High efficiency operation for H-Bridge DC-DC converter

This paper presents two methods of switching operation for higher conversion efficiency and seamless control for wide range of the input voltage in a H-Bridge DC-DC Converter. This converter consists of buck and boost blocks and a feedforward control from the input voltage is employed for the boost block to realize seamless transition between step down and step up operation mode. From the view point of the conduction loss and the switching loss, two methods of the desirable duty ratio of the boost section and different switching frequencies are examined. As a result, higher efficiency was obtained by minimizing the duty ratio of the boost block for wide range of the input voltage and by decreasing the switching frequency of the buck block without increasing output ripple voltage.