Power transmission line protection characteristic identification and voltage sag duration estimation method

Abstract

The invention discloses a power transmission line protection characteristic identification and voltage sag duration estimation method, which comprises the following steps of: firstly, identifying a line protection type according to a sample interval mean value standard deviation, and further providing a DBSCAN clustering method optimized based on a mahalanobis distance and a K nearest neighbor algorithm to accurately calculate a line protection action time characteristic; and finally, a voltage sag duration estimation method based on a protection action characteristic calculation result is provided, so that an extremely important data support is provided for an electric energy quality researcher to evaluate the frequency and risk of the voltage sag of the power grid in actual engineering, and subjective hypotheses and dependence on other systems are reduced. And the defects of difficult implementation and large error of the existing evaluation technology are overcome. As the price of monitoring equipment such as an electric energy quality monitor and a fault recorder is lower and the application is wider at present, the applicability of the method is continuously improved.

Description

technical field [0001] The invention relates to the technical field of voltage sag evaluation, in particular to a method for identifying transmission line protection characteristics and estimating voltage sag duration. Background technique [0002] Voltage sags can trip sensitive equipment and cause huge industrial losses. Estimating the frequency of voltage sags is an important prerequisite for solving the problem of voltage sags. In voltage sag frequency estimation, the main concern is two single-event characteristics of voltage sag, one is voltage amplitude and the other is duration. Accurate voltage sag amplitude and duration estimation results are one of the key bases for calculating the trip probability of sensitive equipment and industrial processes, evaluating the degree of impact on sensitive users and economic losses, calculating site power quality indicators, and evaluating low-voltage ride-through performance of wind turbines. For the estimation of the amplitud...

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Problems solved by technology

[0014] In view of the above problems, the purpose of the present invention is to propose a line protection action time characteristic identification and voltage sag duration evaluation method by using the richness, high precision and high availability of power quality monitoring data from the perspective of data drive. Power quality researchers provide extremely important data support for evaluating the frequency and risk of power grid voltage sags in actual projects, reducing subjective assumptions and dependence on other systems, and making up for the shortcomings of existing evaluation techniques that are difficult to implement and have large errors

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