Research of a New MPPT Strategy Based on Gray Wind Speed Prediction

Abstract

The maximum power point tracking (MPPT) strategy has great impact on the efficiency of the Variable-Speed Wind Turbine Generator (WTG) when the wind speed is below the rated speed. Now the MPPT has two control methods that are power control method and rotor speed control method. All of them had not used the wind speed information because the wind speed measured is usually inaccurate. In this paper, gray predictive theory is introduced in the control of WTG. The previous wind speed information is used to predict the wind speed of next time. The predictive speed obtained by gray method is used to calculate the initial WTG rotor speed of the MPPT searching process. Then rotor speed disturbance is added to the initial speed and finally the maximum power point is found. Simulations show that the gray wind speed prediction method can effectively reduce the MPPT searching area and search time. The effectiveness of the WTG is also improved.