A Plug and Play Operational Approach for Implementation of an Autonomous-Micro-Grid System

In this paper, a plug and play type autonomous-micro-grid system formation is proposed. Multiple distributed generating sources and loads interaction is considered pertaining to the stability of the micro-grid. The proposed method enables communication-less operation of each of the elements of the micro-grid system. It is also considered that the sources are of different power capacity as can be seen in a typical autonomous micro-grid system. Spatial Repetitive Controller (SRC) is proposed to control each of the distributed generating sources in a decentralized manner to stabilize the overall micro-grid system. The proposed system considers sudden change in load as well as other distributed generators conditions like a true plug and play operation. A novel signature frequency voltage injection method is proposed to identify the presence of special distributed generator and operation of backup distributed generators. The implemented control architecture also ensures stability of the micro-grid fundamental frequency even in the case of dynamic conditions unlike the traditional droop-control method. A detailed experimental study is carried out and the experimental results presented show the efficacy of the proposed system.