Permanent magnet synchronous motors(PMSMs)have been widely employed in the industry. Finite-control-set model predictive control(FCS-MPC), as an advanced control scheme, has been developed and applied to improve the p...Permanent magnet synchronous motors(PMSMs)have been widely employed in the industry. Finite-control-set model predictive control(FCS-MPC), as an advanced control scheme, has been developed and applied to improve the performance and efficiency of the holistic PMSM drive systems. Based on the three elements of model predictive control, this paper provides an overview of the superiority of the FCS-MPC control scheme and its shortcomings in current applications. The problems of parameter mismatch, computational burden, and unfixed switching frequency are summarized. Moreover, other performance improvement schemes, such as the multi-vector application strategy, delay compensation scheme, and weight factor adjustment, are reviewed. Finally, future trends in this field is discussed, and several promising research topics are highlighted.展开更多
This paper presents a new four-dimensional(4 D) autonomous chaotic system which has first Lyapunov exponent of about 22 and is comparatively larger than many existing three-dimensional(3 D) and 4 D chaotic systems...This paper presents a new four-dimensional(4 D) autonomous chaotic system which has first Lyapunov exponent of about 22 and is comparatively larger than many existing three-dimensional(3 D) and 4 D chaotic systems.The proposed system exhibits hyperbolic curve and circular paraboloid types of equilibria.The system has all zero eigenvalues for a particular case of an equilibrium point.The system has various dynamical behaviors like hyperchaotic,chaotic,periodic,and quasi-periodic.The system also exhibits coexistence of attractors.Dynamical behavior of the new system is validated using circuit implementation.Further an interesting switching synchronization phenomenon is proposed for the new chaotic system.An adaptive global integral sliding mode control is designed for the switching synchronization of the proposed system.In the switching synchronization,the synchronization is shown for the switching chaotic,stable,periodic,and hybrid synchronization behaviors.Performance of the controller designed in the paper is compared with an existing controller.展开更多
In the conventional chaos synchronization methods, the time at which two chaotic systems are synchronized, is usually unknown and depends on initial conditions. In this work based on Lyapunov stability theory a slidin...In the conventional chaos synchronization methods, the time at which two chaotic systems are synchronized, is usually unknown and depends on initial conditions. In this work based on Lyapunov stability theory a sliding mode controller with time-varying switching surfaces is proposed to achieve chaos synchronization at a pre-specified time for the first time. The proposed controller is able to synchronize chaotic systems precisely at any time when we want. Moreover, by choosing the time-varying switching surfaces in a way that the reaching phase is eliminated, the synchronization becomes robust to uncertainties and exogenous disturbances. Simulation results are presented to show the effectiveness of the proposed method of stabilizing and synchronizing chaotic systems with complete robustness to uncertainty and disturbances exactly at a pre-specified time.展开更多
针对双三相永磁同步电机模型预测共模电压抑制方法存在寻优计算量大、开关频率较高、稳态性能不佳的问题,提出一种改进型模型预测电流控制.首先,改进六相两电平逆变器,降低零矢量共模电压幅值;其次,选择小共模电压矢量构造虚拟电压矢量...针对双三相永磁同步电机模型预测共模电压抑制方法存在寻优计算量大、开关频率较高、稳态性能不佳的问题,提出一种改进型模型预测电流控制.首先,改进六相两电平逆变器,降低零矢量共模电压幅值;其次,选择小共模电压矢量构造虚拟电压矢量,简化价值函数的同时减小共模电压和电流谐波含量;再次,通过计算参考电压矢量直接选择最优电压矢量以减少寻优次数,并引入占空比控制提升电机控制精度,改善电机稳态性能.最后,仿真对比传统模型预测电流控制、RCMV(Reduced Common Mode Voltage)-1、RCMV-2和所提控制方法.结果表明,所提控制方法在减小共模电压的同时,降低了转矩脉动和谐波电流,且较RCMV-2方法开关频率明显降低;此外,寻优代码执行时间相较于RCMV-1和RCMV-2分别降低了约91%和65%,减小了计算量.展开更多
针对传统永磁同步电机(permanent magnet synchronous motor,PMSM)三矢量模型预测电流控制(three-vector model predictive current control,TV-MPCC)存在开关频率不固定和计算复杂的问题,提出一种固定开关频率TV-MPCC策略。利用前一周...针对传统永磁同步电机(permanent magnet synchronous motor,PMSM)三矢量模型预测电流控制(three-vector model predictive current control,TV-MPCC)存在开关频率不固定和计算复杂的问题,提出一种固定开关频率TV-MPCC策略。利用前一周期的零电压矢量和参考电压矢量所在扇区来快速筛选所需最优电压矢量和次优电压矢量,避免了无效枚举计算,从而降低了开关频率和计算复杂度。引入系统d和q轴电流差参数,计算各电压矢量的作用时间,确保电压矢量作用时间恒大于零和开关频率固定。以三相两电平电压型逆变器驱动的表贴式PMSM为被控对象,通过仿真和实验对传统TV-MPCC策略和所提三矢量固定开关频率模型预测电流控制策略进行对比研究,仿真和实验结果表明,所提策略在保证系统稳态和动态性能的基础上,在固定和降低开关频率的同时,降低了计算复杂度。展开更多
Structural vibration control was an active research area for the past twenty years because of their potential applications in aerospace structures,civil structures,naval structures,etc.Semi-active vibration control me...Structural vibration control was an active research area for the past twenty years because of their potential applications in aerospace structures,civil structures,naval structures,etc.Semi-active vibration control methods based on piezoelectric actuators and synchronized switch damping on inductance(SSDI) techniques attract the attention of many researchers recently due to their advantages over passive and active methods.In the SSDI method,a switch shunt circuit is connected to the piezoelectric patch to shift the phase and amplify the magnitude of the voltage on the piezoelectric patch.The most important issue in SSDI method is to control the switching actions synchronously with the maximum vibration displacement or maximum strain.Hence,usually a displacement sensor is used to measure the vibration displacement or a collocated piezoelectric sensor is needed to measure the strain of the structure near the piezoelectric actuator.A self-sensing SSDI approach is proposed and applied to the vibration control of a composite beam,which avoids using a separate sensor.In the self-sensing technique,the same piezoelectric element functions as both a sensor and an actuator so that the total number of required piezoelectric elements can be reduced.One problem in the self-sensing actuator,which is the same as that in the traditional collocated piezoelectric sensors,is the noise generated in the sensor signal by the impact of voltage inversion,which may cause extra switching actions and deteriorate control performance.In order to prevent the shunt circuit from over-frequent on-and-off actions,a simple switch control algorithm is proposed.The results of control experiments show that the self-sensing SSDI approach combined with the improved switch control algorithm can effectively suppress over-frequent switching actions and gives good control performance by reducing the vibration amplitude by 45%,about 50% improvement from the traditional SSDI with a separate piezoelectric element and a classical switch.展开更多
This paper presents an improved virtual synchronous control(VSynC) for the grid-connected voltage source converter(VSC) so as to continuously operate under the grid voltage with steady unbalance.The improved VSynC int...This paper presents an improved virtual synchronous control(VSynC) for the grid-connected voltage source converter(VSC) so as to continuously operate under the grid voltage with steady unbalance.The improved VSynC introduces the negative sequence power controls on basis of conventional VSynC.The improved VSynC is capable of regulating the negative sequence internal voltage to reduce the negative-sequence injected currents and oscillated powers of the VSC aroused by the negative-sequence grid voltage.Three alternative local control objectives for the VSC itself under steady state unbalanced grid conditions and their corresponding power references are deduced and computed.Simulated and experimental results are presented to validate the correctness and effectiveness of the proposed improved VSynC to enhance the continuous operation performance of VSynC-based VSCs during grid voltage steady-state unbalance.展开更多
基金supported in part by the National Natural Science Foundation of China(51875261)the Postgraduate Research and Practice Innovation Program of Jiangsu Province(KYCX21_3331)+1 种基金the Faculty of Agricultural Equipment of Jiangsu University(NZXB20210103)。
文摘Permanent magnet synchronous motors(PMSMs)have been widely employed in the industry. Finite-control-set model predictive control(FCS-MPC), as an advanced control scheme, has been developed and applied to improve the performance and efficiency of the holistic PMSM drive systems. Based on the three elements of model predictive control, this paper provides an overview of the superiority of the FCS-MPC control scheme and its shortcomings in current applications. The problems of parameter mismatch, computational burden, and unfixed switching frequency are summarized. Moreover, other performance improvement schemes, such as the multi-vector application strategy, delay compensation scheme, and weight factor adjustment, are reviewed. Finally, future trends in this field is discussed, and several promising research topics are highlighted.
基金supported by the National Natural Science Foundation of China(Grant No.11772306)
文摘This paper presents a new four-dimensional(4 D) autonomous chaotic system which has first Lyapunov exponent of about 22 and is comparatively larger than many existing three-dimensional(3 D) and 4 D chaotic systems.The proposed system exhibits hyperbolic curve and circular paraboloid types of equilibria.The system has all zero eigenvalues for a particular case of an equilibrium point.The system has various dynamical behaviors like hyperchaotic,chaotic,periodic,and quasi-periodic.The system also exhibits coexistence of attractors.Dynamical behavior of the new system is validated using circuit implementation.Further an interesting switching synchronization phenomenon is proposed for the new chaotic system.An adaptive global integral sliding mode control is designed for the switching synchronization of the proposed system.In the switching synchronization,the synchronization is shown for the switching chaotic,stable,periodic,and hybrid synchronization behaviors.Performance of the controller designed in the paper is compared with an existing controller.
文摘In the conventional chaos synchronization methods, the time at which two chaotic systems are synchronized, is usually unknown and depends on initial conditions. In this work based on Lyapunov stability theory a sliding mode controller with time-varying switching surfaces is proposed to achieve chaos synchronization at a pre-specified time for the first time. The proposed controller is able to synchronize chaotic systems precisely at any time when we want. Moreover, by choosing the time-varying switching surfaces in a way that the reaching phase is eliminated, the synchronization becomes robust to uncertainties and exogenous disturbances. Simulation results are presented to show the effectiveness of the proposed method of stabilizing and synchronizing chaotic systems with complete robustness to uncertainty and disturbances exactly at a pre-specified time.
基金Supported by National Natural Science Foundation of China(60904051)the Innovative Team Program of the National Natural Science Foundation of China(61021002)the Royal Academy of Engineering-Research Exchanges with China and India Awards
文摘针对双三相永磁同步电机模型预测共模电压抑制方法存在寻优计算量大、开关频率较高、稳态性能不佳的问题,提出一种改进型模型预测电流控制.首先,改进六相两电平逆变器,降低零矢量共模电压幅值;其次,选择小共模电压矢量构造虚拟电压矢量,简化价值函数的同时减小共模电压和电流谐波含量;再次,通过计算参考电压矢量直接选择最优电压矢量以减少寻优次数,并引入占空比控制提升电机控制精度,改善电机稳态性能.最后,仿真对比传统模型预测电流控制、RCMV(Reduced Common Mode Voltage)-1、RCMV-2和所提控制方法.结果表明,所提控制方法在减小共模电压的同时,降低了转矩脉动和谐波电流,且较RCMV-2方法开关频率明显降低;此外,寻优代码执行时间相较于RCMV-1和RCMV-2分别降低了约91%和65%,减小了计算量.
文摘针对传统永磁同步电机(permanent magnet synchronous motor,PMSM)三矢量模型预测电流控制(three-vector model predictive current control,TV-MPCC)存在开关频率不固定和计算复杂的问题,提出一种固定开关频率TV-MPCC策略。利用前一周期的零电压矢量和参考电压矢量所在扇区来快速筛选所需最优电压矢量和次优电压矢量,避免了无效枚举计算,从而降低了开关频率和计算复杂度。引入系统d和q轴电流差参数,计算各电压矢量的作用时间,确保电压矢量作用时间恒大于零和开关频率固定。以三相两电平电压型逆变器驱动的表贴式PMSM为被控对象,通过仿真和实验对传统TV-MPCC策略和所提三矢量固定开关频率模型预测电流控制策略进行对比研究,仿真和实验结果表明,所提策略在保证系统稳态和动态性能的基础上,在固定和降低开关频率的同时,降低了计算复杂度。
基金supported by National Natural Science Foundation of China (Grant No. 50775110, Grant No. 50830201)Program for Changjiang Scholars and Innovative Research Team of China (Grant No. Irt0906)+1 种基金Aeronautical Science Fund of China (Grant No. 20091552017)Jiangsu Provincal Graduate Innovation Program of China (Grant No. CX08B_048Z)
文摘Structural vibration control was an active research area for the past twenty years because of their potential applications in aerospace structures,civil structures,naval structures,etc.Semi-active vibration control methods based on piezoelectric actuators and synchronized switch damping on inductance(SSDI) techniques attract the attention of many researchers recently due to their advantages over passive and active methods.In the SSDI method,a switch shunt circuit is connected to the piezoelectric patch to shift the phase and amplify the magnitude of the voltage on the piezoelectric patch.The most important issue in SSDI method is to control the switching actions synchronously with the maximum vibration displacement or maximum strain.Hence,usually a displacement sensor is used to measure the vibration displacement or a collocated piezoelectric sensor is needed to measure the strain of the structure near the piezoelectric actuator.A self-sensing SSDI approach is proposed and applied to the vibration control of a composite beam,which avoids using a separate sensor.In the self-sensing technique,the same piezoelectric element functions as both a sensor and an actuator so that the total number of required piezoelectric elements can be reduced.One problem in the self-sensing actuator,which is the same as that in the traditional collocated piezoelectric sensors,is the noise generated in the sensor signal by the impact of voltage inversion,which may cause extra switching actions and deteriorate control performance.In order to prevent the shunt circuit from over-frequent on-and-off actions,a simple switch control algorithm is proposed.The results of control experiments show that the self-sensing SSDI approach combined with the improved switch control algorithm can effectively suppress over-frequent switching actions and gives good control performance by reducing the vibration amplitude by 45%,about 50% improvement from the traditional SSDI with a separate piezoelectric element and a classical switch.
基金supported by National Natural Science Foundation of China (No.51607130)National Key Research and Development Program (No.2016YFB0900104)National Natural Science Fund for Excellent Young Scholars (No.51322704)
文摘This paper presents an improved virtual synchronous control(VSynC) for the grid-connected voltage source converter(VSC) so as to continuously operate under the grid voltage with steady unbalance.The improved VSynC introduces the negative sequence power controls on basis of conventional VSynC.The improved VSynC is capable of regulating the negative sequence internal voltage to reduce the negative-sequence injected currents and oscillated powers of the VSC aroused by the negative-sequence grid voltage.Three alternative local control objectives for the VSC itself under steady state unbalanced grid conditions and their corresponding power references are deduced and computed.Simulated and experimental results are presented to validate the correctness and effectiveness of the proposed improved VSynC to enhance the continuous operation performance of VSynC-based VSCs during grid voltage steady-state unbalance.