MOISTURE ANALYSIS OF HIGH VOLTAGE BUSHING OIL-PAPER INSULATION BASED ON FREQUENCY DOMAIN SPECTROSCOPY CONSIDERING TEMPERATURE DEPENDENCY

Oil-paper insulated high voltage bushing is widely used in high voltage power system, especially for the high voltage bushing. The estimation of moisture content is crucial to the bushing's oil-paper insulation due to its significant acceleration on the long-term aging process. However, conventional estimation techniques lack adequate accuracy and information for moisture estimation. Recently, polarization-based dielectric response methods such as return voltage (RV), polarization and de-polarization current (PDC), and Frequency Domain Spectroscopy (FDS) used in power transformer oil-paper insulation analysis would be appropriate to solve this problem for high voltage bushing. This paper mainly discusses the moisture estimation of oil-paper insulated bushings based on FDS measurement…