Delivery of electricity to cluster-like consumers

To decide how to deliver electricity to cluster-like consumer, the cost of two options should be compared. In the first option, transformerless one, the cluster is connected by LV line (stem) to the central MV/LV transformer; if conductance of all conductors is the same, minimum annual cost is secured when current densities in stem and in cluster lines are equal. Cost minimization is made considering the derivative of curtailed costs observing that maximum voltage drop and current densities do not exceed admissible values. In the second option, MV/LV transformer located at the cluster is connected by MV stem to the center and cross-sections of the MV stem line and of the cluster lines are defined in a usual way. Most of the annual cost falls on the cluster transformer.