Electromagnetic shielding structure of giant hydro-generator in strong electromagnetic environment

Abstract

The invention provides a new type of electromagnetic shielding structure under the strong electromagnetic environment of a giant hydro-generator, which includes multi-layer silicon steel sheets and a layer of aluminum plates that are stacked and laminated in parallel; the multi-layer silicon steel sheets and a layer of aluminum plates are sequentially stacked and fixedly connected An integrated shielding structure is formed; multiple channel steels are evenly arranged on the surface of the machine pit wall opposite to the copper bar, and the shielding structure is arranged parallel to the machine pit wall and fixedly connected with the channel steel; the silicon steel sheet is close to the machine pit wall, and the aluminum plate is close to the Copper row; silicon steel sheet builds an ultra-high magnetic permeability path within the space of the leakage magnetic field, changing the distribution of the spatial magnetic field, so that the magnetic flux leakage that intentionally enters the steel bar enters the silicon steel sheet; the magnetic field line passes through the aluminum plate vertically and enters the silicon steel sheet. Induced current, the induced current also generates reverse magnetic flux leakage, which offsets the magnetic flux leakage generated by the original copper bar. The invention is used to prevent the overheating of the reinforced concrete structure in the wall of the machine pit caused by the strong electromagnetic environment, and the reduction of the structural strength caused by the overheating.

Description

technical field [0001] The invention relates to the technical field of electromagnetic shielding in a generator pit wall, in particular to an electromagnetic shielding structure for a giant hydraulic generator in a strong electromagnetic environment. Background technique [0002] The hydroelectric generator is arranged in the wall of the machine pit, and the wall of the machine pit is a reinforced concrete structure. The main lead wire of the generator needs to be led out of the machine pit wall through copper bars and cables. The rated current of the generator flows through the main center lead, and the current will form a magnetic field. The alternating magnetic field will form eddy currents in the surrounding metal components including the steel bars in the pit wall. Problems such as aging and accelerated aging will affect the safe and stable operation of the entire power station. [0003] In small and medium-sized units, due to the small capacity and low rated current ...

AI Technical Summary

Problems solved by technology

The super-strong magnetic field brought by the super-large current will cause serious heating of the steel members in the pit wall, and the traditional electromagnetic shielding structure can no longer limit the heating of the members

[0010] The electromagnetic shielding measures in the machine pit wall of units with a capacity of 850MW and above exceed the traditional requirements. At present, there is no research or engineering experience in this area at home and abroad for reference

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