Controle local de potência reativa em geradores fotovoltaicos para a melhoria da regulação de tensão em redes de distribuição

Abstract

This dissertation addresses the major operational problems faced by distribution network operators due to the high integration of photovoltaic (PV) generators, such as overvoltages, excessive tap counts and voltage regulator runaway condition. The overvoltage problem in distribution networks may be caused by significant active power injection from PV generation. Additionally, the rapid and significant variations in PV generator active power associated with cloud transients result in an increase of voltage regulator tap counts, adversely affecting the useful life of that device. Also, when the direction of the power flow is reversed due to PV generator active power injection, the voltage regulator can fail to control voltage at the regulated bus and reach lowest or highest tap limit (runaway condition). This dissertation proposes a local reactive power control for PV inverters to alleviate such problems. The proposed control is evaluated using measurement data from the real rooftop PV system in the city of Belém and dynamic simulations on a single MV feeder with a PV solar plant.