Firstly, we studied the relationship between enhancing the energy conversion efficiency and output power smoothing of generator. Then, a novel MPPT method with fuzzy inference system was proposed to enhance the efficiency. At the same time, the fluctuations of generator power were suppressed significantly. Finally, to verify the effectiveness of this new method, we introduced small signal analysis and simulation studies by MATLAB/Simulation software.
Jizhen Liu, Hongmin Meng, Yang Hu, Zhongwei Lin, Wei Wang.
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China
With the increasing capacity of wind energy conversion system (WECS), the rotational inertia of wind turbine is becoming larger. And the efficiency of energy conversion is significantly reduced by the large inertia. This paper proposes a novel maximum power point tracking (MPPT) method to enhance the efficiency of energy conversion for large-scale wind turbine. Since improving the efficiency may increase the fluctuations of output power, power smoothing is considered as the second control objective. A T-S fuzzy inference system (FIS) is adapted to reduce the fluctuations according to the volatility of wind speed and accelerated rotor speed by regulating the compensation gain. To verify the effectiveness, stability and good dynamic performance of the new method, mechanism analyses, small signal analyses, and simulation studies are carried out based on doubly-fed induction generator (DFIG) wind turbine, respectively. Study results show that both the response speed and the efficiency of proposed method are increased. In addition, the extra fluctuations of output power caused by the high efficiency are reduced effectively by the proposed method with FIS.Go To Energy Conversion and Management