Research And Application Of Power System Voltage Stability Analysis Index

With the improvement of the level of industrialization and modernization,Beijing Tianjin Tangshan,Pearl River Delta and Yangtze River Delta have gradually formed a series of mega cities and heavy load centers.These areas have the characteristics of large proportion of external power supply,the lack of reactive power supply and the limited capacity of active power grid.Voltage stability problem is more serious.The voltage stability index of power system can be used to evaluate the voltage stability of the power system,and to identify the weak area of the power system.Based on the calculation results,the reactive power compensation can be used to improve the voltage stability of the key nodes or regions.Therefore,the appropriate analysis index of power system voltage stability has certain engineering application value.In this paper,the voltage stability index of power system is studied.On the basis of the existing indexes,some new indexes are put forward,which are more applicable and more accurate.And the numerical value of the proposed indexes are calculated in the example systems.According to the calculation results,the configuration scheme of reactive power compensations are put forward,and compared with other configuration schemes.The main contents are as follows:(1)The principle of the impedance margin index and the sensitivity index of the static voltage stability index are analyzed,and a new static voltage stability index,voltage interrelated margin index,is proposed.Using the capital power grid in 2016 as an example,the three kinds of static voltage stability indexes are calculated and sorted,which verifies the evaluation ability of these indexes for weak nodes and weak areas.(2)For a large proportion of receiving system,a transient voltage stability index based on time domain simulation is proposed.For multi infeed HVDC systems,a multi feed short circuit ratio index considering dynamic component characteristics is proposed.The performance of the above two indexes is analyzed by taking Beijing power grid in 2016 and East China prospect power grid as an example.(3)The application of the indexes to guide the allocation of reactive power compensation is studied.According to the above indexes in cases of node system in weak order to make reactive power compensation device installation scheme,and not the installation and other scheme comparison,verify the effectiveness of the proposed index and application value in guiding the allocation of reactive power compensation.The results of the paper can be used to analyze the static and transient voltage stability of power system more effectively.Based on the voltage stability index in this paper,a more efficient dynamic reactive power compensation configuration scheme can be developed to improve the utilization ratio and configuration effect of reactive power compensation.