Magnetically suspended rotor(MSR)systems have gained widespread industrial adoption owing to their frictionless operation and exceptional reliability.However,harmonic current generated by unbalanced mass and sensor ru...Magnetically suspended rotor(MSR)systems have gained widespread industrial adoption owing to their frictionless operation and exceptional reliability.However,harmonic current generated by unbalanced mass and sensor runout threatens the system stability.Repetitive control(RC)effectively suppresses harmonic current,but its parameter design relies on an accurate decoupling model of the system.The decoupling model for the MSR system is often simplified to a second-order linear system.Such a simplification,however,necessitates explicit consideration of system uncertainties caused by unmodeled nonlinearities during the RC design process.Especially under strong gyroscopic effects,the parameter uncertainty is further increased.In this article,an active disturbance rejection controller(ADRC)based on phase compensation(PC)is used to suppress coupling disturbances and improve the control performance of harmonic suppression.Firstly,the dynamic model of the MSR system is established,and both internal and external disturbances are thoroughly analyzed.Then,the RC-PCADRC scheme is designed,integrating the complementary strengths of RC and ADRC,with a particular emphasis on PC to improve stability margins.A comprehensive stability analysis is conducted,along with parameter optimization guidelines.Finally,the effectiveness and superiority of the proposed scheme are validated through both simulations and experiments.展开更多
Currently most of control methods are of one degree of freedom(1-DOF)control structure for the robot systems which are affected by unmeasurable harmonic disturbances,at the same time in order to obtain perfect disturb...Currently most of control methods are of one degree of freedom(1-DOF)control structure for the robot systems which are affected by unmeasurable harmonic disturbances,at the same time in order to obtain perfect disturbance attenuation level,the controller gain must be increased.In practice,however,for robotic actuators,there are physical constraints that limit the amplitude of the available torques.This paper considers the problem of tracking control under input constraints for robot manipulators which are affected by unmeasurable harmonic disturbances.A new control scheme is proposed for the problem,which is composed of a parameter-dependent nonlinear observer and a tracking controller.The parameter-dependent nonlinear observer,designed based on the internal model principle,can achieve an estimation and compensation of a class of harmonic disturbances with unknown frequencies.The tracking controller,designed via adaptive control techniques,can make the systems asymptotically track the desired trajectories.In the control design,the continuous piecewise differentiable increasing function is used to limit control input amplitude,such that the control input saturation is avoided.The Lyapunov stability of closed loop systems is analyzed.To validate proposed control scheme,simulation results are provided for a two link horizontal robot manipulator.The simulation results show that the proposed control scheme ensures asymptotic tracking in presence of an uncertain external disturbance acting on the system.An important feature of the methodology consists of the fact that the designed controller is of 2-DOF control structure,namely,it has the ability to overcome the conflict between controller gain and robustness against external disturbances in the traditional 1-DOF control structure framework.展开更多
This paper considers the boundary stabilization and parameter estimation of a one-dimensional wave equation in the case when one end is fixed and control and harmonic disturbance with uncertain amplitude are input at ...This paper considers the boundary stabilization and parameter estimation of a one-dimensional wave equation in the case when one end is fixed and control and harmonic disturbance with uncertain amplitude are input at another end. A high-gain adaptive regulator is designed in terms of measured collocated end velocity. The existence and uniqueness of the classical solution of the closed-loop system is proven. It is shown that the state of the system approaches the standstill as time goes to infinity and meanwhile , the estimated parameter converges to the unknown parameter.展开更多
多逆变器并联系统内各逆变器的电流和电压在公共连接点(Point of common coupling,PCC)存在耦合,谐波和扰动会通过电流采样信号对连接到PCC的逆变器的控制产生影响,引起逆变器输出电流波形畸变,进一步增加PCC点的谐波注入,给系统的稳定...多逆变器并联系统内各逆变器的电流和电压在公共连接点(Point of common coupling,PCC)存在耦合,谐波和扰动会通过电流采样信号对连接到PCC的逆变器的控制产生影响,引起逆变器输出电流波形畸变,进一步增加PCC点的谐波注入,给系统的稳定运行带来隐患。针对多逆变器并联系统在PCC存在谐波耦合的问题,提出一种降阶自抗扰控制器(Active disturbance rejection control,ADRC)解耦控制策略,通过等效变换降低观测器所需阶次,消除反馈环节中逆变器电流的耦合分量,实现各逆变器的独立控制,有效地减少逆变器对PCC的谐波电流注入,从而改善电流波形。从环路增益角度分析,所提方法能有效消除耦合电流在控制环路的影响,并通过硬件在环试验验证所提方法能显著减少逆变器输出的高次谐波。展开更多
【目的】在复杂电网环境下,LCL型并网逆变器系统的传统控制方法存在并网电流质量不佳、动态性能较差和固有谐振尖峰等缺陷,为了解决这些问题,提出了改进模糊线性自抗扰控制(Fuzzy linear active disturbance rejection control,Fuzzy-LA...【目的】在复杂电网环境下,LCL型并网逆变器系统的传统控制方法存在并网电流质量不佳、动态性能较差和固有谐振尖峰等缺陷,为了解决这些问题,提出了改进模糊线性自抗扰控制(Fuzzy linear active disturbance rejection control,Fuzzy-LADRC)策略。【方法】通过改写传统线性扩张状态观测器的误差方程,增强抗干扰性能,并将改写后的误差方程与模糊逻辑控制相结合,对控制器参数进行自适应控制。将改进Fuzzy-LADRC策略应用于LCL控制系统中的锁相环和电流环,并采用Lyapunov稳定性分析和频域分析对系统的稳定性和抗扰性进行验证。最后,通过MATLAB/Simulink仿真验证该控制策略的有效性。【结果】改进Fuzzy-LADRC策略在3种工况下的并网电流谐波畸变率、偏移量以及动态响应时间均优于其他控制方法,此外,该控制策略无需额外的阻尼环节,简化了控制结构。【结论】改进Fuzzy-LADRC策略能够有效提高系统的抗扰能力和并网电流质量,节约系统成本,具有良好的动态性能,为LCL并网逆变器的控制应用提供了新思路。展开更多
由于统一电能质量调节器(unified power quality conditioner,UPQC)系统结构复杂、控制难度大,单一的控制策略不足以使其应对电网系统中的各种故障情况。因此,文中采用一种线性自抗扰控制(linear active disturbance rejection control,...由于统一电能质量调节器(unified power quality conditioner,UPQC)系统结构复杂、控制难度大,单一的控制策略不足以使其应对电网系统中的各种故障情况。因此,文中采用一种线性自抗扰控制(linear active disturbance rejection control,LADRC)与模型预测控制(model predictive control,MPC)的复合控制策略。在电压外环控制中采用LADRC策略以提高系统快速性与抗扰性,并给电流内环提供更精确的参考电流信号;在电流内环控制中采用电流MPC策略以提高跟踪参考信号的能力与系统的鲁棒性,同时对模型预测的空间电压矢量的分区进行优化,减少控制器计算量,在保证输出电流质量的前提下提高运算速度。最后,基于MATLAB/Simulink仿真实验平台对系统进行建模仿真,结果验证了采用LADRC-MPC控制策略对电网电压暂升/暂降、负载不对称引起的电流畸变与谐波污染等综合电能质量问题,可以起到更好的补偿效果,对电网电压的支撑能力也更强。展开更多
针对传统谐振控制器与PI控制器并联(PIR)无法克服积分环节饱和等因素引起的系统动态过程中超调震荡问题,提出了一种改进双环自抗扰谐振控制器(dual-loop active disturbance rejection control,DLADRC)。DLADRC速度环与电流环均采用自...针对传统谐振控制器与PI控制器并联(PIR)无法克服积分环节饱和等因素引起的系统动态过程中超调震荡问题,提出了一种改进双环自抗扰谐振控制器(dual-loop active disturbance rejection control,DLADRC)。DLADRC速度环与电流环均采用自抗扰控制,速度环采用传统的自抗扰控制。电流环采用一种改进的谐振扩张状态观测器,将观测电流作为谐振控制器的输入,令谐振控制器的输出直接作用到电流环输出,从而降低了谐振电流环设计的复杂性。双环自抗扰谐振控制器保留了谐振控制器抑制特定频率谐波电流的特性,同时优化了系统的超调量与调节时间,有效提升了谐振控制系统的动态性能。仿真结果验证DLADRC系统的有效性。展开更多
基金supported by the Youth Innovation Promotion Association CAS under Grant 2023042the Major Science Facility Project of the Shandong Provincial Natural Science Foundation under Grant ZR2022DKX005。
文摘Magnetically suspended rotor(MSR)systems have gained widespread industrial adoption owing to their frictionless operation and exceptional reliability.However,harmonic current generated by unbalanced mass and sensor runout threatens the system stability.Repetitive control(RC)effectively suppresses harmonic current,but its parameter design relies on an accurate decoupling model of the system.The decoupling model for the MSR system is often simplified to a second-order linear system.Such a simplification,however,necessitates explicit consideration of system uncertainties caused by unmodeled nonlinearities during the RC design process.Especially under strong gyroscopic effects,the parameter uncertainty is further increased.In this article,an active disturbance rejection controller(ADRC)based on phase compensation(PC)is used to suppress coupling disturbances and improve the control performance of harmonic suppression.Firstly,the dynamic model of the MSR system is established,and both internal and external disturbances are thoroughly analyzed.Then,the RC-PCADRC scheme is designed,integrating the complementary strengths of RC and ADRC,with a particular emphasis on PC to improve stability margins.A comprehensive stability analysis is conducted,along with parameter optimization guidelines.Finally,the effectiveness and superiority of the proposed scheme are validated through both simulations and experiments.
基金supported by National Natural Science Foundation of China(Grant No.60736022)
文摘Currently most of control methods are of one degree of freedom(1-DOF)control structure for the robot systems which are affected by unmeasurable harmonic disturbances,at the same time in order to obtain perfect disturbance attenuation level,the controller gain must be increased.In practice,however,for robotic actuators,there are physical constraints that limit the amplitude of the available torques.This paper considers the problem of tracking control under input constraints for robot manipulators which are affected by unmeasurable harmonic disturbances.A new control scheme is proposed for the problem,which is composed of a parameter-dependent nonlinear observer and a tracking controller.The parameter-dependent nonlinear observer,designed based on the internal model principle,can achieve an estimation and compensation of a class of harmonic disturbances with unknown frequencies.The tracking controller,designed via adaptive control techniques,can make the systems asymptotically track the desired trajectories.In the control design,the continuous piecewise differentiable increasing function is used to limit control input amplitude,such that the control input saturation is avoided.The Lyapunov stability of closed loop systems is analyzed.To validate proposed control scheme,simulation results are provided for a two link horizontal robot manipulator.The simulation results show that the proposed control scheme ensures asymptotic tracking in presence of an uncertain external disturbance acting on the system.An important feature of the methodology consists of the fact that the designed controller is of 2-DOF control structure,namely,it has the ability to overcome the conflict between controller gain and robustness against external disturbances in the traditional 1-DOF control structure framework.
文摘This paper considers the boundary stabilization and parameter estimation of a one-dimensional wave equation in the case when one end is fixed and control and harmonic disturbance with uncertain amplitude are input at another end. A high-gain adaptive regulator is designed in terms of measured collocated end velocity. The existence and uniqueness of the classical solution of the closed-loop system is proven. It is shown that the state of the system approaches the standstill as time goes to infinity and meanwhile , the estimated parameter converges to the unknown parameter.
文摘多逆变器并联系统内各逆变器的电流和电压在公共连接点(Point of common coupling,PCC)存在耦合,谐波和扰动会通过电流采样信号对连接到PCC的逆变器的控制产生影响,引起逆变器输出电流波形畸变,进一步增加PCC点的谐波注入,给系统的稳定运行带来隐患。针对多逆变器并联系统在PCC存在谐波耦合的问题,提出一种降阶自抗扰控制器(Active disturbance rejection control,ADRC)解耦控制策略,通过等效变换降低观测器所需阶次,消除反馈环节中逆变器电流的耦合分量,实现各逆变器的独立控制,有效地减少逆变器对PCC的谐波电流注入,从而改善电流波形。从环路增益角度分析,所提方法能有效消除耦合电流在控制环路的影响,并通过硬件在环试验验证所提方法能显著减少逆变器输出的高次谐波。
文摘【目的】在复杂电网环境下,LCL型并网逆变器系统的传统控制方法存在并网电流质量不佳、动态性能较差和固有谐振尖峰等缺陷,为了解决这些问题,提出了改进模糊线性自抗扰控制(Fuzzy linear active disturbance rejection control,Fuzzy-LADRC)策略。【方法】通过改写传统线性扩张状态观测器的误差方程,增强抗干扰性能,并将改写后的误差方程与模糊逻辑控制相结合,对控制器参数进行自适应控制。将改进Fuzzy-LADRC策略应用于LCL控制系统中的锁相环和电流环,并采用Lyapunov稳定性分析和频域分析对系统的稳定性和抗扰性进行验证。最后,通过MATLAB/Simulink仿真验证该控制策略的有效性。【结果】改进Fuzzy-LADRC策略在3种工况下的并网电流谐波畸变率、偏移量以及动态响应时间均优于其他控制方法,此外,该控制策略无需额外的阻尼环节,简化了控制结构。【结论】改进Fuzzy-LADRC策略能够有效提高系统的抗扰能力和并网电流质量,节约系统成本,具有良好的动态性能,为LCL并网逆变器的控制应用提供了新思路。
文摘由于统一电能质量调节器(unified power quality conditioner,UPQC)系统结构复杂、控制难度大,单一的控制策略不足以使其应对电网系统中的各种故障情况。因此,文中采用一种线性自抗扰控制(linear active disturbance rejection control,LADRC)与模型预测控制(model predictive control,MPC)的复合控制策略。在电压外环控制中采用LADRC策略以提高系统快速性与抗扰性,并给电流内环提供更精确的参考电流信号;在电流内环控制中采用电流MPC策略以提高跟踪参考信号的能力与系统的鲁棒性,同时对模型预测的空间电压矢量的分区进行优化,减少控制器计算量,在保证输出电流质量的前提下提高运算速度。最后,基于MATLAB/Simulink仿真实验平台对系统进行建模仿真,结果验证了采用LADRC-MPC控制策略对电网电压暂升/暂降、负载不对称引起的电流畸变与谐波污染等综合电能质量问题,可以起到更好的补偿效果,对电网电压的支撑能力也更强。
文摘针对传统谐振控制器与PI控制器并联(PIR)无法克服积分环节饱和等因素引起的系统动态过程中超调震荡问题,提出了一种改进双环自抗扰谐振控制器(dual-loop active disturbance rejection control,DLADRC)。DLADRC速度环与电流环均采用自抗扰控制,速度环采用传统的自抗扰控制。电流环采用一种改进的谐振扩张状态观测器,将观测电流作为谐振控制器的输入,令谐振控制器的输出直接作用到电流环输出,从而降低了谐振电流环设计的复杂性。双环自抗扰谐振控制器保留了谐振控制器抑制特定频率谐波电流的特性,同时优化了系统的超调量与调节时间,有效提升了谐振控制系统的动态性能。仿真结果验证DLADRC系统的有效性。
基金Supported by the National Natural Science Foundation of China (62173150)the Science and Technology Innovation Project of Shunde,Foshan(2230218004224)the Guangdong Basic and Applied Basic Research Foundation-the Key Joint Research Project (2022B1515120003)。
