贵广二回直流输电系统次同步振荡问题分析

Analysis of the SSO Problem Caused by Guizhou-Guangdong Ⅱ HVDC Transmission System

针对贵广二回直流输电系统可能引起整流站附近汽轮发电机组次同步振荡的问题,采用机组作用系数法和时域仿真方法进行了分析。时域仿真采用NETOMAC程序,建立了适用于次同步振荡问题仿真的详细模型。通过对不同运行方式的分析,得出了在整流站与外部交流系统弱联系以及孤岛方式下会发生次同步振荡不稳定问题的结果,提出了必须设计直流输电附加的次同步振荡阻尼控制器的结论。

To investigate the subsynehronous oscillation （SSO） problem of the steam turbine generators near the rectifier station of Guizhou-Guangdong Ⅱ ±500 kV DC transmission link, the unit interaction factor （UIF） analysis and the time domain simulation methods are adopted. NETOMAC program is used and detailed system model suitable for SSO study is built for time domain transient simulations. Based on the analysis considering different operation modes and load flow situations, it is concluded that the unstable SSO can occur at islanded operation of rectifier station or if only a weak interconnection existing between rectifier station and the rest of the AC system. The design of a supplementary SSO damping controller of the HVDC transmission link is recommended.