Robust Local Inhibitor of Reverse Power Tap Changer Runaway Events in Reconfigurable and Active Distribution Networks

Abstract

Reverse power tap changer runaway has become a challenging voltage issue with the increasing integration of distributed generation (DG) to reconfigurable distribution networks having step voltage regulators (SVRs). Local measurement-based runaway online inhibitor is important for correct tap changer operation when reverse power flow emerges on SVRs. However, gross errors of measurements available in SVR control can be quite significant, which further complicate the issue. This paper proposes a robust inhibitor of reverse power tap changer runaway events in reconfigurable and active distribution networks using local measurements and modes of operation available in SVR controls1. A recursive least squares (RLS) estimation is proposed to mitigate the effect of gross SVR load-side voltage measurement errors on identifying the SVR weak side used for triggering SVR control modes in reverse power flow scenarios. A threshold range to assist in the SVR weak side identification is determined through a sensibility analysis. Simulation results on a real reconfigurable and active distribution network with cascade SVRs validate the effectiveness and robustness of the proposed algorithm.