考虑非线性负荷的发电机励磁与STATCOM协调稳定控制

Coordinated stabilization control of generator excitation with STATCOM in power system with nonlinear loads

在电网的数学模型中,负荷大都采用恒定阻抗模型或恒功率模型。针对电源为凸极式发电机(x_d≠x_q),含非线性负荷环形网络的单机无穷大系统,采用发电机励磁与STATCOM协调控制的方式进行非线性控制,建立系统的微分方程与代数约束方程,并通过坐标变换将系统的非线性方程变换为线性方程,进而采用线性控制策略进行控制设计。由于整个坐标变换过程未作任何近似线性化处理,因此,变换后的线性方程是精确的,很大程度上减小了传统线性化处理引起的误差。仿真分析结果证明了该控制方法的稳定性与可行性。

In the mathematical model of power grid, the loads are usually described by the model of constant impedance or constant power. In the single-machine infinite bus system included salient pole synchronous generator, nonlinear load and loop network, coordination control method of excitation system and STATCOM to realize nonlinear control was proposed in this paper. The differential equation and algebraic equation of the power system was established. The nonlinear equation was transformed into linear equation according to coordinate transformation, and the linear control strategy was presented. Because there was no approximate linearization in the whole process of coordinate transformation, the linear equation was concise and greatly reduced the errors arising from the traditional method of approximate linearization. The simulation results verify the stability and feasibility of the proposed method.