The Research On Voltage Stability Analysis And Reactive Power Optimization Control Of Wind Power System

Large scale wind power generation is an effectivc way to solve the problem of tenvironmental pollution and energy crisis. Due to the reverse distribution of energy and load in China, wind power is connected to the grid with wind farm cluster and high voltage transmission mode. With large capacity wind farm access high voltage transmission network,it has a significant impact on voltage stability of wind power on the grid. In this paper, for the sake of the weaken of the system reactive power support capability and the anti-disturbance ability, four aspects mainly from the operating characteristics of the system, the reactive power source voltage stability analysis, wind power system low frequency oscillation and reactive power optimization control strategy are introduced of voltage stability study of wind power cluster system,Firstly, this paper analyzes the dynamic characteristics of the reactive power compensation equipment common dynamic wind power cluster system, a dynamic model considering wind power fluctuation based on the wind cluster system in Hami Xinjiang is established and in DIgSILENT/Power Factory. Improving the traditional differential algebra,equation, (DAE) model, to overcome the shortage of traditional power flow calculation, which is only based on information in single section operation, A dynamic analysis method is been proposed which combines the continuation power flow (CPF) and time domain simulation(TDS) method based on bifurcation theory.Secondly, based on the measured wind power information, a fast algorithm is proposed for computing the stability margin of the system, this method provides an esctimate of the final convergence point of the system, and improves the convergence speed of the algorithm, it also proves that the bifurcation point is the limit point of the instability of the system. The proposed method tracks the two dimensional Hopf bifurcation (HB) curves of system by using a two-parameter so-called 'two-step' method. It analyses and compares the dynamic response proper ties and voltage control capability of the wind cable set area between different power compensation devices.Finally, according to the anomaly oscillation accidents of wind cluster system in Xinjiang Hami area, considering the multiple time scale and the operating characteristics of cluster system, to study of the predisposing factor and suppression measure of the low frequency oscillation in large-scale wind power cluster system, a modified fruit fly optimization algorithm (MFOA) is proposed to coordinate and optimize the parameters of static VAR compensator (SVC) damping controller to improve the stability of wind power system. The simulation results of wind farm cluster in Xinjiang Hami show the effectiveness of the proposed method.