Wind energy conversion system based on DFIG with open switch fault tolerant six-legs AC-DC-AC converter

Abstract

Continuity of service of wind energy conversion systems as well as their reliability and performances are some of the major concerns in this power generation area. Six-legs AC/DC/AC converters are normally used in modern wind energy systems like as in the system with a doubly-fed induction generator (DFIG). A sudden failure of the converter can lead to the total or partial loss of the control of the phase currents and can cause serious system malfunction or shutdown. Therefore, to prevent the spread of the fault to the other system components and to ensure continuity of service, fault tolerant converter topologies associated to quick and effective fault detection and compensation methods must be implemented. In this paper, a fault tolerant AC/DC/AC converter for a wind energy conversion system based on a DFIG is studied. The presented six-legs converter uses an additional leg that replaces the faulty one after the fault detection. An FPGA is used for experimental implementation of the fault detection scheme, to assure the fast fault detection. A rapid prototyping based on an intermediate “FPGA in the loop” step is used for digital implementation. “FPGA in the loop” results as well as fully experimental results are provided to demonstrate the effectiveness of the proposed fault detection and fault tolerant control.