This paper investigates the impact of different control modes of VSC HVdc to the transient stability of power systems. VSC HVdc offers fast bi-directional power control in addition to fast ac voltage control. This feature is utilized in this study to enhance the transient stability of a conventional generator in a power system. Simulations are carried-out for three scenarios: (i) the generator is connected to the VSC terminal, (ii) the generator is connected at a distance from the VSC terminal, and (iii) the VSC is connected at a distance from the generator terminal. The critical fault clearing time is used as the indicator of the stability of power system. In each scenario, effects of both ac voltage control and reactive power control are studied. This paper shows that the transient stability of power system can be improved by having a VSC with fast ac voltage control near to synchronous generators.
S. Arunprasanth, U. D. Annakkage, C. Karawita and R. Kuffel, "Impact of VSC HVdc on AC system generation," 13th IET International Conference on AC and DC Power Transmission (ACDC 2017), Manchester, 2017, pp. 1-6, doi: 10.1049/cp.2017.0057.
KEYWORDS: High-voltage direct current, modular multilevel converter, real-time digital simulator, short circuit ratio, transient stability