Study On Dynamic Line Parameter Identification Of Shandong Power Grid Based On Measurement Data

With the rapid development of the power grid,the safe and stable operation of the power system is getting higher and higher.The power flow calculation,state estimation and fault analysis are based on accurate grid parameters,which provide effective and stable control means for power grid operation,greatly improve the safe operation level of power grid and increase the reliability of power supply.So the line parameter identification,get accurate grid line parameters is very necessary.Through the establishment of transmission line model,the mathematical expression of transmission line parameter identification is deduced,and the model of line parameter identification is established.In order to realize the engineering application of the line parameter identification method and meet the requirement of real-time dynamic parameter identification of the mass line measurement data of the power grid,the identification software automatically obtains the real-time measurement data of the line identification method,designs the identification software and the EMS system data forwarding interface,and Line modeling program,for the dynamic parameter identification laid the foundation for engineering applications.Based on PMU data,the identification method of line parameters is analyzed.Based on the measured data of PMU,the variation characteristics of line parameters under different conditions are analyzed and the statistical characteristics of parameter fluctuation changes are extracted.Through the summary of the examples,it is concluded that the line parameters and the running mode have strong correlation,The relationship between the method and the method of calculating the parameters of the power flow is verified.The effectiveness of the proposed method is verified by a practical example.This method can effectively improve the planning and design and adjust the accuracy of the method.Based on the SCADA measurement data,the identification method of the line parameters is deduced by the least squares method,and the parameters of the 220kV line of Heze Power Grid are identified.The results of the identification of some lines are not available.In order to distinguish whether the identification result is available,a parameter evaluation method based on SCADA measurement data is proposed.By analyzing the trend of measurement waveform at both ends of the line and identifying the relative standard deviation of the reactance parameter,it is judged whether the identification result is credible,The reliability evaluation method is used to analyze the typical line identification results of Heze Power Grid.In order to solve the problem that the accuracy of the state estimation is low,the state estimation method based on time-varying parameters is proposed.The first stepis to identify the software to obtain real-time measurement data automatically,Automatic identification of the parameters;the second step and then use the credibility of the method of automatic identification of trusted identification results;the third step will eventually identify the results automatically into the EMS system database,EMS modeling is completed after the state estimation calculation.Theresults show that this method can effectively improve the qualified rate of state estimation and has a high value of popularization and application.