Analysis of Inter-Turn Short Circuit Characteristics in the Windings of Dry-Type Air-Core Series and Shunt Reactors

The current methods for monitoring interturn short circuit faults in the windings of dry-type air-core reactors remain inadequate. This paper develops finite element simulation models for dry-type air-core series reactors and shunt reactors, introducing short circuit faults at different winding layers and positions. The study systematically investigates the impact of both interstrand short circuits and interlayer short circuits on the equivalent resistance, equivalent impedance, and power factor of the reactors. The results indicate that series reactors exhibit significantly higher sensitivity to interturn short circuit faults compared to shunt reactors, especially when short circuits occur at the winding ends. Moreover, interstrand short circuits exert a more pronounced influence on electrical parameters than interlayer short circuits. By monitoring variations in equivalent resistance and power factor, effective fault diagnosis for winding short circuits in series reactors can be achieved. However, fault detection in shunt reactors is comparatively more challenging. This research provides a theoretical foundation for the online monitoring and fault diagnosis of interturn short circuit faults in the windings of dry-type air-core reactors.