| Energy is an important cornerstone of human survival and development.With the depletion of fossil energy,the aggravation of the environmental crisis as well as the advancement of science and technology,the in-depth coupling,mutual assistance,and multi-source coordination of different energy networks have become an inevitable trend of energy reform.The energy interconnection system has effectively improved the efficiency of energy utilization,which is a significant way to realize the sustainable development of mankind.In recent years,the frequency and intensity of extreme events with high randomness and destructiveness have gradually increased,causing great economic losses to the energy interconnection system.However,traditional reliability evaluation does not take low-frequency and high-hazard sudden extreme events into account,which is not enough to support the safe operation of the system.Therefore,it is urgent to introduce resilience assessment to study the ability of the system to resist extreme disasters,so as to enhance the resilience of the system,and high resilience is the future development direction of the energy system.However,the current resilience research of the energy interconnection system is still in the exploratory stage,and the characterization of energy system features such as multi-agent,decentralized decision-making and interconnected interaction is not clear enough.The existing resilience evaluation index framework cannot effectively reflect the cascading effect of multiple subsystems,which is not conducive to optimizing the system by digging out the key resilience factors.Therefore,this thesis studies the resilience assessment and improvement measures of the multi-agent decentralized decision-making energy interconnection system.First,the dynamic behavior characteristics of a multi-agent energy interconnection system compared to a single power system under extreme hazards are analyzed from the three stages of fault absorption,fault evolution,and fault repair.Considering the fault propagation and feedback iterative effects among coupled subsystems,a resilience assessment index framework suitable for energy interconnected systems is constructed,and a malicious attack extreme scenario model is established based on the vulnerability of the system in time and space.Then,according to the decision rules in each level subsystem and the coupling relationship of multi-agent energy interconnection system,a decentralized decision-making fault response model for multi-level system facing extreme events is built with the consideration of the difference in time scales.Next,the modified IEEE-30 power grid and the Belgian 20-node natural gas grid interconnection system is taken as a case study,and the effects of fault infection,transfer,and cyclic feedback among subsystems in different scenarios are compared and analyzed through various resilience indicators.Furthermore,the key factors that affect the resilience of the system are explored,which reflects the advantage of the proposed resilience evaluation index compared with the traditional single-dimensional index,as well as verifies the feasibility and effectiveness of the method in this thesis.The results show that 1)the coupling among subsystems will lead to the propagation of fault effects and it has both positive and negative effects;2)the power transmission network,as the core of the energy interconnected system,being attacked will have a more extensive impact.Finally,the impact of energy redundancy,subsystem decision-making behavior,and new energy fluctuations on system resilience are further analyzed.The measures to suppress feedback and strengthen system resilience are also put forward,which provides a decision support for the construction and planning of a highly resilient energy interconnection system. |
PDF Full Text Request