An Efficient Joint Coordination of Volt-Var Support in Medium and Low Voltage Distribution Feeders

The growing number of intermittent distributed generations units has increased the voltage regulation challenges in distribution networks. This paper proposes a joint voltage regulation in medium voltage and low voltage distribution feeders by employing and coordinating both traditional and emerging approaches. The proposed technique is a three-stage control strategy that suits well the integrated and unbalanced radial distribution networks. In this technique, the reactive power support of delta-connected switched capacitors, installed at the medium voltage feeders, are coordinated with that of the PV inverters, available at low voltage feeders. Factors such as the network’s power loss, as well as the voltage magnitude and balance profiles, are aimed to be improved. The effectiveness and superiority of the proposed volt-var optimization model is evaluated by numerical analyses on a real typical distribution network over a 24-hour period.