Solar generation impact on voltage of rural power distribution networks: A case study

Power generation using solar photovoltaics connected to the grid has become popular in the agricultural sector, especially in family farming, as an economic and environmental-friendly alternative. In this case, however, generators are normally installed at remote locations, where total line impedance value seen from the feeder is relatively high, resulting in substantial voltage drop/rise when load/generator is integrated. This paper presents a case study based on the analysis of low-voltage, rural distribution system of Santana da Vargem, MG. Evidence of damage to consumer electronic equipment due to voltage rise caused by distributed generation operation during the off season of coffee harvest is examined. The investigation of the problem is based on a brief review on voltage variation due to distributed generation and on a comparative analysis of measured data to limit values stablished by normative references. It was verified that grid voltage at the point of common coupling of a distributed generator reached a value of 1.23 p.u., which led to the burning of household appliances connected nearby.