Abstract:Configuration,selection and setting of the relay protection should follow the principle of enhancing primary protection and simplifying back -up protection.With speed up power grid construction, increasing the scale of district power grid,the existing line protection configuration and setting principle is difficult to adapt to the current engineering construction speed and the change of operation mode, the difficulty of setting value management and execution. 110 kV line protection is proposed in this paper to simplify the configuration and setting scheme, give full consideration to the protection configuration, system operation and equipment safety requirements, through strengthen the main protection configuration dual optical fiber current differential protection, so as to achieve the purpose of simplify backup protection is cancelled, the ac voltage circuit to cancel the distance protection function, direction element, with two or three without direction and zero sequence over current protection and over current protection circuit backup protection, effectively reduce the workload and reduce the secondary loop, improve the work efficiency of setting calculation, arrangements for operation mode also improves flexibility.