Voltage sag level comprehensive evaluation method

Abstract

The invention discloses a voltage sag level comprehensive evaluation method comprises based on an IEEE Std 1564-2014 standard, selecting amplitude, frequency, energy and severity indexes to constructa node index vector; trending and nondimensionalizing the original index data by using a reverse inverse transformation method and an averaging method so as to preprocess the indexes; constructing a determining matrix based on an analytic hierarchy process, and subjectively weighting the indexes; objectively evaluating the indexes by using a principal component analysis method based on a TOPSIS model; and comprehensively evaluating the node sag level by using combination weighting. The method solves the excessive information redundancy level between sag indexes, combines the advantages of subjective experience and objective information by the combination weighting method, and overcomes the defect that a traditional voltage sag evaluation method just uses a single weighting method and cannot fully describe the defects of the sag feature. A provided test method can describe the performance in all aspects of the comprehensive evaluation method accurately and comprehensively.

Description

technical field [0001] The invention relates to the field of voltage sag evaluation, in particular to a comprehensive evaluation method of voltage sag level based on combining the subjective weighting of the AHP and the objective evaluation of the TOPSIS principal component analysis method. Background technique [0002] With the development of semiconductor, automation and other industries and the application of high technology, the economic loss caused by voltage sag is becoming more and more huge, and it has become one of the most important power quality problems. The measurement and evaluation of the voltage sag level is the basis for scientifically solving the voltage sag problem. Although IEEE Std 1564-2014 has established a sag index system composed of single event, node and system indicators, it has not formed a systematic evaluation How to realize the comprehensive evaluation of node sag level has become an urgent problem to be solved. [0003] The evaluation method...

AI Technical Summary

Problems solved by technology

Based on this standard system, related research uses the K-means clustering algorithm to select representative nodes in the system, and the representative node index vector to characterize the system sag characteristics, but multiple indicators are not conducive to intuitive quantification and comparison of sag levels

In order to combine the sub-items into a comprehensive index, relevant scholars proposed a comprehensive evaluation method for node voltage sag severity based on combined weighting. The multi-type comprehensive index obtained can be compared and analyzed more comprehensively and intuitively. The variation coefficient method and entropy value method only consider the objective characteristics of the data, but ignore the influence of the subjective judgment of weighting, and the evaluation results obtained have the defect that they are contrary to the experience of experts.

Therefore, on this basis, relevant scholars further combined G1 subjective weighting with entropy objective weighting to obtain combined weights, but the method did not consider the impact of index redundancy on evaluation results

The above evaluation methods can only qualitatively analyze and evaluate whether the comprehensive evaluation results are reasonable, and the evaluation results lack scientific basis, let alone a complete comprehensive evaluation process

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