Performance of a 1-phase buck-boost rectifier using two coupled windings and a split DC-rail output voltage

This paper examines the performance of a unity power factor AC/DC buck-boost rectifier operated with a nonisolated split DC-rail output voltage using one switch and one magnetic core. The rectifier topologies described can supply energy to both DC-rails in both half-cycles of the AC-supply and automatically compensate for a load imbalance between the upper and lower output DC rails. During a half-cycle of the AC supply, the power flow balance between the two DC-rails is affected by the per-unit winding leakage inductance. This paper uses extensive simulation and experimental results to illustrate the operation of the various circuit topologies and to determine the relationship between the half-cycle power flow imbalance to each DC-rail and the winding leakage inductance. This relationship is obtained for balanced and differential loads across the two DC rails and related to the magnitude of the leakage inductance