Analysis of Classic Multilevel Inverters for Electric Vehicle Applications

Despite the advantages of multilevel converters, a more in-depth analysis is required to determine which topology is appropriate for this type of converter in electric vehicles across its different applications. Thus, this document explores and compares the classic topologies of multilevel inverters, considering their applicability in electric traction systems. Critical aspects such as (i) efficiency, (ii) power density, (iii) costs, and (iv) reliability are analyzed. A justified choice of one of the topologies presented above is also made. Particularly noteworthy among these is the detailed study of the neutral-point-clamped (NPC) multilevel inverter in high-power, mid-range, and heavy-duty electric vehicles (EVs), highlighting its advantages and specific challenges in these applications. Finally, the results from PSIM® simulations are analyzed, providing an in-depth view of the characteristics and performance of the chosen multilevel inverter in electric vehicle applications. Simulation results confirmed that the selected Neutral Point Clamped inverter is capable of generating near-sinusoidal current waveforms with low harmonic content, even under challenging conditions. In particular, a current total harmonic distortion (THD) of 5% was obtained.