Piecewise fitting method and system of lightning current amplitude probability distribution function

Abstract

In order to improve the condition that a certain deviation of a lightning trip-out rate exists between lightning current amplitude probability distribution functions recommended by regulations and the IEEE (Institute of Electrical and Electronic Engineers) and practical lightning current amplitude probability distribution, the invention discloses a piecewise fitting method of a lightning current amplitude probability distribution function. According to the method, a numerical analysis method is adopted to perform piecewise fitting on the lightning current amplitude probability distribution function, continuity correction is performed, and a curve of the lightning current amplitude probability distribution function, which is obtained in the way, is strongly relevant to a practical lightning current amplitude probability curve. As is well-known, the lightning current amplitude probability distribution function is an important calculating parameter for calculating the lightning trip-out rate of an electric transmission line, and the accuracy of a value directly influences the accuracy of a calculating result of the lightning trip-out rate. Therefore, by using the fitting method disclosed by the invention, the more accurate lightning trip-out rate can be obtained, and operation reference is supplied to the department of electric power operation for designating a lightning protection weak area of a regional power grid.

Description

technical field [0001] The invention relates to the technical field of data fitting, in particular to a method and system for segmentally fitting a lightning current amplitude probability distribution function. Background technique [0002] Among the various accidents in the power system, the faults of transmission lines account for the majority, and the faults of high-voltage transmission lines are mainly caused by lightning strikes. The lightning parameters used to calculate the lightning tripping rate in my country include thunderstorm day, ground flash density, and lightning current amplitude probability function. These parameters are important basic data used to represent the characteristics of lightning activity in lightning protection work. The probability distribution function of lightning current amplitude (that is, the probability of exceeding the lightning current I) is an important calculation parameter for calculating the lightning trip rate of transmission line...

AI Technical Summary

Problems solved by technology

However, when there are many data points, the polynomial order is too low, and the fitting accuracy and effect are not ideal. To improve the fitting accuracy and effect, it is necessary to increase the order of the curve, but too high order will bring computational complexity and other disadvantages

Therefore, if only one polynomial curve function is used to fit more data points, it is difficult to obtain better fitting accuracy and effect

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