Research On The Control Strategy Of The Wind Turbine Doubly Fed Induction Generator Based On The Sliding Mode Control Theory

From the viewpoint of sustainable development, the fossil energy that human currently relying on will be exhausted one day sooner or later. So that looking for alternative sources of energy to replace the traditional power generation energy has become a pressing matter of the moment. Countries all around the world regard the development and utilization of renewable energy as a key to sustainable development and national energy safety strategy. Wind energy is inexhaustible, environmental friendly and clean alternative energy. All these advantages has made the wind power generation kind of the most mature, the largest commercial development scale technology from all these new energy power generation technology. Undoubtedly, wind power has become the fastest growing green energy both in China and the rest part of the world.Firstly, this paper gives a brief overview of the VSCF wind power generation technology, and introduces the basic structure and working principle of AC excitation doubly fed wind turbine power generation system. After that, the paper makes a specific analysis of the operation area and the control strategy of variable speed constant frequency doubly fed wind power generator.Then, the paper establishes the mathematical model of the DFIG in static three-phase coordinates. Applying the coordinate transformation theory to it, we successfully get the mathematical model of DFIG in two-phase synchronous rotating coordinates.After that, the paper makes a brief introduction on the characteristics and development history of the sliding mode variable structure control theory. While describing the basic principle of sliding mode variable structure control in detail, specifically we talk much about the introduction of the Terminal sliding mode variable structure control strategy and the equivalent sliding mode control strategy.Finally, to be concise and to the point, the DFIG control system mathematical model in the stator voltage oriented vector frame is obtained. On the base of models having been built, we theoretically designed the system controller and put it into the reality.