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[IEEE 2018 International Conference on Intelligent and Innovative Computing Applications (ICONIC) - Mon Tresor, Plaine Magnien, Mauritius (2018.12.6-2018.12.7)] 2018 International Conference on Intelligent and Innovative Computing Applications (ICONIC) - Innovative Method for Power Factor Correction using a Solar Plant as a Source of Reactive Power
摘要： Due to the low power factor of an electrical system there is a high demand of reactive power from the transformers which results in overloading of the transformers. Traditionally, this problem is solved by adding a capacitor in parallel with the load in order to correct the power factor. In this paper a new innovative method which utilizes the solar plant at night when it is idling or during the day when it is not producing real power. During these times a solar plant is used as a source of reactive power, the inverters used in solar plants are capable of being used as a source of reactive power. The case study used to test this innovative method is a food processing plant with multiple transformers. The results show that it is possible to use a solar plant for power factor correction and hence relieve the transformers from overloading issues.
关键词： solar,transformer,overloading,power factor,reactive power
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE International Meeting for Future of Electron Devices, Kansai (IMFEDK) - Kyoto, Japan (2018.6.21-2018.6.22)] 2018 IEEE International Meeting for Future of Electron Devices, Kansai (IMFEDK) - Thermoelectric Conversion Devise Using Ga-Sn-O Thin Film Prepared by Mist CVD Method
摘要： We proposed a GTO thin film thermoelectric conversion devise by the mist CVD method. The thermoelectric conversion devise with the best performance had a Seebeck coefficient of -193[μV/K], a conductivity of 6.35[S/cm], and a PF of 0.0179[mW/mK2].
关键词： Ga-Sn-O,Seebeck coefficient,conductivity,mist CVD,power factor
更新于2025-09-23 15:23:52
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Structural, electrical, optical and thermoelectric properties of e-beam evaporated Bi-rich Bi2Te3 thin films
摘要： Bi-rich Bi2Te3 thin films are prepared at 300 K using e-beam evaporation technique. A source power of 45 W for e-beam was used. Post deposition, these as-deposited Bi-rich Bi2Te3 (Bi-BT-AD) films are annealed at 100 °C (Bi-BT-100), 200 °C (Bi-BT-200) and 300 °C (Bi-BT-300) for 1 h under a pressure of 3 × 10-4 Pa. X-ray diffraction measurements reveal the presence of Bi phase together with crystalline Bi2Te3 indicating the possible presence of Bi-rich Bi2Te3 phase in the Bi-BT-AD film. The broad peaks from Bi2Te3 (015) plane indicates nanocrystalline nature of particles. With annealing, no change in diffraction pattern is observed for Bi-BT-100. However, Bi-BT-200 and Bi-BT-300 films show the emergence of x-ray reflection from unknown phases around 2θ ~ 20° and 47°. This indicates Bi related secondary phase segregation and the thermodynamic instability for the presence of Bi in Bi2Te3 lattice. From Raman studies it is discerned that Bi secondary phase coexist along with the Bi-rich Bi2Te3 nanocrystalline grains. On vacuum annealing Bi-rich Bi2Te3 thin films prevails as evidenced from the p-type electrical characteristics, while excess Bi disappears and converts into an unknown minor phase. The resistivity of all the annealed films are ~ 0.9 × 10-4 Ωcm. The Seebeck coefficients also do not show any change and remain around 33 to 36 μV/K. Thermoelectric properties of Bi-BT-100 exhibit high power factors when measured at different ΔT with a maximum of ~ 17.5 × 10-4 W/K2m for ΔT=100 °C. Thus, unlike the near-stoichiometric thin films, Bi-rich thin films require low temperature annealing (~100 °C) to achieve optimized parameters. Bi-rich Bi2Te3 thin films also show higher power factor compared to the near-stoichiometric thin films. Thus, favourable thermoelectric properties can be achieved at 300 K for temperature sensitive device fabrication using Bi-rich Bi2Te3 thin films.
关键词： Bismuth-rich bismuth telluride,thin films,electron-beam evaporation,power factor.
更新于2025-09-23 15:23:52
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[IEEE 2018 International Conference on Electronics, Control, Optimization and Computer Science (ICECOCS) - Kenitra, Morocco (2018.12.5-2018.12.6)] 2018 International Conference on Electronics, Control, Optimization and Computer Science (ICECOCS) - Backstepping Control for Three Phase Single Stage Grid Connected PV System with Improved Power Quality
摘要： The development of PV-systems has increased due to the high demand for clean energy. Used worldwide in the distributed power generation markets, the photovoltaic energy must not only be maximized, but also adapted to the global standards on harmonic emissions towards the power utility. Hence, the tracking of the maximum power point and the harmonic filtering becomes necessary. A three-phase single stage grid-connected Photovoltaic system consisting of a photovoltaic array and a three-phase PWM inverter coupled through the LCL-filter to the electrical grid is studied in this paper. A new control design is developed to maximize power in the side of PV panels and to ensure a unit power factor at the grid side. Grid synchronization is provided by a three-phase PLL (Phase-Locked Loop) and the closed-loop stability is demonstrated using Lyapunov analysis. Simulation results clearly illustrate that the proposed controller has achieved all of its objectives. In order to demonstrate the performance of the LCL-filter in minimizing the harmonics produced by the photovoltaic inverter, the frequency response of the injected currents was compared to that obtained using a simple L-filter.
关键词： backstepping controller,PV systems,maximum power point tracking,three-phase inverter,LCL-filter,unity power factor,grid connection
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE 6th Workshop on Advances in Information, Electronic and Electrical Engineering (AIEEE) - Vilnius, Lithuania (2018.11.8-2018.11.10)] 2018 IEEE 6th Workshop on Advances in Information, Electronic and Electrical Engineering (AIEEE) - 18-pulse Rectifier with Electronic Phase Shifting with Autotransformer in Inverter and Rectifier Mode
摘要： To reduce harmonic distortion of the input current, multipulse rectifiers are used. They require the presence of phase-shifting transformers or autotransformers. Elimination of electromagnetic phase-shifting devices while maintaining small harmonic distortion of the input current and obtaining a power factor close to unity is possible with the use of electronic phase shift. The electronic phase shift is realized by means of the rectifier itself: the introduction of positive and negative control angles in the pairs of rectifiers’ modules. At present, 12-pulse rectifiers with electronic phase shift are known. Unlike classic rectifiers, they do not use phase-shifting transformers and have a unit power factor. Increasing of the rectifier’s pulse makes it possible to improve the harmonic composition of the input current. The use of the principle of electronic phase shift in 18-pulse rectifier leads to different levels of constant voltage at the output of the rectifiers. In this case, to equalize the currents of rectifiers’ modules, one can use both an increase the voltage at the input of rectifiers operating with large control angles and a decrease the input voltage of the rectifiers operating with smaller control angles. The principles of constructing of matching autotransformers for the 18-pulse rectifier with an electronic phase shift are considered in the article. Comparison of 18-pulse rectifiers with use of step-up and step-down autotransformers is made. Data on the installed capacity of autotransformers, power losses are obtained. The results of thermophysical modeling are presented. When comparing the parameters of the matching magnetic elements, it can be concluded that it is more appropriate to use a step-down autotransformer.
关键词： pulse-width modulation,magnetic elements,electronic phase shifting,rectifiers,power factor
更新于2025-09-23 15:22:29
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[IEEE 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Trebic, Czech Republic (2018.9.18-2018.9.20)] 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Electrical Parameters of Dimmable Luminaire
摘要： Lighting systems are currently one of the main uses of electricity. The most popular option for reducing of electricity consumption is the use of dimming. Dimming is a type of regulation in which we can regulate luminous flux of a lamps and luminaires. This system of regulation is used in the road lighting industry, but also in households. Dimming allows adaptation of the lighting system according to specific requirements and various ambient conditions such as traffic density, daylight, etc. The regulation of the luminous flux depending on the dimming system can affect the electrical parameters of the luminaires such as the power factor. The article deals with the electrical parameters of luminaires with various lamps at different types of dimming.
关键词： LED,total harmonic distortion,Power factor
更新于2025-09-23 15:21:21
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An efficient wide input wide output <scp>CrCM flyback</scp> converter <scp>in high</scp> a??power <scp>LED</scp> lighting
摘要： This paper deals with a power factor corrected (PFC) flyback converter for high-power light emitting diode lighting applications. This flyback converter is designed to operate in critical conduction mode to achieve improved power quality at universal AC mains and high efficiency with the low component count. The converter is analyzed using state-space analysis with closed-loop stability under varying input and output conditions. The PFC converter is designed and implemented with wide input and wide output variations. The performance of the prototype is also investigated for improved power quality such as power factor and harmonics distortion of AC mains current at universal AC mains of 85 to 265 V. The achieved efficiency of this converter is 92% and total harmonic distortion is less than 6% over universal AC mains for a prototype of 100 W, which are much improved results as compared to discontinuous conduction mode operation of the same converter.
关键词： state-space analysis,bode plot,power factor correction,critical conduction mode,stability,LED,power quality
更新于2025-09-23 15:21:01
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Three-Legs Interleaved Boost Power Factor Corrector for High-Power LED Lighting Application
摘要： In this article, a three-leg interleaved boost Power Factor Corrector (IBPFC) converter for energy-efficient LED lighting systems connected to the main grid was discussed. This IBPFC circuit presented features 60 kHz of commutation frequency and up to 3 kW of power rating. The controlled rectifier front-end boost PFC supplied a DC/DC converter to drive power LEDs suitable for street lighting or a lighting system for a stadium, etc. The IBPFC operated in continuous current mode (CCM). The ripple impact of the IBPFC converter was analyzed and a novel methodology of inductance design was presented. In the proposed design approach, the derivative calculation of the current ripple peak compared with the derivative of the input current was used to define a critical inductance value to ensure the CCM condition. Experimental validation was provided on a 3kW prototype.
关键词： IGBT,continuous current mode (CCM),interleaved converters,three-phase boost converter,ripple analysis,high-power LED lighting,power factor correction (PFC)
更新于2025-09-23 15:21:01
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[IEEE 2020 IEEE Texas Power and Energy Conference (TPEC) - College Station, TX, USA (2020.2.6-2020.2.7)] 2020 IEEE Texas Power and Energy Conference (TPEC) - A Simplified DC Capacitor Active Voltage-Balance Algorithm with Common-Mode Voltage Reduction using Active-Zero SVPWM for Three-Level Photovoltaic Grid-Tie Inverter Application
摘要： This paper introduces a digitally controlled single-phase rectifier with power factor correction (PFC) based on a modified three-level boost converter topology. In comparison with the conventional boost-based systems, the new PFC rectifier has about three times smaller inductor and significantly lower switching losses. The improvements are achieved by replacing the output capacitor of the boost converter with a nonsymmetric active capacitive divider, with a 3:1 division ratio, and by utilizing the downstream converter stage for the capacitive divider’s center-tap voltage regulation. The nonsymmetric voltage divider and applied switching sequence effectively provide four-level converter behavior using the same number of components as three-level converters. As a result, a 66% reduction of the inductor compared to the conventional boost-based PFC and a 33% compared to the standard three-level solutions operating at the same effective switching frequencies are also achieved. Experimental results obtained with a 400 W, 200 kHz, universal input voltage (85 Vrms –265 Vrms) PFC prototype demonstrate three times smaller inductor current ripple than that of the conventional boost converter allowing for the same inductor reduction. Efficiency improvements of up to a 6% are also demonstrated.
关键词： boost converter,power factor correction (PFC),multilevel converters,AC-DC converters
更新于2025-09-23 15:21:01
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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