Numerical analysis of transient stray field and performance parameters for 500kV converter transformer

The simplified model of calculating transient stray field with non-sinusoidal current for a 500 kV converter transformer is set up. Numerical analysis of both transient stray field and harmonic losses are carried out and their distributing characteristics are acquired by using FEM. Some parameters are validated by comparing with test results of the product. A number of useful suggestions are given for design of HV DC converter transformers.