An Exact Linearization Method for OLTC of Transformer in Branch Flow Model

摘要

The branch flow based optimal power flow (OPF) problem in radially operated distribution networks can be exactly relaxed to a second-order cone programming model without considering transformers. However, the introduction of nonlinear transformer models will make the OPF model nonconvex. This letter presents an exact linearized transformer's on-load tap-changer model to keep the OPF model convex via a binary expansion scheme and big-M method. Validity of the proposed method is verified using IEEE 33-bus test network.