Design Of Transformer . Core of Transformer and Design of Transformer Core Purpose of Transformer Core In an electrical power transformer, there are primary, secondary and may be tertiary windings. The performance of a transformer mainly Over Fluxing in Transformer Electrical4u Causes of Over Fluxing in Transformer As per present day transformer design practice, the peak rated value of the flux density is kept about 1.7 to 1.8 Tesla, while