Studying unbalance and voltage conformity in residential distribution systems due to asymmetric photovoltaic connections

Abstract

As, in Brazil, residential distribution systems present two nominal voltages of supply depending on the state you are (127 V or 220 V, phase-neutral), the solution for photovoltaic systems connection are different. In 127 V, majority of insertions make use of 220 V device, in a phase-to-phase connection. This action can lead to unbalanced distribution of power flow in many situations, with associated problems. This paper study the diversity of aleatory connections in a low voltage distribution system and its influence mainly in voltage and current unbalance but also voltage profile. By simulation, typical situations are explored and the main conclusion is that it is important for energy distributors to rearrange prosumers connections in order to achieve better voltage quality.