Localization of Partial Discharge in Oil-immersed Transformers Based on the Modified Cumulative Energy Method and the Improved Chan Algorithm

In order to address the problem of low positioning accuracy for partial discharge (PD) in oil-immersed transformers, this paper firstly improves the energy accumulation method by setting and adjusting the threshold energy of signal sequences, thereby enhancing the calculation accuracy of signal time differences. Subsequently, measurement error variables are incorporated into the traditional Chan algorithm. By establishing a mathematical relationship between localization results and error variables, positioning error is reduced followed by objective optimization. Finally, the experimental validation is conducted on a 220 kV oil-immersed transformer. Compared with the traditional Chan method, the proposed method achieves higher positioning accuracy.