Multi-cell operation of a high-frequency isolated DC/AC converter for grid-connected wind generation applications

A high-frequency (HF) isolated DC/AC converter was proposed as the interface between a small-scale PMSG-based wind turbine generation system (WTGS) and a single-phase utility line in [4]. In this paper after a brief review of this configuration, different options of the multi-cell operation of this converter for high power wind generation applications are discussed. The effect of multi-cell operation on the harmonics on the input dc current and output line currents are addressed. It is found that both the 2nd harmonic in the input dc current and all triplen harmonics in the output line currents are eliminated when three identical single-phase converters in Delta connection are used. PSIM simulation results are included for the purpose of validation.