Research on back to back cascaded H-bridge converter based on high frequency transformer

Cascaded H-bridge converter is a typical multilevel converter and has been widely used in industry, especially in 6kV or higher occasions. To enable the power to flow bi-directionally and eliminate the 50-Hz transformer, this paper presents a back to back converter, in which cascaded H-bridge topology is applied. And also high frequency which runs at 20 kHz is adopted to reduce the size, weight and cost of the whole converter system. With proper control method, the power can flow bi-directionally and each part of the converter runs normally. The experimental result validates the topology and the algorithm.