Research On Frequency Regulation Ability In Electric Power Systems Considering Uncertainty Caused Bywind Power

With the rapid development of world economic development, the humandemand for energy is growing by the day. Compared with thermal power,hydropower and other traditional electric power energy, wind power is widelyfavored by countries all over the world for its advantages of clean, renewable andhigh economic benefits. But the random fluctuation and uncontrollability ofWind power output form severe challenges for the safe and economic operationof power grid. In order to maintain grid power quality, many areas have to giveup wind power, and cause serious waste of resources.In order to overcome these problems, and reach the goal of improvingresource utilization and the stability of the power grid after large-scaleinterconnection of wind power, we need to improve the prediction accuracy ofwind speed and wind power, evaluate the influence on the power system broughtby wind power uncertainty, and take effective means to control disturbanceimpact of wind power. But at the present stage, starting from the uncertainty ofwind power output, research on the analysis of the impact on power gridstructure and power quality is still not deep enough.So in this article, we first conduct study on Wind power uncertainty fromangles of interval prediction and power spectrum analysis. We use set pairanalysis theory to forecast wind speed range, and provide basis of grid frequencycontrol characteristics considering the uncertainty of wind power. For betterconnection with wind turbine model in the frequency domain, we analyze theimpact of wind speed change rate on the dynamic characteristics of power gridand conduct analysis of the spectrum based on measured data of wind speed andwind power.Secondly, by establishing mathematical models of rigid assembledmulti-machine parallel operation, we study influence of the uncertainty broughtby wind power on frequency modulation characteristics of power system. Usingthe analysis method of stochastic process, we do research on the dynamiccapability of primary frequency control electric network considering theuncertainty of wind power based on the consideration of wind power uncertaintyrandom characteristics of primary frequency. The limits of the power gridfrequency modulation after Large-scale wind power integration is reflected fromaspects of the simulation analysis and numerical quantitative.Finally, by considering uncertainty of wind power grid mathematical model of secondary frequency modulation, we study the various factors affect theperformance of grid secondary frequency modulation. By using previously gotresults of prediction of wind speed range, we estimate the capability of the powergrid secondary frequency modulation range. At the same time, by studying thecontrol boundary of primary and secondary frequency regulation of power grid,the paper analyzes the effects of wind turbine interconnection on power gridperformance. Through simulation research, we point out that Large amount ofwind power integration will reduce wind power grid frequency control safetymargin, and is not conducive to the safe and stable operation of power grid.Research results above can be used to guide the optimization of a variety ofgenerating set, and improve the utilization rate of wind power, thus providereasonable reference for power grid dispatch instructions arrangement and havegreat significance to improve power system running safety, economy andenvironmental protection.This paper is supported by major project “Key Techniques of IntermittentEnergy with High Permeability in the Regional Power Grid” of the National HighTechnology Research and Development Program (863Program)(NO.2011AA05A105).