| With the continuous expansion of wind power in Chinese power grids, the randomness of wind power, as well as the anti-peaking and intermittment characteristics bring negative influences to the operation and control of power systems compared with traditional energy. Different from the traditional and distributed wind power, large-scale wind power integrate with mor than220kV voltage level, which bring the problems of voltage and frequency control in the case of the trip-off accidents of wind power. How to choose the voltage and frequency of area power network’s emergency control strategy after the wind farms off-grid is the key problem. According to the above problems, the main works of this paper are as follows:First, the domestic trip-off accidents of wind power in recent years is introduced, which focus on four cases of trip-off accidents of large-scale wind power in2011, analyzes and summarizes the reasons of frequent accidents for the large-scale wind farms, and studies the present general power system emergency scheduling policies at home and abroad.Researching on the regional power grid emergency strategy management system is an important contens with puting forward area scheduling strategy under trip-off accidents of large-scale wind power. This paper combines the emergency strategy management system with power system containing wind farms based on the actual situation, the emergency strategy management system corresponding to the principles of power system operation state, analysis and establishs the emergency target, the stage and content, which bases on large-scale wind power off line. Based on normal operating state security with power system mathematical model, the critical theory that supports trip-off accidents of large-scale wind power is refined.The equivalent model of wind power is established. First, introduces the general situation of reginal grid in Guangdong, then conbines with the research and actual situation of reginal grid in Guangdong,put forward simplified area network model by using basic operation case solution and the trend of network topology theory under the Ward equivalent and REI equivalent. The method solves the complex newtork external network equivalent model, which static performance matchs with the orginal system, but also has a better dynamic response to meet the requirements of the subject. And built the grid model contained wind power based on DigSILENT/PowerFactory. A possibility of probalitity index Lin(S), a severity index Sev(S) and a comprehensive risk index RISK are adopted. DigSILENT/PowerFactory conduct the summer big way and winter small way N-1static security analysis, mining wind area of system vulnerabilities and enriching the expected accident set.Finally, the paper based on N-1static security analysis combined with the transient simulation analysis of network on the basis of the station’s highest risk index on forecast accident put forward emergency reactive voltage control strategey,which is proved the feasibility of the proposed strategy by calculable example. |
