The Impact Of Wind Power Grid To Power System Security And Stability

With the continuous improvement of wind power technology and the level of equipment, wind power generation technology matures, as it has the conditions for large-scale development and commercial operation, the wind power has developed to become the third largest power in China, after thermal power and hydropower. However, wind power has the characteristics of randomness and volatility, as the penetration of wind power increasing, the integration of wind power into power system brings challenge to the security and stability of power system.In this paper, based on the research of wind turbine structure and characteristic, the impact of integration of wind power on the power system is studied from the aspect of power flow calculation, small signal stability and transient stability.The impact of integration of wind power on the power flow analysis and calculation is the foundation problem requires to be solved firstly. To research the method of power flow calculation after integration of wind power is conducive to determine the wind farm integration scheme, and provides a basis research for the further work of stability and reliability of power system. In this paper, based on the analysis of wind speed model and steady-state power flow model, the structure and model of wind turbine are analyzed and elaborated in detail. Combined with the existing method, the model of power flow calculation of asynchronous wind turbine and doubly-fed wind turbine is established. In order to meet the needs of the actual simulation, the simplified model and processes of asynchronous wind turbine are proposed.As the scale of wind power expanding, the regional power grid interconnection develops rapidly. In such a situation, due to the inherent randomness, volatility and non-regulative of wind power, the power system suffers small disturbances all the time during operation. The analysis of small signal stability and damping characteristics of the power system containing wind farms becomes a very urgent issue. In this paper, a regional power grid simulation model is set up using PSASP software, and this model is analyzed in detail. The results show that, in this regional power grid, the integration of wind power has limited impact on the oscillation model related to other units.Compared to traditional synchronizations, the wind turbine generators have a different steady state and transient characteristics. As the wind power integrated, the original power How distribution and inertia of power system will change. These will have an impact on the transient stability of power system. In this paper, the model of doubly-fed wind turbine, which is widely used at present, is analyzed and elaborated. Based on the analysis of development of power system and wind power in China, the transient stability of the practical example loss of part of the power is calculated and analyzed, using the method of transient stability numerical analysis.