Optimizing LV Voltage Profile by Intelligent MV Control in Autonomously Controlled Networks

The increase of distributed power generation can result in equilibrium of local produced and consumed electrical energy. Power electronics and storage can transform networks in which such equilibrium exists into autonomously controlled networks. These networks remain part of the rest of the power grid. An example of such a network contains several MV feeders and their LV networks. One of the main objectives for the control of such a network is to obtain an optimal voltage profile for the LV customers. This can be achieved by forced active power flows in the network and by intelligent control of the HV/MV transformer. Forced active power flow gives good results in networks with long feeders. The effect is especially noticed by customers on the end of the feeder. For customers close to the HV/MV substation and customers in short MV-feeders other measures must be taken. In this paper an intelligent control system for the HV/MV transformer tap changer is proposed. This control is based on actual measurements of specific feeder currents and prediction of the load profiles in the network