Temporal interpolation of gridded solar radiation data for evaluation of PV fluctuations

As the solar photovoltaic systems (PV) are massively installed into power system on an urban scale, short-term (about 10 seconds) fluctuations of PV output can negatively effect on the power system. Battery storage systems are capable of alleviating the effect of PV fluctuations; power flow simulation of such systems is also meaningful to discuss the practical operation and required capacity of those storages. Recent weather satellites provide quasi real time distribution data of solar radiation which is quite suitable for the power flow simulation. However, they do not equip enough temporal resolution to observe the short-term fluctuations of radiation. This paper proposes a temporal interpolation method for the radiation data derived from weather satellite, and aims to obtain plausible fluctuations in radiation values with high temporal resolution. The proposed method is mainly composed of two steps. The first step is an estimation of cloud movements. An object tracking technique is used to obtain plausible cloud movements by considering characteristics of clouds. The second step is an interpolation based on the estimated cloud movements. The experimental results show that the proposed method can produce more plausible radiation values than the other naive methods. We also compared radiation data collected by a satellite and those collected by ground measurement, and discuss the usefulness of interpolated radiation values for the power flow simulation.