Quasi-Isolated HV/HV-DC/DC-Converter for Electric Driven Vehicles with Multiple High-Voltage Levels

Abstract:
This paper discusses the problems of using a traditional non-isolated DC/DC-converter for the connection of two high-voltage systems in an electric driven vehicle with regard to an asymmetry of the high-voltages referred to the chassis/ground. The asymmetry can be caused by a degradation of the insulation or the measurements of an insulation monitoring device (IMD). To solve those problems, the concept of a quasi-isolated DC/DC-converter that allows an individual control of the positive and negative output potentials is presented. A possible topology and a control scheme for a quasi-isolated concept is explained. Measurement results of the proposed converter topology interacting with an IMD that introduces strong dynamic asymmetry of the high-voltage potentials are included.