Compensation of CM Voltage in Systems Consisting of Interleaved AC-DC Converters

Presented in this paper are the results of research connected with common mode (CM) interference generated by parallel-connected AC-DC power electronic interfaces (PEIs), that are increasingly being used, e.g., in the fast charging infrastructure for electric vehicles or in PV systems. Thanks to parallel connection of lower power AC-DC converters high power capability and modularity would be obtained. Designer can focus only on parameters optimization for one Power Electronic Building Block (PEBB) and predict the necessary features for parallel operation. It is relatively well known that the use of interleaved AC-DC converters aids the reduction of generated Electromagnetic Interference (EMI). However, the aim of this paper is to present a novel approach in the development of a passive CM voltage compensator, dedicated to systems consisting of AC-DC interleaved converters. The presented analyses have shown that the interleaved modulation used for DC-link voltage ripple reduction brings about additional benefits in the context of passive CM voltage compensation. In the presented case CM voltage compensators for individual converters have been replaced by only one, smaller and cheaper CM compensator for all of the parallel-connected interleaved converters.