The Influence Of Wind Power Injection With High Penetration On The Small Signal Stability Of Power System

With rapid development of wind power, the penetration of wind power is keep raising in power system. The wind power has the characteristics of randomness and fluctuation, which can affect the small signal stability of the system. And this effect is exacerbated by increasing penetration. The reasch of the influence of the high penetration integration of wind power on the small signal stability of power system has important thoeretical and practical value.In this paper, the small signal stability model of the double fed wind turbine is established, including the aerodynamic model, the two mass shaft model, induction generator model in rotaing dq coordinate and rotor-side and grid-side converters model with control system, and the accuracy of the model is verified, laying the foundation for the following research. Secondly, using NJW clustering algorithm, the multi machine equivalent model of wind farm is established for studying the scene of high penetration. The accuracy of the multi machine quivalent model is verified by comparing with the detailed model and single machine equivalent model. Taking IEEE 3-machine 9-bus system and Hainan real network as an example in BPA, the influence of high penetration wind power integration to the damping characteristics of interarea and local oscillation mode is studied. And the effects of spinning reserve, the correlation of synchronous generator and the electrical distance are analyzed. The simulation results show that the insteading of thermal power by double-fed wind turbine generate a two-way influence the damping characteristics. The damping of system is improved by increasing of spinning reserve and weakened by accessing of wind turbine. And increasing spinning reserve have more effective influence on improving damping when it on the strong correlation unit to the oscillation. Overall, wind power injection have a greater impact on oscillation modes nearby. Finally, the high penetration wind power injection bring more random sources. According to the problem, a random small signal moed of DFIG is established based on the stochastic differential equtions, and the stochastic stability criterion is given. The correctness of the theory is verified by simulation. And the influence of the fluctuation intensity and cumulative effects on state variables of power system is studied.