Decoupling of Current Balancing and Reference Tracking Control in Parallel Interleaved Converters

An attractive approach to increasing the output power and bandwidth of converters is through the parallel connection of multiple, subrated converter cells via mutually coupled inductors. Achieving a balanced contribution to the output current by all paralleled converter cells is critical; good reference tracking performance, however, should also be maintained. Since these two control tasks are coupled, tuning of the controller parameters is challenging. This article demonstrates a methodology for decoupling the output current reference tracking control task from the current balancing control. We show that once balancing and tracking controllers are decoupled, the controller parameter tuning can be conducted independently, simplifying design and analysis of controller performance. Experimental results are presented, which validate the proposed methodology, applied to a three-cell, parallel interleaved converter with cyclic cascade coupled inductor filter network, operating at 100 <inline-formula><tex-math notation="LaTeX">${\rm V}_{\rm RMS}$</tex-math></inline-formula> and 9 <inline-formula><tex-math notation="LaTeX">${\rm A}_{\rm RMS}$</tex-math></inline-formula>.