  The variability of the solar resource is mainly caused by cloud passing,
causing rapid power fluctuations on the output of photovoltaic (PV) systems.
The fluctuations can negatively impact the electric grid, and smoothing
techniques can be used as attempts to correct it. However, the integration of a
PV+VRFB to deal with the extreme power ramps at a building scale is
underexplored in the literature, as well as its effectiveness in combination
with other energy management strategies (EMSs). This work is focused on using a
VRFB to control the power output of the PV installation, maintaining the ramp
rate within a non-violation limit and within a battery state of charge (SOC)
range, appropriate to perform the ramp rate management. Based on the model
simulation, energy key-performance indicators (KPI) are studied, and validation
in real-time is carried. Three EMSs are simulated: a self-consumption
maximization (SCM), and SCM with ramp rate control (SCM+RR), and this last
strategy includes a night battery charging based on a day ahead weather
forecast (SCM+RR+WF). Results show a battery SOC management control is
essential to apply these EMSs on VRFB, and the online weather forecast proves
to be efficient in real-time application. SCM+RR+WF is a robust approach to
manage PV+VRFB systems in wintertime (studied application), and high PV
penetration building areas make it a feasible approach. Over the studied week,
the strategy successfully controlled 100% of the violating power ramps, also
obtaining a self-consumption ratio (SCR) of 59% and a grid-relief factor (GRF)
of 61%.
