Static Security Assessment Of Power Systems Considering Large-scale Wind Power Generation

With the global energy shortage and environmental pollution,wind power, the most mature renewable clean energy, developed rapidly around the world. However, since the intermittent, unpredictability and uncontrollability, the integration of wind power will change the distribution of power flow and the access of large capacity wind turbine will reduce system static security. Therefore, the study of the impact of large-scale wind power to power system static security is the current trend, which has important theoretical and practical significance to ensure the power system static security. In this paper, a series of researches on the static security risk assessment of wind power integration are carried out, and the main research contents are as follows:This paper describes the current situation of wind power generation at home and abroad. The domestic and foreign research results of static security risk assessment of wind power integration have been studied and analyzed.Considering the influence of the uncertainty factors such as the output of synchronous generator, the output of the wind turbine, and the load, the mathematical model of the power system is established.An improved Monte Carlo method based on chaotic Chua system is proposed by using the inherent randomness of the chaotic system to improve the random number of Monte Carlo method, and the feasibility of the method is verified.Power system probabilistic load flow is calculated through the improved Monte Carlo method,what is more, the paper used the stochastic load flow calculation results to fit the probability density function and cumulative distribution function of node voltage and branch power, established the evaluation index of system voltage limitation and blanch overload risk, programmed and achieved the calculation of probability index and severity index of node voltage limitation and branch power overload, by using AHP (analytic hierarchy process, AHP) calculated weights of risk indicators to the system and quantitatively analyzed the static security risk of system.The simulation and calculation of comprehensive risk index for varieties of wind power integration schemes which are combined with the New England 10 machine 39 bus system and the IEEE 118 node systems are carried out in MATLAB and the possibility and severity index of node voltage limitation and branch active power overload are given. Based on that, the comprehensive risk index of the whole system is calculated, and the comprehensive risk index of each plan is compared and analyzed. The results show that the large-scale wind power integration will lead to the increases of power system static security risk, different forms of integration impact static security risk differently, system static security risk level increases with the increase of wind capacity. The researches in this paper provide a reference for the study of the static security analysis and evaluation of power system.