基于惯量中心动态信号的交直流互联系统稳定控制

针对交直流互联电力系统的稳定控制问题，提出了基于系统惯量中心(center of inertia，COI)动态信号的发电机励磁和直流功率调制综合控制方案。该方案中各发电机功角和频率动态跟踪由广域测量系统提供的系统COI动态功角和频率轨迹。直流输电线路功率调制的目标是阻尼区域COI功角和频率间的相互振荡。考虑到模型误差和外部干扰因素，采用反步法设计了非线性鲁棒控制器。对某4机2区域系统进行仿真实验，结果表明该控制方案和控制器突破了系统只能稳定于工频下的局限，增大了系统的稳定域，显著改善了系统的功角稳定性。

A Study on Control of AC/DC Power Systems Based on COI Information

To realize stable control of interconnected AC/DC power systems,based on dynamic signals of center of inertia(COI) an integrated control strategy for generator excitation and dc power modulation is proposed.In this strategy both rotor angle and frequency of each generator track the angle and frequency of the dynamic COI of the system available from wide area measurement system(WAMS).The objective of DC power modulation is to damp the relative swing of angle and frequency of the two areas from COI.In the design of the controller the model error and external disturbances are considered,and a nonlinear robust controller is developed by back-stepping method while model errors and disturbances are considered.Simulation results of a 2-area-4-machine AC/DC power system show that the proposed control strategy can break through the traditional limitation that the integrated AC/DC power system can merely be stable under power frequency and enlarge the stability region of the power system as well as noticeably improve the transient stability of the power system.