Coupled Three-Phase Inductors for Interleaved Inverter Switching

This paper presents the use of coupled inductors to allow interleaved switching of the upper and lower switches of three-phase inverters. The approach increases the number of output voltage levels and reduces the magnitude of the output line currents at switching frequency. Two possible inductor topologies are investigated. Individual toriodal inductors for each phase are shown to provide more switching possibilities, at the cost of size and required DC fluxes. Three-phase three-limb inductors require more careful operation of the power electronics, but with significantly smaller core requirements. Simulated and measured inductor performance is presented, along with comments on the design of future inductors for similar applications.