Voltage control is designed to minimize the transmission losses while keeping the system away from voltage instability. In this context, reactive power loop flows are undesired because they not only increase transmission losses, but also they decrease the reactive margins of generators diminishing the ability of power system to withstand contingencies. The most common option of removing reactive loop flows consists of formulating an optimal power flow program in order to optimize the reactive power dispatch (minimizing transmission losses and maximizing generator reactive margins). However, convergence problems and lack of interpretability of the results are the main drawback of optimal power flow algorithms. This paper focuses on detecting and removing undesired reactive loop flows proposing a very simple interpretable algorithm based on clustering techniques. The task is addressed in three steps: (a) division of the power system in electrical areas of similar reactive behaviour, (b) identifying undesired reactive loop flows within each electrical area and (c) calculating the new generator voltages in order to remove the harmful reactive flows. The use of the proposed algorithm is illustrated using an actual scenario of the Spanish power system.
Keywords: VAR/voltage control, power loss reduction, optimal power flow, linear programming, reactive power dispatch, clustering
XIII ERIAC - 13er Encuentro Regional Iberoamericano de CIGRE. Puerto de Iguazú, Argentina, 24-28 Mayo 2009
Published: May 2009.