Summary
This paper investigates how power electronic converter parameters influence converter-driven stability in power grids with high-penetration of converter-interfaced devices. To analyse highfrequency interaction mechanisms in multi-converter systems without requiring detailed controller models, the study adopts an impedance-based frequency-domain approach. Converter and grid dynamics are represented in the dq-domain, and stability is assessed using the generalised Nyquist stability criterion applied to the eigenvalues of the system return-ratio matrix.
Read more Read lessThe methodology is demonstrated on an 11-bus test system with current-controlled inverters with ZIP load emulation and voltage-controlled inverters with generator emulation. Two study cases are compared: a lower-penetration case that remains stable and a higher-penetration case that becomes unstable, exhibiting multiple resonance frequencies. For unstable conditions, a sensitivity analysis quantifies how a ±5 % variations in key converter parameters affect gain and phase margins. The results identify the converters and parameters contributing most to instability, offering a methodical approach to mitigating converter-driven stability issues through parameter tuning and converter control modification.
Additional informations
| Publication type | Session Materials |
|---|---|
| Reference | B4_12644_2026 |
| Publication year | |
| Publisher | CIGRE |
| Country | Serbia |
| Study committees | |
| File size | 1 MB |
| Price for non member | 30 € |
| Price for member | 30 € |
Authors
LOKAR Jure - University of Ljubljana, Faculty of Electrical Engineering Slovenia; BLAŽIČ Boštjan - University of Ljubljana, Faculty of Electrical Engineering Slovenia; HERMAN Leopold - University of Ljubljana, Faculty of Electrical Engineering Slovenia
Keywords
Power-electronic converter, power system stability, Nyquist criterion, power grids, renewable sources
