基于多级线性最优方法的多频段直流附加阻尼控制器设计

摘要

The reduced order power system models and relevant oscillation frequencies were identified by the total least squares (TLS)-estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithm. Firstly, using Butterworth band-pass filter to decompose oscillation frequencies into different channels based on system oscillation modes. Thereafter, the multi-channel HVDC supplementary damping controller was designed by the multi-stage LQR method and configured with the state observer by the Ackermann formula. It included one low frequency oscillation channel and two sub-synchronous oscillation channels, which worked separately. The designed multi-channel HVDC supplementary damping controller provided damping for different oscillation modes to suppress low frequency oscillation and sub-synchronous oscillation. The proposed control strategy was demonstrated detailedly in a realistic HVDC system model built in PSCAD. Compared with the multi-stage linear quadratic regulator (LQR) method, LQR method and PI method, the simulation results in power systems computer aided design (PSCAD) have verified the effectiveness and robustness of the designed controller. The multi-stage LQR method has the certain significance for the practical application.%通过总体最小二乘-旋转不变技术辨识出系统振荡模式和降阶模型,对应系统的不同振荡模式,利用巴特沃斯带通滤波器将控制器分解为多个频段,基于多级线性最优方法控制和阿克曼公式,设计出带状态观测器的多频段高压直流附加阻尼控制器,为不同频段的振荡模式提供阻尼,实现同时抑制低频振荡和次同步振荡的功能.同时,在PSCAD实际系统中进行了仿真实验,并对比线性二次型最优控制和比例积分控制,证明了本文所设计控制器的有效性和鲁棒性,对于工程实践具有一定意义.