Improved algorithm for voltage/VAr management on the NGC system

This paper reports on the development of a contingency constrained optimal reactive dispatch (ACCORD) algorithm. It is an improved OPF (optimal power flow) based voltage/VAr management algorithm which combines heuristics with a mathematically rigorous formulation to satisfy the NGC requirements for maintaining pre and post-fault voltages within operational limits. The developed algorithm is primarily intended for short term operational planning applications but it could be adapted for use as an on-line facility. The paper explains briefly the technical details of the underlying OPF algorithm but concentrates on the practical implementation of an integrated operational facility and presents and discusses results obtained for the UK Supergrid transmission system