Sensorless Optimum Power Extraction for Small Scale Stand Alone Wind Turbine Based on Fuzzy Controller

The technology of wind turbines as electric power plants has developed very rapidly because renewable energy is environmentally friendly and has unlimited availability. The use of wind energy conversion systems for the grid non-connected areas has greatly benefits for the community, in which small scale standalone wind turbine systems are well suited to rural areas due to low investment costs and are easily controlled to improve efficiency. However, wind speed highly interfere the output power of the wind turbine. The efficiency of wind turbine can be improved by extracting the maximum power point to get optimal power. In this paper will propose an optimal power extraction control for small scale stand alone wind turbine using permanent magnet synchronous generator (PMSG) based on fuzzy logic controller (FLC) without mechanical sensors. Fuzzy logic determines the optimum power point through the duty cycle controlling on the dc/dc converter based on the uncontrolled rectifier output voltage and current. Based on the simulation results, FLC has better performance, where FLC can capture greater output power than perturb & observe (P&O) method. At wind speeds of 10 m/s, the use of FLC can extract wind power of 4200W while the P&O method is 3700W. In addition, FLC can extract optimum power to wind speeds variation and generate no oscillations.