ABSTRACT
This paper presents a new MPPT control strategy with two fuzzy logic controllers for Maximum Power Point Tracking (MPPT) in wind power system with DFIG. It does not require any mechanical sensors or prior knowledge of the wind turbine characteristics so that it can be easily configured to adapt to any wind turbine. Besides, the new control
1 INTRODUCTION
In recent years, the rapidly increasing of global energy consumption and greenhouse effect had led to an increasing attention to clean and renewable energy like wind power in many countries [1]. Wind Energy Conversion System (WECS) with Doubly-Fed Induction Generator (DFIG) is one of the most mature power generation methods in the aspects of technical level and the actual operation [2]. The rotor side converter capacity of Doubly-fed wind turbine is only about 30% of the generator capacity and greatly reduces the cost and losses in the converter relative to direct drive synchronous generators [3]. Improving the efficiency of WECS is a matter of our concern. When the wind speed is lower than the rated wind speed, the blade pitch angle keep constant and the wind turbine speed will change with the wind speed fluctuation in order to maintain the optimal tip speed ratio and maximum wind power coefficient. When the wind speed is higher than the rated wind speed, adjusting the blade pitch angle and inhibition wind turbine speed can reduce the efficiency of wind power capture and ensure the constant output power [4-6].
