Converter-driven small signal stability and interaction analysis for grid-following converters using emt and phasor simulations

The increasing amount of power electronics, due to the fast dynamics, results in a change in the overall power system dynamics. Thus, stability analysis is required to analyze the converter induced interaction phenomena that can be attributed to converter-driven stability. A prerequisite for stability and interaction studies is the selection of an appropriate model that can represent electromechanical phenomena and electromagnetic transients (EMT) effects. A compromise between accuracy and computation time is required. Therefore, this paper compares the results of small signal stability analyses using converter EMT, detailed and a high level phasor models. The performed eigenvalue, participation factor, and indices analyses show, that interactions between the converters themselves, and between converters and the grid can be best represented using EMT models. We outline a risk of instability for the interactions induced by the phase-locked loop, and the voltage delay. The delay induced interactions can be represented using the detailed phasor model of the converter, while those between the converters can only be represented partially. Even though faster computing time is possible with the high level phasor model, interactions between the converters and the grid cannot be represented.

Schlagworte

Converter-Driven Stability

Electromagnetic Transients

Interactions

Phasor Modelling

Small Signal Stability

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Converter-driven small signal stability and interaction analysis for grid-following converters using emt and phasor simulations