A survey of fault diagnosis for onshore grid-connected converter in wind energy conversion systems

Wind energy is one of the most rapidly developing renewable energy sources during the past decade, supplying about 3% of global electricity consumption. Consequently, the power level and individual capacity of power converters in wind turbines (WTs) keep increasing. However, due to the severe operational environment and varying operational conditions, wind power converters (WPCs) are subjected to different sorts of component failures. According to the statistics, the failure rate of WPC is much higher than that of mechanical components and generator in wind energy conversion system (WECS). In an attempt to reduce system downtime and avoid catastrophic failure, the fault diagnosis (FD) of onshore grid-connected converters has gained increasing attention. Accordingly, this paper aims at presenting a state-of-the-art review on wind converter FDs including both model based and pattern based methods. It intends to provide a wide spectrum on converter operating stress, component failure modes, algorithm performance requirements, FDs for different converter topologies, and challenges in designing FDs. The main purpose of this paper is to provide the current research status of converter FDs and relevant references for the researchers in this area.