Role of Cloud Movement in Generation of Anomalous Data in SCADA Systems of PV Power Plants

In this paper, role of cloud movement in generation of spurious data in PV power plant SCADA systems has been described. Significant deviation from linear relationship between SCADA recorded current vs irradiance in a multi-megawatt PV power plant, which has only one weather station recording the irradiance, is seen in many instances. Such deviations were shown to be the attribution of cloud movements causing varying shading on different blocks of modules connected to different string monitoring boxes (SMBs) and the pyranometer. Such issues leading to spurious signals in SCADA records can be minimized by having more number of pyranometers spread across the plant or by detecting and eliminated these spurious signals from analysis by looking at the time-series data.