A Novel Power Converter Configuration for Open-Winding PMSG based High-Power Wind Energy Conversion Systems

This paper presents a novel configuration of an Open-Winding Permanent Magnet Synchronous Generator (OW-PMSG) based high-power Wind Energy Conversion System (WECS), with a unidirectional five-level (5L) converter on one side and a conventional bidirectional two-level (2L) converter on the other side of the generator. The 5L converter is rated for the full system power while the 2L converter is rated only at a small fraction of the full system power rating. The proposed configuration has several advantages over a conventional star-connected PMSG connected to a unidirectional 5L converter, such as, better utilization of the generator voltage and current ratings, reduced overall machine side converter losses, consequently, higher efficiency, no zero crossing distortion in the machine line currents and hence, better machine current THD and lower harmonic losses and simplified control of the machine side converters. The proposed configuration is analyzed and validated in the MATLAB/Simulink platform and the results are discussed.