Research On Transient Stability Control Of Smart Grid Based On Zonal Optimization

Nowadays,as the social economy develops at a high speed,the capability of national science and technology continuous to improve,the construction of urban infrastructure is getting faster and faster,a variety of infrastructure networks have emerged,and the connections between different infrastructure networks are becoming more and more closely.The integration of advanced cyber network and intelligent power system,which is closely related to our lives,is particularly prominent.As the construction of automation system and sensor network for power grid is gradually advanced and the power grid is deeply integrated with the energy network and Internet,smart grid will continue to evolve into a complex network with autonomous behavior and wide-area coordination.Through the analysis of the unstable operation of the smart grid,it can be seen that the time for information processing and control is very important to the stability of the overall system.Therefore,based on the distributed cooperative control theory of multi-agent system,in order to improve the stability of smart grid,the integration of cyber network and physical network,zoning based on physical state similarity and transient stability control of smart grid are studied in this paper.The main research achievements of this paper are as below:Firstly,the research status of smart grid is summarized,including the structure of integrated cyber network and physical network for smart grid,wide area measurement system which contains PMUs(phasor measurement units),distributed control and external energy storage equipment,which provides a strong scientific basis and theoretical support for the follow-up research work.Secondly,on the basis of cyber-physical agents including information devices and physical devices,the practical significance of multi-agent networked dynamic system model is studied.Based on the interconnected swing equation describing dynamics of power system,a model of cyber-physical interaction for smart grid is proposed,which can fully describe the cyber coupling and physical coupling between agents.Unlike the existing methods for modeling single generator and load connected by lossless linear networks,the complex interaction between active components(such as generators)is studied.Based on the existing swarm intelligence theory,which summarizes the behavior phenomena of biological groups in nature,the important components of smart grid are integrated with information intelligence and control behavior.In view of the existing data acquisition and monitoring control system in power grid,the above model can explore the interaction between the control center and the monitoring system.The simulation results show that the model of cyber-physical interaction for smart grid can rapidly achieve the transient stability of the power grid by power control.This research has certain guiding significance for how to reasonably utilize the behavior of cyber-physical interaction and effectively improve the transient stability of smart grid.Finally,in order to enhance the operation capability of the smart grid,the overdependence on information for system and the overhead of communication and information processing,such as redundancy or weak correlation of information,are considered.A cyber network optimization strategy to improve the flexibility of the smart grid is proposed,which effectively reduces information and communication traffic and the overhead of information processing,can improve the stability of the smart grid.On this basis,the physical state similarity zoning of the smart grid is carried out,and a more realistic and optimized distributed control strategy is adopted to achieve transient stability for smart grid through the coupling of cyber network and physical network and external energy storage in a “leader-assistant” collaborative manner of agents.The effectiveness of the distributed control based on zonal optimization is verified by comparing the simulation results with different scenarios,and the stability of the smart grid is improved and smart grid would return to the stability at a faster speed.This work has a certain guiding role for reasonably allocation of cyber network equipment to reduce construction costs and improve the rapid response ability of the smart grid.