Study On The Power Quality Comprehensive Evaluation And The Method Of Pricing For Different Power Quality

With the development of national economy and science and technology, the power consumers' demand for power quantity and quality is becoming more and more eager. The constant development and perfection of electricity market make the power quality comprehensive evaluation become inevitable and the pricing for different power quality become possible.At present, the power quality comprehensive evaluation was discussed by some scholars at home and abroad, but the evaluation index weight still need further research. For the multiple index comprehensive evaluation, weight determination is a quite important step, as the change of weight will affect the scientific rationality of the integrated evaluation result. Therefore, in this paper, the power quality weight was studied deeply and the pricing for different power quality was discussed.Based on the power quality disturbance characteristics, this paper introduces the combination weight which integrates many objective weight and subjective weight into power quality comprehensive evaluation. The power quality has been divided into five levels in this paper. Firstly, three subjective weights (analytic hierachical process (AHP), expers consultation method, superiority chart) and two objective weights (entropy method, variation coefficient method) are combined together to establish the optimal model and to get the index weight for power quality comprehensive evaluation through solving this optimal model. Secondly, using the combination of probability statistics and fuzzy mathematics to evaluate the 9 indexes of power quality synthetically which contains frequency, harmonic, voltage fluctuation and flicker, voltage deviation, voltage dip, three-phase unbalance, temporary over-voltage and transient over-voltage. The power quality will be grouped into one level after the evaluation and the evaluation result is the only quantitative index which can be used to describe the power quality.The analysis result show that, using combined weight, which integrates many objective and subjective weight to determinate the power quality index weight, considers the power consumer's different demands, reacts the power consumer's subjective will, and as well reacts the objective reality which makes the weight can embody the change of the index's data, so reaches the unification of subjective and objective. The evaluation result is in accord with reality.Finally, based on the evaluation result, this paper uses the risk management and insurance theory to realize the pricing by different power quality. This paper introduces a correction coefficient to adjust the insurance premium properly, so as to attract more power consumers to insure the power quality. Take a sensitive consumer as an example, this paper shows that the consumer can decrease their own economic loss only after they pay the premium of power quality.