A selection method of suppression measures for substation ultra-fast transient overvoltage

Abstract

The invention relates to a suppressing measure selecting method for very fast transient overvoltage of a transformer substation. The selecting method comprises the following steps: (1) establishing a transformer substation calculating model; (2) selecting an electric arc channel resistor between 0.5 ohms and 2 ohms; (3) calculating an operation mode of an isolating switch; (4) determining whether the very fast transient overvoltage VFTO value caused by operation exceeds the voltage of the 2087 KV isolating switch or not; and (5) judging whether the waveform of the very fast transient overvoltage VFTO exceeds a requirement of winding type equipment such as a transformer and a bus potential transformer PT or not. Through the adoption of the suppressing measure selecting method provided by the invention, a calculation model with higher accuracy is placed according to the actual layout of substation equipment, maximum very fast transient overvoltage VFTO and distribution thereof under each operation mode of the transformer substation are sufficiently taken into consideration, an isolating switch parallel resistor is placed in a targeted way so as to suppress the very fast transient overvoltage VFTO, and overvoltage protection is performed on the transformer substation by means of other modes in front of specific winding equipment, so as to achieve a purpose of giving consideration to both safety and economic efficiency.

Description

technical field [0001] The invention relates to an overvoltage protection technology for a power transmission and distribution system, in particular to a method for selecting suppression measures for substation ultra-fast transient overvoltage. Background technique [0002] Very fast transient overvoltage VFTO has the characteristics of high amplitude, steep wave front, high frequency and multiple continuous pulses, which has an important impact on the insulation of GIS and its connected winding equipment (such as transformers). At the beginning of designing a substation, it is generally considered that all equipment layouts are considered for the overall modeling of the substation equipment (assuming that the isolation switch does not have a parallel resistance), and by calculating the breakdown of the voltage on both sides of the most extreme isolation switch at the "peak-peak value", the obtained The maximum VFTO value in various operating modes (ignoring the influence of...

AI Technical Summary

Problems solved by technology

This measure has the following disadvantages: (1) High cost: Generally speaking, there are dozens of isolating switches in a GIS substation. If all parallel resistors are installed, the cost will be as high as 10 million yuan; Parallel resistance greatly increases the complexity of the mechanism, resulting in an increase of about 10 times the failure rate; (3) Only the use of resistance is considered, and other more economical and feasible solutions can be comprehensively used

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