A Voltage Quality Assessment-based Coordination Strategy for the Configuration and Operation of Step Voltage Regulators in Distribution Feeders

Abstract

High penetration of distributed photovoltaic generation can cause simultaneous overvoltage, undervoltage, and increased voltage fluctuations in distribution feeders. This study proposes a voltage-quality-assessment-based strategy for coordinating the configuration and operation of step voltage regulators. An SVR tap-ratio model and a modified Newton-Raphson power-flow formulation are first established. Seven voltage-quality and user-side indicators are then weighted using improved entropy weighting and IAHP, and bus-level regulation demand is mapped to weak branches. A bilevel model coordinates SVR and capacitor-bank planning with daily SVR taps, capacitor switching, and PV-inverter reactive-power operation. The mixed discrete-continuous problem is solved using an improved particle swarm optimization algorithm. In the modified IEEE 33-bus case, the coordinated strategy narrows the voltage range from 0.9073-1.0995 p.u. to 0.9641-1.0358 p.u. and reduces the average network loss from 0.1924 to 0.1603 MW. It also avoids the PV curtailment required by the curtailment-only comparison scenario. The results show that assessment-based candidate screening can be integrated with coordinated SVR-CB-PV operation. The present model assumes deterministic PV and load profiles and does not include tap- or switching-wear costs; these limitations should be addressed through uncertainty modeling and validation on actual feeders. The proposed framework improves the voltage profile and network-loss performance in the tested radial feeders without relying on PV curtailment. Field validation and uncertainty-aware extensions are required before practical deployment.