摘要
为提高柔性直流输电(voltage source converter basedHVDC,VSC-HVDC)受端系统频率的稳定性,同时确保直流系统发生故障或扰动下的可靠运行,提出受端换流器参与电网调频的虚拟同步发电机(virtual synchronous generator,VSG)控制及具有直流电压协调控制能力的VSG改进算法。首先,分析指出大容量VSC-HVDC受端换流器常规控制方式会降低系统频率稳定性,因此有必要通过合理的控制手段参与频率调节;其次,研究了使受端换流器具有惯性响应特性和一次调频能力的VSG控制技术;之后结合直流系统对运行可靠性的基本要求,将直流电压协调控制功能引入VSG技术中得到改进算法;最后,通过Matlab/Simulink构建了三端系统进行仿真。结果表明:VSC-HVDC受端换流器使用VSG控制能有效改善受端交流系统频率暂、稳态性能;VSG改进算法则能进一步提高直流系统运行可靠性。
To improve the frequency stability of the receiving system in voltage source converter based HVDC（VSC-HVDC）, and to ensure the operational reliability of DC system during fault or disturbance, a virtual synchronous generator（VSG） control for the inverter participating grid＇s frequency regulation and its modified algorithm with DC voltage coordinated control ability were proposed. Firstly, the shortcoming of frequency stability reduction when VSCHVDC inverter using the conventional control method was pointed out. Therefore, the necessity for the inverter to participate frequency regulation with proper control means was obtained. Secondly, the VSG control technology was studied which enables the inverter to process inertial response characteristic and primary frequency regulation ability. Once more, with consideration of DC system＇s operational reliability, a modified VSG algorithm was obtained by bringing in the DC voltage coordinated control function. Finally, simulation using a model of three-terminal VSC-HVDC system in Matlab/ Simulink was conducted. The results show that the receiving AC system＇s frequency performances of both transient and steady states are effectively improved by VSC-HVDC inverter using VSG control, and the modified algorithm can further enhance the operational reliability of the DC system.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2017年第2期525-533,共9页
Proceedings of the CSEE
基金
国家电网公司科技项目([2016])~~
关键词
VSC-HVDC
受端换流器
调频
VSG
直流电压协调控制
VSC-HVDC
inverter
frequency regulation
virtual synchronous generator（VSG）
DC voltage coordinated control
