Hybrid-Mode Cuk Inverter with Low-Voltage Ride-Through Capability under Grid-Faults

Abstract

This paper proposes a hybrid-mode Cuk inverter with low-voltage ride-through (LVRT) capability under grid-faults. It operates as an unfolding-type inverter during normal grid condition and two-stage inverter during abnormal grid condition. Thus, it normally transfers the energy to the utility grid highly efficiently, and also has the LVRT ability under grid-faults. Moreover, two types of inverters share the full-bridge circuit on the grid-side and so the proposed circuit can be developed with low cost and reduced size. This paper outlines operation principles and control methods for the proposed inverter. The prototype of the proposed converter was implemented and experimental tests were carried out to demonstrate its practical feasibility.