Micro- grid with distributed power control strategy research
|School||Kunming University of Science and Technology|
|Course||Proceedings of the|
|Keywords||Micro-grid Distributed generation Grid-Connected operation Isolated operation Control strategy|
Micro-grid can treat distributed generation and load as a whole part and form a flexible and controllable minor scale power net, which could operate in parallel style or isolated island style. Micro-grid system based on distributed generation technologies is an important way to develop renewable energy, improve reliability of power supply and increase power system capacity. As a supplementation of the traditional centralized, long distance and large power supply mode, the micro-grid shows a new develop direction. The operate mode of micro-grid contains parallel style and isolated island style, and the secure transition between these two modes would influence the stable operation of micro power grid, but the conversion technology and control method is very challenging. Besides, the flexible operation mode of micro-grid is depended on the stable control system.This paper will take research on the control methods of micro grid. Firstly, the distributed generation and micro-grid concept are introduced. Secondly, the mathematical models of three common distributed power sources such as wind power, solar power and fuel cell are built and analyzed. The control method based on grid-connected inverter of distributed power source and the control strategies of the micro-grid are mainly studied in the paper. Lastly, the control strategy of the micro-grid under the parallel operating mode or isolated island operating mode is discussed.Finally, a simulation Micro-grid model with PQ and V-f control strategy is established in MATLAB/Simulink environment. The inverter as an interface between distributed generation and the main power grid. It through control of the inverter to achieve the PQ and V-f control strategy. The simulation about Grid-Connected, isolated operation and Grid-Connected to isolated operation is carried out in Micro-grid. The simulation results show that the control strategy is feasible, Grid-Connected, isolated operation and the process of switching between two states, have good operating characteristics.