Abstract: This disclosure is directed to a fault-tolerant energy conversion system. A fault-tolerant doubly-fed induction generator (DFIG) for use with a wind energy conversion system (WECS) consistent with the present disclosure may allow for seamless operation during all kinds of grid faults. In one embodiment, a six-switch grid side converter (GSC) commonly used with such systems may be replaced with nine-switch converter circuitry. With three additional switches, the nine-switch converter can provide two independent three phase outputs. For example, one three-phase output may be coupled to the grid through interfacing inductors to realize normal GSC operation, while the other three-phase output may be coupled to neutral side of the stator windings to provide fault ride-through (FRT) capability to the DFIG. A control algorithm may be employed that both achieves seamless fault ride-through during any kind of grid faults and strictly satisfies grid codes requirements.

Abstract: This disclosure is directed to a fault-tolerant energy conversion system. A fault-tolerant doubly-fed induction generator (DFIG) for use with a wind energy conversion system (WECS) consistent with the present disclosure may allow for seamless operation during all kinds of grid faults. In one embodiment, a six-switch grid side converter (GSC) commonly used with such systems may be replaced with nine-switch converter circuitry. With three additional switches, the nine-switch converter can provide two independent three phase outputs. For example, one three-phase output may be coupled to the grid through interfacing inductors to realize normal GSC operation, while the other three-phase output may be coupled to neutral side of the stator windings to provide fault ride-through (FRT) capability to the DFIG. A control algorithm may be employed that both achieves seamless fault ride-through during any kind of grid faults and strictly satisfies grid codes requirements.