- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Effect of fluxes on luminescence properties of color-tunable Ba1.3Ca0.7SiO4:Eu2+, Mn2+ Phosphor for Near-Ultraviolet White-LEDs
摘要： Eu2+/Mn2+-codoped Ba1.3Ca0.7SiO4 (BCS), a promising single-phase and white-light-emitting phosphor, is prepared by the solid-state reaction at a calcination temperature of 1000 °C for 2 h by adding SrCl2, CaCl2, KCl, NaCl, NH4Cl, Li2CO3, BaF2, CaF2, and BaCl2 as fluxes. The samples are characterized by X-ray diffraction and photoluminescence spectroscopy. The emission wavelength and color-rendering index (CRI) can be tuned by adjusting the amount of the BaCl2 flux and are influenced by the different flux types. NH4Cl exhibits the best fluxing effect for the Mn2+ ion doping probably because the formed eutectic mixtures of BaCl2–CaCl2 during the reaction process promote the reaction. The phosphors produced by adding a SrCl2 flux exhibit the highest CRI of 87.2 with Commision International de I’Eclairage (CIE) chromaticity coordinates of (0.347, 0.343) in the white region under near-ultraviolet light excitation.
关键词： Mn2+ ion,Color-tunable,Fluxing effect,Single-phase
更新于2025-09-19 17:13:59
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Direct Usage of Photovoltaic Solar Panels to Supply a Freezer Motor with Variable DC Input Voltage
摘要： In this paper, a single-phase photovoltaic (PV) inverter fed by a boost converter to supply a freezer motor with variable DC input is investigated. The proposed circuit has two stages. Firstly, the DC output of the PV panel that varies between 150 and 300 V will be applied to the boost converter. The boost converter will boost the input voltage to a fixed 300 V DC. Next, this voltage is supplied to the single-phase full bridge inverter to obtain 230 V AC. In the end, The output of the inverter will feed a freezer motor. The PV panels can be stand-alone or grid-connected. The grid-connected PV is divided into two categories, such as with a transformer and without a transformer, a transformer type has galvanic isolation resulting in increasing the security and also provides no further DC current toward the grid, but it is expensive, heavy and bulky. The transformerless type holds high efficiency and it is cheaper, but it suffers from leakage current between PV and the grid. This paper proposes a stand-alone direct use of PV to supply a freezer; therefore, no grid connection will result in no leakage current between the PV and Grid. The proposed circuit has some features such as no filtering circuit at the output of the inverter, no battery in the system, DC-link instead of AC link that reduces no-loads, having a higher efficiency, and holding enough energy in the DC-link capacitor to get the motor started. The circuit uses no transformers, thus, it is cheaper and has a smaller size. In addition, the system does not require a complex pulse width modulation (PWM) technique, because the motor can operate with a pulsed waveform. The control strategy uses the PWM signal with the desired timing. With this type of square wave, the harmonics (5th and 7th) of the voltage are reduced. The experimental and simulation results are presented to verify the feasibility of the proposed strategy.
关键词： photovoltaic,boost converter,pulse width modulation,single-phase inverter
更新于2025-09-19 17:13:59
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A novel photovoltaic inverter topology based on common mode current suppression
摘要： Aiming at the problems of large leakage current and low efficiency of existing transformerless single-phase grid-connected photovoltaic inverters, a novel transformerless single-phase grid-connected photovoltaic inverter topology is proposed. In this topology, two freewheeling diodes are added to the single-phase full-bridge inverter, and the filter inductors are moved between the upper and lower bridge arms, so that the common mode voltage remains constant during the switching period and the common mode current is effectively suppressed. Meanwhile the high frequency switch uses MOSFET to reduce the switching loss, and the power frequency switch uses IGBT to reduce the conduction loss, and additional switches are avoided, thus the overall system losses are reduced. Finally, through simulation and the experimental platform of 3kW single-phase grid-connected photovoltaic inverter, it is verified that compared with the traditional full-bridge topology, the novel topology can effectively suppress the common mode current, while compared with the H5 and H6 topology, the novel topology reduces the system loss and improves the system efficiency.
关键词： efficiency,loss,single-phase grid-connected photovoltaic inverter,transformerless,common mode current
更新于2025-09-19 17:13:59
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[IEEE 2018 3rd IEEE International Conference on Recent Trends in Electronics, Information & Communication Technology (RTEICT) - Bangalore, India (2018.5.18-2018.5.19)] 2018 3rd IEEE International Conference on Recent Trends in Electronics, Information & Communication Technology (RTEICT) - Dynamic Phasor-Based Modeling of a Single-Phase Photovoltaic System
摘要： This paper develops an analytical model for single phase photovoltaic system. The model contains LCL filter and proportional resonance controller for inverter current control. The analytical model is based on dynamic phasor approach. In this technique the system quantities are described as fourier coefficients. These fourier coefficients are varying with time. The model built using dynamic phasor technique has ability to analysis the small signals. The model is built in MATLAB and it finds to be more accurate and allow large step size simulation resulting in less computational time.
关键词： proportional resonance controller,Single phase photovoltaic,dynamic phasor,filter
更新于2025-09-19 17:13:59
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[IEEE 2019 14th IEEE Conference on Industrial Electronics and Applications (ICIEA) - Xi'an, China (2019.6.19-2019.6.21)] 2019 14th IEEE Conference on Industrial Electronics and Applications (ICIEA) - Analysis and Design of a Novel Transformer-less-Inverter in Grid-Connected Photovoltaic System
摘要： The continuous urge for improvement in our standard of living has increased the consumption of electrical energy by leaps and bounds. This hike in energy consumption, draining of fossil fuels and degrading global environment has led to invention of green power generation systems. Thus, the global demand for renewable resources has led to flourishing of photovoltaic (PV) market. The enabling technology in the PV systems is the inverter, which could be either: 1) with transformer isolated or 2) without transformer non-isolated (transformer-less inverter). Recently, single phase transformer- less voltage source inverters (VSI) have been extensively used for distributed photovoltaic grid tied systems. The objective of this paper is to review a few notable topologies and propose a new topology for transformer-less photovoltaic inverter. The analysis and design of the proposed topology is verified by simulating it on PSIM. Furthermore, the simulation results are validated by testing a proof-of-concept laboratory hardware prototype rated at 250 W.
关键词： Photovoltaic (PV) systems,transformer-less,single phase inverter
更新于2025-09-16 10:30:52
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[IEEE 2019 Second International Conference on Advanced Computational and Communication Paradigms (ICACCP) - Gangtok, India (2019.2.25-2019.2.28)] 2019 Second International Conference on Advanced Computational and Communication Paradigms (ICACCP) - Design and Analysis of an $H_{\infty}$ Controller for a Single Phase Grid Connected Photovoltaic System with Parametric Uncertainties
摘要： This paper presents the synthesis of a H∞ controller for a single phase single stage grid connected photovoltaic (PV) system. The PV array is integrated to the utility grid using an inverter and a filter. Many a times while deriving the mathematical model of a system, there exists some discrepancy between the actual and the derived model of the system. Hence these uncertainties should be taken into account while deriving the controller for the system in order to achieve robust stability. Here the robust controller is designed taking into consideration the uncertainty in the parameters R, L and C. An appropriate state space model of the system is derived in order to facilitate the controller design with the perturbations. Here the controller is designed to as to meet the required objective of good reference tracking, disturbance rejection and robust stability. The controller design step involves the proper selection of weighing function and solution of the cost functions. The cost functions in this case are transfer function from exogenous inputs to output of the system to be minimized. It was observed that in order to achieve the required performance criteria the infinity norm of the cost functions should be less than unity. For this an h infinity optimization problem was solved using the hinfsyn command in MATLAB. A transient analysis was done in MATLAB simulation to see the effect of output disturbance on the system performance. A μ-synthesis was further done to test whether the system is robustly stable under parametric uncertainties. It was found that the designed controller is robustly stable, effectively track the reference input given to the system. Also the effect of disturbances in the system output is minimized.
关键词： Photovoltaic system,single-phase grid,H∞ controller,parametric uncertainties
更新于2025-09-12 10:27:22
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Fast synthesis and energy transfer of the tunable single-phase white-emitting phosphor Li2Gd4(WO4)7:Dy3+, Tm3+ for WLEDs
摘要： A series of Dy3+ and Tm3+ co-doped Li2Gd4(WO4)7 (LGW) single-phase white phosphors were fast synthesized by microwave assisted solid-state reaction method. Single-ion doped LGW:Dy3+ and LGW:Tm3+ phosphors were synthesized to obtain quenching concentrations. The ideal white light (0.33, 0.33) locates on the straight line that connects the Commission Internationale de L'Eclairage (CIE) coordinates of LGW:Dy3+ and LGW:Tm3+. Therefore, Dy3+ and Tm3+ were selected to co-dope LGW to realize white light emission. By changing Dy3+ concentration, white light was obtained under the excitation wavelengths of 356 nm and 363 nm. Luminescence decay curves and the emission spectra of the co-doped phosphors were characterized to verify the existence of energy transfer between Tm3+ and Dy3+ in this single-phase phosphor. Energy transfer efficiency and energy transfer mechanism were investigated in detail. This fast synthesized single-phase white phosphor LGW:Dy3+, Tm3+ is a good candidate for the white light emitting diodes.
关键词： White emitting,Energy transfer,Single phase,Fast synthesis
更新于2025-09-12 10:27:22
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AIP Conference Proceedings [AIP Publishing TECHNOLOGIES AND MATERIALS FOR RENEWABLE ENERGY, ENVIRONMENT AND SUSTAINABILITY: TMREES19Gr - Athens, Greece (4–6 September 2019)] TECHNOLOGIES AND MATERIALS FOR RENEWABLE ENERGY, ENVIRONMENT AND SUSTAINABILITY: TMREES19Gr - Optimization of the fuzzy MPPT controller by GA for the single-phase grid-connected photovoltaic system controlled by sliding mode
摘要： This paper focuses on the performance of a single-phase inverter coupled to the grid in terms of optimal photovoltaic transfer, using the concept of sliding-mode variable structure systems. Moreover, a fuzzy logic control technique optimized by genetic algorithm (GA) associated with a boost converter is used to extract the Maximum Power Point Tracking (MPPT).The validation of the results using Matlab/Simulink software is carried under different environmental and operating conditions to verify the satisfactory performance of the proposed control strategies.
关键词： Photovoltaic generator,fuzzy logic_GA,sliding mode,single-phase,MPPT
更新于2025-09-12 10:27:22
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Fault Tolerant Control System for Photovoltaic Panels Application
摘要： The paper presents a solution to control the power delivery system in a microgrid in which the primary energy source is using photovoltaic panels. The proposed mathematical models describe the operation of the main system blocks and are used as reference models in the fault detection mechanism. Using a complex control strategy, the generated power is controlled and the effects of the disturbances which occur in the system, including the faults, are rejected, making the proposed solution a robust and a fault tolerant one. The integrated control solution contains algorithms for the appropriate control of both the boost DC/DC converter and of the single phase inverter blocks. The proposed approaches are directed toward developing algorithms suitable for real-time implementation on 32 bit ARM processors.
关键词： Power Delivery System,Power Electronics Control,32 bit ARM (Advanced RISC Machine) processor,Microgrids,Renewable Energy Systems,Single Phase Inverter,Fault Detection
更新于2025-09-12 10:27:22
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[IEEE 2019 IEEE 16th International Conference on Smart Cities: Improving Quality of Life Using ICT & IoT and AI (HONET-ICT) - Charlotte, NC, USA (2019.10.6-2019.10.9)] 2019 IEEE 16th International Conference on Smart Cities: Improving Quality of Life Using ICT & IoT and AI (HONET-ICT) - Novel Direct Power Control Strategy for Single-Phase Photovoltaic Inverters
摘要： In the design of inverter controllers, a phase-locked loop (PLL) is usually used to synchronize the inverter output with power grids. However, the adoption of PLL may increase the complexity of the controller. In addition, the accuracy of the PLL can be impacted if the power quality of the power grid is distorted, and the inaccurate PLL output can degrade the performance of the controller. To overcome these issues, a number of non-PLL control strategies have been studied for the single-phase PV inverter. In this work, a novel non-PLL direct power control strategy (DPC) for single-phase H-bridge SVPWM photovoltaic (PV) inverters are proposed. In this strategy, instantaneous real and reactive power are calculated respectively by using voltage and current components with specific frequencies. Then a maximum power point tracker (MPPT) technique is integrated with the strategy to maximize PV generation. Simulation results demonstrate the effectiveness of the proposed strategy.
关键词： phase-locked loop,single-phase H-bridge inverter,Direct power control,SVPWM,photovoltaic generation
更新于2025-09-11 14:15:04