Algorithmic techniques for transition-optimised voltage and reactive power control

Over the last two decades voltage control has emerged as a major concern with regard to the secure operation of bulk power systems, worldwide. This is partly a consequence of the newly deregulated market environments that have been introduced to electricity industries. Power systems are now operating under very different conditions, particularly with regard to the distribution and location of generation. A case in point is the large-scale power transmission system operated in England and Wales by National Grid, where the majority of generation has been relocated in the North whereas the majority of load remains in the South. For these reasons, an increasing amount of reactive compensation equipment has been installed by National Grid in order to maintain the required voltage profiles throughout the transmission system. Consequently, the secure and economic control of reactive compensation equipment combined with generator reactive power outputs is an important consideration, particularly with regard to the reactive power market in England and Wales. Voltage control and reactive power optimisation has been researched extensively as a static snap-shot problem, but relatively little research has addressed the time-domain aspects of the problem. In this paper the problem of voltage control and reactive power optimisation is approached front an operational schedule and dispatch viewpoint. Practical constraints such as the number of reactive control actions allowable within a time-domain, the time interval required between actions performed, etc. are considered. Suitably developed algorithmic techniques are presented and their performance is demonstrated with regard to power system modelling.