Stator bar anti-corona structure of large motor capable of increasing winding voltage withstanding level

Abstract

The invention relates to a stator bar anti-corona structure of a large motor capable of increasing a winding voltage withstanding level. When a voltage is increased, an anti-corona material has a stable resistance value, and surface potentials of each stator bar are basically consistent. At end parts of a winding, dislocation inevitably happens to adjacent parts of the bars. The novel inclined anti-corona structure has the advantages that potentials at the nearest distance of the bars on two sides of an inclined side gap of the winding end parts are similar; potential differences among the bars can be effectively reduced; and an inclined side gap electric field at the winding end parts can be reduced. The structure provided by the invention is characterized in that a traditional straight anti-corona structure is transformed into the novel inclined anti-corona structure based on geometrical shape characteristics of the end parts at the stator bars of the large motor; the inclined side electric field among the bar windings is improved and optimized; and a critical coronal voltage of the windings is increased. The novel anti-corona structure has the advantages of a simple structure, high operability and high universality, etc. The structure is applicable to anti-corona design of stator bars of each large generation set. The traditional anti-corona structure can be improved and optimized by the method disclosed by the invention.

Description

technical field [0001] The invention relates to an anti-corona structure for a stator bar of a large electric motor which improves the voltage resistance level of a winding. Background technique [0002] The end of the stator bar of the high-voltage motor is covered with an anti-corona layer structure, the purpose is to reduce the electric field at the end and improve the withstand voltage level. The anti-corona layer at the end is made of non-linear material and has a one- or multi-segment structure, which is difficult to design. At present, a large number of studies have been carried out on the optimal design of anti-halation structures at home and abroad, mainly using research methods based on experiments and supplemented by calculations. The main purpose of these studies is to increase the corona inception voltage level of a single bar. [0003] In fact, the corona inception voltage of a single bar is relatively high, which cannot guarantee the withstand voltage level ...

AI Technical Summary

Problems solved by technology

[0004] According to the traditional anti-halation method, the anti-halation overlapping line is parallel to the vertical line of the wire bar. When the winding is installed, due to the asymmetric shape of the wire bar, there must be misalignment between the ends. This traditional anti-halation lapping structure will cause wire There must be a potential difference between the ends of the rods, which will generate a certain hypotenuse electric field, which will cause corona discharge between different phase wire rods during the withstand voltage test and actual operation.

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