基于线性变参数方法的VSC-HVDC变增益附加阻尼控制器设计

Design of VSC-HVDC Supplementary Damping Controller Using Linear Parameter Varying Approach

电压源型高压直流输电(voltage source converter based high voltage direct current,VSC-HVDC)系统的直流附加阻尼控制器能够提高交/直流并联输电系统的稳定性,增大系统区域间的阻尼,但VSC-HVDC的非线性特性,使附加阻尼控制器的性能受到影响。为解决这个问题,文中通过选取并联交流线路的有功功率作为变参数向量,应用线性变参数(linear parameter varying,LPV)方法,设计了VSC-HVDC的变增益附加阻尼控制器。仿真系统的特征值分析和时域仿真结果均表明:在系统运行方式大范围变化的情况下,文中所设计的LPV附加阻尼控制器能有效抑制交流系统区域间的低频振荡。

The supplementary damping controller （SDC） of Voltage Source Converter （VSC） based High Voltage Direct Current （HVDC） system can improve the stability of a parallel AC/DC transmission system, and increase its damping. However, the performance of SDC is affected much by the nonlinearity of VSC-HVDC. To solve this problem, the Linear Parameter Varying （LPV） approach is employed in the design of SDC for VSC-HVDC system by taking active power through the paralleled AC link-line as the time-varying parameter vector. Both results of the eigenvalue analysis and digital simulation of testing system show that the proposed LPV SDC is effective in damping inter-area low-frequency Oscillations of AC transmission system over a wide operating range.