Capacitor placement in three-phase distribution systems with nonlinear and unbalanced loads

The problem of choosing optimal locations and sizes for shunt capacitors in distribution systems is addressed. The objective of the capacitor placement procedure is not only to minimise the power losses along distribution feeders, but also to make sure that these capacitors will have the minimum possible impact on the harmonic distortion of bus voltages in the system. Furthermore, the fact that distribution systems can operate under unbalanced loading conditions, means that the optimisation will have to account for any unbalances in the system. An optimisation program, which successfully solves the problem is developed and tested. Results obtained by simulation of a distribution test system under various operating conditions, are presented to validate the proposed solution methods.