Capacitive vs Inductive Coupling Based DC-DC Converter Operating in MHz Switching Frequency Range

In this paper galvanically isolated dc-dc interfaces are studied. Capacitive coupling is studied as an alternative solution to magnetic isolation. The recommended converter configuration is combination of a full bridge structure in input side and a full bridge rectifier as output side. Instead of using magnetic isolation, capacitive isolation has been utilized in the proposed topology to provide the galvanic isolation and also the required energy for the load. The proposed converter provide benefits including decreased size, weight, and losses, consequently improving both high power density and high efficiency in compared to the inductive coupling converters. The comprehensive performance comparison between capacitive coupling and inductive coupling converters, have been carried out in this work. An experimental prototype of the suggested converter operated in 1.5 MHz switching frequency and rated power equal to 6 kW is presented to prove the correctness of the theoretical surveys.