Phase-shift controlled DC-DC convertor with bi-directional power flow

A new zero-voltage switching (ZVS) phase-shift controlled bi-directional DC-DC convertor is proposed. It possesses the conventional features of phase-shifted convertors: constant switching frequency, ZVS and voltage regulation by phase-shift control. However, the convertor has been improved by developing a bi-directional power flow capability and applying synchronous rectification; hence, the on-state voltage drop of the active devices is small. It is therefore recommended for use in electric vehicles. The principle of circuit operation of the proposed convertor is described in detail with mathematical analysis, and experimental results are presented to verify the concept.