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

Abstract

The invention provides a novel electromagnetic shielding structure of a giant hydro-generator in a strong electromagnetic environment. The novel electromagnetic shielding structure comprises multiplelayers of silicon steel sheets and a layer of aluminum plate which are overlapped and laminated in parallel, the multiple layers of silicon steel sheets and the layer of aluminum plate are sequentially laminated and fixedly connected to form an integrated shielding structure; multiple pieces of channel steel are uniformly arranged on the surface of the pit wall opposite to a copper bar, and the shielding structure is parallel to the pit wall and is fixedly connected with the channel steel; the silicon steel sheets are close to the pit wall, and the aluminum plate is close to the copper bar; the silicon steel sheets construct an ultrahigh magnetic conduction path in the space range of the leakage magnetic field, and the distribution of the space magnetic field is changed, so that the leakage flux intentionally entering the reinforcing steel bar enters the silicon steel sheets; and magnetic lines of force vertically penetrate through the aluminum plate to enter the silicon steel sheets,current is induced in the aluminum plate, and the induced current also generates reverse magnetic flux leakage to counteract magnetic flux leakage generated by the original copper bar. The novel electromagnetic shielding structure is used for preventing the conditions of overheating caused by a reinforced concrete structure in the pit wall in the strong electromagnetic environment, structural strength reduction caused by the overheating and the like.

Description

technical field [0001] The invention relates to the technical field of electromagnetic shielding in a generator pit wall, in particular to a novel electromagnetic shielding structure in a strong electromagnetic environment of a giant hydroelectric generator. 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 ...

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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