The Simulation Model of Transformer Based on Capacitance Equivalent Circuit for Lightning Strikes

With the continuous development of power systems and the integration of distributed systems, power grids are increasingly vulnerable to lightning electromagnetic pulses. To ensure system reliability and optimize operational costs, the issue of lightning protection for electronic devices in power grid systems has garnered widespread attention. This paper proposes a new transformer modeling method based on a capacitor equivalent model to investigate the dynamic response and coupling characteristics of a three-phase transformer under lightning strikes. The method accurately reflects the inter-phase coupling characteristics of transformers with a delta connection. Simulation and experimental comparisons validate the effectiveness of the capacitor equivalent model in lightning transient simulations, particularly in capturing the inter-phase coupling effects. This modeling approach provides a precise simulation tool for lightning protection design in transformers and offers theoretical support for optimizing lightning protection measures and enhancing transformer lightning strike resistance.