Optimal operation of multiple unbalanced distributed generation sources in three-phase four-wire LV distribution networks

Distributed Generation (DG) in the form of residential roof top photovoltaic installations is driven by consumer action. The placement of DG in the distribution network is not controlled by the network operator. Power quality issues, especially voltage rise and unbalance, is restricting ability of networks to accommodate further connections. There is a growing interest in utilizing the latent capacity of DG inverters to provide reactive power, or to integrate storage into DG systems, to increase the renewable power fraction. This paper presents an optimization method that is able to simultaneously manage the operation of many arbitrary located residential DG sources to reduce system losses and improve power quality. The optimization model is solved by a Sequential Quadratic Programming (SQP) based approach and the validity is tested on an accurate three-phase four-wire unbalanced distribution network model developed during the Perth Solar City trial.