摘要
由电网换相换流器与模块化多电平换流器(line commutated converter and modular multi-level converter,LCC-MMC)组成的混合直流输电系统同时兼备两者的优点,未来发展前景非常好。功率的稳定传输对混合直流输电系统非常关键。该文首先研究LCC-MMC型混合直流输电系统的运行原理以及功率传输条件;然后分析采用触发角作为系统稳定运行判断依据的原理和可行性,并在此基础上提出混合直流输电系统协调控制的目标和方法;最后在PSCAD/EMTDC软件中建立LCC-MMC混合直流输电系统以及协调控制仿真模型,对协调控制策略进行仿真验证。通过研究可知,触发角度α对于LCC-MMC混合直流输电系统运行参数的变化非常灵敏,在此基础上设计的协调控制系统能够迅速并准确地对两端的控制指令进行调节,以使系统快速恢复到稳定运行的状态。
Hybrid high voltage direct current( hybrid-HVDC) system composed of line commutated converter and modular multi-level converter( LCC-MMC) combines the merits of both converters,which will be used widely in the future. The stability of power transmission is very critical for hybrid-HVDC system. Firstly,this paper analyzes the operation principle of LCC-MMC hybrid-HVDC system and the conditions of power transmission. Then,the principle and feasibility of triggering angle used as hybrid-HVDC system normal operation criteria are analyzed,and on this basis the coordinated control objective and strategy are proposed for hybrid-HVDC system. Finally,this paper constructs LCC-MMC hybrid-HVDC transmission system and coordinated control simulation model in PSCAD / EM TDC,simulates and verifies the coordinated control strategy. The results show that the triggering angle of LCC-M M C hybrid-HVDC transmission system is sensitive to operation parameters change. The control parameters of both LCC and M M C can be adjusted quickly and accurately by coordinated control system designed on triggering angle analysis. In addition,the system can be restored to steady operation rapidly.
出处
《电力建设》
北大核心
2016年第11期101-107,共7页
Electric Power Construction