The Influence On Power System Dispatching And Operation With Wind Power

Wind energy is a kind of clean and renewable energy and its reserve is big. Using wind power can protect the environment to avoid pollution, protect the climate, human health and life on earth to avoid bad influence and also can obtain a lot of energy. However, due to changes in wind speed is random, so that credibility of power quality is low. Along with the wind power access grid and access capacity increase, the impact range from local gradually extends to the entire power grid. The grid active, reactive power balance scheduling, system static stability, transient stability, voltage stability, frequency stability and so will have a corresponding impact.For systematic analysis of influence of wind power grid to power system operation and the dispatching work, with the built transient model of wind turbine, the transient voltage stability of wind power grid system is studied with time domain simulation method in consideration of wind speed fluctuation and three phase short circuit fault respectively. Then the influence on the system frequency is investigated, and the method of analyzing the impact of fluctuations in a short time on the grid frequency modulation is put forward. Based on the background of wind power grid integration, comprehensive considering the fluctuation of load and controllability of asynchronous machine slip, this paper proposes a new kind of voltage strategy for power dispatching. At last, the scheduling method of the wind power system is discussed in detail. The main work of this paper is as follows:1. Based on time-domain simulation of Squirrel cage induction and doubly fed induction generators model, to observe grid to fail after disturbance, different wind speed distribution and load on the system transient voltage stability, and the prevention and control of influence of system for wind power grid voltage influence can provides certain theoretical basis.2. Asynchronous wind turbines, for example, based on power flow analysis after wind turbine access grid, research the wind speed changes and load changes on the impact of the frequency of the system. Defines a measure power grid frequency modulation index, and regarding the wind power as a as a negative load, puts forward the method of analyzing the impact of fluctuations in a short time on the grid frequency modulation, providing a certain reference for the power grid scheduling and frequency regulation.3. This paper studies on the static characteristics of the voltage of the power grid dispatching operation of wind power generation system. As a state variable, the slip S is used as a state variable to deal with the random variation of wind power, which provides a new voltage control strategy for wind power grid operation. Established with wind turbine generator set and considering the wind turbine generator slip and randomicity of wind speed and load flow model, and uses the method of sensitivity analysis of grid connected wind power system voltage stability analysis, the effective pointed out that grid connected wind turbine generator system voltage stability is weak and unstable region, provides a certain basis for power dispatch and reactive power compensation. The proposed methods are illustrated on the IEEE 68-bus system and the results show that the stochastic wind penetration and load can significantly affect voltage stability sensitivity index and critical bus also can be identified.3.