Owing to the increased proportion of new energy power generation, such as wind power and photovoltaics, connected to the island grid, the system powered by the voltage source converter-based HVDC (VSC-HVDC) is prone to oscillate or even lose stability when disrupted. In this study, considering the rapid power compensation (RPC), an active power control strategy has been suggested for the receiving-end converter station of VSC-HVDC that could efficiently suppress the low-frequency oscillation of the island power system. First, the mechanism of VSC-HVDC inhibiting low-frequency oscillation of the island grid is analyzed in this study, and then, it theoretically determines that the damping capacity and inertia level of the rapid power compensation control strategy are stronger than those of conventional droop control and inertia control. Second, the receiving-end converter station switches from the RPC mode to droop control in order to allow the system to have a smooth recovery from the steady-state operation in the later stage of oscillation suppression. Moreover, detailed control logic and state-switching strategies have been designed. Finally, the simulation reflects that the proposed control strategy has a stronger oscillation suppression ability, allowing it to obtain rapid suppression of low-frequency oscillation.

The increase in wind power penetration has weakened the equivalent inertia of the power system, posing a significant challenge to frequency stability. In this paper, a frequency trajectory planning (FTP)-based frequency regulation (FR) strategy is proposed for permanent magnet synchronous generator-based wind turbines equipped with an energy storage system (ESS) on the DC link. The core idea is that the frequency index provided by the grid code is used to plan a safe frequency trajectory when the system frequency fluctuates. The FR power provided by the ESS is controlled by tracking the planned frequency trajectory to compensate for the unbalanced power in the system, provide inertia support, and ensure the frequency stability of the power grid. The proposed strategy can suppress the frequency fluctuation and optimize the FR power of the ESS. It also effectively circumvents the complex parameter design process of virtual inertia control. The simulation model is established in Matlab/Simulink to verify the effectiveness of the control strategy.