Sub-Harmonic Problem in Multi-Converter Vehicular Power Systems

Power electronics is an inevitable part of vehicular multi-converter power systems. In a multi-converter power system, various buses and loads are connected through different power electronic converters and inverters. These systems consist of a few to tens of converters in electric and hybrid electric vehicles to hundreds of converters in more electric aircraft, sea vehicles, and international space station. A phenomenon that can occur in cascaded converters and multi-converter systems is sub-harmonic production. The problem with sub-harmonics is that they could not be easily cancelled out by filters. In this paper, this issue is addressed. Furthermore, some precautions to prevent the problem are introduced. Simulation and experimental results confirm the addressed concept