Research On Transformer Models Under Geomagnetically Induced Currents

When Geomagnetically Induced Currents invade the grounded transformer neutrals,the transformer working at the rated state will partially be saturated.And its magnetizing current will be distorted accompanying with various of harmonic.In order to study the GIC problem, considering the core loss the thesis builds a transformer model for simulation with JA theory and UMEC theory.The model is built with S-function.And its key part for customizing the hysteresis loops is implemented with a User Interface.Then the thesis analyses the stability of the model.The thesis compares the saturated model of Matlab and PSCAD with the JA model and gives an evaluation on them.Finally the paper simulates the 750kV transformer in Yongdeng transformer substation which is invaded by the GIC at 2006 and 2004.This validates the model to be practicable.