A study on damping low frequency oscillation in power system by VSC-HVDC

The low frequency oscillation occurs in power sys tem is mainly due to the insufficiency of the system damping. A voltage source converter based high voltage direct current (VSC-HVDC) system with traditional control strategy can not supply damping. To increase the system damping, two damping control strategies for a VSC-HVDC by modulating the active and the reactive power respectively are proposed. Then the VSC-HVDC with the proposed control strategy connected with a single-machine infinite-bus system is analyzed theoretically. Finally, based on the PSCAD / EMTDC simulation software, the simulation platform of the system is established and the simulation results show that both two kinds of damping control strategies can increase the system damping effectively, suppress the low frequency oscillation rapidly, and enhance the stability of power system.