Probabilistic Diagnosis of Short-Circuit Faults and Insulation Deterioration of Stator Winding of Motor

摘要

Short-circuit faults of winding due to deterioration of the insulation are one of the most probable faults in motor drive systems. An easy and effective method for fault diagnosis is very much needed to assure operation with high reliability. This paper proposes a novel method for diagnosing both short-circuit faults and insulation deterioration in windings. This method involves an impulse voltage test and probabilistic process for gauging the probability of fault occurrence by analyzing the distributions of features depending on the condition of the winding. In this paper, first, we discuss the results of several impulse tests on the winding. Second, two features that represent the characteristics corresponding to the condition of the winding are induced, and their feature distributions are determined. Third, we introduce the probability that can be used to diagnose conditions of the winding. The average and standard deviation of both features are calculated. By using the calculated values and features observed in a target winding to be examined, the fault probability is computed. Finally, the usefulness of the proposed diagnosis method is verified by experiments involving the use of faulty and deteriorating windings.