基于同步相量测量单元的观测线性化最优直流附加控制器

OBSERVATIONAL LINEARIZATION AND OPTIMAL HVDC SUPPLEMENTARY CONTROLLER BASED ON PHASOR MEASUREMENT UNIT

提出了一种提高交直流系统性能的基于同步相量测量单元(Phasor Measurement Unit,PMU)的观测线性化最优直流附加控制器。该控制器利用 PMU测量得到的系统实时运行状态量可以实现系统状态方程的线性化,从而可以对直流附加控制器进行线性最优控制设计。与基于一点线性化的模型设计的控制器相比,该控制器考虑了系统的非线性,并且其控制规律随实际运行点的变化而变化。通过对单机无穷 大交直流系统进行的小信号稳定分析和时域仿真结果可见,文中设计的闭环最优控制器能够改善系统的动态特性和提高系统的功率传输能力,并且其鲁棒性比单输入、单输出超前滞后控制器的鲁棒性好。

To enhance dynamic stability of AC/DC power systems an observational linearization and optimal HVDC supplementary controller based on Phaser Measurement Unit (PMU) is proposed. This controller utilizes the real-time state variables obtained by PMU to linearize the state equations of the system, and then the linear optimal control strategy is used to design HVDC supplementary controller. Compared with the controllers based on the models linearized in one operation point, the non-linearity of the system is considered in the presented controller, and its control rule varies with the real-time status of the system. From the results of small signal stability analysis of single-machine infinite-bus (SMIB) AC/DC parallel system and time-domain simulation it is proved that the presented optimal close-loop controller can enhance the dynamic stability of the system and the AC system's transmission capability over a wide range of operation conditions, and the robustness of this proposed controller is better than that of single-input single-output head-lag controller.