A Fluorescent Optical Fiber Sensor Suitable for Detecting Internal Partial Discharge Optical Signals in Transformers

Partial discharge (PD) is a major factor threatening transformer integrity. As an effective method for PD detection, optical detection method can effectively reflect the severity of discharges. However, due to the limited internal space of transformers and the challenges associated with embedding fluorescent optical fibers, most existing optical PD detection techniques remain confined to laboratory research and lack practical fluorescent optical fiber sensors that can be installed inside full-scale transformers for field applications. To address this issue, a fluorescent optical fiber sensor (FOFS) suitable for detecting internal PD optical signals in full-scale transformers was developed. This sensor demonstrated superior sensitivity compared to high-frequency current transformers (HFCT). Furthermore, the sensor was installed inside a ± 400kV converter transformer to verify its effectiveness in detecting internal PD optical signals. The research provides strong support for the advancement and practical application of internal PD detection in transformers.