The Characteristics of UV Strength According to Corona Discharge From Polymer Insulators Using a UV Sensor and Optic Lens

Inspections and diagnoses of corona discharges are important in order to prevent electrical faults of external insulation in power systems. This paper studies the measurement of ultraviolet rays (UV) strength of corona discharges on polymer insulators using a UV sensor with an optic lens. The data have been compared with the images of a UV camera. The UV signal by corona discharge was detected from more than 60 kV, which was equivalent to around 37.5% of the breakdown voltage. The UV strength increased with increasing high voltage and the supplying dc voltage. Also, UV image was observed. However, the longer the distance was, the greater the reduction in UV signals would be. The robust, inexpensive sensor can detect corona discharge activity on polymer insulators when the applied voltage exceeds 37.5% of the breakdown voltage.