基于反馈信号优选的多机电力系统汽门开度广域控制研究

The interconnection of large power grid results in the fact that inter-area low frequency oscillation turns into the main factor of threatening the stability of power systems. The traditional steam valve opening control, taking local signals as its feedback inputs, is difficult to reflect the character of inter-area oscillation accurately. However the wide-area control based on WAMS can be used to solve this problem well. In this project, the wide-area control of steam valve opening of multi-machine power system is developed. First of all, the mathematical models of multi-machine power system, in which the nonlinear interconnected functions satisfy the quadratic norm bounded inequality condition and sector condition respectively, are established. And meanwhile, the delay-dependent wide-area feedback control with full-dimension state are studied. Second, the sufficient conditions in form of LMI are derived based on nonlinear system theory and Lyapunov stability theory which is used to judge the asymptotic stability of the close-loop system. The algorithms of obtaining the gain matrix of the controller and the upper bound of the time delay are presented at the same time. Then, the method of selecting suitable wide-area feedback signal for the given controller are designed according to the comprehensive sensitivity to time delay of wide-area signals in different operating conditions and to the relationship between the loss of the signal and damping effects of closed-loop latent root. At last, simulaitons are performed in PSASP and the optimal design of controller will be carried out according to the simulation results. What’s more, physical experiments are done in a digital dynamical simulation platform to verify the effectiveness of the proposed wide-area control strategies.

大区电网互联使得区域间的低频振荡成为威胁电力系统稳定的主要因素。传统的汽门开度控制以局部信号作为反馈输入，难以准确反映区间振荡的特征，而基于WAMS的广域控制可以用来很好地解决这一问题。项目针对多机电力系统汽门开度的广域控制问题展开研究，建立非线性关联函数分别满足二次范数有界不等式条件和扇区条件的多机电力系统描述模型，研究该系统汽门开度的时滞相关全维状态广域反馈控制问题，根据非线性系统理论和Lyapunov稳定性理论，推导出判别闭环系统渐近稳定的LMI充分条件，并给出求解控制器增益矩阵和时滞上界大小的算法。考虑在不同工况下广域信号对时滞的综合敏感程度，并研究该信号缺失与闭环特征根的阻尼效果之间的关系，来设计为给定控制器选择合适广域反馈信号的方法。在PSASP平台上进行仿真，根据仿真结果对控制器进行优化设计，并在动态模拟数字化平台上进行实验，来验证所提出广域控制策略的有效性。

随着HVDC和FACTS投入运行、跨区域电网互联和电力市场开放，电网结构和动态行为越来越复杂，电力系统的安全裕度变小，稳定性也变差，甚者可能诱发低频振荡。传统的低频振荡抑制控制方法以局部信号作为反馈输入，难以准确反映区间振荡的特征，而基于WAMS的广域附加阻尼控制可以用来很好地解决这一问题。项目针对多机电力系统区域间低频振荡的广域控制问题展开研究，利用小信号分析法对其进行线性化，得到多机电力系统的线性模型，研究了该系统区域间低频振荡的具有期望稳定度的时滞相关全阶/降阶广域动态输出反馈控制问题以及运行点发生变化时区域间低频振荡的时滞相关全阶/降阶广域动态输出反馈控制问题，根据时滞非线性系统理论和Lyapunov稳定性理论，推导出判别闭环系统渐近稳定的LMI充分条件，并给出了求解控制器增益矩阵和时滞上界大小的算法，分析了期望稳定度、阻尼控制效果和时滞上界之间的关系。在PSASP平台上进行仿真，根据仿真结果对控制器进行优化设计。

内容获取失败，请点击重试