- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Realization of a Photonic Topological Z <sub/>2</sub> -Insulator
摘要： The human ankle joint plays a critical role during walking and understanding the biomechanical factors that govern ankle behavior and provides fundamental insight into normal and pathologically altered gait. Previous researchers have comprehensively studied ankle joint kinetics and kinematics during many biomechanical tasks, including locomotion; however, only recently have researchers been able to quantify how the mechanical impedance of the ankle varies during walking. The mechanical impedance describes the dynamic relationship between the joint position and the joint torque during perturbation, and is often represented in terms of stiffness, damping, and inertia. The purpose of this short communication is to unify the results of the first two studies measuring ankle mechanical impedance in the sagittal plane during walking, where each study investigated differing regions of the gait cycle. Rouse et al. measured ankle impedance from late loading response to terminal stance, where Lee et al. quantified ankle impedance from pre-swing to early loading response. While stiffness component of impedance increases significantly as the stance phase of walking progressed, the change in damping during the gait cycle is much less than the changes observed in stiffness. In addition, both stiffness and damping remained low during the swing phase of walking. Future work will focus on quantifying impedance during the "push off" region of stance phase, as well as measurement of these properties in the coronal plane.
关键词： Human ankle,ankle impedance,ankle damping,ankle stiffness
更新于2025-09-19 17:13:59
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[IEEE 2018 IEEE International RF and Microwave Conference (RFM) - Penang, Malaysia (2018.12.17-2018.12.19)] 2018 IEEE International RF and Microwave Conference (RFM) - Simulation Analysis of EDFA in Optical Fiber with WDM System in the Perspective of Bangladesh
摘要： Harmonic stability problems caused by the resonance of high-order ?lters in power electronic systems are ever increasing. The use of passive damping does provide a robust solution to address these issues, but at the price of reduced ef?ciency due to the presence of additional passive components. Hence, a new method is proposed in this paper to optimally design the passive damping circuit for the LCL ?lters and LCL with multituned LC traps. In short, the optimization problem reduces to the proper choice of the multisplit capacitors or inductors in the high-order ?lter. Compared to existing design procedures, the proposed method simpli?es the iterative design of the overall ?lter while ensuring the minimum resonance peak with a lower damping capacitor and a lower rated resistor. It is shown that there is only one optimal value of the damping resistor or quality factor to achieve a minimum ?lter resonance. The passive ?lters are designed, built, and validated both analytically and experimentally for veri?cation.
关键词： voltage-source converters,trap ?lter,resonance damping,LCL ?lter,Harmonic passive ?lters
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Effect of a-Si on CH <sub/>3</sub> NH <sub/>3</sub> PbI <sub/>3</sub> Films and Applications in Perovskite Solar Cells
摘要： In order to reduce size and cost, high-order passive ?lters are generally preferred in power converters to cancel out high-frequency harmonics caused by pulsewidth modulation. However, the ?lter resonance peaks may require the use of passive dampers to stabilize the interactions between the load and source impedances. Furthermore, the stabilizing effect is more dif?cult to be guaranteed for cost-optimized ?lters, which are characterized by low-inductance and high-capacitance passive components. In this paper, several passive ?lter topologies used to interface voltage-source converters with the utility grid are reviewed and evaluated in terms of damping capability, stored energy in the passive components, and power loss in the damping circuit. In addition, the in?uences of different switching frequencies of power converters on the passive ?lter design are discussed in the range 1–15 kHz. Illustrative design examples of the passive ?lters and experimental data are also provided.
关键词： voltage-source converters (VSCs),LC L ?lter,trap ?lter,resonance damping,passive ?lters
更新于2025-09-19 17:13:59
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[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Electro-thermal Model of Approximated Organic Tissue for Investigation of Harmful Electrosurgical Impacts
摘要： The quality factor of a resonator represents the decay of vibrational energy over time, and is directly related to the frequency response and other key parameters that determine performance of inertial sensors and oscillators. Accurate prediction of the quality factor is essential for designing high-performance microelectromechanical (MEMS) devices. Several to the quality factor. Due to computational complexity, highly simplified models for the dominant dissipation mechanism, such as Zener’s model for thermoelastic dissipation (TED), are often the intuition provided by these models employed. However, is inadequate to predict the quality factor of more complex designs and can be highly misleading. In this paper, we construct complete, quantitative, and predictive models with finite-element methods for the intrinsic energy dissipation mechanisms in MEMS resonators using full anisotropic representation of crystalline silicon and the temperature dependence of all parameters. We find that TED is often a more significant source of damping than has been assumed, because of the previously neglected role of crystalline anisotropy and small geometric features, such as etch release holes—all of which can now be included in practical models. We show that these models, along with simpler scaling models for extrinsic dissipation mechanisms, explain measurements of quality factor in diverse sets of MEMS resonators with unprecedented accuracy.
关键词： micromechanical resonators,energy dissipation,Capacitive sensors,frequency-domain analysis,damping,frequency response,geometry,thermal-mechanical coupling,resonance,thermoelastic dissipation,internal friction,microelectromechanical devices,systems
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Comparison of Ideal Transformer Method and Damping Impedance Method for PV Power-Hardware-In-The-Loop Experiments
摘要： The Ideal Transformer Method (ITM) and the Damping Impedance Method (DIM) are the most widely used techniques for connecting power equipment to a Power-Hardware-in-the-Loop simulation. Both methods have been studied for their stability and accuracy in PHIL simulations, but neither have been analyzed when the hardware is providing grid-support services with volt-var, frequency-watt, and fixed power factor functions. In this work, we experimentally validate the two methods of connecting a physical PV inverter to a PHIL system and evaluate them for dynamic stability and accuracy when operating with grid-support functions. It was found that the DIM Low Pass Lead Filter (LPF LD) method was the best under unity and negative power factor conditions, but the ITM LPF LD method was preferred under positive power factor conditions.
关键词： damping impedance method,PHIL,power hardware-in-the-loop,lead filter,PV inverter,ideal transformer method,low pass filter
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 4th International Future Energy Electronics Conference (IFEEC) - Singapore, Singapore (2019.11.25-2019.11.28)] 2019 IEEE 4th International Future Energy Electronics Conference (IFEEC) - Bridgeless Buck-Boost PFC Rectifier with Positive Output Voltage Suitable for LED Driving
摘要： State-space current control enables high dynamic performance of a three-phase grid-connected converter equipped with an LCL filter. In this paper, observer-based state-space control is designed using direct pole placement in the discrete-time domain and in grid-voltage coordinates. Analytical expressions for the controller and observer gains are derived as functions of the physical system parameters and design specifications. The connection between the physical parameters and the control algorithm enables automatic tuning. Parameter sensitivity of the control method is analyzed. The experimental results show that the resonance of the LCL filter is well damped, and the dynamic performance specified by direct pole placement is obtained for the reference tracking and grid-voltage disturbance rejection.
关键词： parameter sensitivity,Active damping,LCL filter,sensorless state feedback,grid-connected converter,current control
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia) - Chengdu, China (2019.5.21-2019.5.24)] 2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia) - Modeling and Simulation of Virtual Synchronous Generator for Photovoltaic Inverter
摘要： The rise of photovoltaic installed capacity brings severe challenges to the safe and stable operation of the power grid. If the grid-connected inverter of the photovoltaic system can simulate the moment of inertia and frequency modulation characteristics of the synchronous generator according to external characteristics, the stability of the photovoltaic system can be improved. Therefore, the virtual synchronous generator control strategy (VSG) is proposed. This paper builds a generic simulation model of current source type photovoltaic inverter based on VSG technology, which can simulate a series of VSG behaviours including virtual inertia control, damping control, primary frequency control, reactive power control and fault ride through. The developed simulation model is also validated comparing to the actual PV power plant testing data, which shows accurate and reliable simulation results. The model of photovoltaic inverter can provide theoretical and model basis for the study of grid-connected stability and grid-connected operational characteristics.
关键词： VSG,photovoltaic inverter,Damping control,Droop control,Microgrid
更新于2025-09-16 10:30:52
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[IEEE 2019 International Conference on Communication and Electronics Systems (ICCES) - Coimbatore, India (2019.7.17-2019.7.19)] 2019 International Conference on Communication and Electronics Systems (ICCES) - Standalone PV System Integrated with Hysteresis Current Controlled Inverter using MPPT Techniques
摘要： Harmonic stability problems caused by the resonance of high-order ?lters in power electronic systems are ever increasing. The use of passive damping does provide a robust solution to address these issues, but at the price of reduced ef?ciency due to the presence of additional passive components. Hence, a new method is proposed in this paper to optimally design the passive damping circuit for the LCL ?lters and LCL with multituned LC traps. In short, the optimization problem reduces to the proper choice of the multisplit capacitors or inductors in the high-order ?lter. Compared to existing design procedures, the proposed method simpli?es the iterative design of the overall ?lter while ensuring the minimum resonance peak with a lower damping capacitor and a lower rated resistor. It is shown that there is only one optimal value of the damping resistor or quality factor to achieve a minimum ?lter resonance. The passive ?lters are designed, built, and validated both analytically and experimentally for veri?cation.
关键词： Harmonic passive ?lters,LCL ?lter,resonance damping,voltage-source converters,trap ?lter
更新于2025-09-16 10:30:52
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A Novel Protocol for Bidirectional Controlled Quantum Teleportation of Two-Qubit States Via Seven-Qubit Entangled State in Noisy Environment
摘要： In this paper, a novel protocol of bidirectional controlled quantum teleportation (BCQT) via seven-qubit state is proposed. Where Alice and Bob, two legitimate users, can teleport two-qubit states to each other. In the whole process, users achieve the initial state based on preprocessing of quantum channel, Bell-state measurement (BSM), single-qubit measurement (SM), unitary operations and so on. The main superiority of the proposed protocol is more efficient compared with previous work. In addition, the proposed protocol is considered in noisy channel, it shows that the fidelities under amplitude-damping (AD) and phase-damping (PD) noise only rest with the amplitude parameter of the initial state and the decoherence noisy rate.
关键词： Bidirectional controlled quantum teleportation,Seven-qubit entangled state,Amplitude-damping noise,Phase-damping noise
更新于2025-09-12 10:27:22
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Design and Implementation of an IDA-PBC for a Grid Connected Inverter used in a Photovoltaic System
摘要： The paper presents an interconnection damping assignment - passivity based control (IDA-PBC) strategy applied to a grid-connected inverter interfaced Photovoltaic (PV) system. The PV power plant is integrated to the grid using a pulse-width-modulated converter. This is done to extract maximum energy from the renewable resource and feed it to the grid. The main contribution of this paper is to design a nonlinear control law based on IDA-PBC with a desired energy function along with an integral action. In the design of IDA-PBC, the Hamiltonian function is considered as a Lyapunov function candidate for analysing the stability criteria. In this paper, a step by step design procedure of the IDA-PBC is presented and the performance of the controller is compared with a conventional PI-based controller. A simulation study of the system is carried out in Matlab/Simulink environment. Finally, the simulation results show that the IDA-PBC with an integral action performs better during both transient and steady state conditions as compared with the PI-based controller.
关键词： Interconnection and damping assignment,Grid connected inverter,Photovoltaic energy conversion system,Port control Hamiltonian,Passivity based control
更新于2025-09-12 10:27:22