Parameter Tuning of LCC-HVDC for Providing Active Frequency Support in Asynchronously Interconnected Systems

Line-Commutated Converter based High Voltage Direct Current (LCC-HVDC) can be used to provide frequency support for to one end of the asynchronously interconnected systems (AIS) owing to its strong power control capabilities. However, existing research overlooks the impact of providing frequency support on the system at the other end, potentially leading to significant frequency drop. This paper proposes a parameter tuning method that ensures an appropriate level of frequency support without jeopardizing the frequency response of the system at the remote end. Firstly, the characteristics of two main control schemes, namely Droop Control (DRC) and Virtual Inertia Control (VIC), used for AIS frequency support, are analyzed. Then this paper demonstrated that, from the perspectives of frequency nadir, DRC can effectively substitute for VIC without affecting the initial Rate of Change of Frequency (RoCoF) while improving the quasi-steady-state frequency. Furthermore, a DRC-based parameter tuning method of LCC-HVDC is proposed, which ensures a reasonable level of frequency support. Finally, simulation results on a modified four-generator two-area (4G2A) power system demonstrate the effectiveness of the proposed method.