Research On Fault Location And Recovery Technology Of Distribution Network Containing Distributed Generation

The growing conflict between traditional energy sources and the environment has promoted the long-term and sustainable development of distributed generation technologies that primarily utilize renewable and clean energy sources for power generation,such as non-fossil energy sources like wind,solar and biomass.With the increasing proportion of renewable energy in the distribution network,the traditional distribution network will inevitably evolve into an active and active distribution network,and the power supply reliability of the power system becomes more stable,but the tidal flow,network structure and fault information of the distribution network are also affected,making the traditional distribution network fault location and fault recovery methods inapplicable.Therefore,this paper focuses on how to quickly and accurately locate fault points in isolated power supply areas in distribution networks containing distributed power sources,and then supply the maximum amount of lost load as soon as possible by means of islanding and contact line transfer to achieve the purpose of reducing outage areas and enhancing distribution network reliability.The following are the main research contents.(1)A hierarchical fault location method based on intelligent algorithms is proposed to address the problem of degradation of real-time performance of complex distribution network location,and the mathematical model of fault location and the division method of complex distribution network are analyzed and the feasibility of the hierarchical method is verified.(2)In order to solve the fault location problem of distribution network with distributed power supply by grey wolf optimization algorithm,we propose a distribution network fault location method based on improved grey wolf algorithm,which uses improved Tent chaotic mapping to generate more diverse initial populations and combines with Lévy flight to improve the global search capability during local search.The analysis results show that the proposed method can achieve accurate localization in the case of both multi-point faults and information distortion,and also improves in fault location speed,accuracy and stability compared with other methods.(3)To address the problem that renewable distributed power sources such as scenery are subject to natural factors,intermittent power output and fluctuating load,a distribution network islanding method is proposed that takes into account the uncertainty of scenery load.The joint power generation model and load characteristics model of scenery and energy storage system are constructed,and a combination of breadth-first traversal and depth-first traversal is used for islanding,and the important loads in the distribution network are restored with priority.the effectiveness of the method.(4)To address the fault recovery problem of the remaining lost area after the islanding of the distribution network,a restoration reconstruction model of the main network and the remaining lost area is established with the minimum number of switch operations and the minimum network loss as the objective function,and the improved grey wolf algorithm is used to solve it and recover the remaining lost load in the distribution network;finally,a simulation analysis is conducted with the IEEE33-node distribution network model as an example,and the experimental results show that the method proposed in this paper can accurately and quickly obtain the fault recovery strategies for different fault moments,which verifies the effectiveness and superiority of the method.