Design of dc-dc converter with phase shift and duty cycle control for full range soft switching

In this paper design of a dual half bridge (DHB) converter as a soft switched isolated bidirectional dc-dc converter is discusses. The operation principles and steady state analysis of the converter with phase shift (θ) plus duty cycle (d) control are explained and soft switching conditions are extracted. The design and selection of main components are discussed for fully soft switching operation against wide range of dc bus voltage variations. Soft switching regions of the designed converter in the control space are extracted. Results show that with the designed converter soft switching can be achieved for full power range in both directions against wide voltage variations on the dc ports. Finally a 1.5KW, 250KHz prototype is implemented to verify the results and some practical issues in implementation of converter to improve its performance are explained.