Power Quality Weak Bus Evaluation Of Distributed Network

The evaluation of weak points of power quality is one of the hot-issues in power research.Scientifically and reasonably detecting and evaluating power quality can promote the comprehensive management of power quality and help to establish a fair power market.In addition,it can also let the decision-makers grasp the power quality of distribution network scientifically and accurately,and provide scientific and accurate basis for the access of power quality control equipment.This paper studies the evaluation of weak points of power quality in distribution network.The main contents includes:According to each index of power quality,the definition and calculation method are given,and the main causes of power quality problems are analyzed briefly.For the common power quality load,a MATLAB model for power quality analysis is built based on the existing literature,and the validity of the model is verified.In order to evaluate the weak points of power quality in a specific voltage level,a method based on combined weighted TOPSIS is proposed.In the objecting weighting part,CRITIC method is introduced to solve the problem that the general object weighting method is too sensitive to abnormal data.In the subject weighting part,the weight process of traditional expert scoring method is improved by using CRITIC method.It makes the weighting process of subjective scoring method more objective and reasonable.In this paper,the weighted TOPSIS method is used to map each node data to more accurate power quality classification data to achieve power quality classification.Aiming at the problem of hierarchical evaluation of weak points of power quality in distribution network,a method of power quality evaluation based on fuzzy Borda combination method is proposed.Firstly,the method of "per unit" processing of power quality data of each voltage level is put forward to realize the unification of power quality index data classification.In the aspect of single evaluation method,TOPSIS method,grey relation analysis method and cluster analysis method are selected.In order to make the combined results have practical significance,it is helpful for Spearman coefficient to test the consistency of the results of the three methods,and the fuzzy Borda method is used to evaluate the combination,which increases the differentiation of the data,so it has certain practical significance.Finally,the example analysis shows that the method in this paper realizes multi-voltage level evaluation,and the method is objective and accurate.Finally,a power quality assessment system from global to local is established.Then,based on the actual distribution network in a certain area,the distribution network model is built and the weak points before and after photovoltaic access are simulated and analyzed,through which verifies the rationality and effectiveness of the method in this paper.This paper makes a useful exploration on power quality evaluation of distribution network.