A Network Layered Control Strategy Research For Multi-inverters In The Intelligent Microgrid

Along with the gradually-missing energy resources, the distributed generation of renewable energy technologies got rapid development in the countries all over the world. Micro power grid is an effective organization form of distributed energy into power grid, to strengthen the effective control, flexible scheduling and optimal allocation of energy integrated control management of micro grid is one of the hot issues in the word.This thesis mainly around the micro grid system in the following two aspects. On the one hand, the research about micro grid system of multiple inverters in parallel network control strategy; On the other hand, the research about realization of maximum use of renewable energy in the micro grid system. Due to the distributed characteristics of micro power grid, the massive amounts of control data and the characteristics of flexible control method, hierarchical control network management platform based on multi-agent system (MAS) is established, in order to realize the coordinated control, flexible scheduling of the micro grid, and ensure the normal and stable operation of micro power grid under different operating mode.In micro grid in island operation mode, considering the existence of circulation between energy storage inverters, different equipment controller operating characteristics, the impact of the existence of low pass filter, a new droop control theory is put forward. The inverter is used to simulate frequency regulating characteristics of synchronous generator to guarantee the stability of micro power grid frequency under load change; the composite compensation device is used to compensate reactive power in order to ensure the stability of the system voltage. And the multiple storage inverters can realize network operation through the coordinated control of various control Agents. In the end, the micro grid island runtime can implement maximize the utilization of renewable energy through the coordinated control and flexible scheduling of various micro power Agent, energy storage equipment Agent and so on.In the thesis, the school dormitory building and bath core power grid is the research object. Based on the hierarchical control network management platform of multi-agent, the improved control strategy is verified. The strategy can improve the problems of voltage and frequency that don’t be met during grid/island conversion transient process. The maximum efficient use of photovoltaic energy is realized through the coordinated control and flexible scheduling of various Agents.