Analysis and Improvement of Transient Voltage Stability for Grid-Forming Converters

This project presents that grid-forming converters also face transient voltage stability problems, which are caused by the violation of reactive power absorption limitations between converters and grids. This is particularly of interest for grid-forming static compensators and different from conventional power system voltage stability problems. Moreover, this article derives the equilibrium points, reactive power absorption limitations, and stable regions of grid-forming converters with two typical reactive power controllers, namely, reactive power proportional–integral (PI) and voltage-droop control. To improve fault-ride through, this article further proposes and designs voltage inertia control, which smoothens the voltage amplitude change and extends the stable region. In addition, this article finds that the active power control deteriorates transient voltage stability. The simulation results can be evaluated by using Matlab/Simulink Software.

Keywords: Fault-ride through (FRT), grid-forming converters, reactive power transfer, static compensators (STATCOMs), transient voltage stability.