Voltage fluctuation caused by PV Systems

An important effect on the distribution system

The output of photovoltaic (PV) systems is variable. It has daily and seasonal variations according to the position of the sun. In moderate climates, short term fluctuations in solar irradiance caused by moving clouds are just as important. What is the impact of these variations on the voltage level of the distribution grid? A major question bearing future large-scale application of embedded PV Systems in mind. A new paper by KU Leuven investigates this impact. The input consists of pseudorandom time series of solar irradiance values, based on measurements. Power-flow calculations determine the impact of solar irradiance variations on the grid voltage. The results allow assessing in which case super-capacitors to mitigate fluctuations are worth the cost.