Based on wetted failure of the capacitance bushing comparative study on offline and online detection methods

With the rapidly growth of the total installed capacity of the power supply system, and the continuously improvement of power supply reliability. Meanwhile, with the aim to reduce the power outage and maintenance costs, the traditional regularly offline detection is being constantly eliminated, contrarily with the online detection being popular. Online detection method has many advantages, such as providing necessary information for predictive maintenance, improving maintenance level. In this paper, the author will make a comparison between the online methods and the offline methods, for the purpose of clearly identifying which is more effective to indicate potential risks of electrical equipment, and whether the former can completely replace the later. Furthermore, whether there is inevitable connection or correlated connection between them is discussed in this paper. Based on the detection of transformer performance parameters, a complete set of equivalence study methods have been proposed. At last, an example of wetted failure of oil impregnated paper capacitance bushing is described in detail.