With the increasing integration of renewable energy,microgrids are increasingly facing stability challenges,primarily due to the lack of inherent inertia in inverter-dominated systems,which is traditionally provided b...With the increasing integration of renewable energy,microgrids are increasingly facing stability challenges,primarily due to the lack of inherent inertia in inverter-dominated systems,which is traditionally provided by synchronous generators.To address this critical issue,Virtual Synchronous Generator(VSG)technology has emerged as a highly promising solution by emulating the inertia and damping characteristics of conventional synchronous generators.To enhance the operational efficiency of virtual synchronous generators(VSGs),this study employs smallsignal modeling analysis,root locus methods,and synchronous generator power-angle characteristic analysis to comprehensively evaluate how virtual inertia and damping coefficients affect frequency stability and power output during transient processes.Based on these analyses,an adaptive control strategy is proposed:increasing the virtual inertia when the rotor angular velocity undergoes rapid changes,while strengthening the damping coefficient when the speed deviation exceeds a certain threshold to suppress angular velocity oscillations.To validate the effectiveness of the proposed method,a grid-connected VSG simulation platform was developed inMATLAB/Simulink.Comparative simulations demonstrate that the proposed adaptive control strategy outperforms conventional VSGmethods by significantly reducing grid frequency deviations and shortening active power response time during active power command changes and load disturbances.This approach enhances microgrid stability and dynamic performance,confirming its viability for renewable-dominant power systems.Future work should focus on experimental validation and real-world parameter optimization,while further exploring the strategy’s effectiveness in improvingVSG low-voltage ride-through(LVRT)capability and power-sharing applications in multi-parallel configurations.展开更多
异地站点之间需要在广域范围实现时间同步。除了采用卫星授时外,希望借助SDH(Synchronous Digital Hierarchy)网络进行时间同步性能的在线监测。但是广域范围内的SDH网络结构复杂、跳数较多,且大量存在上下行线路不对称的现象,对传统网...异地站点之间需要在广域范围实现时间同步。除了采用卫星授时外,希望借助SDH(Synchronous Digital Hierarchy)网络进行时间同步性能的在线监测。但是广域范围内的SDH网络结构复杂、跳数较多,且大量存在上下行线路不对称的现象,对传统网络时间同步技术提出了挑战。因此,针对广域SDH网络,提出了基于WR PTP(White Rabbit Precision Timing Protocol)技术的链路模型。该模型考虑了SDH网络中存在的各个延时环节及其计算方法,并针对实际网络中存在的不对称链路时延,给出了修正方法,推导了时钟偏差的修正计算公式。同时对于SDH环网中存在的链路倒换问题,给出了工程化解决方法。所提各方法在实际的SDH网络上进行了测试,结果表明,能达到的时间同步误差不超过1μs,可满足广域时间同步及时钟同步性能在线监测的需要。展开更多
Propelled by the rise of artificial intelligence,cloud services,and data center applications,next-generation,low-power,local-oscillator-less,digital signal processing(DSP)-free,and short-reach coherent optical communi...Propelled by the rise of artificial intelligence,cloud services,and data center applications,next-generation,low-power,local-oscillator-less,digital signal processing(DSP)-free,and short-reach coherent optical communication has evolved into an increasingly prominent area of research in recent years.Here,we demonstrate DSP-free coherent optical transmission by analog signal processing in frequency synchronous optical network(FSON)architecture,which supports polarization multiplexing and higher-order modulation formats.The FSON architecture that allows the numerous laser sources of optical transceivers within a data center can be quasi-synchronized by means of a tree-distributed homology architecture.In conjunction with our proposed pilot-tone assisted Costas loop for an analog coherent receiver,we achieve a record dual-polarization 224-Gb/s 16-QAM 5-km mismatch transmission with reset-free carrier phase recovery in the optical domain.Our proposed DSP-free analog coherent detection system based on the FSON makes it a promising solution for next-generation,low-power,and high-capacity coherent data center interconnects.展开更多
针对目前广播电视同步数字体系(Synchronous Digital Hierarchy,SDH)微波传输系统部分电路设备老化、故障率高等现实问题,对现有SDH数字微波传输系统进行网际互连协议(Internet Protocol,IP)化升级改造,提出一套切实可行的实施方案,阐...针对目前广播电视同步数字体系(Synchronous Digital Hierarchy,SDH)微波传输系统部分电路设备老化、故障率高等现实问题,对现有SDH数字微波传输系统进行网际互连协议(Internet Protocol,IP)化升级改造,提出一套切实可行的实施方案,阐述方案设计思路、实施方法和注意事项等内容。通过项目实践充分验证了所提方案能够大幅降低电路设备故障率,提升微波传输的效率,充分保障广播电视节目的安全传输。展开更多
针对同步数字体系(Synchronous Digital Hierarchy,SDH)光纤通信系统在长期运行中易发生链路衰耗、光器件性能退化及时钟同步异常的问题,从系统结构与功能单元入手,系统分析典型故障类型及其成因,提出相应维护策略。该策略在缩短链路定...针对同步数字体系(Synchronous Digital Hierarchy,SDH)光纤通信系统在长期运行中易发生链路衰耗、光器件性能退化及时钟同步异常的问题,从系统结构与功能单元入手,系统分析典型故障类型及其成因,提出相应维护策略。该策略在缩短链路定位时间、延长器件使用寿命、提高同步精度等方面取得了显著成效,有效提高了SDH光纤通信系统的运行可靠性与维护效率。展开更多
Permanent magnet synchronous motor(PMSM),known for their compact size and high-power density,is widely used in fields such as electric vehicles and servo drives.However,traditional PID control methods for PMSM cannot ...Permanent magnet synchronous motor(PMSM),known for their compact size and high-power density,is widely used in fields such as electric vehicles and servo drives.However,traditional PID control methods for PMSM cannot dynamically adjust parameters according to varying operating conditions.To address this issue,this paper proposes a PID control method based on a radial basis function(RBF)neural network,which adaptively tunes the PID controller parameters.First,an offline RBF neural network with optimal structural parameters is trained using the current and speed data of the PMSM,and then employed to construct the RBF-PID controller.During online training,the Jacobian information calculated via the RBF neural network is used to adaptively adjust the PID parameters.Simultaneously,the structural parameters of the RBF network are updated in reverse based on the error between the predicted and reference speed values.Finally,numerical simulations and experiments in the context of electric vehicle drive control show that the maximum speed errors of the SMC controller and the RBF-PID controller are 1.97 km/h and 0.17 km/h,respectively.Moreover,the RBF-PID controller outperforms both the SMC and traditional PID controllers in handling sudden speed changes.展开更多
同步数字体系(Synchronous Digital Hierarchy,SDH)数字微波传输系统具有高效、稳定的特点,有利于实现高效的数据传输和可靠的通信.文中从SDH数字微波通信技术的优势入手,对载波键控技术、高速多状态调制解调技术、自适应交叉极化干扰...同步数字体系(Synchronous Digital Hierarchy,SDH)数字微波传输系统具有高效、稳定的特点,有利于实现高效的数据传输和可靠的通信.文中从SDH数字微波通信技术的优势入手,对载波键控技术、高速多状态调制解调技术、自适应交叉极化干扰抵消技术等进行了分析,希望能为相关领域的专业人士提供有益的参考,推动SDH数字微波传输技术的发展.展开更多
2020年,国家电网有限公司发布了相关文件,对5~8级通信设备事件的定义进行了调整,进一步提高了通信安全运行底线。为准确评估光传输网络的性能水平与面临的风险,优化并提升同步数字体系(Synchronous Digital Hierarchy,SDH)网络性能与可...2020年,国家电网有限公司发布了相关文件,对5~8级通信设备事件的定义进行了调整,进一步提高了通信安全运行底线。为准确评估光传输网络的性能水平与面临的风险,优化并提升同步数字体系(Synchronous Digital Hierarchy,SDH)网络性能与可靠性,进一步筑牢电力通信系统安全运行基础,文章提出了一种电力通信SDH网络风险评估体系。展开更多
This study investigates chaotic synchronization via field-coupled nonlinear circuits, achieving both electrical synchronization and energy balance. The driving mechanism biomimetically parallels neuromuscular signal t...This study investigates chaotic synchronization via field-coupled nonlinear circuits, achieving both electrical synchronization and energy balance. The driving mechanism biomimetically parallels neuromuscular signal transduction, where synchronized neuronal firing induces coordinated muscle contractions that produce macroscopic movement. We implement a Chua circuit-driven robotic arm with tunable periodic/chaotic oscillations through parameter modulation and external current injection. Bifurcation analysis maps oscillation modes under varying external stimuli. Inductive coupling between two systems with distinct initial conditions facilitates magnetic energy transfer, optimized by an energy balance criterion. A bio-inspired exponential gain method dynamically regulates the coupling strength to optimize the energy transfer efficiency.The effects of ambient electromagnetic noise on synchronization are systematically quantified. The results indicate electrically modulatable robotic arm dynamics, with the coupled systems achieving autonomous rapid synchronization. Despite noise-induced desynchronization, inter-system errors rapidly decay and stabilize within bounded limits, confirming robust stability.展开更多
Dear Editor,This letter deals with the controller synthesis problem of networked Takagi-Sugeno(T-S)fuzzy systems.Due to the introduction of network communications,the same premise is no longer shared by fuzzy plants a...Dear Editor,This letter deals with the controller synthesis problem of networked Takagi-Sugeno(T-S)fuzzy systems.Due to the introduction of network communications,the same premise is no longer shared by fuzzy plants and fuzzy controllers.This makes the classic parallel distribution compensation(PDC)control infeasible.To overcome this situation,a novel method for reconstructing the membership functions'grades is proposed,which synchronizes the time scales.Then,the membership function dependent method is adopted to introduce asynchronous errors and detailed membership function information.For the event-triggered control strategy,a series of robust H∞stable conditions in LMI form are derived.Finally,a simulation of a practical system is used to demonstrate the method proposed in this letter can reduce conservatism.展开更多
基金financially supported by the Talent Initiation Fund of Wuxi University(550220008).
文摘With the increasing integration of renewable energy,microgrids are increasingly facing stability challenges,primarily due to the lack of inherent inertia in inverter-dominated systems,which is traditionally provided by synchronous generators.To address this critical issue,Virtual Synchronous Generator(VSG)technology has emerged as a highly promising solution by emulating the inertia and damping characteristics of conventional synchronous generators.To enhance the operational efficiency of virtual synchronous generators(VSGs),this study employs smallsignal modeling analysis,root locus methods,and synchronous generator power-angle characteristic analysis to comprehensively evaluate how virtual inertia and damping coefficients affect frequency stability and power output during transient processes.Based on these analyses,an adaptive control strategy is proposed:increasing the virtual inertia when the rotor angular velocity undergoes rapid changes,while strengthening the damping coefficient when the speed deviation exceeds a certain threshold to suppress angular velocity oscillations.To validate the effectiveness of the proposed method,a grid-connected VSG simulation platform was developed inMATLAB/Simulink.Comparative simulations demonstrate that the proposed adaptive control strategy outperforms conventional VSGmethods by significantly reducing grid frequency deviations and shortening active power response time during active power command changes and load disturbances.This approach enhances microgrid stability and dynamic performance,confirming its viability for renewable-dominant power systems.Future work should focus on experimental validation and real-world parameter optimization,while further exploring the strategy’s effectiveness in improvingVSG low-voltage ride-through(LVRT)capability and power-sharing applications in multi-parallel configurations.
基金supported by the National Natural Science Foundation of China(Grant Nos.62405250 and 62471404)the China Postdoctoral Science Foundation(Grant No.2024M762955)+1 种基金the Key Project of Westlake Institute for Optoelectronics(Grant No.2023GD003)the Optical Com-munication and Sensing Laboratory,School of Engineering,Westlake University.
文摘Propelled by the rise of artificial intelligence,cloud services,and data center applications,next-generation,low-power,local-oscillator-less,digital signal processing(DSP)-free,and short-reach coherent optical communication has evolved into an increasingly prominent area of research in recent years.Here,we demonstrate DSP-free coherent optical transmission by analog signal processing in frequency synchronous optical network(FSON)architecture,which supports polarization multiplexing and higher-order modulation formats.The FSON architecture that allows the numerous laser sources of optical transceivers within a data center can be quasi-synchronized by means of a tree-distributed homology architecture.In conjunction with our proposed pilot-tone assisted Costas loop for an analog coherent receiver,we achieve a record dual-polarization 224-Gb/s 16-QAM 5-km mismatch transmission with reset-free carrier phase recovery in the optical domain.Our proposed DSP-free analog coherent detection system based on the FSON makes it a promising solution for next-generation,low-power,and high-capacity coherent data center interconnects.
文摘针对目前广播电视同步数字体系(Synchronous Digital Hierarchy,SDH)微波传输系统部分电路设备老化、故障率高等现实问题,对现有SDH数字微波传输系统进行网际互连协议(Internet Protocol,IP)化升级改造,提出一套切实可行的实施方案,阐述方案设计思路、实施方法和注意事项等内容。通过项目实践充分验证了所提方案能够大幅降低电路设备故障率,提升微波传输的效率,充分保障广播电视节目的安全传输。
文摘针对同步数字体系(Synchronous Digital Hierarchy,SDH)光纤通信系统在长期运行中易发生链路衰耗、光器件性能退化及时钟同步异常的问题,从系统结构与功能单元入手,系统分析典型故障类型及其成因,提出相应维护策略。该策略在缩短链路定位时间、延长器件使用寿命、提高同步精度等方面取得了显著成效,有效提高了SDH光纤通信系统的运行可靠性与维护效率。
文摘Permanent magnet synchronous motor(PMSM),known for their compact size and high-power density,is widely used in fields such as electric vehicles and servo drives.However,traditional PID control methods for PMSM cannot dynamically adjust parameters according to varying operating conditions.To address this issue,this paper proposes a PID control method based on a radial basis function(RBF)neural network,which adaptively tunes the PID controller parameters.First,an offline RBF neural network with optimal structural parameters is trained using the current and speed data of the PMSM,and then employed to construct the RBF-PID controller.During online training,the Jacobian information calculated via the RBF neural network is used to adaptively adjust the PID parameters.Simultaneously,the structural parameters of the RBF network are updated in reverse based on the error between the predicted and reference speed values.Finally,numerical simulations and experiments in the context of electric vehicle drive control show that the maximum speed errors of the SMC controller and the RBF-PID controller are 1.97 km/h and 0.17 km/h,respectively.Moreover,the RBF-PID controller outperforms both the SMC and traditional PID controllers in handling sudden speed changes.
文摘同步数字体系(Synchronous Digital Hierarchy,SDH)数字微波传输系统具有高效、稳定的特点,有利于实现高效的数据传输和可靠的通信.文中从SDH数字微波通信技术的优势入手,对载波键控技术、高速多状态调制解调技术、自适应交叉极化干扰抵消技术等进行了分析,希望能为相关领域的专业人士提供有益的参考,推动SDH数字微波传输技术的发展.
文摘2020年,国家电网有限公司发布了相关文件,对5~8级通信设备事件的定义进行了调整,进一步提高了通信安全运行底线。为准确评估光传输网络的性能水平与面临的风险,优化并提升同步数字体系(Synchronous Digital Hierarchy,SDH)网络性能与可靠性,进一步筑牢电力通信系统安全运行基础,文章提出了一种电力通信SDH网络风险评估体系。
基金Project supported by the National Key R&D Program of China (Grant No. 2023YFD2000601-02)。
文摘This study investigates chaotic synchronization via field-coupled nonlinear circuits, achieving both electrical synchronization and energy balance. The driving mechanism biomimetically parallels neuromuscular signal transduction, where synchronized neuronal firing induces coordinated muscle contractions that produce macroscopic movement. We implement a Chua circuit-driven robotic arm with tunable periodic/chaotic oscillations through parameter modulation and external current injection. Bifurcation analysis maps oscillation modes under varying external stimuli. Inductive coupling between two systems with distinct initial conditions facilitates magnetic energy transfer, optimized by an energy balance criterion. A bio-inspired exponential gain method dynamically regulates the coupling strength to optimize the energy transfer efficiency.The effects of ambient electromagnetic noise on synchronization are systematically quantified. The results indicate electrically modulatable robotic arm dynamics, with the coupled systems achieving autonomous rapid synchronization. Despite noise-induced desynchronization, inter-system errors rapidly decay and stabilize within bounded limits, confirming robust stability.
基金supported by the National Natural Science Foundation of China(62173218,61833011)International International Cooperation Project of Shanghai Science and Technology Commission(21190780300).
文摘Dear Editor,This letter deals with the controller synthesis problem of networked Takagi-Sugeno(T-S)fuzzy systems.Due to the introduction of network communications,the same premise is no longer shared by fuzzy plants and fuzzy controllers.This makes the classic parallel distribution compensation(PDC)control infeasible.To overcome this situation,a novel method for reconstructing the membership functions'grades is proposed,which synchronizes the time scales.Then,the membership function dependent method is adopted to introduce asynchronous errors and detailed membership function information.For the event-triggered control strategy,a series of robust H∞stable conditions in LMI form are derived.Finally,a simulation of a practical system is used to demonstrate the method proposed in this letter can reduce conservatism.
