Condition Monitoring and Fault Diagnosis of Stator and Rotor Interturn Winding Faults in a DFIG-based Wind Turbine System: A Review

Compared with steam/hydro/gas turbines used in traditional power plants, wind turbines (WTs) are usually operated in harsher environments and, therefore, have relatively higher failure rates. DFIGs are commonly used in WT systems and are prone to electromechanical incipient faults, which gradually degrades their operating characteristics and causes major damage in the system. The most common faults in the DFIGs reported in the literature are the inter-turn winding faults in the rotor and stator windings of the DFIG. If these faults are not detected and rectified at early stages, they tend to be catastrophic leading to unexpected outages which are associated with high operating and maintenance costs and significant loss of revenue along with interruption to the business relying mainly on wind energy. Given the projected growth of WTs in the energy market worldwide, further effort needs to be made towards implementing new or improving existing condition monitoring and fault detection strategies to allow the fault diagnosis process to be performed to detect, locate and mitigate the incipient faults before a catastrophic failure occurs. This paper focuses on the review of the techniques used in condition monitoring and early fault diagnosis of the interturn winding faults in the rotor and stator of the DFIGs while in operation. The review of the literature made it evident that the diagnosis of stator interturn winding faults in DFIGs has been researched extensively, although not under transient conditions. Whereas the diagnosis of rotor interturn winding faults of the same machines has remained largely unexplored.