Failure Probability Model And Overload Capacity Of Overhead Lines

Overhead transmission lines are important lifeline sections in power system.Evaluating failure trend and load capacity under complex operating environments,linkage analyzing failure probability and loadability,are of great significance to realize the meticulous management of equipment.In addition,they can support the decision-making of operation and improve the safety and reliability level of power grid.In this paper,the following studies were carried out.Firstly,on the basis of internal and external mechanism which will lead to failure,this paper proposed an overall failure probability model for overhead lines basing on complex space-time states analysis.The modeling process and model architecture were introduced.The overall model consists of two parts:general state model and catastrophic state model.According to the differences between different risk factors harshness,appropriate model was choosen to calculate the final failure probability.The case study quantitatively showed calculation procedure of failure probability and impact of different risk factors.Secondly,a dynamic capacity-increase method which considers the load capacity of equipment is proposed.In an emergency scene,lines were picked by congestion analysis and their load capacities under the constraints of line temperature,failure probability,failure contribution and individual loss were analyzed.In combination with micro-meteorological information we could acquire emergency capacity-increase plans of different lines.The case study demonstrated the calculation procedure of emergency capacity-increase plan under the constraint of load capacity.The effect of load capacity on emergency capacity-increase was also revealed.Load capacity analysis model can provide suggestions for dispatchers to do some operations about capacity-increase and capacity-limit.Finally,on the basis of the above research and the project of Guiyang Power Grid Multi-dimensional Risk Dispatch and Emergency Command Research,the actual engineering application of overall failure probability model,load capacity analysis model and dynamic capacity-increase method was introduced.The system module's hardware architecture,data architecture,software configuration,software architecture logic and actual function effect were also elaborated.The research results will provide theoretical guidance and key technical support for realization of large-scale integrated intelligent dispatching.And the system module is a good supplement for Smart Grid Dispatching Technology Support System.