Distribution network hosting capacity evaluation through a novel Power Index concept

Abstract

Accelerating integration of distributed renewables is straining distribution networks, where voltage rise and thermal overloads emerge once hosting capacity is exceeded. A novel Power Index (PI) is introduced that unifies voltage and loading margins into a single, interpretable indicator of headroom under increasing generation. Deterministic, year-long time-series simulations on coupled medium- and low-voltage models are employed, replacing worst-case snapshots and decoupled assessments. The PI is computed as the product of normalized voltage- and current-margin indices; the first zero crossing identifies hosting capacity, while the spacing between zero crossings indicates the dominant constraint. The index is applied to compare traditional reinforcement (conductor upsizing) with innovative options – inline voltage regulation (IVR), static compensators (STATCOM), and battery energy storage (BESS). Two real feeders with distinct R/X characteristics are analyzed. On a voltage-sensitive rural feeder, hosting capacity is substantially increased by IVR through mitigation of overvoltage driven by reverse power flows; on a more balanced feeder, gains from series voltage control are limited by coincident thermal constraints. In another network structure, 5 MVA BESS offered hosting capacity increase comparable to reinforcement. The PI provides a unified, visual basis for rigorous planning decisions.