Influencing factors and countermeasure analysis of a 800kV coupling capacitor dielectric loss test

Abstract The coupling capacitor is installed on the AC bus side of the converter station for AC filtering to filter out a large amount of harmonics generated by the converter during the AC/DC conversion process. Therefore, the reliability assessment test of its insulation status is of great importance to the safety and stability of the UHV power grid Meaning. In the UHV field test, the dielectric loss factor of the coupling capacitor is tested at a voltage of 10 kV and below, but the device itself has the Garton effect, and the abnormal data measured at some times cannot truly reflect the insulation state of the device. The thesis analyzes the abnormality of the dielectric loss factor test data of 800kV coupling capacitors in UHV converter stations from the structure, use conditions and test methods of the equipment, and gives a detailed analysis of the causes of the abnormality. Recommendations for operation.