Series Stacked Modular DC-DC Converter Using Simple Voltage Balancing Method

This letter proposes a high output voltage dc-dc converter topology with series stacked converter modules. To implement the proposed modular dc-dc converter structure, output voltage balancing of the modules and simplification of the control circuitry were considered the major design objectives. To achieve voltage balancing between the modules, we proposed a split-secondary transformer winding structure and distributed connections to the rectifier circuit blocks. Each transformer includes two secondary windings, with each wire pair connected to a different rectifier circuit. Consequently, one rectifier receives ac power simultaneously by sharing the secondary windings fed fromtwo different transformers. The proposed method was verified using a modular LCC resonant converter, which is widely employed in high-voltage applications. As a result, the control circuit was simplified by using a single controller to regulate the total output voltage and by applying a compact sensing circuit referenced to the output voltage of the module placed at the lowest grounding point.

Automated summary

This letter proposes a high output voltage dc-dc converter topology with series stacked converter modules, focusing on output voltage balancing and simplification of the control circuitry as major design objectives. A split-secondary transformer winding structure and distributed connections to the rectifier circuit blocks are proposed to achieve voltage balancing between the modules. This method was verified using a modular LCC resonant converter, simplifying the control circuit by using a single controller and a compact sensing circuit.