Static Security Analysis Method For Power Network Expansion And Grid Connection

Electric energy is the foundation of a national industrial development and the lifeblood of the development of national economy,which is also the guarantee of the national economy and the people's livelihood and directly related to the healthy development of national economy and social stability.In recent years,China's electric power system is developing to the large units,large power grids,large capacity and long-distance transmission,which could gradually build and improve the construction of UHV power grid backbone network,and plan the strong network construction of each voltage level.The new power transmission and transformation project is like a raging fire.,electricity accidents often happen.In this paper,the method of static security analysis is studied to solve the problem of network stability running in the process of power network expansion and grid connected.The main work of this paper is as follows:1.The structure and mathematical model of each component in the power network are studied.The mathematical model of the power flow calculation and the basic principle and calculation procedure of the Newton Raphson power flow calculation method are summarized.2.Basic principle and method of static safety analysis of power grid are studied,the working flow and specific implementation methods of static safety analysis of power grid are summarized,including load forecasting,power balance,power flow mode selection,static safety analysis,etc.3.Selecting an engineering example,the paper analyzes the static safety problem of the new 500 kV substation expansion and grid connected.Load forecasting and power balance analysis are carried out according to the actual situation of the project.Power flow,overload and regional voltage analysis are carried out,which include the normal operation mode,maintenance mode and special operation mode on the basis of the two basic flow operation mode.Aiming at the problems in the static safety analysis,the concrete control measures are given.4.A low voltage optimization control scheme based on analytic sensitivity is proposed for the low voltage in the voltage limit which is often presented in the static safety analysis.The theory of low-voltage optimization control measures is deduced,which is simulated and verified with the IEEE-39 classical example and the actual grid instance in northeast China,while the order of low-voltage optimization control measures are compared.The result proves that the necessary reactive power compensation is carried out at the load node with high reactive power compensation sensitivity.If the voltage of the low voltage point fails to return to the normal level after the reactive power compensation,then a certain amount of load is gradually cut off at the cutting load point.This low-voltage control method makes the voltage improvement effect more significant.In practical application,such low voltage optimization measures can improve voltage performance more effectively,avoid the dependence on global information,which are simple to calculate,fast processing,and suitable for online applications...