Enhacement of Grid-Synchronization Stability by Means of Disturbance Estimation

Abstract:
Stability of grid-following grid-connected converters is a topic of paramount interest, nowadays. This work analyses grid-synchronization instability phenomena and, eventually, proposes a stiff-grid estimator technique to improve the overall system dynamics. The benefits are proved in the frequency domain for the case of small-signal linearised models. For the non-linear phenomenon, described as a modulation instability problem, the improvements are validated by experimental verification.