Simulation and field validation of Volt-VAr optimization

Abstract The transition to renewable energy introduces significant voltage regulation challenges, particularly in radial feeders. While inverter-based Volt-VAr control offers a solution, standardised settings like IEEE 1547 often fail to address feeder-specific dynamics under high load or low generation conditions, leading to voltage compliance issues. This study presents a framework for tuning inverter Volt-VAr control, tailored to renewable-powered distribution networks. The framework integrates expert knowledge from the local distribution system operator, an existing optimization model for Volt-VAr curve tuning and a newly developed feeder-specific power flow model, using real operational data from a 22 kV radial feeder in Northern Norway supplying an industrial community. Simulations show that the proposed framework for Volt-VAr tuning restored voltage compliance for 153 out of 168 h in a worst-case scenario, compared to only 1 h with no control and under IEEE 1547 settings. Field-informed validation show that in simulations the BESS overcompensate the voltage regulation compared to field measurements, while the reactive power response temporal trends are reproduced. Discrepancies are due to simplified modelling and limited data availability. Additionally, the study highlights the need for coordinated control strategies in feeders with multiple reactive power sources, as uncoordinated responses can undermine regulation. The framework also supports planning decisions, as a long-term analysis reveals that 4 MVAr of inverter reactive power capacity is required in a 2030 industry-growth scenario. This work provides a reproducible and practical framework for improving voltage regulation while deferring costly infrastructure upgrades.