Condition monitoring technology of transformer with multiple sensing methods united

partial discharge detection is an effective way for transformer condition monitoring, and thus different detection methods for partial discharge are developed. However, the fact is that there hasn't been a detection method that can solve all the problems so far. Every detection method has its advantages and limitations. To improve this problem, the paper introduces a united detection method based on ultra-high frequency (UHF) method, high-frequency method and ultrasonic method. It is validated by an experiment that a better performance in the partial discharge detection of transformer can be obtained by the united method compared to conventional detection methods. The common problems in partial discharge detection such as anti-interfere, pattern recognition, defects location and apparent charge measurement can be solved with the united detection technology effectively.