A novel direct power control for open-winding brushless doubly-fed reluctance generators fed by dual two-level converters using a common DC bus

Abstract

A new direct power control (DPC) strategy for open-winding brushless doubly-fed reluctance generators (BDFRGs) with variable speed constant frequency is proposed. The control winding is open-circuited and fed by dual traditional two-level three phase converters using a common DC bus, and the DPC strategy aiming at maximum power point tracking and common mode voltage elimination is designed. Compared to the traditional three-level converter systems, the DC bus voltage, the voltage rating of power devices and capacity of the single two-level converter are all reduced by 50% while the reliability, redundancy and fault tolerance of the proposed system still greatly improved. Consequently its effectiveness is evaluated by simulation tests on a 42 kW prototype generator in MATLAB/SIMULINK.