A method and system for evaluating the operation status of distribution network cables

Abstract

The invention discloses a distribution network cable operation state evaluation method and system, comprising: collecting and obtaining account statistics information of distribution network operation cables in an area to be evaluated; determining a state evaluation influencing factor set U; setting a judgment set V; Calculate the failure probability of the cable, obtain the cable failure probability under each influencing factor and the conditional probability of cable failure and normal operation under the influence of each influencing factor; calculate the influence factors in the influencing factor set U on the cable failure based on the information entropy theory The degree of influence and the degree of change of each influencing factor itself is used to obtain the weight set A; the membership function μ(x) is established to obtain the judgment matrix R; the corresponding relationship between the evaluation set D and the judgment set V is quantified and the state evaluation is made. The weight calculation of the present invention is only determined by the objective statistical data of fault information, which can avoid the interference of human judgment on each factor, and can improve the objectivity of the weight of the influencing factors.

Description

technical field [0001] The invention belongs to the technical fields of power system automation and high voltage and insulation, and relates to a method for evaluating the operating state of a distribution network cable line, in particular to a method and system for evaluating the operating state of a distribution network cable. Background technique [0002] According to the national power supply reliability analysis, the cable length in the 10kV power distribution system was 220,000 kilometers in 2009, and the total cable length in the 10kV system increased to 594,600 kilometers in 2016, a year-on-year increase of 170%. Compared with traditional overhead lines, cable lines are widely used due to the advantages of safe and reliable power supply, improvement of urban aesthetics and saving urban space resources. Therefore, the fault on the cable line will affect the reliability of the power supply of the user and cause huge economic losses. The 10kV distribution network has a...

AI Technical Summary

Problems solved by technology

However, the representation of establishing fuzzy relations is greatly affected by the weight of each factor

At present, the traditional fuzzy evaluation uses the AHP method to calculate the influence degree of each influencing factor, but when calculating through the 1-9 scale method, human subjective judgment will lead to excessive errors in the results

Although many scholars have modified the calculation process of weights, it is still impossible to completely avoid the interference of human judgment on various factors.

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