Abstract

Wind and other renewable energies are more and more developed all over the world, especially in countries with high wind potential such as Vietnam, to replace fossil energy, which would be exhausted in the near future. One important characteristic of wind turbines is that at each different wind speed, there exists a working point, represented by the rotation speed and the mechanical power at the crankshaft of the wind turbine, at which the maximum mechanical power is obtained, called maximum power point (MPP). Therefore, when the wind speed changes, this working point must be changed to be able to extract the maximum power from the wind to improve the total efficiency of the wind turbine system. This, in a wind energy conversion system (WECS), is assigned to the maximum power point tracking (MPPT) controller. In this paper, a MPPT controller is proposed, based on an improved Perturb and Observe (P&O) algorithm, for wind turbines using permanent magnet synchronous generator (PMSG), to maximize energy without measuring the wind speed and power characteristics of the wind turbine. An experimental model is also designed and tested in laboratory conditions, in which two coefficients K₁ and K₂ are used in turn when the working point is far or close to the maximum power point. The experimental results show that the proposed MPPT controller allows the extraction of maximum power from wind turbines under variable wind speed without determining the wind speed and characteristics of the wind turbine system.