Abstract：The hybrid multi-terminal high voltage direct current (H-MTDC) system uses the Line Commutated Converter (LCC) for rectifiers and the Modular Multilevel Converter (MMC) for inverters. When the H-MTDC system is connected to a weak AC system, if the control parameters are set unreasonably, small-signal instability may occur in the system, which limits the application of the H-MTDC system under weak AC condition. In this paper, a control parameter optimization method was proposed to improve the small-signal stability of H-MTDC system under weak AC condition. First, based on the small-signal model of H-MTDC system, the eigenvalue analysis method was used to study the impact of the strength of AC grid connected at different converter stations on the small-signal stability of H-MTDC. The results show that unreasonable selection of control parameters will reduce the stability margin of the system, and then induce the corresponding small-signal instability. Taking the hybrid three-terminal high voltage direct current (HVDC) system as an example, this paper presented a control parameter optimization method based on sensitivity analysis, and optimized the control parameters of the hybrid three-terminal HVDC system. The detailed electromagnetic transient simulation results in PSCAD/EMTDC show that the small-signal stability of hybrid three-terminal HVDC system under weak AC grid condition can be improved by the optimized control system parameters.
郑安然, 郭春义, 殷子寒, 赵成勇. 提高弱交流系统下混合多端直流输电系统小干扰稳定性的控制参数优化调节方法[J]. 电工技术学报, 2020, 35(6): 1336-1345.
Zheng Anran, Guo Chunyi, Yin Zihan, Zhao Chengyong. Optimal Adjustment Method of Control Parameters for Improving Small-Signal Stability of Hybrid Multi-Terminal HVDC System under Weak AC Condition. Transactions of China Electrotechnical Society, 2020, 35(6): 1336-1345.
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2020, Vol. 35 
