Study on Impedance Spectrum Distribution Characteristics of Turn-to-Turn Defects in Dry-Type Air-Core Reactor Under High Frequency Excitation

Turn-to-turn defects frequently occur in drytype air-core reactors, posing significant hazards. This study delves into the high-frequency impedance spectroscopy distribution characteristics of dry-type air-core reactors to propose a novel fault detection method. Initially, a highfrequency distributed parameter equivalent model for dry-type air-core reactors is constructed, analyzing the impact of turn-to-turn short circuits, insulation moisture absorption, and overheating aging defects on the equivalent model and its input impedance spectroscopy at the head end. A impedance spectroscopy testing platform for dry-type air-core reactors is established to measure the impedance spectroscopy before and after turn-to-turn defects under high-frequency excitation, yielding high-frequency amplitude and phase spectroscopy distribution characteristic curves. The results indicate that the direction and magnitude of the resonance point characteristic peak shift can diagnose turn-to-turn defects. This research validates the feasibility of a turn-to-turn defect detection method for DAR based on high-frequency impedance spectroscopy distribution characteristics and provides a reference for it.