Impacts of Voltage-Based Grid-Support Functions on Energy Production of PV Customers: Preprint

This paper presents the impact of grid-support utility-interactive inverter functions, such as volt/volt-ampere reactive and volt/watt controls, on quasi-steady-state feeder voltages and on photovoltaic (PV) customer energy production on a real distribution feeder in Oahu, Hawai'i. These autonomous inverter controls provide an effective means to modulate active and reactive power based on local voltage measurements and therefore serve as good candidates for non-wire alternatives to increase PV hosting capacity. However, because the activation of these functions can result in PV energy curtailment, this study addresses the concerns about the impact of these advanced inverter controls on curtailment through detailed quasi-static time series (QSTS) simulations. This study proposes four metrics-maximum and average grid-support function curtailments, average increased generation, and average net generation change-to assess the impact of a given control on PV systems located on customer sites. For representative scenarios modeled in detail, it was found that curtailment of PV production is negligible for customers where peak voltage is within ANSI C84.1 ranges. A reliable relationship between curtailment and peak customer voltage is demonstrated, allowing peak voltage to be used as an indicator of curtailment without the need to measure curtailment directly.