Security Ang Stability Analysis And Countermeasure Research Of Tai'an Power Grid

The power load of Tai'an power grid is increasing,resulting in excessive transmission power of some lines.Moreover,the grid structure is not perfect.When the system fails,it is prone to safety and stability.In addition,more and more wind farms are connected to the Tai'an power grid,which has a certain impact on their safety and stability.It is necessary to conduct qualitative and quantitative research on this effect.Further,the corresponding safety and stability emergency control measures should be worked out to ensure the safe,stable and reliable operation of Tai'an power grid.In this paper,the operational characteristics of doubly fed induction generator(DFIG)are analyzed,and a mathematical model for safety and stability analysis is established.Combining the wind power model with the power system stability calculation model,a large disturbance stability calculation model and a small disturbance stability calculation model of the power grid with wind power are established.For the large disturbance stability calculation model,trapezoidal implicit integral iteration method is used to solve differential equations of conventional power elements and wind turbines.For the small disturbance stability calculation model,the linear equation of power grid state with wind power is established,and the eigenvalues of the state matrix are calculated by the comprehensive analysis program of the power system,and then the stability of the small disturbance is judged by the real part of the eigenvalue.Based on the security and stability analysis method mentioned above,the safety and stability analysis of Tai'an power grid is carried out.The analysis results show the distribution of power flow in 220kV voltage grade grid and the verification of N-1 and N-2 under steady-state conditions.The effect of wind power on the safety and stability of Tai'an power grid is analyzed and studied in the light of two cases of wind power grid connection or not,combined with the actual operating conditions or failure conditions of the power grid.From the 3 aspects of voltage stability,power angle stability and frequency stability,the analysis results of wind power impact on Tai'an power grid are given.Combined with the results of safety and stability analysis of Tai'an power grid,relevant measures for further improving the safety and stability level of the power grid in the region are worked out.The safety and stability analysis method of wind power grid in this paper can be used to study the safety and stability of regional power grid qualitatively and quantitatively,and provide a reliable reference for the development and construction of the power grid and the planning of wind power development.