Summary
The increasing integration of renewable energy sources, electric vehicles, and powerelectronics-interfaced devices in low-voltage distribution grids has increased grid utilization but reduced the available short-circuit capacity. The low short-circuit current challenges voltage stability but also conventional fuse-based protection. Although power-flow controllers and soft open points improve voltage regulation and thermal loading under normal operating conditions, their behavior during abnormal and fault conditions has received limited attention. This paper presents a protection-oriented control strategy for a compact direct-injection universal powerflow and quality controller (UPFC/QC) with wide operation bandwidth that enables rapid fuse tripping independent of the fundamental short-circuit current magnitude. Short-circuit events are detected using a combined criterion based on instantaneous current measurements and their time derivatives, which allow fast and reliable fault detection. Upon fault detection, the
Read more Read lessUPFC/QC injects a controlled high-frequency current component into the grid. Experimental investigations show that the effective resistance of commonly used low-voltage fuses increases significantly at frequencies above 10 kHz, resulting in accelerated thermal heating of the fuse element. A detailed simulation model incorporating frequency-dependent fuse characteristics demonstrates that the proposed high-frequency current injection significantly reduces fuse tripping times for a more effective and economically viable protection solution for modern lowvoltage distribution grids.
Additional informations
| Publication type | Session Materials |
|---|---|
| Reference | B4_12450_2026 |
| Publication year | |
| Publisher | CIGRE |
| Country | Germany |
| Study committees | |
| File size | 914 KB |
| Price for non member | 30 € |
| Price for member | 30 € |
Authors
KOEHLER Alexander - University of Kaiserslautern- Landau Germany; KESHAVARZI Davood - University of Kaiserslautern- Landau Germany; TASHAKOR Nima - University of Kaiserslautern- Landau Germany; WELLSSOW Wolfram H. - University of Kaiserslautern- Landau Germany; GOETZ Stefan M. - University of Kaiserslautern- Landau Germany
Keywords
distribution grids, grid protection, high-frequency current injection, low-voltage grids, power- flow control, short-circuit, soft open points, universal power-flow and quality controller
