Effects of Direct Current-Link Voltage Sensor Faults on Wind Energy Conversion System Driven by Doubly Fed Induction Generator Performances

Direct current (DC)-link voltage sensor faults in wind energy conversion systems (WECSs) based on a doubly fed induction generator (DFIG) may lead to severe operational issues and potentially affect overall performance. Ensuring efficiency, reliability, and longevity under such conditions requires a comprehensive analysis of fault effects and appropriate mitigation strategies. This study investigates the dynamic behavior of a DFIG-based WECS connected to the grid under additive and multiplicative DC-link voltage sensor faults. The system is modeled considering the grid-side converter (GSC), responsible for DC-bus voltage regulation, and the rotor-side converter (RSC), which controls the exchange of active and reactive power with the grid. Simulation scenarios are conducted to assess the impact of these faults on key electrical quantities, including current, voltage, and power at the grid, stator, and rotor levels. Results show that DC-link sensor faults significantly degrade voltage regulation and power stability. Unlike most previous studies that focus mainly on grid disturbances, this work addresses internal sensor faults within the GSC control loop. It also extends a prior investigation on direct-quadrature rotor current sensor faults, by analyzing DC-link voltage sensing, thereby providing a complementary perspective on the vulnerability of DFIG-based WECS to sensor faults. The findings highlight the importance of developing reliable fault detection, isolation, and fault-tolerant control strategies to enhance system robustness and operational reliability under sensor fault conditions.