Battery-Less Short-Term Smoothing of Photovoltaic Generation Using Sky Camera

Abstract

IEEE There is a growing concern over addressing the adverse effects of variations in the output power of distributed generators such as photovoltaic generation (PVG) systems that continue to be widely introduced into power networks. Nowadays, most network operators are requiring these intermittent energy resources to seek compliance with new regulations pertaining to the restriction of their export power fluctuations. This paper aims to investigate the smoothing of the export power fluctuations primarily attributed to clouds passing over the PVG plant which are traditionally compensated by integrating battery storage (BS) system. The idea of incorporating short-term solar prediction information into the conventional smoothing approach is examined to indicate how it affects the engagement of BS in the smoothing process. Afterwards, an enhanced solar forecasting scheme based on whole-sky imaging is proposed and its performance is demonstrated through several real-time experiments complemented with simulation studies. The results reveal that the proposed PVG smoothing strategy is capable of successfully filtering rapid export power fluctuations to an acceptable extent and the conventional generation reserves will experience a negligible amount of remaining undesired power variation. This clearly bears out the hypothesis of battery-less PVG regulation.