Rapid Position Determination Method for Internal Faults in Power Transformer Bushing

The transformer bushing plays a vital role in ensuring insulation and mechanical stability of the transformer leads. The internal structure of the transformer bushing is compact and requires high manufacturing precision. However, during operation, ground short-circuit faults frequently occur in the bushing. Therefore, it is crucial to identify the root causes of bushing faults, accurately determine the location of internal faults, and understand the fault development process in order to prevent bushing failures. This paper provides a brief description of the internal structure of power transformer bushing in the power grid. Considering the current operation mode and protection configuration of the power grid, it proposes a rapid position determination method for internal faults in the main transformer bushing. This method involves comparing and analyzing the recorded current values and voltage waveform characteristics captured by current transformers in different locations. It allows for the analysis of bushing fault locations without the need for dismantling the faulty bushing. Finally, the proposed method is applied to analyze and inspect two typical bushing fault cases. The results of the dismantling inspection align with the findings obtained from the proposed method, thus further validating the practicality and effectiveness of the method.