多机电力系统中STATCOM与发电机励磁的协调控制

COORDINATED CONTROL OF STATCOM AND GENERATOR EXCITATION IN MULTI-MACHINE POWER SYSTEMS

针对一个典型的两区域且区间联络线中间带 STATCOM的 4机电力系统 ,应用信息结构约束下的最优协调控制理论与算法 ,设计了输出反馈的线性二次型 (LQ)分散控制规律 ,得到的励磁控制器考虑了机组原有 PID自动电压调节器 (AVR)的结构约束 ,并通过在 STATCOM安装处构造一个能反映区间振荡模式的就地观测量 ,以抑制区间低频振荡。应用数字仿真研究了所得控制规律的性能 ,结果表明 ,协调控制器大大地提高了系统暂态稳定水平和区间传输容量 ,而且 ,由于采用了完全分散的信息模式和输出反馈方式 ,控制器实现代价低、可靠性高 。

For a typical two- area four- machine power system with STATCOM connected at the electrical mid- point of the inter- area transmission line,a unified state- space system model is firstly established and then an output- feedback decentralized L Q control strategy is obtained based on the theory and algorithm of inform ation- structure- constrained optim al coordinated control.The structural constraint of generators'original excitation controllers PID- type AVRs is taken into account in the process of designing controllers.In order to damp inter- area low- frequency oscillation,a local m easurem ent, which well reflects the inter- area oscillation mode,is constructed for feedback control of STATCOM.Digital simulations are fulfilled to study the characteristics of the coordinated control developed.Results show that the proposed control schem e greatly enhances the system transient stability and inter- area transfer capability.Moreover,because it is based on the decentralized information m ode and output feedback,the controllers can be im plem ented at a very low cost and are of high reliability,which further m ake it possibly applicable in practical power systems.