Autonomous Control of Soft Open Point for Distribution Network Reliability Enhancement

Power-electronics-interfaced soft open points (SOPs) emerge as a promising solution for the fault-tolerant operation of distribution networks. The conventional SOPs interface two ac terminals with a back-to-back (B2B) circuit configuration. Nevertheless, the SOP will break down if a fault occurs and interferes with the converter responsible for dc-link voltage regulation. To address this problem, a smart SOP with enhanced reliability is developed in this article. The proposed SOP can protect the system from the fault, which occurs at any of the two ac terminals. More importantly, the control of SOP is fully autonomous and does not need remote monitoring, manual activation, or operation mode transformation. This merit makes the proposed SOP more reliable and intelligent than the conventional SOP and normally open point (NOP). Finally, the effectiveness of this proposal is validated by simulation and experimental results.