Research On Transient Stability Analysis Of AC/DC Hybrid Transmission System And Quantitative Transient Stability Assessment

The DC transmission is connected to the AC power grid,which improves the efficiency and stability of the transmission of the large area power grid.At present,the evaluation method of the limit time of power system is not suitable for large system,so it is necessary to put forward a better method to evaluate the transient stability of power system.Based on the understanding of home and abroad on the transient stability of AC/DC hybrid system based on the present research,analysis of AC fault,influence mechanism on system transient stability,influence factor analysis of AC/DC hybrid system transient stability characteristics of the proposed AC/DC hybrid system transient stability evaluation method.According to the power system transient stability analysis method analysis,calculation principle analysis of power system time domain simulation implicit trapezoid method based on extended equal area criterion factors and evaluation index of transient stability of multi machine power system based on impact.Combined with Matlab toolbox power system analysis tool PSAT,the transient stability analysis of AC/DC hybrid system is carried out by using the time domain simulation method and the extended equal area criterion.The mathematical model of PSAT is studied,and the mathematical model of synchronous generator and wind turbine is studied.Based on PSAT,the.Mdl simulation model of AC/DC hybrid system is built based on HVDC.Factor analysis of quantitative evaluation index of power system transient stability and transient stability characteristics,including the effects of HVDC access,before and after the system transient stability HVDC location influence of inertia on system transient stability influence on system transient stability of synchronous machine.In this paper,the method of improving the moment of inertia of the system is proposed.The influence factors of transient stability of AC/DC hybrid system are studied,and the basic principle of BP neural network is studied.Based on the BP neural network,the mathematical model of transient stability quantitative evaluation is established,and the effectiveness of the method is verified by the simulation example of the Northwest Power grid.