An Integrated Inductor for Parallel Interleaved Three-Phase Voltage Source Converters

Three-phase voltage source converters (VSCs) are often connected in parallel to realize the high current output converter system. The harmonic quality of the resultant switched output voltage can be improved by interleaving the carrier signals of these parallel-connected VSCs. As a result, the line current filtering requirement can be reduced. However, an additional inductive filter is required to suppress the circulating current. The integrated inductive component, which combines the functionality of the line filter inductor and the circulating current inductor is presented in this paper. An analysis of the flux density distribution in the integrated inductor is presented and design procedure is described. The analysis has been also verified by performing finite-element analysis. The advantage offered by the use of the integrated inductor is demonstrated by comparing its volume with the volume of the state-of-the-art filtering solution. The performance of the integrated inductor is also verified by the experimental measurements.