基于非线性干扰观测器的风电机组自适应反演滑模控制

为了提高风力发电系统最大功率跟踪控制的工作性能,根据大范围风速波动运行条件的特性,设计了一种基于非线性干扰观测器的自适应反演滑模控制器。针对风力机单质量动态模型中气动转矩不容易获取的特点,利用非线性干扰观测器进行气动转矩的实时估计。基于最佳转速法,设计了一阶滑模控制器和反演滑模控制器。结合不确定项的自适应控制,进一步抑制滑模控制器的输出抖振、平滑转矩输出。通过与传统PI控制和一阶滑模控制的仿真比较,验证了该文所述控制器的正确有效性。     

光伏LCL型并网逆变器的积分滑模容错控制策略

针对光伏LCL滤波并网逆变系统中参数的不确定性故障和外界干扰故障,对系统在不确定性和执行器故障情况下的数学模型进行重构,提出一种基于高阶滑模观测器的连续积分滑模容错控制方法,该算法设计一个高阶滑模状态观测器,可对故障状态进行有效估计,以抑制故障的不利影响。结合滑模控制原理构建一个连续积分滑模控制器,设计系统控制分配律,并推导出系统故障的稳定条件,采用Lyapunov函数证明闭环系统的稳定性。通过仿真验证所提控制策略的有效性。     

基于干扰观测器的电子节气门连续滑模控制

电子节气门是一种典型的非线性系统,采用一般的滑模控制会产生不可消除的抖振,影响控制效果.为解决这一问题,提出基于干扰观测器的滑模控制,其中干扰观测器前馈补偿观测到的干扰,滑模控制器消除其他干扰,因此很大程度上降低了滑模控制器的切换增益值,达到削弱抖振的目的.通过MATLAB/Simulink平台的仿真试验,证明这种控制方法对消除抖振的可行性和有效性.     

基于自适应非奇异智能终端滑模观测器的风力机载荷增广预测控制

为有效降低风力机在高风速运行时的不平衡载荷,提出一种基于自适应非奇异智能终端滑模观测器的载荷增广预测控制策略。首先,针对模型不匹配导致的模型预测控制性能下降的问题,将指令跟踪误差与系统状态的变化量增广为状态向量,设计增广预测模型以消除稳态跟踪误差;其次,设计自适应非奇异终端滑模观测器对系统状态进行估计,以提高控制系统的可靠性;然后,设计多目标变速灰狼优化算法同时对控制器和观测器参数寻优;最后,基于Simulink仿真平台验证了所提控制策略的有效性。结果表明,所提控制策略可有效消除稳态误差,缩短调节时间并提高控制性能。     

燃气锅炉主汽压的RBF神经网络滑模控制策略设计

针对燃气锅炉主汽压控制的非线性、干扰大和模型参数易变的特点,常规比例积分微分(PID)控制方法难以取得满意的控制效果.利用滑模控制对系统参数变化和扰动不灵敏的优点,提出一种基于神经网络和滑模控制相结合的主汽压优化控制策略.采用径向基函数(RBF)神经网络调节滑模控制器的切换增益以降低其在平衡点的抖振,并通过在系统中设计干扰观测器实现对扰动的补偿.结果表明:与常规滑模控制和常规PID控制相比,不同工况下本文提出的控制策略超调量最多减少6.62％,调节时间最多减少57.45 s,且系统抖振小,跟随性能、抗干扰能力和鲁棒性能良好;工程实例表明,采用所提控制策略后,系统抖振比常规滑模控制降低33％,主汽压波动范围在-0.04～0.1 MPa,控制系统抗干扰能力得到显著提高.     

基于模糊控制的自适应超螺旋滑模观测器无传感器控制

针对永磁同步电机传统超螺旋滑模观测器(Super-twisting algorithm based sliding-mode observer,STA-SMO)使用固定滑模参数,从而导致较大抖振和扰动抑制能力差的问题,提出了一种滑模参数可以随着系统转速变化而实时更新的永磁同步电机自适应超螺旋滑模观测器无位置传感器控制方法,并给出了所提方法的稳定性证明,通过在线调整滑模系数可以获得较高的估计精度。针对永磁同步电机传统矢量控制速度环采用固定参数PI控制器、无法满足系统快速响应和参数扰动抑制能力等问题,速度外环采用模糊PI控制器,通过模糊控制器的输出更新PI控制器的参数,增强系统的鲁棒性。最后,通过仿真和试验,验证了基于模糊控制的永磁同步电机自适应超螺旋滑模观测器可以有效抑制系统抖振,且估计精度高,鲁棒性强。     

基于模糊自适应滑模变结构的PWM整流器

摘要： 为了提高三相电压型PWM整流器（VSR）的抗扰能力,通过分析三相VSR的数学模型,提出了基于同步旋转d-q坐标系的模糊自适应滑模变结构控制算法。该算法考虑到传统双闭环PI的缺陷性,将外环设置为模糊控制器和滑模变结构控制器相结合,利用模糊控制规则实时调整滑模趋近律,在提高系统鲁棒性的同时又能削弱滑模面上的抖振;内环将PI控制改为比例控制,简化系统结构。小波分析和MATLAB分析运行数据结果表明,基于模糊自适应滑模控制的三相VSR系统相对于传统双闭环PI系统具有更强的动态性能和跟踪能力。     

永磁直驱风力发电机自抗扰技术及其无位置传感器控制策略

针对永磁直驱风力发电机传统矢量控制动态性能差,抗扰动能力弱的问题,提出一种双环线性自抗扰控制系统。在此基础上针对传统滑模观测器抖振等因素造成的速度和位置角观测误差较大的问题,提出改进型自适应滑模观测器。结果表明所设计的速度和电流双环线性自抗扰控制策略能有效提高转速跟踪性能和电流波形质量;在滑模观测器的基础上结合自适应算法精确观测反电动势,借鉴锁相环原理代替反正切函数估算出转子转速和位置角,相比传统滑模观测器具有更高的估算精度。     

Study on the control strategy for a boost converter used in hybrid energy storage system of electric vehicles

升压型直流变换器采用滑模变结构控制策略存在收敛速度较慢、抖振剧烈等导致的动态响应品质差问题。本文提出一种双幂次滑模趋近滞环控制策略,在电流跟踪误差估计值的基础上定义滑模面以实现电流跟踪控制,依据系统的未知扰动和负载变化建立自适应状态观测器,结合李雅普诺夫函数设计自适应律,并计算自适应占空比。提出一种双幂次趋近律,根据系统不同趋近过程的特点制定参数选择标准,对系统的动态响应品质进行目的性调节,并设计滑模滞环控制器以削弱由符号函数项所引起的抖振。对以上方法进行了仿真验证,结果显示可有效改善系统的动态特性和电流控制鲁棒性。     

基于势能-滑模的双馈风电机组广域阻尼控制设计方法

通过构建模型的方式解决双馈感应发电机并入电力系统中存在的非线性功率振荡问题，提出一种具有非线性和鲁棒性的新型功率振荡阻尼控制器，以减小此类系统中的功率振荡。首先，结合双馈感应发电机特性，构造含风电电力系统的能量函数模型。其次，根据构建的稳定流形构建滑模面，对于建模和仿真过程中存在的一些误差和外部干扰，采用扩展状态观测器进行估计。最后，基于扩展状态观测器、滑模变结构控制理论、能量函数设计双馈感应发电机的功率振荡阻尼控制器，并在四机两区系统中验证该方法的有效性。     

基于扰动观测的漂浮式海上风力机主动滑模结构控制研究

针对漂浮式海上风力机主动结构控制问题,提出一种基于扰动观测的主动滑模控制方法,并应用风力机仿真工具FAST验证所提方法的有效性。在扰动二阶导数有界的前提下,理论证明观测器的稳定性和估计误差的有界性,从而有效估计匹配扰动和非匹配扰动。理论证明一类积分型滑模面的有限时间收敛性和闭环系统稳定性。基于FAST的仿真表明：所提出的主动调谐质量阻尼器（TMD）控制方法与最优被动TMD相比,主动TMD系统的漂浮平台俯仰角度和塔顶位移的均方根值可分别降低11.88%和13.56%,有效提升了风力机承受风浪载荷的能力。     

Nonlinear controller design based on cascade adaptive sliding mode control for PEM fuel cell air supply systems

Optimized robust control for proton exchange membrane (PEM) fuel cell air supply systems is now a hot topic in improving the performance of oxygen excess ratio (OER) and the net power. In this paper, a cascade adaptive sliding mode control method is proposed to regulate oxygen excess ratio (OER) for proton exchange membrane (PEM) fuel cell air supply systems. Based on a simplified sixth-order nonlinear dynamic model, which takes parametric uncertainties, external disturbances and measurement noises into consideration, the nonlinear controller based on cascade adaptive sliding mode (NC-ASM) control is proposed. The method combines the nonlinear terms of super twisting algorithm and two added linear terms, and the modified second order sliding mode (SOSM) algorithm based on an observer is employed to form a cascade structure. Besides, an adaptive law is also utilized to regulate the parameters of the NC-ASM controller online. The performance of the controller is implemented on a real-time emulator. The results show that the proposed strategy performs better than the conventional constant sliding mode (CSM) control and PID method. Though during large range of load current and in the presence of various uncertainties, disturbances and noises, the NC-ASM controller can always converge rapidly, the feasibility and effectiveness are validated.     

基于分数阶滑模和扩张状态观测器的励磁控制器设计

针对具有励磁控制的单机无穷大系统大干扰与小干扰响应不宜同时得到很好抑制的问题,在单机无穷大系统模型的基础上,利用分数阶微滑模理论构造李雅普诺夫稳定函数,并引入扩张状态观测器消除李雅普诺夫稳定函数的非线性项,以同时抑制大干扰和小干扰所引起的系统偏差。在Matlab/Smulink仿真平台上与AVR+PSS法分别进行仿真试验表明,该方法与AVR+PSS法相比,改善了系统的性能。     

An adaptive sliding mode observer based near-optimal OER tracking control approach for PEMFC under dynamic operation condition

Tracking control of oxygen excess ratio (OER) is crucial for dynamic performance and operating efficiency of the proton exchange membrane fuel cell (PEMFC). OER tracking errors and overshoots under dynamic load limit the PEMFC output power performance, and also could lead oxygen starvation which seriously affect the life of PEMFC. To solve this problem, an adaptive sliding mode observer based near-optimal OER tracking control approach is proposed in this paper. According to real time load demand, a dynamic OER optimization strategy is designed to obtain an optimal OER. A nonlinear system model based near-optimal controller is designed to minimize the OER tracking error under variable operation condition of PEMFC. An adaptive sliding mode observer is utilized to estimate the uncertain parameters of the PEMFC air supply system and update parameters in near-optimal controller. The proposed control approach is implemented in OER tracking experiments based on air supply system of a 5 kW PEMFC test platform. The experiment results are analyzed and demonstrate the efficacy of the proposed control approach under load changes, external disturbances and parameter uncertainties of PEFMC system.     

Stabilization of a Wave Equation with a Tip Mass Based on Disturbance Observer of Time-Varying Gain

In this paper, we consider the stabilization problem of a wave equation with a tip mass, which undergoes the external disturbances at the tip mass end. Here, the disturbance may be exponentially increasing. For such a model, the usual sliding mode control method cannot be applied. Therefore, we employ the active disturbance rejection control (ADRC) approach to investigate this problem. At first, by the ADRC method, we design a disturbance observer that has time-varying gain so that the disturbance can be estimated exponentially. We show the disturbance observer is an exponential-type observer. Then, we use the estimate term as negative feedback so as to cancel disturbance. Finally, we prove that the resulted closed-loop system is well-posedness and exponentially stable.     

直驱式波浪发电系统无源-滑模控制策略

针对不规则波输入激励工况下的直驱式波浪发电系统,提出一类无源-滑模控制策略。利用双线性幅度法计算不规则波浪主频,结合波能捕获策略得到期望跟踪曲线,设计无源控制器实时跟踪期望曲线;为削减外部扰动影响并提高系统稳定性,在保证系统无源下引入滑模控制策略。采用扩张状态观测器代替速度传感器,辨识动子速度。仿真结果表明：双线性幅度法能预估不规则波浪主频,扩张状态观测器观测到的速度误差小,所提控制方案能快速响应期望电流变化,准确跟踪期望曲线,鲁棒性强。     

Oxygen excess ratio control of PEM fuel cells using observer-based nonlinear triple-step controller

This paper proposes a novel observer-based nonlinear triple-step controller for the air supply system of polymer electrolyte membrane (PEM) fuel cell. The control objective is adjusting the oxygen excess ratio to its reference value under fast current transitions, so as to avoid the oxygen starvation and obtain the maximum net power. Considering that the cathode pressure cannot be measured directly, we design a disturbance observer to estimate the cathode pressure based on the developed third-order nonlinear model of air supply system. Next, a triple-step nonlinear method is applied to derive an oxygen excess ratio tracking controller, wherein the stability of closed-loop system is guaranteed by Lyapunov-based technique. Subsequently, several key issues of controller in practical implementation are explained, and then the robustness analysis against the considered lumped disturbance is carried out. Finally, the performance of the proposed control scheme is validated through a series of comparative simulations, and the simulation results demonstrate the effectiveness and robustness of the proposed approach under different load variations and parameter uncertainties.     

On-line designed hybrid controller with adaptive observer for variable-speed wind generation system

This paper presents a wind-driven induction generator system with a hybrid controller, which combines the advantages of the integral–proportional and the sliding mode controllers. The proposed controller is designed to adjust the turbine speed to extract maximum power from the wind. The integral–proportional speed controller can be designed on-line according to the estimated rotor parameters, and the observed disturbance torque is feed-forward to increase the robustness of the system. The designed integral switching surface with integral–proportional due to on-line tuning produced a new sliding surface to implement the control, and can ensure the robustness under noisy environment. The rotor inertia constant, friction constant, and the disturbed mechanical torque of the induction generator are estimated by a proposed adaptive observer, which is composed of the recursive least square algorithm and a torque observer.