Modeling and allocation of modern infrastructure deployment in LV European-type distribution systems for solving power quality issues

Voltage magnitude limit violations (under/over-voltage), phase unbalance and occasional conductor overloads are among the most frequent and operationally critical problems in European low-voltage (LV) distribution networks, and their incidence is rising with electrification, power-electronic loads and distributed generation. This paper proposes a DSO-oriented, operationally grounded mitigation framework that coordinates four field-ready devices: autotransformers, on-load tap changers, zigzag filters and a local power-balancing device to restore voltage compliance and reduce unbalance without relying on customer participation, advanced communications or complex power-electronic converters. To keep the assessment tractable over large historical datasets, representative stressed operating conditions are pre-selected from one year of measurements using transformer-level proxy indicators (aggregated loading and phase power disparity), removing the need for extensive power-flow simulations to a few critical cases. The methodology is validated on a standardized European LV benchmark network using real customer demand profiles and evaluated at customer connection points through voltage–magnitude and unbalance KPIs. Results show complete elimination of under-voltage occurrences, more than 95% reduction of over-voltage events, and over 98% reduction in average unbalance factor, demonstrating that coordinated deployment of established, utility-accepted devices can provide an effective and rapidly deployable operational bridge while long-term reinforcements are planned and executed. • Unified framework using four conventional devices to fix voltage issues in LV grids. • Identifies critical cases from transformer data, avoiding year-long simulations. • KPI-driven device allocation for local and system-wide power quality compliance. • Achieves 90%+ unbalance improvement and eliminates all undervoltage violations. • Validated on real Iberdrola LV network; scalable without complex power electronics.