The Research And Implementation Of Microgrid Operation And Control Strategies

Coordinated control of multiple microsources in microgrid is one of the technical difficulties on microgrid operation. The trasient conversion process between grid-connected operation mode and isolated operation mode in microgrid, which have different configurations, is the key problem in research of the operation and control strategies.Based on their different characteristics, this paper classifies interface inverter system of microsources, and proposes different individual types of microsource control methods. Conversion criterion and operation time of microgrid operation mode changing are formulated according to domestic power system requirement. The equivalent simulation models of microsources, as well as the logic model of microgrid operation mode conversion are established in PSCAD/EMTDC.Microgrid operation control mainly considers how to guarantee the stability and power quality of microgrid operation when microgrid has isolated from the grid or transferring between connected and isolated mode. Peer-to-peer control strategy and master-slave control strategy are introduced in this paper. Combined with microsources control methods, focused analysis are on the single-master control strategy and the multi-master control strategy of mater-slave control strategy. Specific achieve methods and steps of both strategies are described in detail. The results are analyzed after transient simulation of different control strategies under the microgrid condition of mode transferring and load disturbance when isolated. The result shows that different control strategies have their own utility characteristics. The control strategies should be programmed according to the actual microgrid situation. Furthermore, logic criterion of convertion between connected mode and isolated mode is proved correct in PSCAD.