针板电极下酯类绝缘油放电特性及产气规律研究

Ester insulating oil has been widely used in power systems, and there are differences in its discharge characteristics and gas production laws from those of the traditional mineral oil. The purpose of this paper is to study the discharge characteristics and gas production law of ester insulating oil transformers during the development of discharge faults. Taking the natural, the modified and the synthetic esters as the research objects, the oil-paper insulation discharge fault simulation test platform is built. After repeated tests with the constant voltage method, the discharge characteristic parameters and the dissolved gas in oil are acquired and analyzed in the process of the discharge development. The results show that the discharge pulse amplitude is higher and the pulse repetition rate is lower in the ester insulating oil, while the discharge energy released during the discharge development is greater. Under the same electrical stress, the ester insulating oils are prone to produce more gas products, among which more abundant CO, C₂H₆ and C₂H₂ are produced, especially in the natural ester FR3. According to the discharge statistical characteristic parameters and the dissolved gas in oil, the discharge stage can be divided into the initial discharge stage, the discharge development stage and the pre-breakdown stage, which may provide a certain basis for the fault diagnosis of the ester insulating oil transformer.