Study On Operation Of AC Micro-grid Connected By Doubly-Fed Induction Generator System

As the energy and environmental problems become increasingly prominent, the distributed power generation technology is undergoing a significant development in the world. However, due to distributed generation's own limitations and weaknesses of the traditional power grid, there are many difficulties in large-scale distributed generation's grid-connected operation. Micro-grid, which takes a part together with the power grid, is the most effective way to make use of the distributed power supply. Wind power generation is an important form of renewable energy sources, this paper made fully studies about the control strategy of doubly-fed wind power generation system which is connected to the micro-grid. Both in grid-connected and islanded state of the micro-grid, the maximum point power tracking control and vector-oriented control should be adopted for the wind power generation system to ensure it's smooth running when connected to micro-grid. When the micro-grid is running in islanded mode, it is need for other controllable micro-sources to be adopted coordinate control, so that the volatility of the wind power generation system's output power can be balanced. In order to ensure uninterrupted operation of wind turbines and the reliability of micro-grid's power supply, when micro-grid voltage is unbalanced, there's need to adopt corresponding unbalanced control for doubly-fed wind power generation system.