柔性直流耦合鲁棒控制器设计

Design of Coupling Robust Controller for VSC-HVDC

为增强柔性交直流系统中特定低频振荡模式的阻尼,利用不同控制回路之间的相互作用,提出了一种基于多输入多输出(multi-input multi-output,MIMO)系统模型的耦合鲁棒控制器设计方法。首先,利用主模比(dominant mode ratio,DMR)指标选取最佳的反馈信号发送给控制器。然后,采用总体最小二乘-旋转不变技术(total least squaresestimation on signal parameters via rotational invariance technique,TLS-ESPRIT)对MIMO系统模型进行辨识。最后,基于混合H_(2)/H_(∞)鲁棒控制理论设计了具有区域极点配置的HVDC附加鲁棒控制器。在PSCAD/EMTDC中以一个简化直流输电馈入系统为例进行仿真,与传统无协调配合设计的超前-滞后补偿器相比,仿真结果验证了所设计控制器具有更好的控制效果和更强的鲁棒性。

Aiming to enhance the damping of certain low frequency oscillation modes in voltage sourced converter based high voltage direct current(VSC-HVDC)systems,a coupling robust controller design method based on multi-input multi-output(MIMO)system model is proposed by utilizing the interaction between different control loops.Firstly,the optimal feedback signal is selected by using the dominant mode ratio(DMR)index and then sent to the controller.Then,the total least squaresestimation on signal parameters via rotational invariance technique(TLS-ESPRIT)is used to identify the MIMO system model.Finally,the mixed H_(2)/H_(∞)robust control theory is applied to design the HVDC supplementary robust controller with regional poles placement.A simplified multi-infeed HVDC transmission system is simulated in PSCAD/EMTDC.Compared with the traditional lead-lag compensators without coordination design,the simulation results verify that the designed controller has bet⁃ter control effect and stronger robustness.