Advances in Frequency Response Techniques for Diagnosing Inter-Turn Faults in Salient Poles

Frequency Response Analysis (FRA) technique has been widely used for many years to diagnose winding transformers. However, more recently, there has been a concerted effort to apply this technique to other types of windings, including large salient poles. This paper presents two new FRA diagnostic techniques that have been specifically developed and proven to work effectively on large salient poles. These two techniques - the FRA ungrounded test and the fault diagram method - are combined to provide a novel approach for predictive and corrective diagnosis of inter-turn faults on large salient poles. The fault diagram is constructed using the ungrounded technique test results, and an analysis is carried out to identify new properties and enhance the diagnostic sensitivity. The laboratory tests are described in detail, and a comparison with on-site tests is provided to validate the effectiveness of the new techniques.This paper presents a new and innovative approach to diagnose inter-turn faults on large salient poles using FRA techniques. The FRA ungrounded test and the fault diagram method have been specifically developed for this purpose and provide a reliable and cost-effective diagnosis compared to traditional methods. The comprehensive laboratory tests and comparison with on-site tests demonstrate the effectiveness and practicality of the proposed techniques.