Assessment of Sudden Voltage Changes and Flickering for a Grid-Connected Photovoltaic Plant

Abstract

In this paper, sudden voltage changes studies are carried out for a 20 MW grid-connected photovoltaic plant to assess the impact of energization of the step-up transformers, which may cause a voltage dip that could be a nuisance to the point of common coupling (PCC) of the transmission system. In addition, the flicking performance of the plant is checked. At the design stage, these studies are necessary to verify compliance of the photovoltaic plant and to design its connection with regulatory grid codes and international standards. The photovoltaic plant is compliant with the FICHTNER standard for long-term flicker severity and with the short-term flicker severity requirements of Engineering Standard P28. Based on the study results, the main breaker which is connected to the PCC should be ordered with 150 Ohm Pre-Insertion Resistor to make the Photovoltaic plant comply with grid code requirements of sudden voltage changes.