Reactive power control in distribution systems by using advanced techniques

Reactive Power control represents an efficient method of reducing the cost of utility operation. The savings brought about by Var/voltage control does not end at the monetary value the energy saved: the released system capacity can serve to delay a costly expansion and reduce the ageing of components. Var control is to provide appropriate placement of compensation devices to ensure a satisfactory voltage profile while minimizing the power losses and the cost of compensation. A cursory review of trade and scholarly journals reveals that researchers advocate the use of different conventional techniques for reactive power control in distribution systems. Since 1980´s,the focus has shifted away from the conventional methodologies which were suited to the fields of control theory, operational research and numerical analysis, to the techniques of artificial intelligence (AI). In this paper the AI methods; expert systems, fuzzy systems, artificial neural networks, evolutionary computing, and tabu search var/voltage control, and hybrid systems for var control in distribution systems are reviewed.