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 regulatio n by phase-shift control. However the convertor has been improved by develo ping a bi-directional power flow capability and applying synchronous rectif ication; hence, the on-state voltage drop of the active devices is small. I t is therefore recommended for use in electric vehicles. The principle of c ircuit operation of the proposed convertor is described in detail with math ematical analysis, and experimental results are presented to verify the con cept.