Corona Measurement Test in Correlation with Predictive Maintenance on Extra High Voltage Transmission Line

In 2019, one of the dominant causes of 500kV transmission lines disturbances in PLN UIT JBT is pollutants exposure. Most of the disturbance occurred in the transmission lines that lie in the south of Java island. Geographically, the location is near the coastal area. Usually, the disturbance started to happen as the rainy season changed to the dry season. The phenomenon occurs due to the process of insulator natural self-cleaning has stopped along with the changing seasons. Corona intensity measurement is one approach to determine the condition of how severe pollutants are attached to the surface of the insulator. The high density of pollutants attached to the insulator will have an impact on the amount of leakage current that occurs. Those conditions will reduce the BIL of the insulator. It will affect the performance of the insulator in withstanding impulse currents that occur due to lightning strikes or switching surges. This paper will review some corona measurements results using an ultraviolet camera. The results obtained will be correlated with maintenance strategies to prevent disturbance or unscheduled outage.