LCCT-Z-Source inverters

Many renewable generation units (e.g. PVs, fuel cells, small wind turbines) require integrated DC-AC converters providing efficient high step-up power conversion. On the basis of recent developments in impedance source (Z-source) inverters the present paper proposes an integration of quasi-Z-source inverter (qZSI) with a built-in high frequency transformer. Two new type LCCT-Z-Source inverters are presented by author. Proposed inverters characterize continuous input current, improved relationship between boost coefficient and modulation index and improved EMI performance. Application of four element (Inductor — Capacitor — Capacitor — Transformer) LCCT impedance network provides higher voltage gain than obtained in quasi-Z-source inverter. The advantage of proposed topology over other recently developed trans Z-source inverters (TZSI) is that two built-in capacitors block DC currents in transformer windings and prevents core saturation. Simulation and experimental results are shown to verify the proposed topologies.