Summary
The rapid growth of photovoltaic (PV) generation in distribution networks has introduced new challenges for protection systems, as inverter-interfaced PV plants contribute fault current very differently from synchronous generators. These differences create uncertainties in protection coordination, fault detection, and equipment rating. To obtain realistic short-circuit behavior, this work uses a Simscape Electrical component-level model rather than simplified current-source inverter representations. The model includes a 2.445 MW PV plant, inverter interface, transformers, and the grid, with MPPT, PLL, DC-link regulation, and dq-current control loops, enabling accurate reproduction of steady-state and transient behavior.
Read more Read lessFour fault scenarios were examined—single-line-to-ground (SLG) and three-phase faults applied at both the high-voltage (HV) and low-voltage (LV) sides of the substation—along with additional tests evaluating PI saturation limits and two filter inductances (86 μH and 200
μH). Results show negligible PV contribution for HV-side faults due to the strong grid, while
LV faults near the point of common coupling produce meaningful contributions. For LV SLG faults, the PV share reaches approximately 7–9%, and for LV three-phase faults it increases to 11–17% depending on filter inductance. Increasing the filter inductance significantly reduces peak fault currents, whereas PI saturation limits have only minor effects in specific HV cases.
Overall, the study demonstrates that inverter-interfaced PV plants can influence protection coordination on distribution feeders, particularly for LV faults in close electrical proximity to the plant. The findings underscore the importance of detailed physical modeling when assessing short-circuit behavior and provide practical guidance for protection settings, current-limiting strategies, and component rating assessments in networks with growing PV penetration. This modeling framework supports utilities and researchers in evaluating the impact of distributed PV resources on substation protection performance.
Additional informations
| Publication type | Session Materials |
|---|---|
| Reference | B5_11112_2026 |
| Publication year | |
| Publisher | CIGRE |
| Country | Italy |
| Study committees | |
| File size | 737 KB |
| Price for non member | 30 € |
| Price for member | 30 € |
Authors
GRILLO Samuele - POLITECNICO MILANO
Keywords
Inverter-Based Resources (IBRs), photovoltaic systems, protection systems, simulation-based fault analysis, adaptive protection
