Research On Power System Transient Stability Assessment Method Considering Fault Location

Power system is one of the most complex man-made systems in the world.Because of its complex design,there is coupling in the system.As time goes on,some lines in the system are aging and approaching the critical operating point,which leads to faults.In addition,weather,environmental changes and human error operation are also the main causes of the failure.When the fault is not found or cleared in time,other lines in the system are easy to have faults one after another,which will lead to cascading faults.In serious cases,it will lead to the transient instability of the whole system,resulting in immeasurable losses.By finding and locating the fault location quickly,the necessary operation of the system can be carried out in time;by determining the vulnerability of the lines in the system,the vulnerable lines can be protected in advance to prevent the propagation of faults and serious transient instability.In view of the above problems,the main research contents of this paper include:1)This paper analyzes the mechanism of each index in the power system when the fault occurs.The power system analysis synthesis program(PSASP)is used to set different faults for two large power systems,obtain transient data for data analysis,and extract effective index change rules.2)The accurate fault location model of power system is designed.Extracting effective features of the system,because the traditional manual feature extraction requires professional prior knowledge,and for different system structures,different features play different roles.Therefore,a deep learning model based on long-term and short-term memory network is used to extract temporal features.The dual structure system framework is adopted,and the fault line module provides features for the fault location module to overcome the problems caused by the coupling of system.The attention mechanism is used to analyze the change of system current before and after the fault,and extract the dynamic characteristics of current effectively.3)Determining the vulnerability of transmission lines in advance is also one of the means to ensure the stable operation of the power system.The traditional method to analyze the vulnerability of transmission lines in the power system needs to simulate the transmission of cascading faults in the power grid.With the continuous expansion of the power system,the simulation time increases exponentially with the expansion of the scale.Combined with the link analysis method,this paper first obtains the active power changes of each line when the fault occurs,constructs the system connection diagram,and uses HITS method to quickly determine the vulnerability of the power system.4)In order to further verify the accuracy of the method,a variety of different fault types,fault locations and other conditions are designed for two large power system architectures,and a large number of simulation data are obtained to verify the effectiveness of the method.The average error of fault location method is less than0.1%,and the accuracy of vulnerability ranking top-10 line is 80%.Combined with the characteristics of the algorithm,the importance of transmission line is obtained,and compared with a variety of related algorithms,the effectiveness of the proposed method is proved.