Method for discriminating requirements of ultra-high voltage (UHV) line steady-state overvoltage device

Abstract

The invention relates to a method for discriminating requirements of an ultra-high voltage (UHV) line steady-state overvoltage device, which is based on the lossless transmission line theory. According to the lossless transmission line theory, the voltage relationship and the current relationship between any two points on a line can be analyzed as long as distribution parameters of wires are known. By using the characteristic, the method analyzes the voltage distribution situations when a power system with a UHV idle line operates, comprehensively considers the parameters, the lengths and the high-resistance configurations of UHV wires, and judges whether steady-state overvoltage problems occur in the UHV line and whether a steady-state overvoltage device needs to be configured. Traditional discriminating methods completely use power system simulation software to conduct large amounts of verbose simulations, however, the discriminating method of the invention overcomes the problems, has the characteristics of good adaptability, simple operation and less calculation amounts, and can be used for the quick discrimination of the requirements of a UHV steady-state overvoltage device.

Description

technical field [0001] The invention belongs to the field of electric power systems, and in particular relates to a method for judging the demand of steady-state overvoltage devices of UHV lines based on the theory of lossless transmission lines. Background technique [0002] UHV AC lines have the characteristics of long power transmission distance and high charging power. When the three-phase trip of any UHV equipment switch is caused by the switch sneak trip or the action of the UHV de-loading device, the system will run with UHV empty line, and the voltage along the UHV line will increase significantly. Considering the line charging capacitance and high voltage Anti-resistance configuration, the highest point of the line voltage is not at the end of the line, but at a certain point at a certain distance from the end. At this point, the UHV charging power and the capacitive reactive power of the third winding of the UHV transformer rush to the 500kV system on both sides. ...

AI Technical Summary

Problems solved by technology

[0003] At present, the UHV power grid is still in the early stage of development. Whether UHV lines need to be equipped with steady-state overvoltage devices depends entirely on the use of power system simulation software to simulate the voltage distribution along UHV air-charging lines under a large number of different working conditions. To judge whether there is a steady-state overvoltage problem, the workload is huge and very cumbersome; at the same time, using the enumeration method for the research conditions will inevitably lead to missed judgments and misjudgments

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