Feasible Operation Region-Based Constraint Management of Distribution Networks With Soft Open Points

Abstract

Soft open points (SOPs) are power electronic devices placed at normally open points of electricity distribution networks. With millisecond-level control, SOPs are promising in constraint management of distribution networks facing the significant uncertainties from renewable power generation and customer behaviors (such as electric vehicle travelling behaviors). This paper develops a novel feasible operation region (FOR)-based method for optimal SOP control. The FOR, denoted as the allowable range of nodal power injections of distribution networks, can be used to replace the power flow equations and network constraints in a conventional optimal power flow (OPF)-based model. Due to the one-to-one correspondence between FOR boundaries and thermal/voltage constraints, FOR-based constraint management method can adapt to various measurement conditions. Moreover, the FOR constraints can be converted into a format based on line flows and node voltages, allowing for the use of real-time measurements of these operating parameters rather than the measurements of nodal power load/generation that are normally not accessible online. The proposed method is validated on the IEEE 33-node distribution network and IEEE 123-node distribution network. The performance of the method is also compared with that of conventional OPF-based control.