Line filter design for parallel connected converter systems

The authors analyze and design line filters for a parallel connected power converter system under central-limit control with maximum current limit. Since the parallel connected converter modules (CMs) in the system may not all be in the active state simultaneously, an optimal line filter is designed for each CM instead of using only one design for the overall system. In addition, a second line filter is inserted between the source and the converter system to further reduce the EMI. The design procedure is described in detail and a design example is used to illustrate this approach