极弱受端交流系统下LCC-MMC型混合直流输电系统的附加频率-电压阻尼控制  

Supplementary Frequency-Voltage Damping Control for LCC-MMC Hybrid HVDC System Connected to Extremely Weak Receiving AC Grid

作　　者：王燕宁 郭春义[1] 郑安然[1] 殷子寒 Wang Yanning;Guo Chunyi;Zheng Anran;Yin Zihan(State Key Laboratory for Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University,Beijing 102206 China)

机构地区：[1]华北电力大学新能源电力系统国家重点实验室,北京102206

出　　处：《电工技术学报》2020年第7期1509-1520,共12页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51877077);国家电网公司总部科技项目(±800kV特高压柔性直流输电换流阀和控制保护关键技术研究)资助。

摘　　要：针对换相换流器(LLC)-模块化多电平换流器(MMC)型混合直流输电系统在联接极弱受端交流系统时容易出现的系统小信号失稳现象,提出一种附加频率-电压阻尼控制(SFVDC)。该控制方法基于逆变站模块化多电平换流器锁相环的角频率偏差信息产生附加直流电压阻尼分量,引入外环定直流电压控制器中,用以抑制极弱受端交流系统时LCC-MMC型混合直流输电系统的小信号失稳现象,从而提升系统的小信号稳定性。结果表明,所提出的SFVDC方法能够有效地抑制极弱受端交流系统下容易出现的系统小信号失稳现象,降低了系统稳定运行对于受端交流系统强度的要求,同时能够保证系统在较大的功率扰动下也具有良好的动态响应特性,在受端交流系统故障情况下具有良好的故障恢复特性。In this paper, a novel supplementary frequency-voltage damping control(SFVDC) is proposed to suppress the small-signal instability of line commutated converter-modular multilevel converter(LCC-MMC) hybrid HVDC system under extremely weak receiving AC grid. The proposed control approach generates supplementary DC voltage damping component based on the angular frequency deviation from the phase-locked loop(PLL) of MMC station, and the component is then introduced into the outer loop constant DC voltage controller. The proposed control is used to suppress the small-signal instability of the LCC-MMC hybrid HVDC system connected to extremely weak receiving AC grid, so as to improve the small-signal stability of the system. The results show that the proposed SFVDC method can effectively suppress the small-signal instability under extremely weak receiving AC grid and reduce the requirements of the receiving AC grid strength for stable operation. In addition, the good dynamic responses of the system were also obtained under large power disturbance and single-phase to ground fault at receiving AC bus.

关 键 词：电网换相换流器 模块化多电平换流器 混合直流输电系统 附加频率-电压阻尼控制 弱受端交流系统 小信号稳定性 

分 类 号：TM712[电气工程—电力系统及自动化] TM722