Design of Preventive Insulation Diagnosis Sensors for Power Equipment

Pole-mounted transformers are essential components of distribution systems, requiring reliable fault diagnosis to prevent outages and ensure stable operation. Conventional methods—ultrasonic testing, infrared thermography, and wireless load monitoring—depend heavily on human judgment and are affected by environmental factors such as weather and temperature, making accurate detection of internal faults difficult. To overcome these limitations, a radiated electromagnetic wave detection technique based on partial discharge (PD) is necessary. Effective PD detection requires identifying the frequency characteristics of emitted electromagnetic waves and using a high-sensitivity sensor capable of detecting signals at distances of at least 10 meters.<br/> This study designs and simulates a high-sensitivity conical dipole sensor optimized for broadband performance to detect PD-induced electromagnetic radiation in distribution-level transformers. The proposed sensor improves bandwidth and detection sensitivity, and its application is expected to help prevent insulation-related outages and enhance the reliability of distribution network operation.