Transformerless Onboard Charger for Electric Vehicles with 800 V Power System

摘要

The powertrains of new electric vehicles are characterized by increasing drive power and charging power requirements. Because of increasing currents and wire cross sections the step from 400 V to 800 V power systems seems to be inevitable in the medium term. This will probably allow DC fast charging with about 350 kW and offers some interesting possibilities for AC onboard chargers as well. This publication describes the design of an onboard charger demonstrator for 22 kW AC charging according to IEC 61851-1 “Mode 2”. Silicon carbide power devices and coupled filter inductors are used in a single stage transformerless topology. This design results in a charging system with a power density of about 7 kW/l.