High-Frequency Ladder Network Synthesis of Transformer Winding for Its Mechanical Condition Assessment

Abstract

Fault localization and severity evaluation of transformer winding is crucial for its mechanical condition assessment. Ladder network synthesis of winding entity based on its frequency response analysis (FRA) data is an elegant solution to this problem. This paper proposes a generic method for high-frequency (HF) ladder network synthesis of winding in different mechanical conditions for its fault diagnosis. The simplified HF network used in the synthesis process is firstly built. Afterwards, the synthesis algorithms with high precision and efficiency and the mathematical model for normal HF ladder network are elaborated. Further, the synthesis method for defective network is proposed to locate the winding fault positions and evaluate their severities. Finally, the network synthesis method is applied on a distribution transformer, with the fact that the obtained network components comply with all the constraints and the diagnostic results also match well with the actual mechanical conditions of winding, which verifies its feasibility and accuracy.