Investigation on Impact of Fast Moving Cumulus Clouds on Power Quality in Deregulated Powergrid with Large Scale Solar Integration

Emerging deregulation policies together with the distributed renewable resource had led to the restructuring of power grid operation as several interconnected self-reliant clusters. Forecasting models play a vital role to handle its inherent variability so that the safe and reliable operation of the grid can be ensured. However, the irradiance variation caused by a fast-moving cumulus cloud in the nowcasting horizon results in a fairly higher forecast error. This in turn leads to fluctuating power injections with considerable ramp rates. In a deregulated grid with weaker reactive power support, these fluctuating injections can cause severe voltage quality issues. Since the availability of the resources is uncertain in the deregulated grid, conventional decentralized control may not be sufficient to handle these voltage quality issues. Though much research is happening on these issues, the characteristics of fast-moving cumulus cloud-induced power quality issues are not well investigated. In this regard, this work investigates the voltage quality issues caused by the grid tied solar farms. Real-world data of irradiance variation under fast-moving cumulus clouds are considered for the investigation. The investigation carried out and the results demonstrated can benefit the power quality remedial measures in emerging deregulated grids.