Loss reduction by combining electrical steels in the core of power transformers

摘要

This paper analyzes a practical methodology to assemble/combine commercial electrical steels in a singlephase core-type power transformer. The main advantage of these electrical steel combinations is thernreduction of core losses and their associated cost, without compromising the integrity of the transformer.rnAn explanation of the improved performance with a combination of electrical steels in core-type powerrntransformers is presented in this paper. The steel combinations are studied using transient, nonlinear, 3Drnfinite-element simulations, with proper calculation of core losses. Electrical steels in the core are modeledrnusing their magnetization curves. Five commercial electrical steels are considered: four conventional steelsrn(M-6, M-5, M-4, and M-3) and a laser-scribed electrical steel (TRAN-COR H0). From the simulations, thernattainable reduction in core losses by means of steel combinations is determined. Results from thernsimulations are compared with laboratory tests. Finally, 3Dfinite element static thermal formulations arernused to rule out hot spots in the cores made of electrical steel combinations. Copyright © 2015 John Wileyrn& Sons, Ltd.