Method for comprehensively evaluating electric energy quality

Abstract

The invention discloses a method for comprehensively evaluating the electric energy quality by applying a TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) of a grey correlation coefficient matrix, which comprises the following steps of: taking electric energy quality data at all time intervals and standard data at all grades as an original decision matrix; determining subjective weights through an improved AHP (Analytic Hierarchy Process); determining objective weights through an entropy method; establishing a least square method decision model to obtain a comprehensive weight, so that the deviation of decision results under the subjective weights and the objective weights of all indexes is the least; carrying out standardization and weighted standardization on the decision matrix and obtaining the grey correction coefficient matrix by utilizing the grey theory; taking the grey correction coefficient matrix as a decision matrix of the TOPSIS to obtain the distance between positive ideal solutions and negative ideal solutions of all schemes and the relative closeness of the positive ideal solutions and the negative ideal solutions; and comparing the electric energy quality closeness at all the time intervals with the standard closeness at all the electric energy quality grades to finally obtain the electric energy quality grades at all the time intervals. With the adoption of the method, the electric energy quality evaluation result can be objectively and reasonably obtained under the situation of poor information, so that the practicability and the feasibility are stronger.

Description

technical field [0001] The invention relates to a method for comprehensive evaluation of power quality, which can effectively perform comprehensive evaluation on various power quality indicators, and belongs to the field of power system power quality. Background technique [0002] In the electricity market environment, power quality has received more and more attention from power supply departments and power users. On the one hand, the widespread use of a large number of nonlinear and impact devices in the power system has caused serious pollution to the power quality of the power supply system; on the other hand, due to the extensive use of sensitive instruments and equipment, users have more and more requirements for power quality higher. Although relevant power quality standards have been formulated, they can only simply judge whether each certain index is qualified, but cannot reflect the quality of the overall power quality. How to convert the multi-index problem into...

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Problems solved by technology

However, it only judges the relative closeness of gray correlation based on the similarity of the geometric shape of the data curve, which is not conducive to decision-making and cannot obtain accurate decision-making results.

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