摘要
针对直流孤岛送电系统规划与运行面临的安全稳定问题,从送电规模、工频过电压和滤波器投切引起系统电压波动3个方面研究直流孤岛接入系统应具有的最小短路比,并考虑发电机和升压变压器电抗影响,推导出满足短路比要求的交流线路长度及各因素对短路比的影响程度;同时,基于机组作用系数法,通过研究送端系统短路比与次同步振荡之间的关系,分析了避免次同步振荡所需的送端最大短路比要求与接入系统最小短路比要求之间的矛盾,提出了解决方案;并通过推导直流孤岛送端频率波动特性,论证了发电机惯性常数、故障切除时间与送端系统频率波动的关系,为送端发电机调速器参数选取提供依据。
Facing the security and stability problems in planning and operation of DC island sending system,the minimum short circuit ratio（SCR） required for interconnection was studied in three aspects that were transmission scale,power frequency overvoltage and voltage fluctuation during filter switching.Considering the influence of the generator and transformer reactance,the AC line length for the required SCR was calculated and various influence factors were studied.Meanwhile,based on the unit interaction factor method,the contradiction between the requirements of maximum SCR to avoid sub-synchronous oscillation（SSO） and minimum SCR for interconnection was analyzed by studying the relationship between SCR of the sending system and SSO,and the solution was proposed.Through deriving the frequency fluctuation characteristics of the DC island sending system,the relationship among the frequency fluctuation,generator inertia constant and fault clearing time was demonstrated,which can provide the basis for the selection of generator governor parameters.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2012年第34期42-49,8,共8页
Proceedings of the CSEE
关键词
直流
孤岛
短路比
频率
次同步振荡
direct current（DC）
island system
short circuit ratio（SCR）
frequency
sub-synchronous oscillation（SSO）
