Performance Comparison of Multilevel Inverters for E-transportation

To fulfil the increasing power demand for electric vehicles, their drives require advanced power electronic converters. The existing 2-level inverter technology with high frequency, though widely used, exhibits some issues like high dv/dt or common mode voltage in motor windings leading to performance degradation and potential problems, such as overheating, and failures etc. Multilevel inverters address these issues due to the reduced dv/dt of phase voltage and sinusoidal output voltage profile. Amongst all multilevel topologies, cascaded H-bridge topology is well suited for e-transportation, as battery cells can be easily configured such as to obtain separate dc sources each supplying a single H-bridge. Higher number of levels yield smoother output waveform and drive performance, but at the cost of increasing complexity, production cost and potential failure rate, due to the higher component count. Therefore, the optimum choice of the number of levels has to be done, which includes complex trade-offs among various parameters which is pivotal for the wide acceptance of the technology. Hence, this paper is devoted to a comparative study among multilevel inverters and conventional 2-level inverter and suggests a unique level to enhance vehicle performance. Cascaded H-bridge topology with different levels uses permanent magnet synchronous motor with a field oriented control, have been simulated to evaluate the performance of power train.