Research On AC Microgrid Operation Control

Microgrid is an aggregation of the distribution generation techniques. Thedistribution generation will still inject the power into the AC bus if they runsuitable control strategies even if in islanded mode. In this way, people can makefull use of the distribution generations. When the power grid cannot satisfy theload demand,the microgrid system can keep the stable power supply in suitablecontrol strategies. The microgrid system can supply stable power whether ingrid-connected mode or in islanded mode.A three-sources system with photovoltaic generation, micro-turbinegeneration and DC source generation has established in the platform ofMATLAB/SIMULINK. The whole system consist of two master sources and oneslave source. The micro-turbine and DC source work as master sources, and thephotovaltic generation works as slave source.The mathmatic model of photovaltic and micro-turbine has been built inMATLAB/SIMULINK. And the research on the grid-connected PV system andmicro-turbine generation system has been conducted.The controller parameter design of the voltage-current loop PI controller hasbeen done in the DC source system. PQ control has been taken by all the threesources in grid-connected mode. In islanded mode, the DC sources andmicro-turbine take droop control, and the PV system takes PQ control.At last, the small signal model in grid-connected and islanded mode hasbeen built. The influence on system stablity of inverters’ parameters, like loadreactance and the droop parameters has been figured out.