Research on Direct Power Control for Open-Winding Brushless Doubly-Fed Reluctance Wind Power Generator with Fault-Tolerant Strategy

The power devices fault is a serious disaster for any wind energy conversion systems (WECS). In this paper, a novel direct power control (DPC) with fault-tolerant strategy for an open-winding brushless doubly-fed reluctance generator (OW-BDFRG) applied in variable speed constant frequency (VSCF) WECS is proposed. Where, the three phase control winding of BDFG is open-circuited and fed with dual two-level converters (D-TLCs), compared to the traditional neutral-point-clamped three-level converter (NPC-TLC), both the nominal capacity and DC-link voltage in any converter of DTLCs can only be half of the NPC-TLC, but the redundancy of switching combinations of D-TLCs is up to 64 more than 27 of the latter, which can be used to further improve the robustness of DPC for OW-BDFRG. Finally, the proposed DPC with fault-tolerant strategy for OW-BDFRG allowing for one IGBT fault and cut-off in D-TLCs is discussed and simulated based on MATLAB/Simulink, and the correctness and feasibility of the improved DPC are all be validated by the detailed simulation results.