共查询到17条相似文献,搜索用时 180 毫秒
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张乐 《信息技术与信息化》2023,(3):177-181
针对LLC谐振变换器传统零电压软开关(zero voltage switch, ZVS)在MHz频率条件下不再适用的问题,提出了精确的MHz的ZVS边界模型。首先对LLC谐振变换器在死区时间内的工作模态进行详细分析;然后通过详细模态的数学建模得出ZVS实现的边界模型;最后在该边界模型的基础上,发现LLC工作在兆赫兹时采用调频控制方式存在软开关范围受限的问题,搭建了一套1 MHz工作频率的半桥LLC样机。实验结果表明,所提方法重新定义了LLC谐振变换器MHz工作时的ZVS边界,并验证了理论分析的准确性。 相似文献
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提出了LLC谐振变换器的一种简化时域增益曲线。在一个开关周期内,将LLC谐振变换器分为两种工作模态,通过建立每个工作模态下的时域状态方程,以及初始条件和边界条件,推导得到LLC谐振变换器的简化时域增益曲线。提出了一种基于简化时域增益曲线的宽范围输入的设计方法,该方法以品质因数Q和电感比h为设计关键要素。最后完成了一台200 W的样机制作,样机在120 V~220 V工作电压范围内均能实现高效率功率变换,实验结果验证了该方法的有效性。 相似文献
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LLC谐振变换器可以实现原边开关管的ZVS和副边整流管的ZCS,变换效率较高,但传统的LLC谐振变换器具有输入电压范围不宽、且在宽输入电压范围下效率较低的缺点,针对这个缺点,本文在拓扑和控制方法上做出改进,提出了一种利用磁控制的可变电感来实现定频模式下输出电压控制与调节的全桥双谐振腔LLC变换器,在没有牺牲效率的前提下拓宽了输入电压的范围。并且制作了一台输入为120~400V,输出为48V/5A的实验样机,验证了理论分析的正确性。 相似文献
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针对全桥LLC谐振变换器在脉冲频率调制(Pulse Frequency Modulation, PFM)下存在电压增益范围较窄和动态响应较差的问题,提出一种定频移相-变频时移混合控制策略。该方法在结合PFM和移相调制的基础上,当电压增益大于1时,采用变频时移控制;当电压增益小于1时,采用定频移相控制,同时改善了变换器的电压增益范围和响应速度。详细分析了混合控制策略在LLC谐振变换器上的工作原理及增益范围,并搭建了一台240W的实验样机,实验结果验证了该策略的可行性和优越性。 相似文献
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分析了并联LLC谐振变换器的特性,并做了开关顺序并联与交错并联情况下变换器特性的比较,以UC3863芯片为核心控制芯片的开关电源,电路采用半桥结构的LLC谐振电路,这种模式很少被提出,通过实验证明了可行性和实用性,大大提高了LLC的工作效率。通过对各器件参数的理论计算,运用SABER仿真软件对变换器电路进行仿真和分析。文中以300V电压输入,12V-18V输出电压为例,2.5kW,500kHz并联LLC谐振变换器设计和仿真来进行模型分析,从而总结出并联LLC谐振变换器相对于传统单一LLC谐振变换器的优点。仿真结果验证了设计的可行性与结论的准确性。 相似文献
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针对模拟电源效率较低的现状,提出一种基于DSP的数字电源方案。在对LLC谐振全桥变换器工作原理简单分析的基础上,采用DSP TMS320F28335设计了一款输入为DC300-400V,输出为DC48V/12A的原理样机,利用Saber仿真软件对其进行仿真与调试,仿真结果与实验数据表明,本文设计的LLC全桥谐振变换器能够在全负载范围内实现初级零电压开通(ZCS)以及次级零电流关断(ZVS),输出电压纹波小于±0.5%,效率达到95%以上,满足设计要求。结论表明,LLC谐振变换器符合电源高功率密度、高效率的发展要求。 相似文献
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在海洋科学研究和海洋观测领域中,水下系统的供电方式大多是岸基负高压传输到海底接驳设备。海底接驳设备中的功率变换器将岸基电源的数千伏至十几千伏的直流高压转换成低压375 V供海底设备供电。针对变换器高电压输入、宽电压范围输入及输入输出电压变比大的技术难点,提出了模块化多电平的LLC谐振变换器拓扑结构,文中对变换器进行了模型搭建和电路仿真,并完成了一台40 kW工程样机的设计,最后根据仿真和实验结果验证了模块化多电平谐振变换器工作原理的正确性及可行性。 相似文献
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文中提出了一种单变压器结构双LLC网络谐振型变换器。该拓扑实现了Mosfet零电压导通(ZVS),整流二极管零电流关断(ZCS),低整流二极管电压应力以及宽范围调压,变压器两个原边绕组同时工作。这种工作模式能够有效地均分励磁电流,降低变压器的设计要求,减小了变压器的尺寸,同时还能减小原边绕组的有效电流,从而减少变压器的铜损。两个串联LLC谐振网络互差半个开关周期工作。输出侧采用全波整流方式,因此整流二极管电压应力为输出电压。由于副边无需电感,因此,设计中可进一步减小变换器尺寸。最后,通过仿真和实验,验证了理论分析的正确性,变换器满载效率可达95.8%。 相似文献
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A resonant converter is a kind of electric power converter that contains a system of inductors and capacitors called a resonant tank, tuned to resonate at a particular frequency in this work recommends a better-quality dual bridge LLC resonant converter with a novel controller technique. The resonant converters include the serial or parallel connections of inductors and capacitors to activate the switch to realize the Zero Current Switching (ZCS) and Zero Volt Switching (ZVS) under resonance conditions. The resonant effects are switching sufferers, turning strain and electromagnetic interference problems the switching resonant converter controls the output voltage through changing frequency and generally can be sub classified in ZCS converter and ZVS converter. This scheme had combined wireless monitoring for dual bridge LLC resonant converter for dc distribution applications based on sophisticated distribution controller (SDC) through the internet of things and embedded structure access and other mechanisms. The consequence of our exhibition demonstrates that the framework can monitor and store the manipulate data from the converter. Thus, the wireless monitoring functions are realized in real-time. This converter permits both forward and reverses power exchange between the source and the load, to keep up the output voltage consistent, regardless of load and line unsettling influences, it is important to work the converter as a closed loop system. The proposed SDC based dual bridge resonant converter has validated through simulation in Matlab Simulink environment. A hardware setup is also developed to validate the simulation. General 97% effectiveness accomplished at full load condition in light of the dual bridge resonant converter. 相似文献
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de Groot H. Janssen E. Pagano R. Schetters K. 《Power Electronics, IEEE Transactions on》2007,22(6):2307-2320
In this paper, the design of a 1-MHz LLC resonant converter prototype is presented. Aiming to provide an integrated solution of the resonant converter, a half-bridge (HB) power metal oxide semiconductor (MOS) module employing silicon-on-insulator technology has been designed. Such a technology, which is suitable for high-voltage and high-frequency applications, allows enabling HB power MOSFET modules operating up to 3MHz with a rated voltage of 400V. The power device integrates the driving stages of the high-side and low-side switch along with a latch circuit used to implement over-voltage/over-current protection. The module has been designed to be driven by a digital signal processor device, which has been adopted to perform frequency modulation of the resonant converter. By this way, output voltage regulation against variations from light- to full-loaded conditions has been achieved. The issues related to the transformer design of the LLC resonant converter are discussed, too. Owing to the high switching frequency experienced by the converter, 3F4 ferrite cores have been selected for their low magnetic power losses between 0.5 and 3 MHz and core temperatures up to 120degC. The resonant converter has been designed to operate in an input voltage range of 300-400V with an output voltage of 12V and a maximum output power of 120W. Within these design specifications, a performance analysis of the LLC converter has been conducted, comparing the results obtained at the switching frequencies of 500kHz and 1MHz. A suitable model of the LLC resonant converter has been developed to aid the prototype design. 相似文献
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文中详细分析了全桥型LLC变换器在三种工作模式下的状态轨迹特征,提出了一种宽输入条件下改进的最优轨迹控制策略,并讨论了电路参数选择对控制策略适用性的影响。仿真结果证明了所提策略的有效性。 相似文献
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《Power Electronics, IEEE Transactions on》2008,23(5):2290-2300
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This article analyses and presents an LLC resonant converter with a high power factor for LCD-TV applications. It integrates the advantages of power factor correction and the LLC resonant converter. It can improve not only power quality but also circuit efficiency. Since the power factor corrector is used in the first stage of the LLC resonant converter, it is suitable for wide input voltage range application. On the basis of the resonant behaviour, zero voltage switching is achieved for the power switches and ZCS is achieved for the rectifier diodes. An experimental prototype of 90–260V rms input and 12V/10A and ?12V/10A outputs with 92.6% efficiency for 32″ LCD-TV application is built in the laboratory to verify the operation principle of the adopted converter. 相似文献
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A new harmonic resonant DC-DC converter is proposed. The harmonic resonant converter is related to the multi-resonant converter and is used for transformers with low coupling. Two harmonic frequencies are present during any resonant state and the switch voltage can be less than two times the input voltage 相似文献
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This paper presents a new topology named zero-voltage switching (ZVS) resonant reset dual switch forward dc-dc converter, which, compared with resonant reset single switch forward dc-dc converter, maintains the advantage that duty cycle can be more than 50%, at the same time disadvantages of high voltage stress for main switches and low efficiency are overcome. In addition, ZVS is achieved for all switches of the presented topology. Therefore, this proposed topology is very attractive for high voltage input, wide range, and high efficiency applications. In this paper, the operation principle and characteristic of this topology are analyzed in detail. Next, the design consideration is presented. Finally, the advantages mentioned above are verified by experimental results 相似文献