Study On Control Strategy Of Turbo-generator Torsional Vibration

At present for improving the transmission efficiency, series compensation capacitors widely existing in domestic electric power system, will produce subsynchronous oscillations, in large part this will likely stimulate torsional vibration of Turbo-generator shaft,and it makes the torsional vibration research become a very important topic. Firstly this paper analysis the wide-area measurement of torsional vibration problem, introduce the formation of the wide-area measurement technology,and the key components, PMU is analyzed in detail. Considering the application of the torsional vibration signal in the wide-area measurement,make the qualitative analysis of the controller effect. This paper summarizes the torsional vibration control measures,both the active and passive, and makes a series of organic research on control strategy of torsional vibration, deeply analyses the mechanism of subsynchronous oscillation, emphatically analyses IEEE recommended measures—SVC for torsional vibration control, calculates and analyses the relationship between the control angles and reactive current of SVC. At the same time for conventional SVC cannot effectively restrain the multi-mode torsional vibration problems, so this paper puts forward modal separation control strategy based on SVC, and proposes two methods including both extracting input signals and adding subsynchronous portion in SVC reference to analyze the mechanism of modal separation and corresponding control structure parameters. and successfully carries on the corresponding simulation in IEEE first standard model of subsynchronous oscillation. This paper put forward the control strategy jointing SVC and TSR.At last, based on the analyses of torsional vibration fault characteristics of a certain power plant of 600 MW unit,this paper calculates the characteristics of shaft torsional vibration,makes the correponding control strategy, establishes the system modeling of the power plant in PSCAD/EMTDC simulation platform, two-phase fault wis simulated, and the simulation results proves the effectiveness of the control strategy of SVC in the power plant.