For the typical first-order systems with time-delay,this paper explors the control capability of linear active disturbance rejection control(LADRC).Firstly,the critical time-delay of LADRC is analyzed using the freque...For the typical first-order systems with time-delay,this paper explors the control capability of linear active disturbance rejection control(LADRC).Firstly,the critical time-delay of LADRC is analyzed using the frequency-sweeping method and the Routh criterion,and the stable time-delay interval starting from zero is accurately obtained,which reveals the limitations of general LADRC on large time-delay.Then in view of the large time-delay,an LADRC controller is developed and verified to be effective,along with the robustness analysis.Finally,numerical simulations show the accuracy of critical time-delay,and demonstrate the effectiveness and robustness of the proposed controller compared with other modified LADRCs.展开更多
Blade tip clearance(BTC) is one of the key factors affecting the efficiency and reliability of high performance turbomachinery such as heavy duty steam turbines, aircraft engines and other gas turbo machines. The self...Blade tip clearance(BTC) is one of the key factors affecting the efficiency and reliability of high performance turbomachinery such as heavy duty steam turbines, aircraft engines and other gas turbo machines. The self-adjusting ability of BTC according to the operation condition changing is important to meet the requirement of performance. In this paper, the principle and method of adjusting the BTC by controlling the axial displacement of the rotor were proposed and studied. The basic principle is that the BTC of the turbomachinery with a conical tail shroud will be affected by the axial displacement of rotor and thereby can be adjusted by controlling the axial position of rotor, which can be adjusted by the controllable oil pressure acting on the thrust bearing. To reach a higher control precision, lower noise and model perturbation, an adaptive quasi-sliding mode control(AQSMC) algorithm based on the disturbance observer(DOB) was designed, and numerical and experimental investigations were carried out. The numerical simulation results show that this algorithm can not only effectively suppress the disturbance, but also, compared with the general reaching law, effectively reduce the chattering and transient high gain switching effect of the closed-loop controller system and avoid the instability caused by the controller. Based on the DOB-AQSMC algorithm, the BTC was stabilized within 2 s with no overshoot and no misalignment in the test rig, and this algorithm achieves a better control performance than the proportion-integral-differential(PID) algorithm. These achievements can be used to push forward the intelligent turbomachinery development.展开更多
针对电压源型换流器VSC(voltage source converter)的超导磁储能SMES(superconducting magnetic energy storage)系统,提出了一种自抗扰控制ADRC(active disturbance rejection control)策略。首先,分别建立了SMES的交流侧VSC、直流侧...针对电压源型换流器VSC(voltage source converter)的超导磁储能SMES(superconducting magnetic energy storage)系统,提出了一种自抗扰控制ADRC(active disturbance rejection control)策略。首先,分别建立了SMES的交流侧VSC、直流侧斩波器数学模型;其次,基于非线性扩张状态观测器和线性误差反馈律设计了SMES的交、直流侧ADRC;然后,通过描述函数法分析了ADRC的稳定性;最后,在Matlab/Simulink平台中搭建了仿真模型。仿真结果表明,与传统PI控制相比,ADRC具有更好的动态响应性能和抗扰动特性,并针对不确定的系统参数具有更好的鲁棒性,有效地提高了SMES的运行可靠性。展开更多
当使用线性自抗扰控制器(linear active disturbance rejection controller,LADRC)控制时滞系统时,闭环系统的稳定性与控制器参数的选取有较大的关系.如何定量求取线性自抗扰针对时滞系统的参数稳定域还没有有效的方法.本文针对线性自...当使用线性自抗扰控制器(linear active disturbance rejection controller,LADRC)控制时滞系统时,闭环系统的稳定性与控制器参数的选取有较大的关系.如何定量求取线性自抗扰针对时滞系统的参数稳定域还没有有效的方法.本文针对线性自抗扰控制器控制一阶时滞系统,利用双轨迹法精确求解出了线性自抗扰控制器参数的稳定域.该方法利用双轨迹的图形性质,有效地将求解具有时滞的控制系统闭环特征方程根的分布问题转化为求解双轨迹交点频率的问题,从而得到能够保证闭环系统稳定性的控制器参数稳定域.求得的稳定域为时滞系统线性自抗扰控制器的整定提供了理论依据.仿真结果验证了所提出方法的有效性.展开更多
为了消除调速器死区非线性对系统的影响和保证系统稳定,针对存在调速器死区的负荷频率控制(load frequency control,LFC)系统,采用了自抗扰控制(active disturbance rejection control,ADRC)方法,并通过描述函数法验证控制方法的有效性...为了消除调速器死区非线性对系统的影响和保证系统稳定,针对存在调速器死区的负荷频率控制(load frequency control,LFC)系统,采用了自抗扰控制(active disturbance rejection control,ADRC)方法,并通过描述函数法验证控制方法的有效性。提出死区线性化方法,并采用了广义自抗扰控制(generalized active disturbance rejection control,GADRC)方法。为能有效地消除死区非线性,提出了一种误差补偿策略。仿真结果显示,提出的误差补偿策略能有效地消除死区非线性,保证了系统的控制性能。提出通过描述函数法获得补偿系数的取值范围也是可行。展开更多
基金supported by the National Natural Science Foundation of China(61973175,61973172,62073177)the Key Technologies R&D Program of Tianjin(19JCZDJC32800)Tianjin Research Innovation Project for Postgraduate Students(2020YJSZXB02).
文摘For the typical first-order systems with time-delay,this paper explors the control capability of linear active disturbance rejection control(LADRC).Firstly,the critical time-delay of LADRC is analyzed using the frequency-sweeping method and the Routh criterion,and the stable time-delay interval starting from zero is accurately obtained,which reveals the limitations of general LADRC on large time-delay.Then in view of the large time-delay,an LADRC controller is developed and verified to be effective,along with the robustness analysis.Finally,numerical simulations show the accuracy of critical time-delay,and demonstrate the effectiveness and robustness of the proposed controller compared with other modified LADRCs.
基金supported by the National Natural Science Foundation of China(Grant Nos.51775030&11802153)the Fundamental Research Funds for the Central Universities(Grant No.BHYC1703A)
文摘Blade tip clearance(BTC) is one of the key factors affecting the efficiency and reliability of high performance turbomachinery such as heavy duty steam turbines, aircraft engines and other gas turbo machines. The self-adjusting ability of BTC according to the operation condition changing is important to meet the requirement of performance. In this paper, the principle and method of adjusting the BTC by controlling the axial displacement of the rotor were proposed and studied. The basic principle is that the BTC of the turbomachinery with a conical tail shroud will be affected by the axial displacement of rotor and thereby can be adjusted by controlling the axial position of rotor, which can be adjusted by the controllable oil pressure acting on the thrust bearing. To reach a higher control precision, lower noise and model perturbation, an adaptive quasi-sliding mode control(AQSMC) algorithm based on the disturbance observer(DOB) was designed, and numerical and experimental investigations were carried out. The numerical simulation results show that this algorithm can not only effectively suppress the disturbance, but also, compared with the general reaching law, effectively reduce the chattering and transient high gain switching effect of the closed-loop controller system and avoid the instability caused by the controller. Based on the DOB-AQSMC algorithm, the BTC was stabilized within 2 s with no overshoot and no misalignment in the test rig, and this algorithm achieves a better control performance than the proportion-integral-differential(PID) algorithm. These achievements can be used to push forward the intelligent turbomachinery development.
文摘针对电压源型换流器VSC(voltage source converter)的超导磁储能SMES(superconducting magnetic energy storage)系统,提出了一种自抗扰控制ADRC(active disturbance rejection control)策略。首先,分别建立了SMES的交流侧VSC、直流侧斩波器数学模型;其次,基于非线性扩张状态观测器和线性误差反馈律设计了SMES的交、直流侧ADRC;然后,通过描述函数法分析了ADRC的稳定性;最后,在Matlab/Simulink平台中搭建了仿真模型。仿真结果表明,与传统PI控制相比,ADRC具有更好的动态响应性能和抗扰动特性,并针对不确定的系统参数具有更好的鲁棒性,有效地提高了SMES的运行可靠性。
文摘当使用线性自抗扰控制器(linear active disturbance rejection controller,LADRC)控制时滞系统时,闭环系统的稳定性与控制器参数的选取有较大的关系.如何定量求取线性自抗扰针对时滞系统的参数稳定域还没有有效的方法.本文针对线性自抗扰控制器控制一阶时滞系统,利用双轨迹法精确求解出了线性自抗扰控制器参数的稳定域.该方法利用双轨迹的图形性质,有效地将求解具有时滞的控制系统闭环特征方程根的分布问题转化为求解双轨迹交点频率的问题,从而得到能够保证闭环系统稳定性的控制器参数稳定域.求得的稳定域为时滞系统线性自抗扰控制器的整定提供了理论依据.仿真结果验证了所提出方法的有效性.
文摘为了消除调速器死区非线性对系统的影响和保证系统稳定,针对存在调速器死区的负荷频率控制(load frequency control,LFC)系统,采用了自抗扰控制(active disturbance rejection control,ADRC)方法,并通过描述函数法验证控制方法的有效性。提出死区线性化方法,并采用了广义自抗扰控制(generalized active disturbance rejection control,GADRC)方法。为能有效地消除死区非线性,提出了一种误差补偿策略。仿真结果显示,提出的误差补偿策略能有效地消除死区非线性,保证了系统的控制性能。提出通过描述函数法获得补偿系数的取值范围也是可行。
