Controller for optimizing voltage profile of distribution networks with distributed generation

Abstract

The distribution networks to which distributed generators (DG) are connected were not designed for direct connection of generators. DG cause changes to stability, voltage profile and protection systems. Because distribution networks were not designed to accommodate generators, constraints are placed on DG utilization. One such limitation is the level at which DGs supply power to the network. Supply of real power causes voltage to rise around the power source. If the real power supplied is too high, voltage level may rise beyond acceptable limits. This paper presents a coordinated network controller whose objective is to maintain an optimal voltage profile across radial and meshed distribution networks with distributed generation. Voltage profile is said to be optimal if the voltages at every bus have the minimum possible deviation from the ideal voltage of unity per unit. This is achieved by varying the output of the distributed generators. The controller is modeled as an optimization problem which is solved using Particle Swarm Optimization.