Due to high power density,high efficiency,and accurate control performance,permanent magnet synchronous motors(PMSMs)have been widely adopted in equipment manufacturing and energy transformation fields.To expand the s...Due to high power density,high efficiency,and accurate control performance,permanent magnet synchronous motors(PMSMs)have been widely adopted in equipment manufacturing and energy transformation fields.To expand the speed range under finite DC-bus voltage,extensive research on field weakening(FW)control strategies has been conducted.This paper summarizes the major FW control strategies of PMSMs,which are categorized into calculation-based methods,voltage closed-loop control methods,and model predictive control related methods.The existing strategies are analyzed and compared according to performance,robustness,and execution difficulty,which can facilitate the implementation of FW control.展开更多
This paper presents a novel non-singular fast terminal sliding mode control(NFTSMC)based on the deep flux weakening switching point tracking method in order to improve the control performance of permanent interior mag...This paper presents a novel non-singular fast terminal sliding mode control(NFTSMC)based on the deep flux weakening switching point tracking method in order to improve the control performance of permanent interior magnet synchronous motor(IPMSM)drive systems.The mathematical model of flux weakening(FW)control is established,and the deep flux weakening switching point is calculated accurately by analyzing the relationship between the torque curve and voltage decline curve.Next,a second-order NFTSMC is designed for the speed loop controller to ensure that the system converges to the equilibrium state in finite time.Then,an extended sliding mode disturbance observer(ESMDO)is designed to estimate the uncertainty of the system.Finally,compared with both the PI control and sliding mode control(SMC)by simulations and experiments with different working conditions,the method proposed has the merits of accelerating convergence,improving steady-state accuracy,and minimizing the current and torque pulsation.展开更多
This paper presents an approach for the optimal design of a new retrofit technique called weakening and damping that is valid for civil engineering inelastic structures. An alternative design methodology is developed ...This paper presents an approach for the optimal design of a new retrofit technique called weakening and damping that is valid for civil engineering inelastic structures. An alternative design methodology is developed with respect to the existing ones that is able to determine the locations and the magnitude of weakening and/or softening of structural elements and adding damping while insuring structural stability. An optimal polynomial controller that is a summation of polynomials in nonlinear states is used in Phase I of the method to reduce the peak response quantities of seismically excited nonlinear or hysteretic systems. The main advantage of the optimal polynomial controller is that it is able to automatically stabilize the structural system. The optimal design of a shear-type structure is used as an example to illustrate the feasibility of the proposed approach, which leads to a reduction of both peak inter-story drifts and peak total accelerations.展开更多
基金supported by the Research Fund for the National Natural Science Foundation of China(52125701).
文摘Due to high power density,high efficiency,and accurate control performance,permanent magnet synchronous motors(PMSMs)have been widely adopted in equipment manufacturing and energy transformation fields.To expand the speed range under finite DC-bus voltage,extensive research on field weakening(FW)control strategies has been conducted.This paper summarizes the major FW control strategies of PMSMs,which are categorized into calculation-based methods,voltage closed-loop control methods,and model predictive control related methods.The existing strategies are analyzed and compared according to performance,robustness,and execution difficulty,which can facilitate the implementation of FW control.
基金supported by the Natural Science Foundation of China under Grant No.61733004the Scientific Research Fund of the Hunan Provincial Education Department under Grand No.18A267.
文摘This paper presents a novel non-singular fast terminal sliding mode control(NFTSMC)based on the deep flux weakening switching point tracking method in order to improve the control performance of permanent interior magnet synchronous motor(IPMSM)drive systems.The mathematical model of flux weakening(FW)control is established,and the deep flux weakening switching point is calculated accurately by analyzing the relationship between the torque curve and voltage decline curve.Next,a second-order NFTSMC is designed for the speed loop controller to ensure that the system converges to the equilibrium state in finite time.Then,an extended sliding mode disturbance observer(ESMDO)is designed to estimate the uncertainty of the system.Finally,compared with both the PI control and sliding mode control(SMC)by simulations and experiments with different working conditions,the method proposed has the merits of accelerating convergence,improving steady-state accuracy,and minimizing the current and torque pulsation.
文摘This paper presents an approach for the optimal design of a new retrofit technique called weakening and damping that is valid for civil engineering inelastic structures. An alternative design methodology is developed with respect to the existing ones that is able to determine the locations and the magnitude of weakening and/or softening of structural elements and adding damping while insuring structural stability. An optimal polynomial controller that is a summation of polynomials in nonlinear states is used in Phase I of the method to reduce the peak response quantities of seismically excited nonlinear or hysteretic systems. The main advantage of the optimal polynomial controller is that it is able to automatically stabilize the structural system. The optimal design of a shear-type structure is used as an example to illustrate the feasibility of the proposed approach, which leads to a reduction of both peak inter-story drifts and peak total accelerations.
文摘永磁同步电机(Permanent Magnet Synchronous Motor,PMSM)弱磁控制系统常用于电动汽车领域。电动汽车运行于低速时,PMSM需要输出大转矩,以响应快速起步、加速及爬坡需求;电动汽车运行于高速,且超过额定速度时,PMSM处于弱磁状态,需具备一定的带载能力,以满足高速行驶和超车工况。针对PMSM弱磁控制中的转速突变,文章设计了自抗扰控制器(Active Disturbances Rejection Controller,ADRC)替代速度外环PI控制器,对扰动项快速观测和补偿,减小速度突变对系统造成干扰,实现转速精准跟踪。针对转矩项干扰,结合转矩和磁链输出值设计有限集模型预测控制(Finite Control Set Model Predictive Control,FCS-MPC)以替代传统直接转矩控制(Direct Torque Control,DTC),构建令转矩和磁链脉动最小的价值函数,再通过价值函数的计算寻优,选取出最优空间矢量控制信号输送给逆变器。基于ADRC和FCS-MPC的优化作用,弱磁控制系统的抗扰能力、电流和转矩输出精度增强,试验验证了所设计系统的可行性和性能优势。
