Multiphysics simulation analysis of copper lead arrangement in a very high power transformer

Abstract

This paper presents a thorough investigation into the copper lead arrangement within a 191 MVA very high-power transformer through multiphysics simulation. Utilizing electromagnetic, thermal, and Computational Fluid Dynamics (CFD) methodologies, the study scrutinizes lead positioning relative to steel components, with a specific focus on the area between the On-Load Tap Changer (OLTC) and winding. Identified as a critical scenario, lead proximity to steel necessitates protective measures like M5 and Aluminum tank shields. Despite their implementation, potential high-temperature issues stemming from geometric variations and additional leakage losses in steel parts remain concerns, challenging traditional analytical approaches and emphasizing the indispensability of multiphysics simulations throughout the design and manufacturing phases. Validation of simulation results against real test data via 3D electromagnetic and thermal coupled simulations reveals close agreement between simulated and experimental outcomes. Further validation employing 2D electromagnetic and CFD techniques confirms the findings, showcasing minimal disparities compared to test results. Ultimately, the study advocates for a final transformer design integrating both M5 and Aluminum shields, effectively mitigating temperature fluctuations on the tank surface. This research underscores the pivotal role of multiphysics simulation in optimizing transformer design, mitigating operational risks, and providing valuable insights for future transformer development endeavors.