Magnetic shielding device for stationary induction electrical apparatus

TLDR: In this article, the authors proposed a method to prevent local overheating in magnetic material shields and a tank and the thermal degradation of insulators protecting the shields or the like, by a method wherein insulators are respectively provided vertically between the shields and the inside of the tank in the height direction of a tank to form cooling flow paths.

Abstract: PROBLEM TO BE SOLVED: To prevent local overheat in magnetic material shields and a tank and the thermal degradation of insulators protecting the shields or the like, by a method wherein insulators are respectively provided vertically between the shields and the inside of the tank in the height direction of the tank to form cooling flow paths. SOLUTION: Magnetic material shields 8 formed by laminating silicon steel plates of a thin plate thickness in a width W are provided side by side at the positions opposing to inside and outside winding wires 4 and 5 on the inside of a tank 7 housed with a transformer body, comprising a main leg 1, side legs 2, upper yoke parts 3 and the inside and outside winding wires 4 and 5, via prescribed gap parts in the lateral directions, in such a way that the longitudinal directions of the shields 8 are made perpendicular and the shields 8 are respectively provided with press metal fittings. Insulators are provided for protecting the shields 8, and insulators 10 are respectively provided vertical between the insulators and the inside of the tank 7 in the height direction of the tank to form cooling flow paths 11. As a result, local overheating in the shields 8 and the tank 7 and the thermal degradation of the insulators for protecting the shields 8 can be prevented from being caused.