Application of Rough Set Theory and Causality Diagram in Transformer Troubleshooting of Distribution Network

As the hub equipment in the distribution network, the transformer fault is difficult to diagnose because of its complexity and diversity. The reasons causing these failures are very complex and unobvious which make the transformer fault diagnosis and analysis very difficult. If the state of the transformer can be timely determined, pre-detection of hidden dangers, and excluded quickly, the accidents and maintenance costs will be greatly reduced. So the fault diagnosis of the transformer has a very practical value and significance. In this paper, the method which combines the Rough set theory with Causal Network is proposed to find out the faults in the transformer by diagnosing the oil. A streamlined decision table is formed, which can help diagnosing faults accurately and rapidly. Compared with the conventional IEC triple ratio method, the proposed method has higher fault tolerance and diagnosis precision.