Reactive Power Availability of a 20 kW Three Phase Three Level PFC

Three phase rectifiers are gaining importance with the increase in charging infrastructure demand for EVs. This paper proves the reactive power availability of a three phase three level unidirectional rectifier consisting only two active switches per phase, with a power factor up to ± 0.9. Each phase leg of the converter is connected to the grid with a L-C-L filter and the filter star point of the capacitors is connected to the middle point of the DC link. The neutral of the grid being not connected to the start point of the filter capacitors enables start point modulation. In this paper, a current controller is proposed for the star point modulation with two main objectives; achieving a desired power factor and minimizing the DC link voltage. Detailed mathematical derivations and simulation results proving the reactive power availability of the converter are presented.