This paper presents a nonlinear control approach to variable speed wind turbine(VSWT)with a wind speed estimator.The dynamics of the wind turbine(WT)is derived from single mass model.In this work,a modified Newton Rap...This paper presents a nonlinear control approach to variable speed wind turbine(VSWT)with a wind speed estimator.The dynamics of the wind turbine(WT)is derived from single mass model.In this work,a modified Newton Raphson estimator has been considered for exact estimation of effective wind speed.The main objective of this work is to extract maximum energy from the wind at below rated wind speed while reducing drive train oscillation.In order to achieve the above objectives,VSWT should operate close to the optimal power coefficient.The generator torque is considered as the control input to achieve maximum energy capture.From the literature,it is clear that existing linear and nonlinear control techniques suffer from poor tracking of WT dynamics,increased power loss and complex control law.In addition,they are not robust with respect to input disturbances.In order to overcome the above drawbacks,adaptive fuzzy integral sliding mode control(AFISMC)is proposed for VSWT control.The proposed controller is tested with different types of disturbances and compared with other nonlinear controllers such as sliding mode control and integral sliding mode control.The result shows the better performance of AFISMC and its robustness to input disturbances.In this paper,the discontinuity in integral sliding mode controller is smoothed by using hyperbolic tangent function,and the sliding gain is adapted using a fuzzy technique which makes the controller more robust.展开更多
Heating, ventilation, and air conditioning (HVAC) system is significant to the energy efficiency in buildings. In this paper, temperature control of HVAC system is studied in winter operation season. The physical mode...Heating, ventilation, and air conditioning (HVAC) system is significant to the energy efficiency in buildings. In this paper, temperature control of HVAC system is studied in winter operation season. The physical model of the zone, the fan, the heating coil and sensor are built. HVAC is a non-linear, strong disturbance and coupling system. Linear active-rejection-disturbance-control is an appreciate control algorithm which can adapt to less information, strong-disturbance influence, and has relative-fixed structure and simple tuning process of the controller parameters. Active-rejection-disturbance-control of the HVAC system is proposed. Simulation in Matlab/Simulink was done. Simulation results show that linear active-rejection-disturbance-control was prior to PID and integral-fuzzy controllers in rising time, overshoot and response time of step disturbance. The study can provide fundamental basis for the control of the air-condition system with strong-disturbance and high-precision needed.展开更多
该文首先分析注入式混合型有源滤波器(injection hybrid active power filter,IHAPF)的结构特点,进而建立起对其进行电网侧谐波电流零逼近控制的模型。文章把比例积分(proportional integral,PI)控制算法运用于这一控制当中,以使系统稳...该文首先分析注入式混合型有源滤波器(injection hybrid active power filter,IHAPF)的结构特点,进而建立起对其进行电网侧谐波电流零逼近控制的模型。文章把比例积分(proportional integral,PI)控制算法运用于这一控制当中,以使系统稳态无静差;为改善系统的动态性能,用模糊算法对PI控制的系数进行在线调整;为提高系统的控制精度和稳定性,用选择谐波分次预补偿相位的方法来进行谐波检测,实现对系统延时的分频率补偿,提高系统的控制精度和稳定性。仿真结果和工程实际应用均表明,文章提出的控制方法能满足IHAPF系统控制的要求。展开更多
负载和参数变化带来有源电力滤波器(Active Power Filter,APF)精确数学模型难以获得和系统稳定性问题。针对该问题,分别在APF的直流电压控制中引入模糊比例积分(Proportional-Integral,PI)控制器,在电流控制中引入基于李亚普诺夫稳定性...负载和参数变化带来有源电力滤波器(Active Power Filter,APF)精确数学模型难以获得和系统稳定性问题。针对该问题,分别在APF的直流电压控制中引入模糊比例积分(Proportional-Integral,PI)控制器,在电流控制中引入基于李亚普诺夫稳定性理论的控制方法,保证了APF的控制精度和稳定性。首先通过对直流侧电压误差和误差变化率进行模糊PI控制得到源电流参考值的幅值,再结合源电压的角频率计算参考电流,最后采取李亚普诺夫方法设计APF的开关函数,通过确保能量函数的导数始终为负来保证系统的全局稳定。通过Matlab/Simulink分别对四种控制方法进行对比实验,在负载和系统参数变化的情况下,应用该方法的控制效果最好。展开更多
文摘This paper presents a nonlinear control approach to variable speed wind turbine(VSWT)with a wind speed estimator.The dynamics of the wind turbine(WT)is derived from single mass model.In this work,a modified Newton Raphson estimator has been considered for exact estimation of effective wind speed.The main objective of this work is to extract maximum energy from the wind at below rated wind speed while reducing drive train oscillation.In order to achieve the above objectives,VSWT should operate close to the optimal power coefficient.The generator torque is considered as the control input to achieve maximum energy capture.From the literature,it is clear that existing linear and nonlinear control techniques suffer from poor tracking of WT dynamics,increased power loss and complex control law.In addition,they are not robust with respect to input disturbances.In order to overcome the above drawbacks,adaptive fuzzy integral sliding mode control(AFISMC)is proposed for VSWT control.The proposed controller is tested with different types of disturbances and compared with other nonlinear controllers such as sliding mode control and integral sliding mode control.The result shows the better performance of AFISMC and its robustness to input disturbances.In this paper,the discontinuity in integral sliding mode controller is smoothed by using hyperbolic tangent function,and the sliding gain is adapted using a fuzzy technique which makes the controller more robust.
文摘Heating, ventilation, and air conditioning (HVAC) system is significant to the energy efficiency in buildings. In this paper, temperature control of HVAC system is studied in winter operation season. The physical model of the zone, the fan, the heating coil and sensor are built. HVAC is a non-linear, strong disturbance and coupling system. Linear active-rejection-disturbance-control is an appreciate control algorithm which can adapt to less information, strong-disturbance influence, and has relative-fixed structure and simple tuning process of the controller parameters. Active-rejection-disturbance-control of the HVAC system is proposed. Simulation in Matlab/Simulink was done. Simulation results show that linear active-rejection-disturbance-control was prior to PID and integral-fuzzy controllers in rising time, overshoot and response time of step disturbance. The study can provide fundamental basis for the control of the air-condition system with strong-disturbance and high-precision needed.
文摘该文首先分析注入式混合型有源滤波器(injection hybrid active power filter,IHAPF)的结构特点,进而建立起对其进行电网侧谐波电流零逼近控制的模型。文章把比例积分(proportional integral,PI)控制算法运用于这一控制当中,以使系统稳态无静差;为改善系统的动态性能,用模糊算法对PI控制的系数进行在线调整;为提高系统的控制精度和稳定性,用选择谐波分次预补偿相位的方法来进行谐波检测,实现对系统延时的分频率补偿,提高系统的控制精度和稳定性。仿真结果和工程实际应用均表明,文章提出的控制方法能满足IHAPF系统控制的要求。
文摘负载和参数变化带来有源电力滤波器(Active Power Filter,APF)精确数学模型难以获得和系统稳定性问题。针对该问题,分别在APF的直流电压控制中引入模糊比例积分(Proportional-Integral,PI)控制器,在电流控制中引入基于李亚普诺夫稳定性理论的控制方法,保证了APF的控制精度和稳定性。首先通过对直流侧电压误差和误差变化率进行模糊PI控制得到源电流参考值的幅值,再结合源电压的角频率计算参考电流,最后采取李亚普诺夫方法设计APF的开关函数,通过确保能量函数的导数始终为负来保证系统的全局稳定。通过Matlab/Simulink分别对四种控制方法进行对比实验,在负载和系统参数变化的情况下,应用该方法的控制效果最好。
