Online load transfer criterion using soft normally-open points for distribution networks with renewable energies integration

With the increasing penetration of renewable energies, the intense uncertainty has been brought to the power system, especially the distribution network. Load transfer is essential for distribution networks to keep continuous operating after the occurrence of a fault. However, conventional load transfer schemes can cause more significant power loss. In this paper, the soft normally-open points (SNOP) is introduced to solve this problem in a better way. An online load transfer scheme is put forward, taking both the load to be transferred and the voltage requirement of the healthy feeders into consideration. First, the relationship between the power at each line terminal and the voltage profile of the feeder is studied. On this basis, an optimal power distribution scheme is discussed. Finally, considering the security of healthy feeders, an online load transfer criterion is put forward. Simulation results indicate that the proposed scheme works well in holding the maximum load capacity online.