Dynamic analysis of OLTC and voltage regulator under active network management considering different load profiles

Abstract

This paper provides a comparative study of coordinated voltage control (CVC) strategies for on-load tap-changers (OLTCs) and voltage regulator (VRs) under active and passive network management schemes (ANM and PNM). In PNM scheme, OLTC and VR are restricted to only regulate the secondary bus voltages at fixed set-points, while in ANM scheme, control of the secondary bus voltages within the statutory voltage range is allowed, thus providing area-based voltage controls. In this paper, the dynamic model of a 33kV 16-bus United Kingdom generic distribution system (UKGDS) is firstly implemented in PSCAD/EMTDC and validated with a steady-state model, using optimal power flow (OPF)-based technique, developed in GAMS software. Secondly, the OLTC and VR controls under ANM and PNM schemes are developed with discrete tap-changers, and tested considering different load profiles and dynamic loads. The results show that the ANM scheme allows considerable utilization of OLTC and VR compared to PNM scheme, but also may increase the loading of these devices depending on load levels and voltage profile in the power network.