Voltage regulation methodology for low-voltage distribution networks with photovoltaic distributed generation

Abstract

This paper proposes a methodology for voltage regulation at the Point of Common Coupling (PCC) of a secondary distribution network following the integration of photovoltaic distributed generation. Simulations were performed using data from a real distribution network in the state of Paraíba, Brazil. The study aimed to (1) investigate whether the insertion of distributed generation leads to violations of equipment limits established by the Brazilian Electricity Regulatory Agency (ANEEL), (2) assess whether the transformer tap position affects voltage regulation at the PCC, and (3) evaluate the influence of seasonal variations on the frequency of limit violations at the PCC. Results show that, prior to applying the proposed methodology, 142 exceedances of the maximum allowable voltage occurred over the year. It was also observed that changes in the transformer tap position increased both the number of violations and the voltages recorded at the PCC. After applying the methodology, redistributing 27 loads onto the phase served by the generating unit, the voltage never exceeded the maximum permitted limit. The voltage regulation achieved by the proposed approach enhances safety for consumers and equipment connected to the distribution network, reduces costs for the utility, and represents a viable solution to one of the main challenges associated with integrating distributed generation into distribution networks.