Research On Operation Analysis And Optimization Based On Low Voltage Distribution Network

With the increasing scale of the distribution network and the increasingly complex network structure,the quality requirements for the construction and development of the distribution network are also increasing.The assessment of the operation of the distribution network through scientific means will help to identify weak links in the operation and guide the sustainable development of the distribution network.This paper takes the operation of distribution network as the research object,and starts from the perspective of the line to carry out research on the comprehensive evaluation model of distribution network and the reconstruction of distribution network.Firstly,this paper studies the relevant theories of comprehensive evaluation of distribution network,including the basic elements of comprehensive evaluation of distribution network and the specific steps of comprehensive evaluation work,and the basic principle of comprehensive evaluation of distribution network is elaborated from the aspects of purpose,representativeness,comprehensiveness,conciseness and operability.Aiming at the fishbone diagram analysis method,the analytic hierarchy process and the Delphi method which will be used in the comprehensive evaluation work of this paper,the basic principle and calculation process of each method are briefly studied.From the point of view of line operation,the comprehensive evaluation index system of distribution network line operation is established by selecting four indexes of voltage quality,load level,three-phase imbalance and comprehensive line loss.Secondly,establishing the evaluation model of distribution network operation on the basis of relevant theories,setting the weight of each level indicators and secondary indicators through the analytic hierarchy process,fully to the opinions of the experts into the index system,and according to the evaluation criteria set by the experts of each index and measure of first-class distribution network level,adopt the method of curve fitting selection index of evaluation criterion.According to the basic data of line operation in A city,the designed operation evaluation model of distribution network is applied to the operation evaluation of A certain urban power supply company,and the comprehensive scores of lines and distribution network in each region are calculated.In addition,horizontal comparison is made among all regions to understand the operation performance of all regions.The routes are classified by K-means clustering algorithm to find out the routes with poor operation performance.Weak indicators are found from the routes with good operation performance to do a good job in the inspection and remedy of defects in operation.This paper analyzes the influence of the equipment on the operation index from the two aspects of the service life of the line and the distribution and transformation capacity of the line,and puts forward corresponding Suggestions according to different situations.Finally,aiming at the operation problems of distribution network mentioned above,the paper puts forward the modification strategy.Taking load balance,network loss and voltage level as the objective function,considering the constraints of network power flow,voltage amplitude and network structure,a distribution network reconstruction model is established.According to the characteristics of the model,a binary particle swarm optimization algorithm is proposed to find out the optimal switch combination of the distribution network and determine the optimal operation mode of the distribution network through searching for particles.Some distribution networks in A city are used for simulation analysis to verify the rationality and practicability of the distribution network reconstruction model.