Analysis Of Influence Of Large-capacity Camera On Small Interference Stability Of Power Grid

Due to the commissioning of UHV AC and DC lines,the operating conditions of the Henan Provincial Network have changed.Camera adjustment is an important basic work to ensure the safe and stable operation of large power grids.This paper combines the field test of camera adjustment with system application research in combination with the Shao Ling transposition camera project.Investigate the control performance of the camera to improve the dynamic operation characteristics of the power grid.Analyze the control parameters of the camera excitation system from the perspective of small interference stability,and study a new auxiliary controller that can be used to adjust the camera to increase system damping and thus increase system stability.The research content of the thesis mainly includes:(1)For the analysis of the camera excitation system characteristics,the expressions of electromagnetic power and work angle are derived under the third-order and sixth-order linearization models of the single-machine infinite system,and the amplitude and phase shift of the two at different frequencies are obtained by programming Then,under the different reactive power output of the tuning camera,the amplitude-frequency characteristic curve of the two is used to study the influence of the tuning system excitation system on the torque;the tuning camera is used as a generator to change its active output,and the generator excitation is analyzed based on the amplitude-frequency characteristic curve.Effect of the system on torque.(2)Derive the relationship between the system voltage V_S and the high-voltage bus voltage V_T with and without the system voltage regulator PSVR and draw the amplitude-frequency phase-frequency characteristic curve through programming.For the V_T-V_S phase frequency characteristics of PSVR-adjusted cameras,the phase shift value reflects the effect of the adjuster on the active power.The smaller the value,the smaller the effect on the active power.Therefore,by adjusting the time of the PSVR phase shift link Constant value,can change the VT-VS phase frequency characteristic curve of the camera.Based on this,the time constant value of the PSVR phase shifting link is determined.(3)For the adjustment of the PSVR gain coefficient,This paper uses a sixth-order model of a synchronous generator and uses the GMR/PMT technology to establish a small disturbance linearization model,and on this basis,the state space equation of the system is formed.The system's state equation can be used to find the system's eigenvalues and participation factors.This can determine the system's electromechanical oscillation mode and voltage oscillation mode.Use the correlation coefficients between the eigenvalues and the potentials of the two cameras to analyze the camera-related eigenvalues;Under the three operating modes of flat,peak,and valley,calculate the system's eigenvalues and use the participation factors to determine the camera-related(potential)correlation The voltage oscillation mode of the PSVR is adjusted according to whether the voltage oscillation mode is stable or not.(4)In the flat running mode,the PSVR gain coefficient and the camera reactive power take different values,calculate the system characteristic value,and use the participation factor to determine the power angle oscillation mode related to the camera adjustment.The influence of the two modes on the power mode oscillation mode of the camera is analyzed.So as to provide a reference for adjusting camera PSVR parameters.