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Model and Experimental Study on Optical Fiber CT Based on Terfenol-D
摘要： A nonlinear hysteresis model of magneto-mechanical-thermo coupling for Terfenol-D materials is presented according to Wiss ferromagnetic theory, thermodynamics relations and Jiles–Atherton model. Numerical calculation and experimental results show that the mode well reflects the magnetostrictive characteristics of Terfenol-D rod under the coupling of stress, temperature and magnetic field. A fiber Bragg grating current transformer based on Terfenol-D material is designed according to the strain sensing mechanism of fiber Bragg grating and the demodulation principle of unbalanced M–Z interferometer. The theoretical analysis and research on the working characteristics of the fiber current transformer under the influence of different prestressing force and bias current are carried out. The results are important for the design and application of the current transformer with the Terfenol-D material.
关键词： current transformer,fiber Bragg grating,Terfenol-D,unbalanced M–Z interferometer
更新于2025-09-23 15:19:57
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Switched Capacitor-Coupled Inductor DCa??DC Converter for Grid-Connected PV System using LFCSO-Based Adaptive Neuro-Fuzzy Inference System
摘要： In this paper, the Levy °ight-based chicken swarm optimization (LFCSO) is proposed to follow the highest power of grid-joined photovoltaic (PV) framework. To analyze the grid-associated PV framework, the characteristics of current, power, voltage, and irradiance are determined. Because of the low yield voltage of the source PV, a big advance up converter with big productivity is required when the source PV is associated with the matrix power. A tale great advance up converter dependent on the exchanged capacitor and inductor is illustrated in this paper. The LFCSO algorithm with the adaptive neuro-fuzzy inference system is used to generate the control pulses of the transformer-coupled inductor DC–DC converter-less switched capacitor. While using the switched capacitor-coupled inductor, the voltage addition is expanded in the DC–DC converter and the power of PV is maximized. Here, the normal CSO algorithm is updated with the help of Levy °ight functions to generate optimal results. To get the accurate optimal results, the output of the proposed LFCSO algorithm is given as the input of the ANFIS technique. After that, the optimal results are generated and they provide the pulses for the system. The working guideline is analyzed and the voltage addition is derived with the utilization of the proposed technique. From that point forward, it predicts the exact maximum power of the converter according to its inputs. Under the variety of solar irradiance and partial shading conditions (PSCs), the PV system is tested and its characteristics are analyzed in di?erent time instants. The proposed LFCSO with ANFIS method is actualized in Simulink/MATLABstage, and the tracking executing is examined with a traditional method such as genetic algorithm (GA), perturb and observe (P&O) technique–neuro-fuzzy controller (NFC) and fuzzy logic controller (FLC) technique.
关键词： irradiance,Levy °ight-based chicken swarm optimization algorithm,partial shading conditions,transformer-less switched capacitor-coupled inductor DC–DC converter voltage,current,power,grid-connected PV,GA-NFC and FLC methods
更新于2025-09-23 15:19:57
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Equal and unequal quad-band Gysel power dividers
摘要： This article presents for the first time a quad-band Gysel power divider capable of achieving equal and unequal power division at four arbitrary frequencies. The structure of the proposed divider is similar to its single-band counterpart but loaded with quad-band reactive networks. The design procedure and theoretical analysis of the proposed divider are presented. A quad-band Gysel power divider with equal division and another with 2:1 unequal division are designed at the operational frequencies of 0.85, 1.6, 2.4, and 3 GHz. Simulation and measurement results of the two dividers are presented, and good performance is observed at each band. For both designs, the realized power division ratios are within 1 dB from their ideal values, whereas the matching and isolation levels are below ?10 dB at the four bands.
关键词： quad-band,impedance transformer,power divider,multi-band
更新于2025-09-23 15:19:57
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[IEEE 2018 International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM) - Algiers, Algeria (2018.10.28-2018.10.31)] 2018 International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM) - Comparison between existing transformer-less PV inverter topologies
摘要： In recent years, the interest in installing more photovoltaic systems to generate electricity power has rapidly increased. A number of reasons such as environmental concerns, electricity business restructuring, the fast developments of small-scale power generation technologies and micro-grid related systems can explain this trend. In order to improve the efficiency and reduce the cost of a photovoltaic system, many people are interested in PV inverter perfection, and this is due to the importance of this part in PV systems, it is the interface between produced and used electricity. In this paper we will focus on PV inverters, we will review available transformer-less PV inverters topologies and those topologies will be classified on the basis of applicability for photovoltaic uses.
关键词： Boost Inverter,Transformer-less Inverter,PV Inverter,PV inverter topologies
更新于2025-09-19 17:15:36
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[IEEE 2018 International Conference on Power System Technology (POWERCON) - Guangzhou, China (2018.11.6-2018.11.8)] 2018 International Conference on Power System Technology (POWERCON) - Partial Discharge Detection in Transformer Based on Optical Method
摘要： The paper presents a method for detecting partial discharge (PD) in transformer oil using fluorescence sensor and optical method. The main components and the experimental setup are described. The results show that the fluorescence sensor can effectively detect PD signals with high sensitivity and accuracy. The method has great potential for application in power equipment monitoring.
关键词： fluorescence sensor,power equipment,optical detection,transformer oil,partial discharge
更新于2025-09-19 17:15:36
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[IEEE 2018 18th Mediterranean Microwave Symposium (MMS) - Istanbul, Turkey (2018.10.31-2018.11.2)] 2018 18th Mediterranean Microwave Symposium (MMS) - Wideband Quarter Wave Transformer Based on Defected Ground and Split Ring Resonator Structures
摘要： This article examines a wideband impedance transformer based on a split ring resonator and defected ground structures. The transformer was designed as a 4-section binomial one and it provides a transformation from 50 Ω to 100 Ω. Reversed “Z” shaped defects are formed on the ground plane of the design in order to increase the bandwidth. The design has been simulated using a 3D electromagnetic simulator which utilizes finite integration technique. Three distinct resonances are exhibited at specific frequency spots as proofs of the concept of impedance matching. Theoretical and simulated results are in a good agreement with each other and the proposed design might be tailored in many microwave circuits and antenna applications.
关键词： broadband,quarter wave transformer,defected ground,split ring resonator
更新于2025-09-19 17:15:36
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Enhanced hydrogen sensing properties of Pd-coated SnO2 nanorod arrays in nitrogen and transformer oil
摘要： We report enhanced sensing properties of Pd-coated SnO2 nanorod (NR) arrays for detecting H2 gas in N2 and dissolved in transformer oil. The Pd nanoparticles were coated on randomly ordered vertical SnO2 NR arrays by the glancing angle deposition (GLAD) method, which utilizes an electron-beam evaporator and a DC magnetron sputtering system. The Pd-coated SnO2 NR arrays exhibited high response (104 at 1% H2) in N2. Pd-coated SnO2 NR arrays were immersed and in mineral oil that contains various concentrations of dissolved H2 and the electrical response was measured. We found that the Pd-coated SnO2 NR arrays showed superior response (R = ?96), low detection limit (0.3 ppm), and fast response times (300 s). The Pd-coated SnO2 NR arrays had a temperature coefficient of resistance (TCR) of 3.69 × 10-3 °C-1 at various oil temperatures (20–80 °C), indicating good thermal stability at high temperatures. The sensing mechanism of the Pd-coated SnO2 NR arrays was also demonstrated by using changes in the Schottky barrier height at the Pd/SnO2 interface upon exposure to H2.
关键词： Pd,SnO2,Transformer oil,Nanorod arrays,Hydrogen sensing
更新于2025-09-19 17:15:36
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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) - Quantum Rangefindng
摘要： Transformer parasitics such as leakage inductance and self-capacitance are rarely calculated in advance during the design phase, because of the complexity and huge analytical error margins caused by practical winding implementation issues. Thus, choosing one transformer architecture over another for a given design is usually based on experience or a trial and error approach. This paper presents analytical expressions for calculating leakage inductance, self-capacitance, and ac resistance in transformer winding architectures (TWAs), ranging from the common noninterleaved primary/secondary winding architecture, to an interleaved, sectionalized, and bank winded architecture. The calculated results are evaluated experimentally, and through finite-element simulations, for an RM8 transformer with a turns ratio of 10. The four TWAs such as, noninterleaved and nonsectioned, noninterleaved and sectioned, interleaved and nonsectioned, and interleaved and sectioned, for an EF25 transformer with a turns ratio of 20, are investigated and practically implemented. The best TWA for an RM8 transformer in a high-voltage bidirectional flyback converter, used to drive an electro active polymer based incremental actuator, is identified based on the losses caused by the transformer parasitics. For an EF25 transformer, the best TWA is chosen according to whether electromagnetic interference due to the transformer interwinding capacitance, is a major problem or not.
关键词： energy efficiency,switch-mode power converters,transformer winding architectures,Actuator,high-voltage dc–dc converters,high-voltage transformer,transformer parasitics
更新于2025-09-19 17:13:59
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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) - Gravitational Physics with Atomic Quantum Sensors
摘要： This paper proposes a practical solution of high-frequency-link dc transformer based on switched capacitor (SCDCT) for medium-voltage dc (MVDC) power distribution application. Compared to the traditional dc transformer scheme, the proposed SCDCT can disconnect from MVDC distribution grid effectively as a dc breaker when a short fault occurs in the distribution, can enhance power transfer capacity, and always ensures high-frequency-link voltage match to improve current impact and ef?ciency performances, and the redundancy design can be achieved when some submodules fail to improve the reliability. In the paper, the topology, voltage and power characterization, control strategy, startup, and fault solution of SCDCT are presented and analyzed comprehensively. At last, an SCDCT prototype is built and the experimental results verify the correctness and effectively of the proposed solution.
关键词： switched capacitor,dc transformer,dc–dc converter,solid-state transformer (SST),DC distribution,high-frequency-link,dual active bridge (DAB)
更新于2025-09-19 17:13:59
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Copper particle contamination detection of oil-immersed transformer using laser-induced breakdown spectroscopy
摘要： The deterioration of transformer oil caused by particle contamination, especially copper particle, seriously affects the safe operation of oil-immersed transformers. Therefore, it is very important for the detection of metal particles in transformer oil. A new method based on laser-induced breakdown spectroscopy (LIBS) was first applied in the transformer oil diagnosis field. By screening out effective spots, the correlation between Cu particle concentration and LIBS signal was obtained after testing a set of oil samples with concentration range from 0.54 to 12.4 μg/g; the calibration curves of Cu I 324.75 nm / CN 358.6 nm and Cu I 327.39 nm /CN 358.6 nm were therefore established. The results shown high linearity, and the determination coefficient R2 of the two calibration curves in range from 0.54 to 3.1 μg/g were superior to 0.99. The limit of detection (LOD) inferred from Cu I 324.75 nm /CN 358.6 nm fitting curve was 0.77 μg/g and met the critical value specified by industry standards. Due to its flexibility, it can be used as a new-type of particle concentration detection method for transformer oil.
关键词： copper particle,filter paper substrate,transformer oil,laser-induced breakdown spectroscopy
更新于2025-09-19 17:13:59