Research On Location Method Of Disturbance Source Line Caused By Low Frequency Oscillation In Substations

Because of the influence of the terrain of Inner Mongolia power grid, the electrical distance is long and network structure is weak. With access to a large number of power sources, the burden of transmission lines is heavier and the dynamic stability problem of power system is becoming more and more serious. Low frequency oscillation phenomena often occur. As this phenomenon can do harm to the safe and stable operation of power system, when low frequency oscillation occur, determining the disturbance source of oscillation and removing them in time can ensure the safety and stability of power grid. Therefore, it is very important to do the further research about low frequency oscillation.This paper presents a method that extracts the maximum value by measuring the bus voltage signal of different voltage levels in substations, and calculates the maximum envelope by utilizing function fitting, and further calculates the low frequency disturbance variables. According to the attenuation characteristic of variables when spreading in power grid, the disturbance variables will produce attenuation when passing the transformer windings. By extracting and comparing the amplitude of disturbance variables of different voltage levels in substation, it can be concluded that line with biggest change of variable amplitude is the line in which low frequency oscillation is triggered.