Method for reducing potential difference in transformer substation grounding grid caused by impact current

Abstract

The invention discloses a method for reducing potential difference in a transformer substation grounding grid caused by impact current, which is realized by laying a plurality of split copper bars in a cable trench of a transformer substation, and optimizes and selects reasonable split number and sectional area of the copper bars according to the potential difference condition in a secondary system grid. The method can effectively reduce the potential difference in the grounding grid of the transformer substation caused by the impact current, protects the reliable operation of a secondary system of the transformer substation, guarantees the safety of national energy, has obvious advantages in the aspects of economy, operability and accuracy, and provides reliable power supply for the development of national economy and society.

Description

technical field [0001] The invention belongs to the technical field of high voltage, and in particular relates to a method for reducing the potential difference in a substation grounding network caused by an impulse current. Background technique [0002] Good grounding is the basic guarantee for the safe operation of the power system. When a short-circuit fault occurs with the substation or is struck by lightning, the inrush current entering the ground will cause safety problems such as ground potential rise, mesh potential difference, step potential, contact potential and secondary disturbance voltage, which will affect the safety of equipment and staff in the station. Threat, because the grounding body is not a good conductor, a large potential difference will also be generated on the grounding grid when a large current passes through it. There are a large number of scattered grounded equipment in the substation, and the ground potential difference will be applied to the ...

AI Technical Summary

Problems solved by technology

At present, the actual engineering design specification only states that copper bars should be added in the cable trench to reduce the potential difference. However, due to the large reactance of a single copper bar, even if a single copper bar is laid in the cable trench, it may still not be able to achieve the design. Safety limit requirements, and at the same time, only experience can be used to select the size of the cross-sectional area of ​​the copper bar during construction, which is poor in economy, operability and accuracy

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