基于改进扩展状态观测器的交流孤岛微电网鲁棒性电压滑模控制

针对交流孤岛微电网中系统参数和负荷变化等不确定因素导致的电压不稳定的问题,提出了一种基于改进的扩展状态观测器(MESO)的鲁棒电压滑模控制策略。首先,将系统内部和外部扰动视为集总不确定性,并以此建立孤岛微电网系统的状态空间模型。其次,基于线性扩展状态观测器(ESO)设计了一种改进的扩展状态观测器(MESO),从而通过MESO估计系统的不确定性。最后,提出了一种具有多幂次趋近律的滑模控制器,从而使系统的输出电压能够快速、准确地跟踪参考电压,增强系统的鲁棒性,并通过仿真对比实验验证所提策略的有效性。实验结果表明,所提鲁棒性电压滑模控制策略可有效抵抗系统的内部和外部干扰,能够在不同负载类型下快速跟踪其参考输入电压,使输出电压具有良好的动态调节能力和稳态性能。

双馈感应风力发电机组的滑模直接电压控制

为解决PI矢量控制动态响应慢且依赖电机精确参数的问题,本文将滑模控制与空间矢量调制结合,提出了一种开关频率固定的滑模直接电压控制(SMDVC)方法,以实现双馈感应电机(DFIG)的电网同步控制.实验结果表明,提出的SMDVC方法具有比PI矢量控制更好的动态性能,即使在电网电压不平衡工况下,也能较好地控制DFIG定子电压实现对电网电压的精确跟踪.

基于滑模观测器的孤岛风柴混合电力系统SVC滑模补偿控制器设计

针对独立风柴混合电力系统中风能和无功负荷变化所引起的电压波动问题,提出了利用静止无功补偿器(static var compensator,SVC)稳定电压的控制策略。实际SVC存在模型参数不确定及状态变量不完全可测的问题,故利用滑模控制算法,设计基于鲁棒观测器的SVC附加滑模电压控制器。为此,首先建立孤岛情况下包含SVC的风柴混合电力系统的数学模型;然后选择适当的比例切换面和趋近律到达条件,并基于观测器估计值来构造SVC鲁棒电压控制器;最后基于Matlab仿真平台搭建算例模型,对所设计SVC滑模电压控制器的鲁棒性进行验证。仿真结果表明,所设计的SVC滑模电压控制器与传统的SVC控制策略相比,可有效抑制电压波动。

Control of the DC Output Voltage of the AC/DC Converter Using Sliding Mode Control： Application to PMSG

This paper presents sliding mode technique associated to the direct torque control （DTC） for an isolated-loaded permanent magnet synchronous generator （PMSG）. The machine delivers an active power to a DC-load via a converter connected to a single capacitor on the DC side. Since the converter/capacitor model is nonlinear, the sliding mode technique constitutes a powerful tool to ensure the DC-bus voltage regulation. The computer simulations are provided to verify the validity of the proposed control algorithm.

Sliding Mode Control with Perturbation Estimation and Hysteresis Compensator Based on Bouc-Wen Model in Tackling Fast-Varying Sinusoidal Position Control of a Piezoelectric Actuator

In this paper,a sliding mode control with perturbation estimation(SMCPE) coupled with an inverse hysteresis compensator is proposed for the motion tracking control of a microposition system with piezoelectric actuation.The inverse hysteresis compensator is employed to cancel the hysteresis nonlinearity,thus reducing the nonlinear system to a linear system with an inversion error.Then,a SMCPE controller is adopted to deal with all the unmodeled dynamics and disturbances,aiming at improving the dynamic performance and the robustness of system.An experiment of a piezoelectric actuator is presented to demonstrate the feasibility and effectiveness of the proposed control scheme.The result shows that for a fast-rate control input,the proposed method is capable of leading to a good performance of system behavior.