Research On Cascading Failures In Power Grid Based On Complex Network Theory

With the continuous reinforcement of the cross-regional interconnection of the grid,the scale of power network is larger than ever,which improves the efficiency of the whole system.Yet,it also increases the uncertainty of the widespread transmission.Once the system have a disturbance,the sweeping scope is tremendous,so the partial failure can travel through the Internet to affect the entire network,then causing a cascading failure.The position of the grid in the national economy is more and more significant,so the research on how to insure the grid safety and stable operation is imperative.The research based on complex network is increasingly mature now,which provides a new method to study the power grid cascading failures.Therefore,the complex network theory is applied to study the power grid cascading failures in this paper,including the following aspects:This thesis introduced the basic theory of complex networks,the topological structure parameters and the topology model,and analyzed the characteristics of parameters and model features.Based on complex network theory,the simplified power grid models of north China and central China are made,then,studied the different nature of the power grid with different parameters and the influence of the different parameters on the power grid cascading failures.As a case study of dynamic model sand,using the self-organized criticality theory to explain the reason and developing process of the accident,and explore the generation mechanism of blackouts accident chain.Then introduced an OPA cascading failure model with self-organized criticality and based on this,the Self-organized critical point of Guizhou power grid and the standard system of IEEE 30 nodes with different nature are solved.Reasonable power grid cascading failures threshold is set up to prevent cascading failures,and is of great scientific theory and practical significance.Combining the complex network basic characteristics with the Northeast China,the Northwest China,the Central China power grid blackout data,this paper used the theory of probability to calculate the probability of cascading failure in the next 5-20 years.Explained the causation that when the fixed number of year is certain,that the greater the probability,the loss of load is less and the smaller the probability,the loss of load is more.After considering the influences of the grid structure and the key components of different network structures,some effective measures to mitigate the probability of cascading failures are expored.