Analysis on multilevel inverter powertrains for E-transportation

The existing electric vehicles uses conventional 2-level inverters with high frequency modulation. But, they manifest some issues like high dv/dt, high torque ripple and high blocking voltage, leading to performance deterioration. Multilevel inverters address these issues and yield quasi sinusoidal output waveform, thus they represent a valuable solution to above issues, but at the cost of increased complexity, cost, and potential failure rate, due to the increased component count. Therefore, while developing multilevel converters for powertrains, the optimal number of levels has to be determined which affects overall performance and cost. Hence, accurate trade-offs among various parameters which are critical for the wide acceptance of the technology are a prerequisite. Therefore, this article is dedicated towards an evaluation of the effects of the number of levels in multilevel converters for e-powertrains and recommends a unique choice to enhance vehicle performance over conventional 2-level inverters. To validate the simulation results, a prototype of powertrain is implemented and the output is fed to a 3-phase permanent magnet synchronous machine. It is also concluded that use of multilevel inverter is worthwhile compared to the conventional 2-level inverter for electrification of the car fleet.