电网技术2016，Vol.40Issue(8)：2324-2329,6.DOI:10.13335/j.1000-3673.pst.2016.08.011
电力系统超低频率振荡模式排查及分析
Troubleshooting and Analysis of Ultra-Low Frequency Oscillation Mode in Power System
摘要
Abstract
Recently,ultra-low frequency oscillation (ULFO) emerges in DC island sending system and isolated power system,especially where high proportion of hydro-turbine generators exists.To find oscillation reasons,this paper established a typical DC island sending system,and analyzed ULFO stability with eigenvalue analysis and time domain simulation method to quickly troubleshoot negative damping oscillation modes caused by prime mover and governor.Simulations indicate that if turbine governor works,ULFO may appear in power system and damping ratio will decrease when generator governor operates at a higher speed.Eigenvalue analysis shows that real parts of eigenvalues are located in right side of complex plane and not stable.Study indicates that governor control mode and parameters,such as water hammer effect time constant,frequency gain,PID parameters,can significantly change eigenvalue positions in complex plane.Governor parameter optimization based on sensitivity analysis can enhance mode damping ratio,but with drawback of reducing primary frequency regulation ability of generator.Frequency limit controller (FLC) can regulate DC power or DC current in a fast and stable way,beneficial to primary frequency adjustment of governor optimization.Dead band of FLC should not be too wide and its value can be set with reference of primary frequency regulation dead zone of generator.关键词
超低频率振荡/水轮机调速系统/频率限制控制/孤网系统Key words
ULFO/hydro-turbine governor/FLC/isolated power system分类
信息技术与安全科学引用本文复制引用
王官宏,于钊,张怡,李莹,陶向宇,李文锋,汤涌..电力系统超低频率振荡模式排查及分析[J].电网技术,2016,40(8):2324-2329,6.基金项目
国家电网公司总部科技项目(渝鄂柔性直流联网与电网配合特性以及电网动态稳定适应性研究).Project Supported by State Grid Science & Technology Project. （渝鄂柔性直流联网与电网配合特性以及电网动态稳定适应性研究）
