Hybrid Switched Inductor Impedance Source Converter—A Decoupled Approach

Power electronic converters having capability of driving hybrid (ac and dc) loads are becoming popular in specific applications such as standalone nanogrid. The proposed hybrid switched inductor impedance source converter (HLZSC) is derived from the switched inductor impedance source inverter (LZSI). It can independently regulate both ac and dc voltages in continuous conduction mode (CCM). However, discontinuous conduction mode (DCM) injects significant dc ripple voltage that restricts HLZSC operation for wide load variations and standalone ac or dc loads. Modification in the form of forced continuous conduction mode to replace DCM is, therefore, proposed for modified HLZSC (or MHLZSC), which can decouple the voltage regulation of ac and dc load without getting affected by the modes of operation. MHLZSC also permit the standalone operation of ac/dc load. The control scheme for HLZSC/MHLZSC, which is similar to the established simple boost control of ZSI, is discussed briefly to utilize the salient features of the proposed converter. Theoretical analysis of the proposed converters is supported with the simulation and experimental results. Interestingly, the proposed converters—HLZSC and MHLZSC—avoid the use of lossy snubber resistance.