Analysis of the Impacts of Distribution Connected PV Using High-Speed Datasets

Abstract

High penetrations of distribution connected photovoltaic (PV) systems are becoming more common. However, the impact of these variable generators on system voltage and automatic voltage regulation equipment is not well quantified. In contrast to load which generally has some diversity, PV systems are often non-diverse over small geographic areas. Variability caused by PV can range from relatively slow changes in system voltage to high frequency impacts on real and reactive power. These changes have the ability to impact the operation of a distribution circuit from a protection, voltage control and load prediction/modeling point of view. This paper utilizes information from high resolution data acquisition systems developed at the National Renewable Energy Laboratory and deployed on a high-penetration PV distribution system to analyze the variability of different electrical parameters. High resolution solar irradiance data is also available in the same area which is used to characterize the available resource and how it affects the electrical characteristics of the study circuit. This paper takes a data-driven look at the variability caused by load and compares those results against times when significant PV production is present. Comparisons between the variability in system load and the variability of distributed PV generation are made. Additionally, the potential impacts of high-penetration PV on voltage regulation equipment such as capacitor banks and load tap changing transformers are quantified.