基于广域测量信息的HVDC鲁棒控制器设计

Robust Design of HVDC Supplementary Controllers Based on WAMS Signals

高压直流输电(high voltage direct current,HVDC)附加控制可以提高交直流系统的稳定性,但由直流简化模型引起的误差、信号时滞及各种干扰给附加控制器的设计增加了需要考虑的不确定因素。为克服不确定因素的影响以提高交直流系统的稳定性水平,提出一种HVDC广域鲁棒控制器(wide area robust controller,WARC)设计方法。首先根据区域惯量中心的运动方程和滑模控制设计方法确定滑模切换面,然后利用李雅普诺夫稳定性定理保证系统在不确定因素存在的情况下渐近稳定。分别以交直流并联系统和多馈入系统为例,通过PSCAD/EMTDC的时域仿真将WARC与传统极点配置及PID控制方法相比较,时域仿真结果和区间振荡模式分析均表明所提WARC能有效提高系统稳定性,且比传统控制方法性能优越。

The supplementary control of high voltage direct current（HVDC） transmission is capable of enhancing the stability of AC/DC power systems;however,inaccuracies of the reduced HVDC model,signals’ time delays and disturbances increase the uncertainties which should be considered in the control design process.In order to enhance the stability of AC/DC power systems despite the presence of these uncertainties,a wide area robust controller（WARC） design method for HVDC supplementary controller was proposed.The sliding mode manifold was designed according to the dynamics of the center of inertia and the sliding mode control method;and then the Lyapunov stability criterion was adopted to guarantee that the AC/DC power system would be asymptotically stable in the presence of the uncertainties.The validity of the WARC was verified by comparing with the conventional pole placement method and PID control method in a parallel AC/DC power system and a multi-infeed AC/DC power system,respectively.The results from both time-domain simulation and inter-area oscillation mode analysis prove that the proposed WARC can improve system stability effectively and has obvious superiority over the conventional methods.