Static Voltage Stability Analysis And Reactive Power Compensation Based On Node Vulnerability Index

Since the 1970 s,over a hundred power system voltage collapse accidents have occurred in the world's major power systems,which have seriously affected the daily life of the people of all countries and the normal operation of the country,causing huge losses.It is an important research direction in the field of power system analysis and control to explore the mechanism of voltage stability,to study the method of voltage stability analysis and to improve the voltage stability of the power grid.The voltage stability level of the power system depends on the adequacy of the reactive power supply and the rationality of its distribution.Reactive power compensation is the key measure to improve the distribution of reactive power and improve the level of voltage stability.This paper focuses on the practical analysis method of power system voltage stability.The general definition and mechanism of voltage stability in power system are expounded.The main research methods and voltage stability evaluation index es of static voltage stability and dynamic voltage stability are analyzed and summarized systematically.The main measures to improve and improve the voltage stability are systematically discussed,which lays the foundation for further research on the volt age stability analysis method.Based on the understanding of the non analytic complex system in the power system,the dynamic analysis method and the dvenan equivalent principle are used to demonstrate that the condition of the maximum transmission power o f the non analytic power system is that the integrated dynamic equivalent impedance mode is equal to the static equivalent impedance mode of the load.Based on the theory of electrical coupling,the load rate and fluctuation index of the load node are defi ned,and a new index to measure the voltage stability of the power system,the vulnerability index,is put forward,and the calculation method of the vulnerability index is expounded.The index can effectively evaluate the degree of voltage stability and sort the vulnerability degree of the load node,the stronger the vulnerability of nodes,the more easy the instability is,the more easy to cause the voltage collapse of the system,which provides the theory and method support for selecting the key nodes of the voltage stability of the power system.Based on the proposed voltage stability vulnerability index,a dynamic optimal allocation method of reactive power compensation based on the order of vulnerability is proposed in this paper.By analyzing the vulnerability of the load node,the optimal configuration node for reactive power compensation is dynamically searched,and the most economical compensation scheme and operation mode are determined considering the capacity restriction and specification constra int of the actual reactive power compensator.Through the simulation and analysis of IEEE 39 node system,it is proved that the dynamic optimal allocation scheme based on vulnerability index is reasonable and effective.