A 3D-Coupled Field-Circuit Model for Analyzing the Internal Short-Circuit Faults of Power Transformer

摘要

To characterize the complex physical behavior of power transformer's internal fault is very important for its protection and fault detection. Therefore, this chapter presents a complete three-dimensional-coupled field-circuit model to analyze the internal short-circuit faults of power transformer. The coupled mechanism and modeling which are used to evaluate the performance of transformer under internal short-circuit fault condition are introduced as well. A 500 kVA, three-phase, oil-immersed, core-type transformer is modeled by this field-circuit 3D-coupled method. Based on this, a deep analysis for turn-to-turn and internal phase-to-phase faults is made. The distribution of magnetic field and electrical characteristics which contribute to the development of reliable and sensitive fault detection methods are discussed in this study.