- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[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) - A New Step-Up Transformerless Inverter Topology for 1-é? Grid-connected Solar Photovoltaic System
摘要： In this paper, a step-up transformerless inverter topology is investigated for the grid-connected solar PV system. This proposed topology combines the features of the DC-DC step-up converter and two-level inverter. The important features of this topology are: First, the proposed topology keeps the negative terminal of the PV source directly connected with the neutral of the grid. Therefore, there is no variation in the CMV, which appears across the PV parasitic capacitance, resulting in negligible leakage current and higher efficiency. Negligible leakage current makes this topology highly suitable for transformerless grid-connected solar PV application; second, due to the step-up feature of the proposed topology, the inverter output voltage can be greater than the input DC voltage of solar PV which makes the proposed topology suitable for connecting lower voltage solar PV modules. The topology works with a simple and dedicated PWM scheme, which consists of certain logic operations as explained in the text. The modes of operation, design of the converter, PWM strategy, and analysis are presented in detail. The MATLAB/Simulink environment is used to simulate the proposed grid-connected system for 300W power rating and all the results are included in the paper, which shows that the proposed system gives higher efficiency with lower THD in grid-current.
关键词： PV fed system,Leakage current,Two-level inverter,step-up transformer-less inverter,DC-DC converter
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 25th International Symposium for Design and Technology in Electronic Packaging (SIITME) - Cluj-Napoca, Romania (2019.10.23-2019.10.26)] 2019 IEEE 25th International Symposium for Design and Technology in Electronic Packaging (SIITME) - Analysis of positioning errors for LED
摘要： Conventional practice for transformer dissolved gas analysis (DGA) is to use concentrations of several fault gases, with or without total dissolved combustible gas, for evaluating apparent fault severity. We suggest a simpler approach based on the normalized energy intensity (NEI), a quantity related directly to fault energy dissipated within the transformer. DGA fault severity scoring based on NEI is shown to be sensitive to all IEC fault types and to be more responsive to shifts in the relative concentrations of the fault gases than scoring based on fault gas concentrations. Instead of eight or more gas concentration limits, NEI scoring requires only two or three limits that can be empirically derived to suit local requirements for any population of mineral-oil-filled power transformers.
关键词： fault energy,fault severity,Dissolved gas analysis (DGA),normalized energy intensity (NEI),transformer,enthalpy
更新于2025-09-23 15:21:01
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[IEEE 2019 20th International Conference on Intelligent System Application to Power Systems (ISAP) - New Delhi, India (2019.12.10-2019.12.14)] 2019 20th International Conference on Intelligent System Application to Power Systems (ISAP) - Voltage Control Using Smart Transformer for Increasing Photovoltaic Penetration in a Distribution Grid
摘要： Uncertainty and variation of power generation through photovoltaic (PV) sources are major challenges for their integration with the distribution grid. Voltage rise and voltage drop issues limit the increase in PV penetration and loading level, respectively. It is important to maintain voltage levels within specified limits of grid code for providing long life, more efficiency, and good performance of consumer equipment while ensuring that the PV power generation is not curtailed. In this paper, a voltage control method for the smart transformer (ST) is proposed to improve voltage profile in the distribution network. Voltage control capability for ST is added through the method of switching among three setpoints based on the voltage. The proposed method is compared with the conventional method of switching between two setpoints based on current. The proposed method provides better voltage profile in the distribution network as compared to conventional method. Performance indicators are developed to understand the impact of voltage control methods on the system voltage profile. Proposed voltage control method is tested on a CIGRE low voltage residential distribution network.
关键词： voltage control,smart transformer,Renewable energy sources
更新于2025-09-23 15:21:01
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Optimization of optical current sensor based on rare-earth magneto-optical glass
摘要： Compared to the present diamagnetic glass used in the sensing element of optical current sensors (OCSs), the high-sensitivity characteristics of the rare-earth magneto-optical glass (REMOG) can significantly improve the performance of an REMOG sensing element. The optimization objective of this study was to enhance the sensitivity of the sensing element and reduce linear birefringence. Theoretical analysis and experimental data were combined to study the practical influences of a few factors, such as the size and spatial position of the glass, the wavelength of the incident light, and the rare-earth doping concentration, on the sensitivity of an OCS sensing element. Finally, an optimal parameter combination was obtained. The experimental results showed that the response sensitivity of the REMOG sensing element is seven times the sensitivity using diamagnetic glass.
关键词： sensitivity,paramagnetic material,optical current transformer
更新于2025-09-23 15:21:01
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[Lecture Notes in Electrical Engineering] Microelectronics, Electromagnetics and Telecommunications Volume 521 (Proceedings of the Fourth ICMEET 2018) || Performance Analysis of a PV System Using HGB Converter
摘要： A photovoltaic array based system using a transformer-less high gain interleaved dc–dc boost converter is proposed in this paper. The renewable energy sources such as photovoltaic array and fuel cells provide only a time-varying and low dc voltage which cannot be directly used as the front-end for the loads or dc grid. Hence, there is a need for power electronic interfaces for matching the environmental-friendly sources of energy to the load. The interleaved converter used in the proposed system has the capability of canceling the input current ripple without increasing the component counts in the converter using a preselected duty cycle. Also, the large voltage gain and high ef?ciency of the converter are the added advantages to the proposed system. Analysis, simulation, and experimental investigation of the system proposed were carried out and the results are compared to validate the proposed system effectiveness.
关键词： Photovoltaic array,Interleaving technique,A high gain boost converter,Transformer-less dc–dc converter
更新于2025-09-23 15:21:01
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An Ea??band digitally controlled oscillator with <i>effective</i> tuning bank
摘要： An E-band digitally controlled oscillator (DCO) with effective tuning bank is presented and fabricated in 40 nm CMOS technology. The DCO is promoted with an effective fine tuning bank based on a binary-weighted switched capacitors array connected with the secondary coil of an effective flipped stacked transformer with weak mutual coupling factor to improve the tradeoff relationship among tuning range, circuit complexity and frequency resolution. The measured best fine tuning step of the DCO is 2.21 MHz. The operating frequencies range of the DCO covers from 76.61 to 84.51 GHz. The DCO also achieves a figure of merit normalized for area (FoMA) of ?185.1 dBc/Hz.
关键词： CMOS,tuning bank,transformer,DCO,E-band
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE BiCMOS and Compound semiconductor Integrated Circuits and Technology Symposium (BCICTS) - Nashville, TN, USA (2019.11.3-2019.11.6)] 2019 IEEE BiCMOS and Compound semiconductor Integrated Circuits and Technology Symposium (BCICTS) - A Compact Ka-Band Transformer-Coupled Power Amplifier for 5G in 0.15um GaAs
摘要： In this paper we present the design of a compact and broadband transformer-coupled power ampli?er in a 0.15μm GaAs technology. The power ampli?er achieves an output power of 26.5dBm and 31% power added ef?ciency, 12.6dB of small signal gain with a fractional bandwidth of 40%. The ampli?er enables up to 21.6dBm, 19.9dBm of average output power while amplifying a 6Gb/s, 9Gb/s 64-QAM signal respectively at 28GHz with an EVM<-25dB without any digital pre-distortion. To the author’s knowledge, this is the ?rst time transformer-coupled matching networks are used in a GaAs power ampli?er leading to very compact matching structures compared to bulky transmission line.
关键词： 5G,Power Ampli?er,Millimeter wave integrated circuits,Transformer-Coupled,Ka-band
更新于2025-09-23 15:19:57
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Ultra-high sensitivity temperature sensor using a fiber loop mirror based on a water-filled asymmetric two-hole fiber
摘要： Conventional practice for transformer dissolved gas analysis (DGA) is to use concentrations of several fault gases, with or without total dissolved combustible gas, for evaluating apparent fault severity. We suggest a simpler approach based on the normalized energy intensity (NEI), a quantity related directly to fault energy dissipated within the transformer. DGA fault severity scoring based on NEI is shown to be sensitive to all IEC fault types and to be more responsive to shifts in the relative concentrations of the fault gases than scoring based on fault gas concentrations. Instead of eight or more gas concentration limits, NEI scoring requires only two or three limits that can be empirically derived to suit local requirements for any population of mineral-oil-filled power transformers.
关键词： enthalpy,Dissolved gas analysis (DGA),normalized energy intensity (NEI),fault energy,transformer,fault severity
更新于2025-09-23 15:19:57
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[IEEE 2019 8th International Conference on Renewable Energy Research and Applications (ICRERA) - Brasov, Romania (2019.11.3-2019.11.6)] 2019 8th International Conference on Renewable Energy Research and Applications (ICRERA) - The Closed Loop Controller Gain Characterization for Enhanced Current Quality in Solar Inverters Coupled with Weak Grid
摘要： Majority of solar installations are coming up in remote locations where the stiffness of the grid is very weak, enforces to connect solar inverters to weak grid. In weak grid scenario, solar inverter would inject harmonic current into the grid that affect the power quality of the system. The solar inverters are designed to operate with stiff grid in which the closed (feedback and feed forward) loop control is planned by considering absolute decoupling between the direct and quadrature grid injected current. With the conventional design speci?cations in weak grid scenario, the absolute decoupling between the direct and quadrature current cannot be achieved due to grid inductance. The improper decoupling would create the oscillations in the grid injected current that result in increased harmonic distortion. To compensate the current oscillations, the current controller feedback loop gain need to be designed by accessing the degree of coupling. Since the grid injected current sensed at the point of common coupling and transformed to DC quantities (direct current id and quadrature current iq) using synchronous angle, the same current oscillations appear in d-axis and q-axis current control loop. In this work, the d-axis and q-axis loop oscillations with respect to grid inductance are analyzed analytically. Based on the analysis the d-axis and q-axis PI controllers are designed independently unlike conventional PI controller to ensure not only faster dynamic response of the system but also improved power quality.
关键词： closed loop control,weak grid,PI controllers,current THD,Grid connected solar inverter,single stage transformer less grid connected inverter,Power quality
更新于2025-09-23 15:19:57
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[IEEE 2018 Eighth International Conference on Instrumentation & Measurement, Computer, Communication and Control (IMCCC) - Harbin, China (2018.7.19-2018.7.21)] 2018 Eighth International Conference on Instrumentation & Measurement, Computer, Communication and Control (IMCCC) - Research on Internal Temperature of Transformer Internal Temperature Based on Optical Fiber Sensing Technology
摘要： Transformer is an important link of power system, and its operation state directly affects the security and stability of power system operation. With the continuous development of the national economy and the continuous improvement of the people's needs, the power grid load has been continuously improved, and the capacity of the transformer has been continuously expanded, and the accident rate has increased accordingly. According to related statistics, more than 66 kv transformer of the world's average accident rate over 0.89%, especially for winding in transformer winding overtemperature operation, result insulation aging and breakdown, accident of burning large ratio (according to the statistics, about 80% of the accident rate above). For oil-immersed power transformer, the time depends on the service life of solid insulating materials (fiber paper), prompting insulation materials is the main factor of aging temperature, moisture and oxygen, heat effect of transformer insulation aging is the decisive factor, therefore the transformer internal main parts (winding and iron core, the place such as insulating oil) temperature decides the service life of the transformer temperature due to the electric power equipment testing environment with high voltage and strong electromagnetic interference, and space is narrow, the traditional method cannot directly on the power equipment temperature state of online measurement, and a new temperature measuring system based on semiconductor optical fiber sensing technology has small volume, good insulation, good resistance to electromagnetic interference, temperature measurement consistency, can be directly installed on the transformer and other power equipment inside, can accurate and fast reflect the change of the internal temperature of main components of power transformer, the transformer winding and iron core, the place such as insulating oil temperature real-time online measurement.
关键词： Fiber coupler,Fiber Bragg grating,F-P filter,transformer
更新于2025-09-23 15:19:57