为能完全可靠地抑制次同步振荡(SSO),有必要研究可控串联补偿(TCSC)对SSO的主动抑制策略,为其本身已有的对SSO的自然抑制作用增加保障.文中通过分析抑制SSO的原理,提出一种主动阻尼控制策略--TCSC次同步振荡附加阻尼控制.该控制通过测量远端或本地具有振荡特征的信号,利用相位补偿原理,结合TCSC原有控制提供附加电磁转矩,增大电气阻尼;并以基于远端转速偏差信号的阻尼控制为主,以基于本地电气量信号的控制为备用,从而兼顾阻尼效果和控制可靠性.针对某一实际串联补偿系统,通过小干扰稳定分析和时域仿真,比较TCSC附加阻尼控制加入前后的振荡变化、不同输入信号对阻尼效果的影响以及有无备用控制的区别.结果表明基于该控制原理,无论采用远端信号抑或本地信号,系统阻尼均得以增强;就阻尼效果而言,远端的转速偏差信号明显优于本地的功率偏差信号.%In order to damp subsynchronous oscillation (SSO) completely and reliably, it is necessary to study the active suppressing strategies of TCSC for SSO, which can provide additional guarantee besides the damping effect of TCSC's nature characters. Based on the analysis of the principles of attenuating SSO, a TCSC supplementary damping control for SSO is proposed as an active suppression approach. Using phase compensation principle, the proposed method extracts the subsynchronous components through measuring the remote or local signals and provides supplementary electromagnetic torque for electrical damping when integrated with existing TCSC controls. Considering both damping effect and controller reliability, controls based on remote shaft speed deviation are used as the main and those based on local electrical quantities are treated as standby. A test system is derived from a real system for research purpose. Through small signal stability analysis and time domain simulation, the oscillation variation is compared between cases with and without the TCSC supplementary damping control for SSO. The effect of different control inputs and the standby control is also studied. The results show that based on this control principle, the electrical damping increases using whether remote or local input, and the effect of remote shaft speed deviation is better than that of local active power deviation.
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