Control of prosumer energy sources in power grid feeded by three-phase distribution transformer

The co-operation of single-phase, prosumer power sources with three-phase grid powered by a distribution transformer Medium Voltage / Low Voltage (MV/LV), depends on the transformer windings arrangement and the control of the prosumers inverters. In the paper, the influence of the transformer windings arrangement on the flow of active power in a three-phase grid is discussed and the inverter control is shown, limiting the return of active power to the MV grid by the transformer. The control also reduces the power losses in the transformer and power losses in the MV grid. The transformer winding arrangement was chosen because of the possibility of transforming the energy from a single-phase prosumers source to the loads connected to the other phases of the transformer's LV side. Inverter control system was studied by simulation. Analysis and experiments are carried out to verify the effectiveness of the proposed solution.