基于连续高阶模滑的多机电力系统励磁控制

为了提高多机电力系统暂态稳定性,提出一种连续高阶滑模励磁控制策略。各发电机功角偏差为滑模变量,把具有非线性和不确定性多机电力系统的高阶滑模控制转化为不确定积分链系统的有限时间稳定问题,控制器结合几何齐次连续控制律和二阶滑模超螺旋算法,实现系统状态有限时间收敛,克服系统未建模动态、测量误差和外部扰动等不确定性,利用精确鲁棒微分器观测功角微分,理论分析证明了闭环系统的有限时间稳定。所设计高阶滑模励磁控制器能够保持机端电压稳定,并能有效提高电力系统的暂态稳定性。针对3机系统的仿真结果验证了该控制方法的有效性。

Multi-machine power system excitation control based on continuous higher-order sliding mode

A continuous higher-order sliding mode excitation control strategy was proposed for improving transient stability of multi-machine power system. Each power angle deviation was chosen as sliding variable. Higher-order sliding mode control for nonlinear and uncertain multi-machine power system was converted to finite time stability problem of uncertain integral chain. The controller was composed of geometric homogeneous continuous control law and second-order sliding mode super-twisting algorithm to achieve finite time convergence and conquer system uncertainties. The derivatives of power angles were estimated by so-called exact robust differentiator. Finite time stabilization of closed-loop system was theoretically proved. The proposed excitation control scheme could stabilize terminal voltage and enhance transient stability effectively. Simulation results for a three-machine system verified the validity of the proposed control method.