Optimizing Fault Ride-Through of DGs in Distribution Networks to Preserve Recloser-Fuse Coordination

Fuse saving protection is usually applied in distribution networks, through auto-reclosing, to prevent fuse burning under transient faults. The modern fault ride-through (FRT) standards, which require distributed generators (DGs) to remain connected during the fault, may lead to the miscoordination of recloser-fuse. This paper proposes a discrete coordinate-descent (DCD) approach that optimizes the FRT of DGs so that the coordination between recloser and fuse is preserved. First, the method performs a short-circuit calculation (SCC) considering the currents contributed by the DGs, according to the FRT standards of each country. Then, if a miscoordination between recloser-fuses is observed, it optimally scales down the DG currents, until the coordination is restored. The proposed method has simple implementation, low communication requirements and offers adequate voltage support during the fault. Simulations were carried out in the IEEE 13-bus and the IEEE 8500-node network to highlight the distinct features of the proposed approach against the state-of-the-art current limiting approaches.