Strategy of research and application for the microgrid coordinated control

By studying the dynamic characteristics and the controllable quasi-load external characteristics of microgrid with multiple distributed power supply, firstly, this paper proposes a PQ Control Strategy Inverter System based on a control of both power and electrical current in order to improve the quality of electrical energy and increase the output of distributed power supply. Secondly, based on the analysis of the characteristics of microgrid´s internal balanced load flow, it designs an outer ring controller based on improving the sagging shape and solves the problem of controlling the frequency under island model in microgrid. And then, it puts forward a coordinated control strategy of the microgrid which combined master-slave control strategy and peer-to-peer control strategy between various types of distributed power supply without data correspondence. With the coordinated control, the improvement in the availability of intermitted energy resource which cause distributed power supply to join in the frequency adjustment of the microgrid is derived. At last the correctness and validity of this coordinated control strategy is verified by converting the microgrid between the island model and grid-connected mode, this paper imitating and emulating of the varying characters with voltage and frequency under the transient operation of the island model.