Research On Power System Frequency Dynamic Process With The Integration Of Large-Scale Wind Power

Analysis of dynamic frequency process of power system is basis to ensure the safe operation of the system, to make plans for under frequency load shedding and to evaluate different measures of voltage regulation and frequency regulation. With continuous development of power system, more and more factors affect dynamic frequency process and make it more and more complicated.With the crisis of energy shortage getting worse, wind power, as a new renewable energy, is being developed and utilized widely in the world. Wind power, a kind of energy form, is different from any other conventional power and its output is volatile and unpredictable, it may bring a new influence on power grid dynamic frequency process. Wind generators inside decide the characteristics of wind farms, and different wind generators give different frequency response to power grid. It cannot be ignored that new factors which effect to power system frequency dynamic process is increased based on the traditional ones.At first, the constant speed wind generator and the double-fed induction generator are brought out as the research objects in this paper. The mathematical model of these two kinds of wind generator are built, the operating characteristics of these two kinds unit are analyzed in detail, and the idea of using lumped model to establish a wind farm equivalent model is put forward. Secondly, static characteristics and dynamic characteristics of power system frequency are analyzed, the frequency dynamic process of single-machine model and multi-machine model are analyzed in detail from the theory and the influence factors of the frequency dynamic process are analyzed. Thirdly, the situations of grid side appears active disturbance and wind power side appears active fluctuations after wind power combined into the grid are simulated and analyzed based on the end of2009the Northeast Power Grid. The effects of frequency dynamic process and the support ability to system frequency based on two kinds of wind farms, which are composed of different types of wind power generators, are researched. Then, the situation of increasing spinning reserve to improve the power system ability to resist the active fluctuations is researched. At last, the frequency dynamic process of large-scale wind power generators are taken off from grid due to the lack of low voltage across ability or frequency protection device installed is simulated and analyzed.