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反激式开关电源因成本低、外围元器件少、可宽电压范围输入能耗小、支持多组输出而备受欢迎,但因输出电压纹波大而严重影响其工作性能。从反激式开关电源的工作原理出发,采用反激式开关电源输出端增加输出滤波电路的方法,解决反激式开关电源输出电压纹波大的问题。运用Saber仿真软件分别对普通反激式开关电源和增加 输出滤波电路的反激式开关电源进行建模和仿真。试验仿真对比表明,通过该方法可改善反激式开关电源的输出电压纹波,提高了反激式开关电源的工作性能。 相似文献
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提出了一种降压型两相交错直流转换器。与传统单相转换器相比,该两相转换器具有输出纹波低、瞬态响应快、重载效率高等特性,适合为多核处理器供电。采用峰值电流模式,基于公共电压反馈回路及峰值电流信息,实现两相支路电流的均衡。依据负载电流范围自动选择运行支路个数,保证转换器在整个负载范围内具有高转换效率。基于TSMC 0.18 μm工艺进行设计,电源电压范围为2.7~5 V,支持330 nH~1 μH的小封装电感,最大电流驱动能力为5 A。仿真结果显示,在输入电压为4.2 V,输出电压0.9 V的条件下,整个负载范围内转换器的峰值效率为86%,最大稳态输出纹波低于2 mV,在5 A/1 μs负载瞬变条件下,负载调整率不超过28 mV/A。 相似文献
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基于0.18 μm BCD工艺,设计了适用于电压模式恒定导通时间(COT)架构DC-DC降压型变换器的纹波补偿电路。分析了使用电解电容作为输出电容以及片外纹波补偿电路的缺点,并设计了一种新颖的片内纹波补偿电路来克服这些缺点。在芯片系统典型应用环境下,利用Cadence和Hspice软件进行电路设计和仿真。结果表明,在电源电压为5 V,温度为25 ℃的条件下,芯片输出电压的纹波仅为2.15 mV,通过纹波补偿电路的反馈电压的纹波为37 mV,完全满足系统稳定要求。当温度在-20 ℃~125 ℃内变化时,输出最大纹波仅为12.6 mV。 相似文献
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采用恒流源技术设计了1种适合于DC-DC开关电源的模拟加法器。基于CSMC 0.5 μm混合标准CMOS工艺对所设计电路进行了仿真验证。在3 V电源电压条件下,瞬态仿真结果显示模拟加法器输出VA为参考电压Vref与输入信号VA1的加权。当输入信号VA1从0~1.2 V变化时,模拟加法器的输出电压VA与VA1成线性关系,且VA与VA1的差值恒为一常数。当温度在0~110 ℃范围内变化时,模拟加法器的输出VA偏差仅为1.18 mV。仿真结果显示:该模拟加法器具有非常好的性能特性,适用于DC-DC开关电源。 相似文献
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反激式开关电源具有体积小、成本低、运行可靠,高效提供多路直流输出,输入电压在很大的范围内波动时,仍可有较稳定的输出.本文基于Mathcad计算软件设计一款输出(15V/0.7A)的单端反激式开关电源. 相似文献
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在采用锂电池储能供电的降压斩波电路恒流激光二极管驱动源系统的设计中,建立了电池组、激光二极管的集成电路个人仿真程序(PSPICE)器件模型和闭环控制系统模型,经过仿真计算,确定了输出滤波电感电容的参数和实现闭环稳定的比列积分微分调节(PID)参数,并研究了在负载变化和输入变化的条件下系统的稳定性。研究表明,采用该技术方案能实现恒流源输出电流大于100 A,输出电压230 V,电流纹波小于3%。 相似文献
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一种新型的低纹波开关电源 总被引:5,自引:0,他引:5
传统开关电源具有输出纹波大、辐射干扰大等缺点,应用场合受到限制.文中分析了传统开关电源输出纹波的产生机理,介绍了斜波驱动方式的优点和新型电源专用集成电路LT1533的工作原理,给出了非隔离式24 V输入,5V、1A输出的推挽变换器设计实例.试验结果表明输出纹波降低到小于2 mV(峰-峰值). 相似文献
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应用于计算机的低噪声开关电源电路设计 总被引:1,自引:0,他引:1
设计了一种应用于计算机的低噪声开关电源电路,通过调节PWM占空比来达到系统稳定输出的目的,同时通过内部保护电路来监控和保护3.3 V/±5 V/±12 V输出电压.根据计算机电源系统对该电路以及内部模块电路进行了介绍和分析.仿真和测试结果表明,采用该开关电源控制电路组成的系统在提高电路性能的同时,可以有效提高系统的稳定性和抗噪性,具有输出电压精度高、输出纹波小、低噪声、安全可靠等特点. 相似文献
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An analysis and design of single-stage, single-switch bi-flyback ac/dc converter is presented. The main flyback stage controls the output power from the link capacitor voltage with Discontinuous Conduction Mode (DCM) or Continuous Conduction Mode (CCM) operation, while an auxiliary flyback stage supplies the power to the output directly from ac line input with DCM operation. This scheme can effectively reduce the voltage stress on the link capacitor and can achieve the power factor correction (PFC) without a dead band at line zero-crossings, which reduces the harmonic distortion in ac line current. Theoretical analysis of the converter is presented and design guidelines to select circuit components are given. The experimental results on a 60?W (15?V, 4?A), 100?kHz ac/dc converter show that maximum link voltage and maximum efficiency are around 415?V and 82%, respectively. The power factor is above 0.96 under universal line input and load conditions. 相似文献
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Jinn-Chang Wu Hurng-Liahng Jou Ping-Hao Chuang 《International Journal of Electronics》2013,100(10):1398-1413
In this article, a voltage equaliser is proposed for a battery string with four Li–Fe batteries. The proposed voltage equaliser is developed from a flyback converter, which comprises a transformer, a power electronic switch and a resonant clamped circuit. The transformer contains a primary winding and four secondary windings with the same number of turns connected to each battery. The resonant clamped circuit is for recycling the energy of leakage inductance of the transformer and for performing zero-voltage switching (ZVS) of the power electronic switch. When the power electronic switch is switched on, the energy is stored in the transformer; and when the power electronic switch is switched off, the energy stored in the transformer will automatically charge the battery whose voltage is the lowest. In this way, the voltage of individual batteries in the battery string is balanced. The salient features of the proposed voltage equaliser are that only one switch is used, the energy stored in the leakage inductance of the transformer can be recycled and ZVS is obtained. A prototype is developed and tested to verify the performance of the proposed voltage equaliser. The experimental results show that the proposed voltage equaliser achieves the expected performance. 相似文献
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Often scientific instruments on exploratory satellites are used to collect cosmic particles. These instruments, such as the Faraday cup, require a high-voltage regulated power source. On the proposed solar probe satellite there will be instruments which will collect cosmic particles close to the sun. Naturally temperature effects on the voltage regulator are a concern. Specifically power dissipation within the regulator must stay within stringent guidelines. The high-voltage regulator circuit is a resonant flyback topology with a dissipative series switch whose on resistance controls the output voltage level. The extreme temperatures in space will change the inductance of the flyback transformer which will affect the output voltage. State space analysis techniques are used to determine how the value of the transformer inductance and capacitance in the flyback converter affects the output voltage and consequently the power dissipated by the transformer and the switch. The accuracy of the analysis is verified by comparing results with those obtained from an experimental circuit. The results can then be used to help the designer chose nominal capacitance and inductance values that will work over the temperature range of interest. 相似文献
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Kwok-Wai Ma Yim-Shu Lee 《Power Electronics, IEEE Transactions on》1996,11(2):318-327
An integrated flyback power converter performing the combined functions of uninterruptible power supply (UPS) and switch-mode power supply (SMPS) is presented. This power converter has a high voltage main power input and a low voltage backup battery input. DC output is obtained from the main input via a flyback power converter during normal operation and from the backup battery via another flyback power converter when input power fails. High conversion efficiency is achieved in normal, backup, and charging modes as there is only a single DC-DC conversion in each mode. The power converter circuit is very simple, with two switching transistors, a relay for mode switching, and a single magnetic structure only. This new design offers substantial improvement in efficiency, size, and cost over the conventional cascade of UPS and SMPS due to single voltage conversion, high frequency switching, and removal of design redundancy. The operation, design, analysis, and experimental results of the power converter are presented 相似文献
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Lee S.T.S. Henry Shu-Hung Chung Hui S.Y. 《Power Electronics, IEEE Transactions on》2005,20(6):1441-1449
A two-stage, two-wire TRIAC dimmable electronic ballast for fluorescent lamps is presented in this paper. It is constructed by using a flyback converter as the input power factor corrector to supply a half-bridge series-resonant parallel-loaded inverter to ballast the lamp. The flyback converter is operated in discontinuous conduction mode so that the filtered input current profile is the same as the TRIAC-controlled voltage waveform. The switches in the inverter are switched at a constant frequency slightly higher than the resonant frequency of the resonant tank. Based on the constant average input current characteristics of the inverter, the dimming operation is simply achieved by pulsewidth modulation control of the magnitude of the flyback converter output voltage. No synchronization network is required between the input and output stages. In addition, a linear power equalization scheme is developed so that the dc-link voltage (and hence the lamp power) is in a linear relationship with the firing angle of the TRIAC. The average output voltage of the dimmer controls the equalized flyback converter output voltage. Modeling, analysis, and design of the ballast will be described. A prototype was implemented to verify the experimental measurements with the theoretical predictions. 相似文献
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Hren A. Korelic J. Milanovic M. 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2006,53(5):369-373
An RCD clamp circuit is usually used in flyback converters, in order to limit the voltage spikes caused by leakage transformer inductance. Oscillation ringing appears due to the clamp diode, which deteriorates the converter's power rate. This brief describes this ringing phenomenon and the use of an RC-RCD clamp circuit for damping the clamp diode's oscillation. This clamp circuit is capable for improving a flyback converter's power ratio. 相似文献
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Single-stage power factor correction (PFC) AC/DC converters integrate a boost-derived input current shaper (ICS) with a flyback or forward DC/DC converter in one single stage. The ICS can be operated in either discontinuous current mode (DCM) or continuous current mode (CCM), while the flyback or forward DC/DC converter is operated in CCM. Almost all single-stage PFC AC/DC converters suffer from high bulk capacitor voltage stress and extra switch current stress. The bulk capacitor voltage feedback with a coupled winding structure is widely used to reduce both the voltage and current stresses in practical single-stage PFC AC/DC converters. This paper presents a detailed analysis of the bulk capacitor voltage feedback, including the relationship between bulk capacitor voltage, input current harmonics, voltage feedback ratio, and load condition. The maximum bulk capacitor voltage appears when the DC/DC converter operates at the boundary between CCM and DCM. This paper also reveals that only the voltage feedback ratio determines the input current harmonics under DCM ICS and CCM DC/DC operation. The theoretical prediction of the bulk capacitor voltage as well as the predicted input harmonic contents is verified experimentally on a 60 W AC/DC converter with universal-line input 相似文献
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电流模式反激变换器中功率限制电路的设计 总被引:1,自引:0,他引:1
讨论电流模式反激变换器的工作原理与优点,重点分析反激变换器中的过功率保护模块的功能与实现方式。提出在过功率保护电路中利用斜坡电压取代传统的固定电压,以达到不同输入电压下的恒定功率限制。基于CMOS工艺设计了相应的斜坡电压产生电路,该电路结构简单,可广泛适用于各类反激开关电源控制电路。最后并对电路进行了仿真。 相似文献