Real-time Optimal Power Flow (OPF) Model with Second Order Cone Programming (SOCP) for Radial Power Distribution Networks

Previously, optimal power flow (OPF) analysis was only subject to the power transmission networks but due to the advancement of modern power distribution networks with distributed energy resources (DERs), the OPF analysis in distribution systems has recently gained significant importance. With the randomness and fluctuations of the DERs, the existing nonlinear OPF models sometimes fail to provide optimal feasible solutions, and the linear models suffer from solution accuracy. So, convex OPF models are appropriate for OPF analysis for radial distribution networks. With the angle and conic relaxations, second-order cone programming (SOCP) based convex OPF models have a less computational burden, and the relaxations are tight. Being convex, the SOCP-OPF models also promise a globally optimal solution. This article proposes a second-order cone programming (SOCP) based time-dependent OPF model for distribution networks. Due to the fast convergence capacity, the SOCP-OPF model is applied for real-time network operational analysis with different loading conditions and variations of the DER intermittency. A real-time simulator (OPAL-RT) is considered for the time-dependent OPF analysis. The analysis shows that the proposed SOCP-OPF model is robust with network fluctuation and provides an exact and globally optimal solution.