An analysis technique of steady state and stability for closed-loop PWM DC/DC switching converters is presented. Using this method, the closed-loop switching converter is transformed into an open-loop system. By means...An analysis technique of steady state and stability for closed-loop PWM DC/DC switching converters is presented. Using this method, the closed-loop switching converter is transformed into an open-loop system. By means of the fact that in steady state, the two boundary values are equal in one switching period. The exponential matrix is evaluated by precise time-domain-integration method, and then the related curve between feedback duty cycle and the input one is obtained. Not only can the steady-state duty cycle be found from the curve, but also the stability and stable domain of the system. Compared with other methods, it features with simplicity and less calculation, and fit for numerical simulation and analysis for closed-loop switching converters. The simulation results of examples indicate the correctness of the presented method.展开更多
This paper explores the model reference adaptive control problem for a class of switched linear systems under arbitrary switching with no need for the measurability of the system state.Based on the state of reference ...This paper explores the model reference adaptive control problem for a class of switched linear systems under arbitrary switching with no need for the measurability of the system state.Based on the state of reference model and the measurable output error, adaptive laws and controllers are designed for switched systems.Each subsystem may have its individual reference model and controller, which increases the design flexibility.The introduction of the closed-loop reference model is to get a better transient performance of the whole switched systems.A numerical example is provided to verify the effectiveness of the main results.展开更多
软件定义网络(Software Defined Network,SDN)架构是使用软件编写代码的方式构建网络,实现控制转发平面分离,并对控制平面实现集中管理.生成树协议(Spanning Tree Protocol,STP)是交换式网络的环路避免协议,通过生成树算法(Spanning Tre...软件定义网络(Software Defined Network,SDN)架构是使用软件编写代码的方式构建网络,实现控制转发平面分离,并对控制平面实现集中管理.生成树协议(Spanning Tree Protocol,STP)是交换式网络的环路避免协议,通过生成树算法(Spanning Tree Algorithm,STA),将带有环路的物理拓扑中某台设备的接口设置为阻塞状态,构建逻辑无环拓扑.该文通过Python代码编制网络拓扑文件和RYU控制器文件的方式,实施SDN中的网络环路设计,按照STA算法设计和实现STP环路避免,并在仿真实验平台运行,测试结果表明,实现了SDN网络中环路避免.展开更多
随着光伏和风能等可再生能源在柔性配电网中的比例不断提高,可再生能源发电的间歇性输出给电力系统带来了不稳定性与波动性。现有的柔性合环开关因为硬件参数和容量限制,无法应对负荷超容量波动带来的频率超限及潮流转移造成的电网开路...随着光伏和风能等可再生能源在柔性配电网中的比例不断提高,可再生能源发电的间歇性输出给电力系统带来了不稳定性与波动性。现有的柔性合环开关因为硬件参数和容量限制,无法应对负荷超容量波动带来的频率超限及潮流转移造成的电网开路问题。因此,有必要将柔性合环开关与储能技术相结合,构建新型柔性互联配电网,对带电池储能系统的多端口柔性合环开关设计相应的控制策略。首先,对于硬件参数不同和工作状态差异造成的储能单元荷电状态(state of charge,SOC)不均衡,设计自适应的SOC均衡控制策略。其次,对负荷大波动和稳压侧开路故障,设计切换策略以调节电网频率并进行短时直流电压支撑,确保下级负荷的稳定运行。最后,利用基于MATLAB/Simulink平台的仿真模型和RTLAB硬件在环平台验证了所提协调控制策略的有效性和实用性。展开更多
The meminductive system can be regarded as the generalization of the meminductor. This paper focuses on exploring the generic meminductive characteristics of the switched reluctance machine (SRM). The dynamical equa...The meminductive system can be regarded as the generalization of the meminductor. This paper focuses on exploring the generic meminductive characteristics of the switched reluctance machine (SRM). The dynamical equations of SRM sys- tems are derived and discussed in comparison with the typical constitutive relation equations of the meminductive system. Memory ability and pinched hysteresis loop (PHL) are taken as the indicative fingerprints to draw forth the theoretically comparative analysis. Based on the theoretical analysis, in addition to simulation and experimental confirmation, it can be concluded that from the viewpoint of circuit, SRM can be considered as a generic meminductive system.展开更多
According to the soft-switching pulsed SAW (Submerged arc weld) weld power supply based on the double closed-loop constant current control mode, a small signal mathematic model of main circuit of soft-switching SAW in...According to the soft-switching pulsed SAW (Submerged arc weld) weld power supply based on the double closed-loop constant current control mode, a small signal mathematic model of main circuit of soft-switching SAW inverter was established by applying the method of three-terminal switching device modeling method, and the math-ematic model of double closed-loop phase-shift control system circuit was established by applying the method of state-space averaging method. Dynamic performance of the inverter was analyzed on base of the established math-ematic model, and the tested wave of dynamic performance was shown by experimentation. Research and experimentation show that relation between structure of the power source circuit and dynamic performance of the controlling system can be announced by the established mathematic model, which provides development of power supply and optimized design of controlling parameter with theoretical guidance.展开更多
To achieve a high precision capacitive closed-loop micro-accelerometer,a full differential CMOS based on switched-capacitor circuit was presented in this paper as the sensor interface circuit.This circuit consists of ...To achieve a high precision capacitive closed-loop micro-accelerometer,a full differential CMOS based on switched-capacitor circuit was presented in this paper as the sensor interface circuit.This circuit consists of a balance-bridge module,a charge sensitive amplifier,a correlated-double-sampling module,and a logic timing control module.A special two-path feedback circuit configuration was given to improve the system linearity.The quantitative analysis of error voltage and noise shows that there is tradeoff around circuit's noise,speed and accuracy.A detailed design method was given for this tradeoff.The noise performance optimized circuit has a noise root spectral density of 1.0 μV/Hz,equivalent to rms noise root spectral density of 1.63 μg/Hz.Therefore,the sensor's Brown noise becomes the main noise source in this design.This circuit is designed with 0.5 μm n-well CMOS process.Under a ±5 V supply,the Hspice simulation shows that the system sensitivity achieves 0.616 V/g,the system offset is as low as 1.456 mV,the non-linearity is below 0.03%,and the system linear range achieves ±5 g.展开更多
文摘An analysis technique of steady state and stability for closed-loop PWM DC/DC switching converters is presented. Using this method, the closed-loop switching converter is transformed into an open-loop system. By means of the fact that in steady state, the two boundary values are equal in one switching period. The exponential matrix is evaluated by precise time-domain-integration method, and then the related curve between feedback duty cycle and the input one is obtained. Not only can the steady-state duty cycle be found from the curve, but also the stability and stable domain of the system. Compared with other methods, it features with simplicity and less calculation, and fit for numerical simulation and analysis for closed-loop switching converters. The simulation results of examples indicate the correctness of the presented method.
基金Sponsored by the National Natural Science Foundation of China(Grant No.61233002)the 111 Project(Grant No.B16009)the IAPI Fundamental Research Funds(Grant No.2013ZCX03-01)
文摘This paper explores the model reference adaptive control problem for a class of switched linear systems under arbitrary switching with no need for the measurability of the system state.Based on the state of reference model and the measurable output error, adaptive laws and controllers are designed for switched systems.Each subsystem may have its individual reference model and controller, which increases the design flexibility.The introduction of the closed-loop reference model is to get a better transient performance of the whole switched systems.A numerical example is provided to verify the effectiveness of the main results.
文摘软件定义网络(Software Defined Network,SDN)架构是使用软件编写代码的方式构建网络,实现控制转发平面分离,并对控制平面实现集中管理.生成树协议(Spanning Tree Protocol,STP)是交换式网络的环路避免协议,通过生成树算法(Spanning Tree Algorithm,STA),将带有环路的物理拓扑中某台设备的接口设置为阻塞状态,构建逻辑无环拓扑.该文通过Python代码编制网络拓扑文件和RYU控制器文件的方式,实施SDN中的网络环路设计,按照STA算法设计和实现STP环路避免,并在仿真实验平台运行,测试结果表明,实现了SDN网络中环路避免.
文摘随着光伏和风能等可再生能源在柔性配电网中的比例不断提高,可再生能源发电的间歇性输出给电力系统带来了不稳定性与波动性。现有的柔性合环开关因为硬件参数和容量限制,无法应对负荷超容量波动带来的频率超限及潮流转移造成的电网开路问题。因此,有必要将柔性合环开关与储能技术相结合,构建新型柔性互联配电网,对带电池储能系统的多端口柔性合环开关设计相应的控制策略。首先,对于硬件参数不同和工作状态差异造成的储能单元荷电状态(state of charge,SOC)不均衡,设计自适应的SOC均衡控制策略。其次,对负荷大波动和稳压侧开路故障,设计切换策略以调节电网频率并进行短时直流电压支撑,确保下级负荷的稳定运行。最后,利用基于MATLAB/Simulink平台的仿真模型和RTLAB硬件在环平台验证了所提协调控制策略的有效性和实用性。
基金Project supported by the National Natural Science Foundation of China(Grant No.51277174)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20120095110019)+1 种基金a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Research and Innovation Program of Postgraduates of Jiangsu Province,China(Grant No.KYLX 1382)
文摘The meminductive system can be regarded as the generalization of the meminductor. This paper focuses on exploring the generic meminductive characteristics of the switched reluctance machine (SRM). The dynamical equations of SRM sys- tems are derived and discussed in comparison with the typical constitutive relation equations of the meminductive system. Memory ability and pinched hysteresis loop (PHL) are taken as the indicative fingerprints to draw forth the theoretically comparative analysis. Based on the theoretical analysis, in addition to simulation and experimental confirmation, it can be concluded that from the viewpoint of circuit, SRM can be considered as a generic meminductive system.
文摘According to the soft-switching pulsed SAW (Submerged arc weld) weld power supply based on the double closed-loop constant current control mode, a small signal mathematic model of main circuit of soft-switching SAW inverter was established by applying the method of three-terminal switching device modeling method, and the math-ematic model of double closed-loop phase-shift control system circuit was established by applying the method of state-space averaging method. Dynamic performance of the inverter was analyzed on base of the established math-ematic model, and the tested wave of dynamic performance was shown by experimentation. Research and experimentation show that relation between structure of the power source circuit and dynamic performance of the controlling system can be announced by the established mathematic model, which provides development of power supply and optimized design of controlling parameter with theoretical guidance.
基金Sponsored by the National High Technology Research and Development Program of China(863Program)(Grant No.2008AA042201)
文摘To achieve a high precision capacitive closed-loop micro-accelerometer,a full differential CMOS based on switched-capacitor circuit was presented in this paper as the sensor interface circuit.This circuit consists of a balance-bridge module,a charge sensitive amplifier,a correlated-double-sampling module,and a logic timing control module.A special two-path feedback circuit configuration was given to improve the system linearity.The quantitative analysis of error voltage and noise shows that there is tradeoff around circuit's noise,speed and accuracy.A detailed design method was given for this tradeoff.The noise performance optimized circuit has a noise root spectral density of 1.0 μV/Hz,equivalent to rms noise root spectral density of 1.63 μg/Hz.Therefore,the sensor's Brown noise becomes the main noise source in this design.This circuit is designed with 0.5 μm n-well CMOS process.Under a ±5 V supply,the Hspice simulation shows that the system sensitivity achieves 0.616 V/g,the system offset is as low as 1.456 mV,the non-linearity is below 0.03%,and the system linear range achieves ±5 g.