A Design Of Windfarm Active/reactive Power Control Method

Wind power,as the most mature new energy power-generation technology in business application,is now widely applied in all over the world.Meanwhile,the wind power generation in China is developing at full speed.As of the end of 2013,total capacity of the wind power generation is up to 91.4GW,ranking the first place in the world.However,as its features of volatility,intermittency and difficulties in forecasting,grid-connected power generation is greatly limited.According to the operating experience in Europe,the passive mode of"underloading" still controlling the wind power in the power grid with high wind power penetration rate will bring high impacts to the safety and economic operation of the power grid[quote].For the stable operation of the power grid,State Grid Corporation of China stipulates that the wind power plant shall possess active power regulation ability to control its active power output according to the instructions of the power grid dispatching department[quote].The wind power plant shall also possess the ability to coordinate and control wind turbine generators and static var compensators,thus can adjust the aggregate reactive power[quote].Thus,how to initiatively control the active and reactive power output,change the existing operation mode of load in wind power plant,optimal utilize the wind energies,and to improve the wind power generation of the power grid in China,is an important issue concerning the power grid and wind power plant[quote].This paper mainly carries out reseaches from aspects of active power control of wind power plant,reactive power algorithm and realization of algorithm routine,and the main tasks are as follows:(1)Designing an intelligent active power control algorithm.Intelligence is reflected in the real-time and ultra short-term prediction algorithm of power generation capacity in wind power plant and allocation strategy specific to unit wind turbine control.Power generation capacity prediction refers to collecting and uploading the wind speed data in real time through wind turbine,predicting the following wind speed with simple,rapid and accurate mathematical method,and then predicting the power generation capacity with the corresponding point on wind speed-power output curve;intelligent allocation method refers to allocating the total generation target according to the power generation capacity of wind turbine by summarizing the power generation capacity and current power output of all wind turbines,thus ensuring the adjustment speed and accuracy.Under the adjustment and control of the intelligent algorithm,the active power output will be more adjustable and controlled,which will accelerate the wind power developing into a "wind grid friendly" power supply.(2)Analyzing the mutual influence relation of the voltage and reactive power,and simplifying and summarizing a simple and easy computational formula which will be applied to the voltage/reactive power control algorithm;by carrying out further modeling for all reactive powers in the wind power plant,designing a reactive power control algorithm which can accept the voltage instruction dispatched by the power grid as well as execute rapidly and adjust accurately.(3)Take all the potential safety hazards which may encountering during power regulation into overall consideration,and avoiding these hazards through setting up safety constraint conditions,thus preventing the algorithm routine from endangering the safely operating of wind power plant or wind grid during adjustment and control process.(4)According to the foregoing,and based on the software engineering requirements,compiling software requirements specifications,structure design instructions,general design instructions and detailed design instructions,and realizing the algorithm routine.Carrying out actual operational testing to the algorithm routine,and examining the indexes like operational stability and functional completeness,etc.