不确定单机无穷大系统的预测变结构控制  

Predictive Variable Structure Control of Uncertain Single Machine Infinite Bus System

作　　者：李明军[1] 刘莉娜[1] 

机构地区：[1]北京交通运输职业学院,北京100096

出　　处：《华北电力大学学报（自然科学版）》2015年第2期50-54,共5页Journal of North China Electric Power University：Natural Science Edition

摘　　要：将不确定单机无穷大系统的非线性三阶模型转换成二阶模型,以便在相平面中直观地设计变结构控制律。使用系统不确定参数的上下限来设计控制律,以获得良好的鲁棒性。通过预测相轨线的走势确定控制切换时机,保证了系统轨迹以指数速率收敛到平衡点。由于控制律的切换不是连续的,因此避免了传统变结构控制中的抖振。在仿真时,系统的初始状态较大地偏离了平衡点,在仿真过程中,机械功率遭受了30%的临时干扰,仿真结果表明,系统轨迹能够快速地回到原来的平衡点,控制律具有很好的鲁棒性。The third-order nonlinear model of the uncertain single machine infinite bus system is changed into a second-order model,and then the predictive variable structure controller can be intuitively designed in the phase plane.The upper and lower limits of the uncertain system parameters are used to achieve good robustness. The control is switched according to the trend of phase trajectory,which guarantees the trajectory converges to the equilibrium point at an exponential rate. The discontinuity of the control switches eliminates the chattering phenomenon existing in the traditional variable structure control. Before simulation,the initial state is set far from the equilibrium point; during the simulation,the mechanical power is attached with a temporary interference of 30%. Simulation results show that the system can quickly converge to the original equilibrium point and that the control law is robust.

关 键 词：单机无穷大系统 预测变结构控制 鲁棒控制 不确定性 相轨线 

分 类 号：TM712[电气工程—电力系统及自动化]