Research On Micro-Grid Control Technology For Ocean Energy Power System

With the rapid development of economy, electric load of power grid largely increases in recent years and the stabilization and reliability of power grid suffer more impact. Electric industry undergoes severe test when environmental problem and energy crisis are increasingly serious. In view of this, micro-grid technology, which combines renewable energy and distributed power generation has get extensive world-wide attention. Ocean energy micro-grid integrates multiple distributed power generation as an island and offshore power distribution network. It is environmentally-friendly, flexible and efficient. The micro-grid project in this paper is such an ocean energy power system, including wave energy generation, ocean current generation and multiple power storage.Micro-grid system’s control technology is one of main parts of the research on ocean energy micro-grids. Distributed power sources in micro-grid have source diversification and its output power is intermittent and fluctuated. And in micro-grid, the control complexity of diverse power electronic equipment has impact on power quality of the grid. Therefore, the coordinated operation of diverse distributed generations and power electronic equipment should be based on reasonable control strategy.This paper firstly introduced the research background of this paper, the domestic and abroad development of micro-grid and the research status of micro-grid control technology. Secondly the paper introduced the main structures of grid-connected micro-grid and off-grid micro-grid and analyzed basic control strategy of distributed micro-grid system. Then distributed source control technology and micro-grid integrated system control strategy, which are suitable for ocean energy micro-grid, are further researched and analyzed. By MATLAB/Simulink software, the control models for different distributed power generation control technology are built. Base on the intermittency and fluctuation of power generation end and the circumstance of island in the ocean energy micro-grid system, micro-grid control technology and strategy with the application of power storage technology for the off-grid ocean energy power system is designed in this paper. The system level control strategy applied master-slave control, power storage system used V/f control which is based on SVPWM technology and ocean energy sources used PQ control. The result of simulation proved the validity and effectiveness of the designed control strategy.