Emergency Optimization Strategy Of Active Distribution System Integrated With Distributed Generations Considering Communication Failure

As the well-known writer Rifkin pointed out in his book the Third Industrial Revolution,decentralized communication technology is being combined with the distributed renewable energy to form the infrastructure of the third industrial revolution.In the recent years,with the development of communication technology and new energy power generation technology,distributed generation has received increasing attention from governments and enterprises as an important form of energy utilization.Actually,the increase proportion of distributed generation integrating further strengthens the dependence of the energy system on the communication system,which may bring potential system security risk.Especially,it may cause state fluctuations and load shortage to the power grid,when a communication interruption occurs.Therefore,the design of emergency strategies for power system with high-penetration new energy during the communication interruption has important practical significance.Thus,an optimized model for the emergency operation strategy of the active distribution system has been proposed in this paper,which aims to ensure the safety and stability of the energy system during the fault.The main work includes:First of all,through summarizing analysis methods of the power system,the basic characteristics of the system during the failure process are analysed from the aspects of reliability,security and vulnerability.Also,the current research on offline emergency strategies has been summarized to design the optimization model.Secondly,considering the basic concepts in the traditional vulnerability theory,a method characterizing the operational vulnerability and the structural vulnerability has also been proposed.Specifically,though analysing the fluctuations of voltage and flow,the mathematics descriptions of the system state are established.Meanwhile,based on the networks,the user structure indexes are introduced to construct the comprehensive vulnerability expression.Thirdly,to ensure the high efficiency and applicability of the emergency strategy,a multi-scenario emergency strategy optimization model is established in this paper.Specifically,the sampling scenarios including wind power and photovoltaic is divided into several typical scenarios based on the ISODATA clustering algorithm.According to the results,the comprehensive vulnerability is used as the objective function,while the output of each distributed unit is calculated as optimization variable.Also,the model is solved by the improved intelligent single particle algorithm,based on which the emergency strategy are designed.Finally,to verify the accuracy of the model,the case study is proposed according to the modified IEEE-33 system.By comparing the electric parameters under different emergency strategies,the effectiveness of the optimization model is proved.Also,the processes of optimized strategies varying with change of integrating mode and new energy penetration are compared,which prove the applicability of the model in further.