The study of energy transfer between coupled subsystems in a hybrid system is very important for applications. This paper presents an analytical analysis of energy transfer between plates of a visco-elastically connec...The study of energy transfer between coupled subsystems in a hybrid system is very important for applications. This paper presents an analytical analysis of energy transfer between plates of a visco-elastically connected double-plate system in free transversal vibrations. The analytical analysis shows that the visco-elastic connection between plates is responsible for the appearance of two-frequency regime in the time function, which corresponds to one eigen amplitude function of one mode, and also that time functions of different vibration modes are uncoupled, but energy transfer between plates in one eigen mode appears. It was shown for each shape of vibrations. Series of the two Lyapunov exponents corresponding to the one eigen amplitude mode are expressed by using the energy of the corresponding eigen amplitude time component.展开更多
在中国“双碳”目标下,新能源风光发电飞速发展。然而,新能源风光发电具有较强的波动性、间歇性,给电网的安全稳定运行带来极大影响。抽水蓄能机组是当前技术最成熟、经济性最优、最具大规模开发条件的灵活调节电源,其中全功率变速抽水...在中国“双碳”目标下,新能源风光发电飞速发展。然而,新能源风光发电具有较强的波动性、间歇性,给电网的安全稳定运行带来极大影响。抽水蓄能机组是当前技术最成熟、经济性最优、最具大规模开发条件的灵活调节电源,其中全功率变速抽水蓄能机组(variable speed pumped storage unit with full-size converter,FSC-VSPSU)响应速度快,能平抑新能源出力的快速波动,应用前景广阔。FSC-VSPSU转速特性对整个机组的运行表现至关重要。为充分掌握FSC-VSPSU转速运行特性,建立了机组调速系统的开环传递函数,通过绘制机组调速系统伯德图,分析了水锤效应、比例-积分控制器对机组转速特性的影响规律。最后通过仿真验证了所建模型及所得转速运行特性的正确性,为FSC-VSPSU的安全稳定运行提供重要保障。展开更多
This paper proposes a new loop recovery method to solve the reduced order problem of H∞/ LTR method. The resulted lower order controller shares almost the same performance and robustness as the original H ∞/LTR cont...This paper proposes a new loop recovery method to solve the reduced order problem of H∞/ LTR method. The resulted lower order controller shares almost the same performance and robustness as the original H ∞/LTR controller. Further more, this paper develops a new order reduction method: slow-fast mode order reduction (SFMOR) method. This order reduction method is particularly effective for those controllers whose modes can be divided into a slow part and a fast part according to their velocities. Application of these methods to a benchmark example and a certain turbofan engine is described.展开更多
The drive control system of the permanent magnetic direct current motor with the enhanced magnetism windings used in the electric transit bus is developed. The mathematics model of the drive control system for this mo...The drive control system of the permanent magnetic direct current motor with the enhanced magnetism windings used in the electric transit bus is developed. The mathematics model of the drive control system for this motor is established. The new mode that the added exiting magnetism field could be weakened and the speed of the motor could be controlled automatically is proposed and realized. The method of root locus design is applied to analyze the acceleration control characteristic. The results of simulation show that the new drive motor control system has extraordinary response characteristic and adjustable performance. Experiments of vehicle running show that the drive control system's antijamming ability is strong and the adjustable performance is fast and smooth, it can meet the demand of power characteristic very well.展开更多
In an active control system, time delay will occur due to processes such as signal acquisition and transmission, calculation,and actuation. Time delay systems are usually described by delay differential equations(DDE...In an active control system, time delay will occur due to processes such as signal acquisition and transmission, calculation,and actuation. Time delay systems are usually described by delay differential equations(DDEs). Since it is hard to obtain an analytical solution to a DDE, numerical solution is of necessity. This paper presents a frequency-domain method that uses a truncated transfer function to solve a class of DDEs. The theoretical transfer function is the sum of infinite items expressed in terms of poles and residues. The basic idea is to select the dominant poles and residues to truncate the transfer function,thus ensuring the validity of the solution while improving the efficiency of calculation. Meanwhile, the guideline of selecting these poles and residues is provided. Numerical simulations of both stable and unstable delayed systems are given to verify the proposed method, and the results are presented and analysed in detail.展开更多
This paper addresses a digital controller for a real time magnetic levitation system using series expansion of pulse transfer function, which achieves desired closed loop response. The proposed digital controller desi...This paper addresses a digital controller for a real time magnetic levitation system using series expansion of pulse transfer function, which achieves desired closed loop response. The proposed digital controller designed, based on series expansion of pulse transfer function by solving a linear equation using the method of least squares, which improves the transient performance and step tracking capability of the compensated system. The designed algorithm used for the control input is not iterative, so the calculation is very fast. The proposed control scheme has successfully applied on maglev system and also validated through the simulation and hardware experimental results.展开更多
基金the Ministry of Sciences and Enviromental Protection of Republic Serbia through Mathematical Institute SANU Belgrade Grants No.ON144002
摘要The study of energy transfer between coupled subsystems in a hybrid system is very important for applications. This paper presents an analytical analysis of energy transfer between plates of a visco-elastically connected double-plate system in free transversal vibrations. The analytical analysis shows that the visco-elastic connection between plates is responsible for the appearance of two-frequency regime in the time function, which corresponds to one eigen amplitude function of one mode, and also that time functions of different vibration modes are uncoupled, but energy transfer between plates in one eigen mode appears. It was shown for each shape of vibrations. Series of the two Lyapunov exponents corresponding to the one eigen amplitude mode are expressed by using the energy of the corresponding eigen amplitude time component.
摘要在中国“双碳”目标下,新能源风光发电飞速发展。然而,新能源风光发电具有较强的波动性、间歇性,给电网的安全稳定运行带来极大影响。抽水蓄能机组是当前技术最成熟、经济性最优、最具大规模开发条件的灵活调节电源,其中全功率变速抽水蓄能机组(variable speed pumped storage unit with full-size converter,FSC-VSPSU)响应速度快,能平抑新能源出力的快速波动,应用前景广阔。FSC-VSPSU转速特性对整个机组的运行表现至关重要。为充分掌握FSC-VSPSU转速运行特性,建立了机组调速系统的开环传递函数,通过绘制机组调速系统伯德图,分析了水锤效应、比例-积分控制器对机组转速特性的影响规律。最后通过仿真验证了所建模型及所得转速运行特性的正确性,为FSC-VSPSU的安全稳定运行提供重要保障。
摘要This paper proposes a new loop recovery method to solve the reduced order problem of H∞/ LTR method. The resulted lower order controller shares almost the same performance and robustness as the original H ∞/LTR controller. Further more, this paper develops a new order reduction method: slow-fast mode order reduction (SFMOR) method. This order reduction method is particularly effective for those controllers whose modes can be divided into a slow part and a fast part according to their velocities. Application of these methods to a benchmark example and a certain turbofan engine is described.
摘要The drive control system of the permanent magnetic direct current motor with the enhanced magnetism windings used in the electric transit bus is developed. The mathematics model of the drive control system for this motor is established. The new mode that the added exiting magnetism field could be weakened and the speed of the motor could be controlled automatically is proposed and realized. The method of root locus design is applied to analyze the acceleration control characteristic. The results of simulation show that the new drive motor control system has extraordinary response characteristic and adjustable performance. Experiments of vehicle running show that the drive control system's antijamming ability is strong and the adjustable performance is fast and smooth, it can meet the demand of power characteristic very well.
基金supported by the National Natural Science Foundation of China (11272235)
摘要In an active control system, time delay will occur due to processes such as signal acquisition and transmission, calculation,and actuation. Time delay systems are usually described by delay differential equations(DDEs). Since it is hard to obtain an analytical solution to a DDE, numerical solution is of necessity. This paper presents a frequency-domain method that uses a truncated transfer function to solve a class of DDEs. The theoretical transfer function is the sum of infinite items expressed in terms of poles and residues. The basic idea is to select the dominant poles and residues to truncate the transfer function,thus ensuring the validity of the solution while improving the efficiency of calculation. Meanwhile, the guideline of selecting these poles and residues is provided. Numerical simulations of both stable and unstable delayed systems are given to verify the proposed method, and the results are presented and analysed in detail.
摘要This paper addresses a digital controller for a real time magnetic levitation system using series expansion of pulse transfer function, which achieves desired closed loop response. The proposed digital controller designed, based on series expansion of pulse transfer function by solving a linear equation using the method of least squares, which improves the transient performance and step tracking capability of the compensated system. The designed algorithm used for the control input is not iterative, so the calculation is very fast. The proposed control scheme has successfully applied on maglev system and also validated through the simulation and hardware experimental results.