Reliability Evaluation Of Active Distribution Network And Its Application In Switching Devices Optimal Location

In recent years,the development and utilization of renewable energy,energy saving and emission reduction,building a new smart grid have become an common strategic plan in many countries,and a concept of clean alternative and energy alternative is gradually produced as well.The active distribution network(ADN),as a rising model to increase the penetration level of renewable energy and distributed generation in demand-side energy supply system,has receieved a widespread concern.Security and reliability is one of the important goals of construction and operation in ADN.However,the intermittent output of renewable energy,multi-status of network topology and other uncertainties will lead to a great challenge of the reliability and its evaluation in distribution system.The discriptions for the influences of source-load uncertainty and the source-net-load coordinated control on the reliability become key points in the reliability evaluation of ADN.For the issue of source-load model accuracy,the baisc reliability models of photovoltaic,wind turbine and load are summerized as well as application range of these basic models.Then,the improved models for photovoltaic and wind turbine considering the constraints of work condition are further presented,as well as a multi-state load model considering the rebound effect.The simulation results based on IEEE-RBTS Bus4 system demonstrate that improved photovoltaic model has a better performance with high effectiveness and superiority.Aining at the issue of source-net-load coordinated control model in ADN,coordinated control models of DG-storage and storage-load are established respectively.Then,based on the source-load improved model,the source-load coordinated control model and the sequential Monte Carlo simulation method,the reliability evaluation method for ADN is proposed,and the specific reliability evaluation process is designed as well.Considering the high computational complexity caused by improved models and the sequential Monte Carlo simulation method,reliability evaluation method based on parallel computing is further designed to improve the efficiency and the computing platform is also constructed.The simulation results based on IEEE-RBTS Bus2 system demonstrate that reliability evaluation method based on parallel computing has a better performance with high effectiveness and superiority.Considering the limit of actual automatic development level in ADN,a practical evalutaion method with considering the partitioning effect of switching devices and the topology constraints is furher proposed for ADN with limited switching devices.Considering switching devices locating has direct effect in promoting the automation of distribution system,according to the evaluation method above,a programing model of switching devices optimal location is proposed,as well as a solution method based on multiple population genetic algorithm.The verification results based on RBTS BUS6 F4 system demonstrate the validity of the optimal location model in the scope of application.