The Method Of Microgrid Adaptive Protection And System Design Based On Multi-arent

Continued growth in the load, energy issues, environmental issues and high powerquality requirements of the user, has become a serious challenge which all the electricityindustries of the countries in the world are facing together. Micro-grid with flexible,intelligent features can reduce feeder loss, increase local supply reliability, improve energyefficiency, has great advantages in solving the above problems. However, the structuralcharacteristics of the micro-grid present new challenges in protective relaying. Faultcurrent distribution in the different micro-grid topology is large because of a wide range ofdistributed generation and energy storage devices in various forms, especially fault currentdisparity between the island and grid-connected model. Power generation equipment inmicro-grid Plug and Play, the grid-connected and island mode switch randomly makes themicro-grid topology flexibly. Protection systems are required to be able to makeadjustments accordingly to meet changing micro-grid.In order to achieve the autonomy and adaptability of micro-grid protection, based onthe analysis of fault characteristics of the distributed generation and micro-grid, ahierarchical, whole information decision based micro-grid adaptive protection system ispresented. The main protection based on local information or backup protection based onregional information is used by the system. The protection system is composed of thecentral protection&decision unit and local protection&monitoring units. The centralprotection&decision unit collect the global information and make decisions in real timeaccording to the state of the micro-grid operation to adjust the local protection programand backup protection.Moreover, multi-Agent technology is employed to provide intelligent softwarearchitecture for micro-grid protection system. Task planning of individual agent,cooperation processing among the multi-agents are depicted to carry out adaptive settingof the primary protection and online action of the backup protection. The workflow of themulti-agents based micro-grid adaptive protection system is illustrated with a typicalmicro-grid. Discussion and demonstration show that the adaptive protection system can online produce protecting schemes, and appropriately coordinate protections ingrid-connected/islanded modes and of primary/backup.