Transient Stability Analysis and Its Improvement of Isolated Renewable Energy Bases with VSC-DC Transmission

This paper researches the transient stability analysis and improvement of isolated renewable energy bases with VSC-DC transmission. First, the transient stability of the system is decomposed into two sub-issues: the transient stability focusing on the dynamics of grid following (GFL) and grid forming (GFM) generators inside the base, as well as the transient stability concerning the interaction between the base and the VSC-DC station. Second, these two sub-issues are analyzed separately, showing that switching GFM generators between the current source state and the voltage source state may negatively affect the transient stability. Finally, an adaptive voltage booster suitable for GFM generators is proposed, which has been proved through a case study to be beneficial for transient stability in the discussed scenes.