Calculation and research of hotspot temperature analysis of converter transformer

This study aims to propose a thermal loop model-based simulation and analysis method for predicting the hotspot temperature of converter transformers in Ultra-High Voltage Direct Current (UHVDC) transmission systems, aiming to address the technical deficiencies in hotspot temperature monitoring of converter transformers in UHVDC transmission engineering. With the advancement of UHVDC transmission technology, converter transformers have emerged as critical electrical components. Operating at elevated voltage levels and accommodating large capacities, these converter transformers experience substantial losses within their windings. Consequently, the issue of winding overheating has become increasingly prominent. The method involves utilizing MATLAB/Simulink to simulate the temperature rise model of converter transformers. The hotspot temperature model adopted in this paper is simple and easy to understand, enabling effective simulation analysis of the top-oil temperature and hotspot temperature of the converter transformer. Configuring simulation parameters derived from existing technical specifications and monitoring data, and subsequently computing the hotspot temperature to satisfy engineering criteria. The simulation analysis of the converter transformer with a rated capacity of 412 300 kVA is conducted using Infolytica MagNet. By comparing the measured data of the top oil temperature and hotspot temperature of the converter transformer with the calculation results of the standard model and the simulation results, the rationality and accuracy of the heat circuit model calculation are verified. This hotspot temperature simulation analysis method provides a new solution for the hotspot temperature detection of the converter transformer.