Research For Stability Of Power System Considering The Integration Of The Wind Power

With the rapid development of China's power industry as well as the current energy crisis intensified,Studies of wind power paralleling in the grid become a hot spots,as a new and mature method of energy utilization, system capacity of wind power grid integration and the proportion of the system is increasing,the stability issue of system integration is becoming more and more prominent. Doubly-fed wind turbine system based on variable speed constant frequency generation technology is used widely,but the stability analysis and study of its integration on grid is not much now. This paper has established the steady and transient mathematic model of a large-scale wind farm grid-connected model based on DFIG,other mathematical models of generating units (Hydraulic turbine,Steam turbine),static var compensator(SVC) and power system stabilizer(PSS) and their linear equations of state. Under Matlab/Simulink environment, use practical examples and prony algorithm to analysis and research the impact of system stability when a large-scale wind power system besed on DFIG integration on grid,and the dynamic response of wind power system after taking a series of measures to enhance system stability. Through the simulation analysis,from the study on impact of a large-scale wind power based on DFIG integration on power system,we can draw the following conclusions:1,In the case of ignoring the wind's change,a large-scale wind farm based on doubly-fed induction generator accessing system will reduce the damping of the original system,and the system will show a weak or negative damping.2,Under the situation of system faults,and after taking a series of measures to enhance the stability of system,although the system of synchronous generator's rotor phase angle difference and the rotor angular velocity have been in a steady,but there are certain frequency oscillations for the system tie-line power.3,For the multi-band power system stabilizer and the generic power system stabilizer,they have the same capacity to inhibit the system power oscillation,but in a way, the multi-band power system stabilizer haves a better capacity to enhance the system dynamic stability than the generic power system stabilizer.4,In power system based on doubly-fed induction generator,using power offset as the input of supplementary damping control system,the SVC can damp system oscillation and provide voltage support for the system to enhance the stability of system.The depth studies of these problems can provide certain reference basis for grid connection practice of megawatt wind farm based on double-fed induction generator and coordinated development between China's wind power and grid.