General multi‐mode control method for optimising the efficiency of full bridge converter based on prominent control modes and transition points calculation

The theme of this article is to propose a general multi‐mode control method to optimise the efficiency of the full‐bridge converter based on prominent control modes for the whole range of load variations. This method selects the most efficient prominent control mode in each load sub‐range, including variable delay phase shift, fixed delay phase shift, pulse width modulation (PWM) and burst control while the load current varies in its entire range from full down to no load. In this regard, for the first time, three transition points between control modes are analytically determined based on full‐bridge converter power losses analysis. Determining transition points and load current sub‐ranges, being functions of converter parameters, is in fact the process of optimising the proposed method for the entire range of the load current in terms of four control modes. The accuracy of the analytically determined transition points and the optimal control mode selection over the load variations are justified by experimental results on digitally implemented proposed control method and full‐bridge converter.