The Calculation Of The Static Voltage Stability Margin Of The Grid Based On The Thevenin Equivalent

At present,China's power system has entered a comprehensive network era,UHV,DC power network coexistence has been formed,and many use of renewable distributed generation as raw materials has become the trend of future grid,they not only solve the shortage problem of our country,but also protect our environment.The arrival of the era of large power grid,to the power industry has brought high efficiency and intelligent,but also caused a series of problems and challenges.How to effectively monitor and control the stability of power system in the process of power system becomes more efficient and more complex,so that it is more and more difficult to ensure the safe and reliable operation of power system.This paper introduces the method of static voltage stability analysis,analysis of the Thevenin equivalent in the research of voltage stability in the role.The paper introduces a kind of method based on sensitivity method to obtain the accurate position of the node system Thevenin equivalent parameters,the method for linear equations according to the node voltage division principle equations listed in the course of the study,only when solving triangular decomposition can be,does not need two traditional algorithm or multi-point flow data,small amount of calculation.After the calculated load node Thevenin equivalent parameters,the impedance modulus margin of the current state of each load node voltage stability analysis,can achieve the estimation of total network load margin,at the IEEE30 and Modified Weifang area 57 node system verify the correctness and effectiveness of the proposed method.