共查询到20条相似文献，搜索用时 15 毫秒
1.
Hadi Moradisizkoohi Jafar Milimonfared Meghdad Taheri Sina Salehi 《International Journal of Circuit Theory and Applications》2016,44(6):1290-1307
This paper presents a high step‐up soft switched dc–dc converter having the feature of current ripple cancelation in the input stage that is specialized for power conditioning of fuel cell systems. The converter comprises a special half‐bridge converter and a rectifier stage based upon the voltage‐doubler circuit, in which the coupled‐inductor technology is amalgamated with switched‐capacitor circuit. The input current with no ripple is the principal characteristics of this topology that is achieved by utilizing a small coupled inductor. In addition, the low clamped voltage stress across both power switches and output diodes is another advantage of the proposed converter, which allows employing the metal–oxide–semiconductor field‐effect transistors with minuscule on‐state resistance and diodes with lower forward voltage‐drop, and thereby, the semiconductors' conduction losses diminish considerably. The inherent nature of this topology handles the switching scheme based on the asymmetrical pulse width modulation in order for switches to establish the zero voltage switching, leading to lower switching losses. Besides, because of the absence of the reverse‐recovery phenomenon, all diodes turn off with zero current switching. At last, a 250‐W laboratory prototype with the input voltage 24 V and output voltage 380 V is implemented to verify the especial features of the proposed converter. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Javad Javidan 《International Journal of Circuit Theory and Applications》2016,44(5):977-995
In this paper, a pulse width modulation DC‐DC converter with high step‐up voltage gain is proposed. The proposed converter achieves high step‐up voltage gain with appropriate duty ratio, coupled inductor, and voltage multiplier technique. The energy stored in the leakage inductor of the coupled inductor can be recycled in the proposed converter. Moreover, because both main and auxiliary switches can be turned on with zero‐voltage switching, switching loss can be reduced by soft‐switching technique. So the overall conversion efficiency is improved significantly. The theoretical steady‐state analyses and the operating principles of the proposed converter are discussed in detail for both continuous conduction mode and discontinuous conduction mode. Finally, a laboratory prototype circuit of the proposed converter is implemented to verify the performance of the proposed converter. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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In this paper, a current sensorless MPPT control method for a stand‐alone‐type PV generation system is proposed. This control method offers advantages of the simplified hardware configuration and low cost by using only one sensor to measure the PV output voltage. When used as a stand‐alone‐type with a battery load, the experimental results show that the estimated values of PV output current are accurate, and the use of the proposed MPPT control increases the PV generated energy by 16.3% compared to the conventional system. Furthermore, the authors clarified that the proposed method has an extremely high UUF (useful utilization factor) of 98.7%. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 157(2): 65– 71, 2006; Published online in Wiley InterScience ( www.interscience. wiley.com ). DOI 10.1002/eej.20424 相似文献
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Yuen‐Haw Chang Yu‐Jhang Chen 《International Journal of Circuit Theory and Applications》2016,44(3):709-728
A novel closed‐loop switched‐inductor switched‐capacitor converter (SISCC) is proposed by using the pulse‐width‐modulation (PWM) compensation for the step‐up DC–DC conversion/regulation, and together by combining the adaptive‐stage‐number (ASN), control for the higher switch utilization and wider supply voltage range. The power part of SISCC is composed of two cascaded sub‐circuits, including (i) a serial‐parallel switched‐capacitor circuit with nc pumping capacitors and (ii) a switched‐inductor booster with mc resonant capacitors, so as to obtain the high step‐up gain of (nc + 1) × mc /(1 ? D) at most, where D is the duty cycle of PWM adopted to enhance output regulation as well as robustness to source/loading variation. Besides, the ASN control is presented with adapting the stage number n (n = 0, 1, 2, …, nc) of pumping capacitors to obtain a flexible gain of (n + 1) × mc /(1 ? D), and further in order to make the SISCC operating at a properly small duty cycle for improving switch utilization and/or supply voltage range. Some theoretical analysis and control design include formulation, steady‐state analysis, ASN‐based conversion ratio, efficiency, output ripple, stability, inductance and capacitance selection, and control design. Finally, the performance of this scheme is verified experimentally on an ASN‐based SISCC prototype, and all results are illustrated to show the efficacy of this scheme. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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S. Salehi Dobakhshari M. Taheri Amin Banaiemoghadam J. Milimonfared S.H. Fathi 《International Journal of Circuit Theory and Applications》2018,46(10):1899-1916
This study presents a new high step‐up, high efficiency, flyback‐forward converter. The proposed converter employs 2 transformers, operating in flyback and forward modes at different intervals, to achieve the high voltage gain. In favor of high power density, transformers have been installed on 1 core. Furthermore, all switches are turned on under zero voltage switching condition, and all diodes are turned off under zero current switching condition. Also, the proposed converter utilizes resonant operation that leads to a reduction in switching loss, turning the converter to a highly efficient one. A 150‐W prototype has been implemented to verify the theoretical analysis, and a complete analysis has been done to investigate the effect of transformers integration. 相似文献
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Yie‐Tone Chen Wei‐Cheng Lin Ruey‐Hsun Liang 《International Journal of Circuit Theory and Applications》2015,43(8):967-983
This paper proposed a novel high step‐up converter with double boost paths. The circuit uses two switches and one double‐path voltage multiplier cell to own the double boost and interleaved effects simultaneously. The voltage gain ratio of the proposed DC‐DC converter can be three times the ratio of the conventional boost converter such that the voltage stress of the switch can be lower. The high step‐up performance is in accordance with only one double‐path voltage multiplier cell. Therefore, the number of diodes and capacitors in the proposed converter can be reduced. Furthermore, the interleaved property of the proposed circuit can reduce the losses in the rectifier diode and capacitor. The prototype circuit with 24‐V input voltage, 250‐V output voltage, and 150‐W output power is experimentally realized to verify the validity and effectiveness of the proposed converter. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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提出了一种集成开关耦合电感升压-反激变换器SCIBFC(switched-coupled inductor boost-flyback converter)。该变换器具有电压增益大、效率高等特性,适合应用于光伏发电等需要高电压增益的场合。在分析电路稳态工作原理和工作模式的基础上,推导出了电路各部分的相关关系;研究了电路寄生参数对电路升压增益等的影响,为选择高电压增益电路提供定量依据。SCIBFC电路的MOS管能够实现ZCS导通和ZVS关断,同时整流二极管能够ZCS关断,实现软开关,因此可以提高电路效率并改善电路EMI。最后搭建了20 W的实验样机,验证了所提电路的正确性和可实施性。 相似文献
8.
光伏系统的最大功率点跟踪方法可以最大限度地利用光伏电池所能产生的电能,因此成为提高光伏发电系统运行效率、降低光伏电能成本的研究热点。针对目前常用的扰动观察法速度较慢、电导增量法在最大功率点附近有较大振荡的问题,提出一种改进变步长电导增量的最大功率点跟踪控制方法,该方法既具有电导增量法快速跟踪的优点,又能准确、稳定地跟踪到最大功率点,因此更适于提高光伏电源的能源利用率。对所提方法进行了仿真分析,并比较了几种MPPT算法的跟踪效果,结果表明,所提方法具有快速性、稳定性和有效性。 相似文献
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提出一种带三绕组耦合电感的级联型高增益功率变换器。采用三绕组耦合电感、开关电容技术和级联结构,该变换器可实现更高电压增益。变换器的输入电感可有效降低输入电流纹波,从而减小输入电源应力。此外,耦合电感的漏感能量由输出端回收利用,提升效率的同时,能够抑制开关管的电压尖峰,降低其电压应力。详细分析带三绕组耦合电感的级联型高增益功率变换器的工作原理,以及连续导通模式下变换器的稳态性能。最后搭建一台30V输入、380V/0.3A输出的实验样机,实验结果验证了理论分析的正确性。 相似文献
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Kuo‐Ching Tseng Jia‐Huei Kang Ming‐Han Tsai Chun‐An Cheng 《International Journal of Circuit Theory and Applications》2016,44(10):1814-1827
This paper presents a high step‐up converter, which utilizes a three‐winding coupled inductor and a rectified voltage‐doubler circuit to obtain high step‐up gain for fuel cells. The proposed converter functions as an active‐clamp circuit, which relieves large voltage spikes across the power switches. Thus, power switches with low‐voltage‐rated can be utilized to reduce conduction losses and circuit cost. Energy stored in leakage inductances of the coupled inductor is recycled to the output terminal, resulting in efficiency improvements. In addition, the coupled inductor in the presented converter can also have extra windings in order to achieve higher voltage gain. Finally, a prototype circuit with an input voltage of 60 V and an output voltage of 380 V is developed for a 1000 W‐rated fuel cell power‐generation system to validate its performance, and experimental waveforms and measured efficiency under different input voltages and output power level are demonstrated. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
13.
The Vinh Nguyen Pierre Petit Michel Aillerie Chafic Salame Jean‐Pierre Charles 《International Journal of Circuit Theory and Applications》2015,43(8):1042-1062
This paper presents a specific analysis of an individual basic magnetically coupled direct current‐to‐direct current (DC–DC) converter specially designed for integration in a distributed architecture of renewable energy generators for smart grid applications. In such distributed architecture dedicated for renewable energy, parallel high‐voltage DC presents many advantages over the classical centralized one. We show that in such setup, high voltage can be advantageously produced using a specific magnetically coupled boost converter, and we point out the influence of the coupling factor, generally considered equal to one, on the overall performance of the converter and on the global energy efficiency of the installation. In this study, the generalized concepts of system energy parameters of DC–DC converters are introduced and applied to the transient analysis. Consequently, the operation of a magnetic coupled DC–DC converter with a recovery stage is modeled. The simulation results are compared with those of the behavioral study, deduced from the model pointing out the large influence of the coupling factor value on the global behavior and mainly on the value of the recovery voltage, in all the various parts of the switching cycle. The renewable energy generator operating parameters, such as current and voltage values, can then be predicted in a more useful way to compute new similar DC–DC converter systems. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Photovoltaic simulators are practical and useful tools for the evaluation of photovoltaic energy production system components, avoiding time-consuming and expensive field-testing process. This article presents an original electronic bench simulating a photovoltaic generator system including photovoltaic modules, DC-DC converters, and loads. This new electronic simulator allows the development and optimization of different topologies of generators or different converters. It can replace the load and inverter working under random external parameters. It can be used for works about photovoltaic grid injection as well as stand-alone photovoltaic systems. This simulator constitutes a specific tool for a laboratory to test photovoltaic modules under various temperature and illumination conditions, making transparent many other issues and thus allowing a complete set of simulation parameters not easily and repeatedly available in practice for the development of new photovoltaic generators. For validating the efficiency of the simulator, a detailed analytical study, using the OrCAD® PSpice® software environment of a distributed generator based on a high-voltage DC bus topology, is presented and compared to in situ experimental results achieved with the operational prototype finally developed. 相似文献
15.
Keshav Patidar Amod C. Umarikar 《International Journal of Circuit Theory and Applications》2016,44(4):817-832
A step‐up pulse width modulation (PWM) direct current (DC)–DC converter is presented in this paper, which has its origin in quasi Z‐source inverter. Analysis of this converter in steady state is presented, and relevant expressions are derived for the proposed converter operating in continuous conduction mode. The power loss expressions for each component of the converter are derived, and thereby, obtained expressions for overall converter efficiency are presented. Further, a dynamic model is derived to design an appropriate controller for this converter. The simulation and experimental results are presented to support the theoretical analysis. The advantages such as continuous input current, high step‐up gain at lower duty ratio, and common ground for source, load, and switch makes the converter suitable for renewable energy applications. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
16.
Low-concentration photovoltaic (LCPV) system has huge potential for further cost reduction of solar photovoltaic (PV) power as compared to flat panel PV. The dependence of steady state and dynamic parameters on concentration and temperature is crucial to extract maximum power from solar photovoltaic system. This article aims to present the effect of varying concentration and temperature on steady state and dynamic parameters of LCPV system under actual test conditions (ATC). The rate of change in ISC with solar irradiation i.e., dISC/dG is found as 0.25 A/W assuming ≈±1 °C change in module temperature. The effect of temperature on inherent material properties responsible for photo-conversion efficiency is studied using impedance spectroscopy technique. A linear response of series resistance of LCPV module is observed with respect to change in module temperature, i.e. dRS/dT from 297 to 333 K is in the range of 1.15–1.20 Ω with a rate of 1 mΩ/K. From real-time analysis of LCPV system open-circuit voltage found decreasing from 21 to 20.6 V with temperature coefficient of voltage ≈−0.061 V/K. The dynamic resistance has a positive coefficient of module temperature i.e., drd/dT given by 0.49 Ω/K. 相似文献
17.
光伏发电近几年得到快速发展,其出力特性的分析研究逐步深入,但还没有形成成熟的光伏出力评价指标体系。针对这个问题,提出了面向电网运行的光伏出力特性指标体系。通过理论研究和数据测算,发现光伏出力的波动性较风电明显要小、规律性较强,完全可以采用简单、精炼的指标体系来表述。提出采用指标\"季节属性\"来表征光伏发电在不同季节的可出力时段,指标\"平均出力\"来表征光伏全天出力整体水平,指标\"全日最大出力\"来表征光伏出力对系统调节能力的影响。以某实际光伏电站出力为例,分析了所提评价体系的具体指标和分类结果。计算结果说明了通过核心指标体系,可以直观描述光伏出力特性,并有助于形成典型出力曲线,具有很好的应用前景。 相似文献
18.
Abdelali El Aroudi Kuntal Mandal Damian Giaouris Soumitro Banerjee Abdullah Abusorrah Mohammed Al Hindawi Yusuf Al‐Turki 《International Journal of Circuit Theory and Applications》2016,44(5):1127-1141
There are many applications in power electronics that demand high step‐up conversion ratio between the source and the load. A simple way of achieving such a high voltage ratio is by cascading DC–DC boost converters in a few stages. The individual converters in such a cascaded system are usually designed separately applying classical design criteria. This paper investigates the stability of the overall system of a cascade connection of two boost converters under current mode control. We first demonstrate the bifurcation behavior of the system, and it is shown that the desired periodic orbit can undergo fast‐scale period doubling bifurcation leading to subharmonic oscillations and chaotic regimes under parameter variation. The value of the intermediate capacitor is taken as a design parameter, and we determine the minimum ramp slope in the first stage required to maintain stability. It is shown that smaller capacitance values give rise to wider stability range. We explain the bifurcation phenomena using a full‐order model. Then, in order to simplify the analysis and to obtain a closed‐form expression to explain the previous observation, we develop a reduced‐order model by treating the second stage as a current sink. This allows us to obtain design‐oriented stability boundaries in the parameter space by taking into account slope interactions between the state variables in the two stages. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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针对非隔离型级联H桥逆变器的漏电流问题,首先建立带有寄生电容参数的逆变器共模等效模型,分别分析单电感电路与对称电感电路中漏电流的特点及其影响因素,指出在对称电感电路中通过优化调制策略可以有效抑制系统漏电流,而在单电感电路中调制手段无法解决漏电流问题。为此针对对称电感电路提出一种改进型载波层叠多电平调制策略,能够有效地抑制系统漏电流,而且实现简单、运算量小。最后仿真与实验结果验证了该方法的有效性与正确性。 相似文献