Application Of Power System Stabilizer To Suppressing Low Frequency Oscillation

With the rapid development of smart grids and regional interconnected power grids,the study of the stability of modern power systems is becoming increasingly important.When power systems are subjected to different types of disturbances,low-frequency oscillations occur in the system.If they are not suppressed,the system may lose stability or even appear to be disconnected.In this case,the Power System Stabilizer(PSS)has been widely used at home and abroad as a measure to mainly suppress low-frequency oscillations.Firstly,this paper introduces the definition of low-frequency oscillation,its generation mechanism,modal identification methods and measures to suppress low-frequency oscillations.At the same time,it points out the superiority of power system stabilizers in suppressing low-frequency oscillations.Secondly,the definition of power system stabilizer,the principle of suppression and the mathematical structure of PSS(PSS1/2)are described.Then the IEEE standard PSS4 B mathematical model is described in detail.Finally,the PSS2 parameter preset method and the characteristics of suppressing power oscillation for PSS4 B sub-band are discussed.Symmetric bandpass filters are used to set the parameters of each frequency band,reducing the complexity of parameter settings.In combination with the measured parameters of a power plant at Huaneng,a single-machine infinite-bus system simulation model was built using MATLAB.Simulations show that the PSS(PSS2A)suppression effect on local oscillation is very consistent with the on-site experiment.The effect of general PSS and PSS4 B on the suppression of low-frequency oscillations under various types of fault disturbances is compared.The simulation shows that PSS4 B is more effective than ordinary PSS in suppressing local oscillations.The establishment of two area system simulation model and four machine three area system simulation model based on the research on the simulation of a single machine infinite bus system.By using the IEEE standard to set up PSS4 B parameters,the suppression effect of ordinary PSS and PSS4 B on low frequency oscillations is simulated when the system has different fault disturbances.Experiments show that when the system oscillates and the area ultra-low frequency oscillation,PSS4 B can provide appropriate damping to effectively reduce the oscillation amplitude,shorten the oscillation time and the suppression effect is obviously better than Ordinary PSS.