Optimal design of a magnetically coupled filter for high efficiency, low cost and low volume dc-dc battery storage converter

The paper presents the optimal design of a magnetically coupled filter for a 500 kVA dc/dc converter. The converter is used for batteries storage applications in UPS systems. The high efficiency and low cost ;14% of converter total price saving; are obtained by using a magnetically coupled filter rather than classical chokes. The design of the filter is achieved using a multi-objective optimization algorithm. Several solutions are compared, including interleaved chokes, coupled monolithic interleg-transformer and coupled separated interleg- transformers. Two prototypes were built. Tests and validations were performed in an industrial environment.