Impact of short-duration voltage variations on VSC-HVDC performance

The growing load demand globally necessitates increasing the penetration of renewable energy sources into electrical grids as well as interconnecting grids from different countries and even continents through HVDC transmission systems. Since these applications rely on power electronics devices, several power quality issues arise, namely voltage sags and swells. This paper analyzes the response of a VSC-HVDC transmission system that interconnects two asynchronous AC grids to short-duration voltage variations like sag and swell by adjusting the voltage of the controllable AC source. The system is simulated with the help of MATLAB/Simulink. The study records the effect of the manipulated AC voltage on the active/reactive powers and AC/DC voltages at both converter stations to evaluate the system stability due to these prevalent power quality challenges. The obtained results reveal that the system hardly withstands voltage variation for a short period.