中文摘要：

采用传统的线性控制方法控制高压大功率条件下的静止同步补偿器（STATCOM）时,动态稳定性较差。因此,通过对STATCOM系统的数学模型与工作原理的分析,建立EL（Euler-Lagrange）系统模型,提出基于无源性理论的非线性控制策略,该策略可以保证系统的Lyapunov函数的稳定性。通过控制d轴有功电流维持功率单元直流侧电容电压稳定,减少系统期望平衡点数量。为了提高系统的收敛速度,对系统注入阻尼,加速系统能量耗散,并对注入阻尼的量进行了分析;构造离散状态观测器对系统参考指令电流进行预测,以消除参考指令电流滞后1个采样周期造成的影响。仿真与实验结果表明,所提控制策略具有良好的动态性能和较强的鲁棒性,有效地降低了STATCOM输出电流的谐波。

英文摘要：

Aiming at the poor transient stability of traditional linear control method for STATCOM in the conditions of high voltage and large power,a nonlinear control strategy based on the passivity theory is proposed for the STATCOM with cascaded H-bridges,which guarantees the Lyapunov function stability of the system. The mathematical model and operating principle of STATCOM system are analyzed,based on which,its Euler-Lagrange system model is built. In order to reduce the number of expected stable equilibrium points,the DC capacitor voltage of power unit is kept stable by controlling the active current on d-axis. The amount of damping injected into the system to accelerate the system energy dissipation for faster convergency is analyzed. In order to eliminate the influence of one-sampling-period delay,a discrete state observer is constructed to predict the reference current. Simulative and experimental results show that,the control strategy has better dynamic performance and robustness,effectively reducing the harmonic component of STATCOM output current.