Extra-high-voltage GIS field impact test transient overvoltage inhibition apparatus

Abstract

The invention discloses an extra-high-voltage (EHV) GIS field impact test transient overvoltage inhibition apparatus comprising a plurality of unit modules connected in series through leading copper bars and transformer oil. Each unit module is composed of a resistor and a capacitor which are connected in series through the leading copper bar. A grounding copper bar is disposed under the lowest unit module. In the case that two interval devices of an EHV GIS field impact test are connected in series and three interval devices are connected, the EHV GIS field impact test transient overvoltage inhibition apparatus may guarantee that the overvoltage amplitude in GIS equipment is less than 2.4MV. By means of a weak damping characteristic of the serial connection of the low-value resistor and the capacitor, the EHV GIS field impact test transient overvoltage inhibition apparatus inhibits the EHV GIS field impact test transient overvoltage, and has obvious advantages of good overvoltage inhibition effect in breakdown states, low influences on waveforms in non-breakdown states, and flexible use and high efficiency.

Description

technical field [0001] The disclosure belongs to the technical field of overvoltage protection for power equipment, and is especially suitable for suppressing transient overvoltage during on-site impact tests of UHV GIS equipment. Background technique [0002] With the rapid growth of grid load, UHV power transmission has become an inevitable trend of my country's power grid construction. UHV GIS is widely used because of its good insulation performance, small footprint, safe operation, and convenient maintenance. The GIS equipment in operation will inevitably be invaded by lightning waves. If there are some insulation defects inside the GIS, under the impact of lightning waves, the GIS equipment is likely to have a flashover failure, which poses a threat to the safe and stable operation of the power system. Great threat. Therefore, the on-site impact test is of great significance to detect the internal insulation defects of GIS equipment and eliminate hidden troubles. [...

AI Technical Summary

Problems solved by technology

[0003] During the on-site impact test, if there is an insulation defect somewhere inside the GIS equipment and a breakdown occurs, due to the small size of the GIS equipment and the small node spacing, the voltage waves caused by the breakdown will be reflected multiple times inside the device and superimposed on each other. High-frequency voltage waves are generated. When this voltage wave reaches the cut-off point between the equipment and the power grid, a high-amplitude high-frequency transient overvoltage will be generated due to the total reflection of the voltage. The location poses a threat, causing unnecessary damage such as secondary breakdown

[0004] Different from normal operation, on the one hand, during the on-site impact test, there is a break point in the disconnected GIS equipment, which provides conditions for the total reflection of the voltage wave to cause high-amplitude transient overvoltage; on the other hand, the traditional The magnetic ring, lightning arrester and other equipment can only play a protective role after the GIS is connected to the power grid, and the GIS equipment in the disconnected state is not protected by the magnetic ring and lightning arrester during the field impact test.

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