A Low-cost Hybrid Back-to-Back Soft Open Point

The soft open point (SOP) using the back to back power converter can flexibly, fast and accurately regulate the power flow among the adjacent feeders by implementing the multi-targets control including nodes voltages and network losses and also has the capability to isolate the fault and recover the power supply. However, the range of power restoration is strictly limited by the SOP capacity. This paper proposes a hybrid soft open point system with a partial scale back to back converter and a load switch parallel connected. The power flow and voltage distribution could be regulated by the back to back converter as usual. And the load switch could realize power recovery for all the customer interruption under the fault condition. Moreover, the back to back converter can flexibly regulate the power flow through the load switch and help realize the zero current turning off of the load switch, which can effectively extend the working life of the load switch and reduce the equipment cost. Furthermore, the performance of the proposed hybrid SOP is verified by the simulation results.