Design of Micro-grid Protection based on The Communication System

This paper firstly analyzes the problems in the existing micro-grid protection. Then, the paper puts forwards a new method for micro-grid protection judgment and fault location. By using the communication system, the over-current protection device can satisfy the protection-requirements of alternative and speed. It needs no significantly increase in the cost. In current protectors, this protection method downloads a script of the export of the protection in accordance with the actual situation of the distribution network. And it has more flexibility and greater range compared with differential protection. It will adapt to the new requirements as long as changing the script of the protector when the network structure changes such as single power changing to dual power.