A Distributed Protection and Control Scheme for Distribution Network with DG

High penetration level of distributed generation (DG) connected to distribution network makes the protection and control in the traditional distribution network face great difficulties, so this paper proposed a protection and control technology based on advanced feeder terminal unit (AFTU). According to DG's capability and load, the scheme divides the distribution network into several zones in advance, each of which can operate in island mode. Circuit breakers (CB) together with AFTU are installed at the beginning of feeder, the border of two zones and the point of DG connection. AFTUs interconnect with each other through the fiber optic network. AFTU detects the local electrical quantities in real-time and exchanges information with others through the fiber optic network. It can locate the faulted zone quickly to achieve fault isolation and island operation according to local and neighboring information. The reclosing of CB and the control of reconnection of DG are also designed. The case analysis illustrates the feasibility of the proposed distributed protection and control scheme.