be able to perform well in all four quadrants as they act like a motor as well as a generator during driving based on the road conditions. To conduct this study, a mathematical model of motor controller, inverter and PMSM plant model has been developed entirely on Simulink, MathWorks without using any additional toolboxes, as it saves cost by eliminating the use of other toolboxes for modeling purposes. All the dynamics have been modeled only by using mathematical equations. Two, three and five levels of inverter have been developed for the purpose of comparison. The models have been validated by comparing the simulation results of the requested signal with the actual signal for torque and speed in each level of inverter separately over all the four quadrants of operation. Simulation results demonstrated better performance of multi-level inverters over the conventional two-level inverters in all the quadrants for an EV application.