Power quality analyses of a large scale photovoltaic system

This work presents the results and analysis of a power quality measurement realized in a large scale PV system. The evaluated system is a 1 MVA centralized PV plant with different technologies of photovoltaic panels and inverters. The power quality measurement was made in accordance with the Brazilian and international power quality regulation. The magnitudes measured were voltage, current, power, power factor, unbalance and harmonic distortion. Additionally with the results of the measurements was evaluated the behavior of the inverters in different power demand situations. The inverter response for low power generation periods was worse than for high power generation periods. In photovoltaic system, low power periods occur at sunrise and sunset. Along these periods, high current harmonic distortion and low power factor levels were monitored. The results and analysis presented in this work contribute with the evaluation of the impact of large scale PV systems upon the power quality of the electric grid and the behavior of the commercial inverters for difference power generation levels.