- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Saint Petersburg, Russia (2018.10.22-2018.10.23)] 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Band-Pass ARC-Filter Based on the Classical Wien Bridge with the Pole Frequency Rise and Independent Adjustment of the Main Parameters
摘要： A new topology of the band-pass active RC filter (BP) based on the classic Wien bridge is proposed. This scheme, implemented on two Op-Amps, is recommended for the use as a second-order link in more complex BPs. The analysis of the modified band-pass ARC filter is carried out, the main parameters of the BP are found. The computer simulation of the developed PF tuning algorithm is completed. The graphs of changes in the frequency response and phase response when changing various parameters of the BP are obtained. It is shown that in the considered BP an independent adjustment of the main parameters is ensured - transmission coefficient in the passband, pole attenuation and pole frequency.
关键词： ARC filter,trimming,active RC filter,band-pass RC filter,high-order BP,Wien bridge,parameter adjustment
更新于2025-09-23 15:22:29
-
[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - High-Speed Railway Bridge Vibration Measurement and Analysis Based on Radar Interferometry
摘要： A newly designed radar based on interferometry is proposed and well designed in the paper. The designed radar can detect the vibration of the railway bridge with a super-resolution and a high precision, which also has remote sensing ability. The general bridge monitoring methods are expensive and time-consuming since it is difficult to install sensors that should be directly contact with the bridge, such as accelerometer and dynamometer. Based on the designed radar, experiments are constructed on a Beijing-Tianjin Inter-City high-speed railway bridge to prove that the radar interferometry can be used to preciously and accurately monitor the railway bridge’s vibration.
关键词： Vibration,Railway bridge,Interferometry
更新于2025-09-23 15:21:21
-
LCL-T Resonant Converter Based on Dual Active Bridge Topology in Solar Energy Applications
摘要： Resonant LCL-T converter can operate as stable voltage source, being fed from current, for instance, the photovoltaic battery. It is shown that LCL-T resonant tank has intrinsic ability to convert stable AC current into stable AC voltage thus parametrically regulating output voltage at a fixed value. This mode of operation is made possible by the use of active (synchronous) rectifier to recoup energy from the output back to the LCL-T resonant tank. Basic characteristics of resonant LCL-T converter regulated by phase shift between inverter and rectifier regardless of a solar battery current drift have been defined. It is shown that phase control guarantees 0 voltage and 0 current on switching; however, turn-off current could be substantial. Calculations and assumptions made in this study have been confirmed by simulation and hardware prototype.
关键词： Bidirectional dual active bridge,ZCS,LCL resonant converter,Resonant converter,Spacecraft power supply system,ZVS
更新于2025-09-23 15:21:21
-
Synthesis and mesomorphic properties of 4,4”-dialkynyl-2’,3’-difluoro-p-terphenyls – the influence of C≡C acetylene linking bridge
摘要： Dielectrically negative liquid crystals (LC) based on the terphenyl molecular core are widely used class of rod-like mesogenes. One of the most important parameters from applications point of view is optical anisotropy at nematic phase. Hence some applications require high values of birefringence (optical anisotropy in the case of nematic medium), which can be ensured by mesomorphic molecules having high anisotropy of electronic polarisabilities Δα. The molecular design of presented terphenyls is based on the idea of elongation of conjugated π electronic system by terminal acetylene bridge (C ≡ C), as a linking element to terminal alkyl chains. In this work, we developed synthesis of 4,4’’-dialkynyl-2’,3’-difluoroterphenyls with different length of terminal alkyl chains. All synthesised compounds have wide nematic phase ranges. Synthetic problems of this work will be presented. The purity and structures of the final products and intermediates were confirmed by spectral methods: gas chromatography GC-MS, GC-FID, IR spectroscopy and nuclear magnetic resonance NMR. The phase transition temperatures, phase situation and enthalpy data were determined by polarising optical microscopy (POM) and differential scanning calorimetry.
关键词： Terphenyl,acetylene bridge,nematic
更新于2025-09-23 15:21:21
-
[IEEE 2020 IEEE International Conference on Power Electronics, Smart Grid and Renewable Energy (PESGRE) - Cochin, India (2020.1.2-2020.1.4)] 2020 IEEE International Conference on Power Electronics, Smart Grid and Renewable Energy (PESGRE2020) - Improved H-bridge Multilevel Inverter for Grid Integration of Photovoltaic Power Conversion System with Power Quality Enhancement
摘要： This paper proposes an improved H-bridge multi-level inverter in the photovoltaic power conversion system (PPCS) system which is connected to the distribution grid. The power quality is improved with the number of levels and balanced active power sharing between the sources has been achieved. The bidirectional power ?ow is achieved. The two-stage SPVS extracts the maximum power from the solar panels through the incremental conductance (IC) algorithm based control of the DC-DC converter. The system is designed with multi-functional objectives such as reactive power support and load harmonic mitigation in addition with the active power penetration to the grid. The system is modelled and simulated in MATLAB/Simulink platform and the laboratory prototype is developed, and test results are produced for result validation.
关键词： Photovoltaic,Cascaded H-bridge,Maximum Power Extraction,power quality
更新于2025-09-23 15:21:01
-
[IEEE 2019 International Conference on Intelligent Computing and Control Systems (ICCS) - Madurai, India (2019.5.15-2019.5.17)] 2019 International Conference on Intelligent Computing and Control Systems (ICCS) - Controlled PV Systems Power Quality Retention and Output Power Escalation
摘要： Due to the burden on fossil fuels the trend of generating power through renewable energy resources is gaining more importance day by day. In such systems there are issues related to efficiency and reliability. The paper focuses mainly on developing a model using MATLAB / SIMULINK software to overcome the above mentioned obstacles to the PV system and improve its overall performance by introducing appropriate control schemes. The aim of the PV system design is to escalate the output power under varying environmental conditions and also to retain the power quality of the PV system during faulty conditions. MPPT is applied to optimize through Incremental conductance thus ensuring the system is running at its maximum power point irrespective of the partial shading effect and temperature variations in the environment. With the employment of power quality compensation scheme that in turn uses a DVR, the system is capable of restoring the power quality thereby commuting the power quality issues. Significant fall in the THD levels is attained by usage of DVR control scheme along with a CHB multilevel DC/AC converter. The significance of developing MPPT algorithm is illustrated by examining the impact of partial shading condition and the temperature variations on its productivity. The demonstration of the power quality compensation capability of the PV system is achieved by the power quality compensation control scheme under faulty conditions.
关键词： Cascaded H-Bridge Multilevel Inverter (CHB),Incremental Conductance (IncCond),Total Harmonic Distortion (THD),Dynamic Voltage Restorer (DVR),Maximum Power Point Tracking (MPPT)
更新于2025-09-23 15:21:01
-
A High-Power-Factor Dimmable LED Driver with Integrated Boost Converter and Half-Bridge-Topology Converter
摘要： This paper proposes a dimmable light-emitting diode (LED) driver featuring a high power factor and zero-voltage switching on (ZVS). The circuit is obtained by integrating a boost converter and a dc-dc converter with half-bridge topology. The high power factor is achieved by operating the boost converter in discontinuous current mode (DCM). The LEDs are dimmed by the control scheme of asymmetrical pulse-width modulation (ASPWM). The developed circuit eliminates the inherited dc-o?set current of the transformer in a conventional asymmetrical half-bridge converter by introducing a balance capacitor. Both active switches can operate at ZVS by freewheeling the boost inductor current and the transformer magnetizing current to discharge the energy stored in their parasitic capacitance. The circuit operation is analyzed in detailed, and mathematical equations are derived. Finally, a 115-W prototype circuit for driving high brightness LEDs was built and tested. The experimental results verify the feasibility of the proposed LED driver with satisfactory performance. It can achieve a high power factor and ZVS operation.
关键词： power-factor correction,half-bridge converter,zero-voltage switching on (ZVS),asymmetrical pulse-width modulation (ASPWM),light-emitting diode (LED)
更新于2025-09-23 15:21:01
-
Benchmarking Digital Die-to-Die Channels in 2.5-D and 3-D Heterogeneous Integration Platforms
摘要： In this paper, compact circuit models and HSPICE simulations are used to benchmark die-to-die communication channels in 2.5-D and 3-D heterogeneous integration platforms. The delay, energy-per-bit, and bandwidth-density of the considered integration platforms are simulated and benchmarked. Compared to other 2.5-D integrated systems with a 1-mm interconnect length, heterogeneous interconnect stitching technology (HIST)-based 2.5-D integration shows a maximum latency and energy reduction of 6.2% and 15.1%, respectively. 3-D ICs show further performance enhancement compared to 2.5-D integration; the link latency and energy are approximately 19.4% and 48.0% smaller than those of HIST (1-mm wire) for through-silicon via (TSV)-based 3-D integration (75-μm TSV height). Next, the impacts of the physical I/O interconnect dimensions and device process technology scaling are evaluated and we observe that advanced process technologies must be integrated with smaller physical I/O dimensions and shorter wire lengths to attain full advantages of scaling. Finally, we consider the thermal impact of dense heterogeneous integration and investigate the thermal and electrical signaling tradeoffs in 2.5-D and 3-D integration.
关键词： Die-to-die interconnect,interposer and bridge-chip 2.5-D ICs,signaling
更新于2025-09-23 15:21:01
-
Symmetry controlled photo-selection and charge separation in butadiyne-bridged donora??bridgea??acceptor compounds
摘要： Electron transfer (ET) in donor-bridge-acceptor (DBA) compounds depends strongly on the structural and electronic properties of the bridge. Among the bridges that support donor - acceptor conjugation, alkyne bridges have attractive and unique properties: they are compact, possess linear structure permitting access to high symmetry DBA structures, and allow torsional motion of D and A, especially for longer bridges. We report conformation dependent electron transfer dynamics in a set of novel DBA compounds featuring butadiyne (C4) bridge, N-isopropyl-1,8-napthalimide (NAP) acceptors, and donors that span a range of reduction potentials (trimethyl silane (Si-C4-NAP), phenyl (Ph-C4-NAP), and dimethyl aniline (D-C4-NAP)). Transient mid-IR absorption spectra of the C≡C bridge stretching modes, transient spectra in the visible range and TD-DFT calculations were used to decipher the ET mechanisms. We found that the electronic excited state energies and, especially, the transition dipoles (S0→Sn) depend strongly on the dihedral angle (θ) between D and A and the frontier orbital symmetry, offering an opportunity to photo-select particular excited states with specific ranges of dihedral angles by exciting at chosen wavelengths. For example, excitation of D-C4-NAP at 400 nm predominantly prepares an S1 excited state in the planar conformations (θ ~ 0) but selects an S2 state with θ ~ 90o, indicating the dominant role of the molecular symmetry in the photophysics. Moreover, the symmetry of the frontier orbitals of such DBA compounds not only defines the photo-selection outcome, but also determines the rate of the S2→S1 charge separation reaction. Unprecedented variation of the S2-S1 electronic coupling with θ by over four orders of magnitude results in slow ET at θ ca. 0o and 90o but extremely fast ET at θ of 20-60o. The unique features of high-symmetry alkyne bridged DBA structures enable frequency dependent ET rate selection and make this family of compounds promising targets for the vibrational excitation control of ET kinetics.
关键词： transient absorption spectroscopy,electron transfer,donor-bridge-acceptor,TD-DFT calculations,butadiyne bridge
更新于2025-09-23 15:19:57
-
Interfacial Chemical Bridge Constructed by Zwitterionic Sulfamic Acid for Efficient and Stable Perovskite Solar Cells
摘要： A simple-structure zwitterion of sulfamic acid (+H3N-SO3-, SA) is introduced to construct effective chemical bridge between SnO2 and perovskite layer through a coordination bond via the –SO3- anion for remedying the oxygen vacancies of SnO2 and meanwhile to passivate charged defects of perovskite through electrostatic interaction via the –NH3+ cation. The introduced SA results in high-quality perovskite films with large grain size, due to the better wettability for perovskite solution. Consequently, the SA-modified solar cell generates an enhanced efficiency from 18.2% to 20.4% with negligible hysteresis. Remarkably, the unsealed device with SA-modification also exhibits considerably improved stability.
关键词： chemical bridge,SnO2,solar cells,perovskite,sulfamic acid (SA)
更新于2025-09-23 15:19:57