柔性直流附加鲁棒阻尼控制器设计

针对包含柔性直流(VSC-HVDC)的交直流互联系统区间低频振荡现象,提出把基于线性矩阵不等式的多目标控制方法应用到柔性直流附加控制中。具体包括运用最小二乘旋转不变方法(TLS-ESPRIT)辨识出系统降阶模型,综合考虑控制器的鲁棒性和控制代价,设定多目标函数,设计出H₂/H_∞多目标鲁棒附加阻尼控制器,并设计传统极点配置控制器进行比较。在PSCAD/EMTDC中搭建包含柔性直流的四机两域电磁暂态模型,特征值分析和时域仿真结果表明:在系统内部参数发生较大变化情况下,多目标鲁棒阻尼控制器具有更好的阻尼特性,并兼顾了控制器的控制代价。

Design of Additional Robust Damping Controller for VSC-HVDC

As to the low frequency oscillation of AC/DC parallel power system which contains VSC-HVDC, multi-objective control method based on linear matrix inequalities is applied in additional control of VSC-HVDC. The reduced order model of the system is identified by the least square-estimation method via rotational technique (TLS-ESPRIT). By comprehensively taking both the robustness and control cost performance of controller into account, a multi-objective function is determined, additional damping controller for H₂/H_∞ multi-objective robustness is presented, and designed traditional pole placement controller is compared. The electromagnetic transient system model for VSC-HVDC system with four machines and two areas is built in PSCAD/EMTDC, the results of the eigenvalue analysis and digital simulation of the testing system show that robust damping controller has better damping characteristics and lower control costs in such case when inner parameters of system change greatly.