Single-stage impedance source inverters with quasi-DC–DC output cell for working in dual inductor current modes

Single-stage impedance source inverters with quasi-DC–DC output cell (QDDOC) are proposed here. The QDDOC is derived from DC–DC converters, and QDDOC can be applied in all the existing impedance source inverters. Compared to the traditional impedance source inverters without QDDOC, the proposed inverters with QDDOC can adapt to the wider inductor parameter range and flexibly work into dual inductor current states: continuous conduction mode (CCM) and discontinuous conduction mode (DCM). Also, the proposed inverters can retain the single-stage voltage-boost performance, and solve the DC-link voltage drop produced by DCM. Under DCM, the proposed inverters improve the boost ability, lower the inductor values, size and weight, and reduce the voltage stresses across passive components. The circuit topologies, modulation strategies, and operating principles are analysed in detail. Finally, experiment results verify the validity of proposed topologies.