Research On The Enhancement Of The Resilience Of Power Grids Under Ice Storms Disaster

As an important attribute beyond vulnerability and reliability,resilience has been widely concerned in recent years,and the research on resilience of infrastructure has become an increasingly popular research topic.As an important part of the infrastructure and the key foundation for the normal operation of the society,it is of great significance to ensure the normal operation of the power grid.However,due to global climate change,natural disasters occur frequently,and natural disasters such as ice storms will seriously damage the power grid system.Therefore,it is crucial to improve the resilience of the power grids under ice storms disaster.However,due to the low probability of natural disasters,insufficient historical scenario information and many uncertainties have a huge impact on power grids.Therefore,it is the key to study the improvement of the resilience of power grids under uncertainty.In this context,this paper will mainly study the qualitative and quantitative of grid resilience under natural disasters,as well as the upgrading planning of the resilience of power grids under ice storms disaster.Specific contents include:1)Aiming at the problems of insufficient natural disaster scenario data,unclear mechanisms of disaster occurrence,and difficulty in assessing the probability of disaster scenarios,this research combines the characteristics of grid performance changes under the background of natural disasters.Based on the “dynamics”,“phases” of grid losses,and the “diversity” of disaster scenarios,this research makes full use of historical disaster data to effectively characterize and measure the resilience of power grids,which lays a foundation for the following research.2)In the context of complete uncertainty of ice snows disasters information,this paper makes investment planning for power transmission network from the perspective of resilience to reduce losses of the power grid system,and at the same time takes into account the investment benefits of investors.A resilience-oriented investment planning on power system infrastructure to minimize the load shedding and the investment budget is also considered in this paper.A designer-attacker-defender(DAD)model is proposed to enhance power system resilience in absorption and adaptation.Transmission lines classification protection and DC deicer devices are taken into account as investment strategies to minimize impacts of the ice storm.In addition,differentiated dynamic protection is achieved.A tri-level optimization model is solved by a two-level column and constraint generation algorithm(C&CG).Numerical simulation on the power system of Qujing in Yunnan province is performed to demonstrate the rationality and effectiveness of resilience-oriented investment planning.3)In the context of incomplete uncertainty of ice snows disaster information,this paper makes investment planning for the distribution network from the perspective of resilience to reduce the loss of the grid system and proposes a multi-objective stochastic robust optimization model for distribution network resilience enhancement.The biobjective model aims to minimize the risk preference coefficient of decision-makers and the total investment cost.In the case that the probabilities of the scenarios are not fully known,the model can effectively reduce the conservativeness of the model while improving the distribution network resistance against the uncertainties caused by forecast errors.In this paper,distribution network lines up-gradation,installation of distributed generations,the configuration of on-site distribution network emergency repair team and allocation of diesel generators by important users are selected as the grid resilience enhancement measures to minimize the negative impact of cryogenic freezing rain and snow disasters.The epsilon constraint algorithm is combined with the decomposition algorithm to obtain the Pareto front of the multi-objective problem.Numerical simulation on the distribution network of Zhaotong in Yunnan province is performed to demonstrate the rationality and effectiveness of the resilience-oriented investment planning.The method proposed in this paper can improve the power grid's ability to cope with ice snows disaster,reduce the huge impact of ice snows disaster on power grids and society,and the research provides technical support for the improvement of the safety and reliability of power grids,which has certain guiding significance.