Calculation of Inrush Current in Three-Phase Transformers During No-Load Closing

This article provides a detailed explanation of inrush current calculation for three-phase transformers during no-load closing operations. We begin by defining inrush current and examining its impact on transformer performance. Subsequently, we demonstrate computational methodologies for quantifying inrush current and implementing protective measures against transformer damage. Specifically, the discussion covers mathematical formulations for magnetizing current computation, methods for calculating magnetizing reactance, and guidelines for selecting appropriate reactance values. The implementation section includes algorithmic approaches for practical inrush current simulation, featuring code structures for phase-angle-dependent current calculations and flux linkage modeling. Furthermore, we present practical application scenarios with embedded code snippets demonstrating numerical integration techniques for transient analysis. The technical discussion incorporates key functions such as remanent flux initialization and switching angle optimization algorithms. In summary, this comprehensive guide elucidates computational techniques for three-phase transformer inrush current analysis, enabling readers to effectively implement these methodologies in engineering applications.