The Research Of Maximal Wind Energy Capture Base On Short-term Wind Speed Forecast

The technology which can improve the efficiency of wind turbines and capture the largest wind powerin real time has become the important part of the wind power study. Variable speed constant frequency(VSCF) wind power generation technology can achieve maximum wind power captured. With theincreasing of wind turbine capacity, wind turbine response delay and wind turbine control system responsedelay affects the real-time maximum wind power capture seriously.In this paper, a maximum wind capture control system of the nonlinear VSCF doubly fed wind powergeneration is discussed under the stochastic wind speed. In discussing the double-fed induction motorequivalent circuit and mathematical model, a stator flux orientation decoupling control strategy has beenused in this paper. To meet the two-way flow energy of double-fed generation, a pulse width modulation(PWM) converter and its mathematical model is analyzed.Secondly, a short-term wind speed forecasting method based on auto-regressive integrated movingaverage and least square support vector machine is proposed. At first, the wind series are decomposed intodifferent frequency characteristics based on wavelet transform method, and then according to the featuresof the decomposed components, least squares support vector machine (LS-SVM) model is selected topredict the low frequency components, while auto-regressive moving average (ARMA) model used topredict the high frequency components. And then the forecasted signal of the components is reconstructedto obtain the ultimate wind forecasting result.Finally, starting from the analysis of wind turbine characteristics, this paper focus on the operationalcharacteristics of the wind turbine to determine the use of doubly fed induction generator stator activepower control to achieve maximum power tracking control scheme, and maximum power tracking based onthe stator reference power is calculated. In the simulation study, the overall simulation model of VSCFdoubly fed wind power generation system has been built, which helps to achieve a different function with amaximum wind speed tracking control of the running simulation. Simulation proves that the wind turbineresponse delay and wind turbine control system response delay impact the largest wind energy capture. Theeffectiveness of maximum wind capture has been discussed under the random wind speed prediction, andthe comparisons of simulation results verify the correctness of this theory.