Research On Power Quality Evaluation Of Rural Grid

Together with the development of new rural electrification, the number and the nature of rural load both have changed. People paid more attention to the quality of rural power supply. In order to meet with the rural users' requirements of power quality, enhance the quality of service, it's necessary to make the synthetic evaluation of power quality.This thesis have made depth study of the current methods of the power quality synthetic evaluation, proposing three different types of indexes system, based on classification of indicators, based on the different objectives of evaluation and based on the voltage levels. And under the actual situation of the new rural grid, establishing a realistic indexes system of power quality synthetic evaluation; Comparing the methods of evaluation at present, propose a new theory which is Analytic Hierarchy Process (AHP) combining with D-S evidential theory. This method keep the advantage of AHP, clear gradation and getting weights of the indexes easily, and eliminate the shortcoming of AHP by using the data fusion technology, D-S evidential theory, eliminating the influence of the individual factor to the result of evaluation in the greatest degree. Find out a new way to power quality evaluation.This thesis uses VB to compile practical computational program in this method. After that, carry out synthetic evaluation of power quality of some areas of Henan Province, and analysis the problems of the power grid reflected by the evaluation results. All of this proves the system of indexes is suitable and the method is scientific, effective and applicable.