基于综合几何指标的广域电力系统稳定器设计

摘要

选择适当的控制器落点和反馈信号是广域电力系统稳定器(WPSS)设计的一个关键步骤.而作为应用最为广泛的留数法,在面对多种不同类型备选信号时会因为不同类型信号幅值比例问题而失效.文中采用基于系统可观性和可控性的综合几何指标来选择控制器的落点和反馈信号,能够有效克服留数法的缺陷.重点讨论了在考虑实际电网量测和通信要求条件下的广域反馈信号选择问题,把反馈输入备选信号范围扩大到线路功率、母线频率偏差、区域惯性中心角差、机端功率及发电机角频率等.研究表明,联络线有功功率最适合作为WPSS的反馈输入信号.最后,结合设计控制器参数的留数相位补偿法完成WPSS的设计.2区4机系统算例详细说明了WPSS的设计过程,表明所提出的方法能够从不同类型的反馈信号中选择最优的信号.数值仿真结果表明,按照该方法设计的WPSS能够有效提高电网稳定性,抑制区间模式低频振荡.%The selection of control locations and feedback signals is a key step in designing wide-area power system stabilizers (WPSSs). The residue method, which is the most commonly used method to select locations and feedback signals, suffers a scaling problem when comparing different signals. The joint observability/controllability geometric index is used to select the most effective stabilizing signals and control locations. The observability of different types of signals such as tieline active power flows, bus voltage angle differences, center-of-inertia (COI) difference between areas, generator output powers and generator rotor speeds are considered in this method. The tie-line active powers are found to be the most effective input signals, considering the requirement of measurement devices and communication channels in actual power systems. Taking a 2-area power system as case study, the joint geometric index based WPSS design procedure is illustrated. The importance and feasibility of the method are also discussed in the same study. The simulation results demonstrate the advantages of the proposed WPSS through improved system damping.