功率极低的32kHz振荡器

功率极低的32kHz振荡器与采用CMOS变换器的传统振荡器电路相比，具有很多优势。传统变换器电路存在着一些问题，如电源电流的波动范围较宽（3～6V），同时耗电很难低于250μA。而且，由于电源变化大且变换器的输入特性会因生产厂家的不同而有所不同，因此其工作不可靠。     

基于Zeta变换器的单相功率因子校正电路

分析了基于Ｚｅｔａ变换器的功率因子校正（ＰＦＣ）电路；研究了工作在不连续导电模式的Ｚｅｔａ变换器实现功率因子校正的机理；推导出了保证电路实现功率因子接近１的临界电感值。ＳＰＩＣＥ仿真和实验结果都证明了理论分析是正确的，为设计功率因子校正的Ｚｅｔａ变换器提供了理论依据。     

多电平变换器——功率变换器新品种

多电平变换器是大功率应用优选功率变换器新品种时才引人注目的，本文阐述最新发展的三种多电平变换：（１）二极管箝位；（２）浮动电容器；（３）有各自直流源的级联逆变器，经计算机仿真，并用ＩＧＢＴ作功率开关器件和ＤＳＰ作全数字控制器的样机验证，给出了工作原理、特点，优缺点和应用范围。     

一种高效开关电容AC—DC变换器

针对开关电容ＤＣ－ＤＣ变换器的效率会随着输入电压的增高而显著下降的现象，提出了一种新型的基于开关电容网络的ＡＣ－ＤＣ变换器，它采用根据输入电压变化而动态确定功率开关的导通和关断的方法，从原理上解决了开关电容ＤＣ－ＤＣ变换器的输入电压动态范围与变换器效率之间的矛盾。理论分析和实验结果表明，该转换器可以在较宽的输入电压范围获得较高的转换效率。     

变速风力发电系统的电源变换技术

本文对变速型风力发电系统功率变换器的多种拓扑结构及控制方式作了较为详细的阐述，并指出目前采用双馈异步感应发电机系统加转子功率控制方式或低速永磁同步发电机组直接驱动变换器两种电路具有较高的性能价格比和较好的市场前景。     

数字电源论坛展示实用化进展

会议的重点是电子系统中的数字电源管理及功率变换器中数字控制技术的运用     

功率滤波器的研究

功率滤波器的研究倪志中，罗荣华（四川联合大学无线电系，成都６１００６４）一种新型的ＡＣ－ＤＣ功率变换器由两部分组成：直流成分产生和直流功率提取．前一部可由波形变换的方式来完成，比如经可控整流将交流市电变为含有特定直流成分的切削正弦波．第二部分由功率滤...     

零电压转换（ZVT）功率变换器

本文叙述的是一种零电压转换（简称ＺＶＴ）功率变换器，该变换器是在传统的ＰＷＭ变换器拓扑结构基础上，增加一个谐振网络来使有源开关和无源开关在开关转换过程中均在零电压状态下进行。     

使用反向阻断型IGBT的4kW ZCS DC／DC功率变换器

反向阻断型IGBT（RB-IGBT）是一种具备承受正反向电压能力的新型器件，以它为基础，本文研究了一种4kW，可控相移全桥零电流关断（ZCS）DC/DC功率变换器。本文首先简单介绍了反向阻断型IGBT器件和这种功率变换器的理论分析，如工作阶段分析和零电流关断的条件，随后给出了在4kW变换器样机所得到的实验结果。     

高压驱动器NCP5181及其应用

安森美公司生产的NCP5181单片JC是一种高压功率MOSFET驱动器,被用作驱动半桥配置中两个N沟道功率MOSFET。NCP5181的应用领域主要是大功率电源管理、半桥功率变换器、互补驱动变换器（非对称半桥、有源钳位）、全桥变换器及UPS系统桥式变换器等。     

智能型多通道DC-DC变换器设计

采用多种智能型电压转换芯片,根据每个芯片的不同特征参数,搭建不同性能需求的电压转换电路;该设计由光电耦合器、三极管、PMOS管搭建切换电路,实现适配器供电与电池组供电的自动、快速切换;利用FPGA输出的高低电平控制由三极管和PMOS管搭建的开关电路,实现对部分供电通道的智能通断控制。该变换器已应用于微波探测仪的供电系统中,经测试表明该变换器具有效率高、纹波电压低、良好的稳态和动态响应的优点。     

Solar power generation system for reducing leakage current

This paper proposes a transformer-less multi-level solar power generation system. This solar power generation system is composed of a solar cell array, a boost power converter, an isolation switch set and a full-bridge inverter. A unipolar pulse-width modulation (PWM) strategy is used in the full-bridge inverter to attenuate the output ripple current. Circuit isolation is accomplished by integrating the isolation switch set between the solar cell array and the utility, to suppress the leakage current. The isolation switch set also determines the DC bus voltage for the full-bridge inverter connecting to the solar cell array or the output of the boost power converter. Accordingly, the proposed transformer-less multi-level solar power generation system generates a five-level voltage, and the partial power of the solar cell array is also converted to AC power using only the full-bridge inverter, so the power efficiency is increased. A prototype is developed to validate the performance of the proposed transformer-less multi-level solar power generation system.     

Implementation of zero current switch turn-ON based buck-boost-buck type rectifier for low power applications

A single-stage single-switch AC–DC integrated converter is proposed in this paper, as a tight DC voltage regulator with unity input power factor for the fundamental component of the input current. Proposed converter is formed by the integration of buck-boost configuration with a buck converter operated by a single switch. The buck-boost section of the proposed configuration is operated in current discontinuous conduction mode (DCM) to get unity input power factor at the supply terminals and the buck section is operated up to boundary current conduction mode (BCM). The features acquired by the converter operating in complete discontinuous conduction mode (DCM) are unity input power factor, zero-current turn-ON for the Switch, fast and good DC output voltage regulation with extensive conversion range and low voltage stress on the switch. Additionally, the intermediate capacitor voltage stress is independent of converter load variations and so the switch also is subjected to constant peak voltage stress. A comprehensive study is carried out to obtain the necessary design equations. A design model is implemented using simulation and hardware. The results confirm the performance of the proposed configuration.     

A robust low quiescent current power receiver for inductive power transmission in bio implants

In this paper, a robust low quiescent current complementary metal-oxide semiconductor (CMOS) power receiver for wireless power transmission is presented. This power receiver consists of three main parts including rectifier, switch capacitor DC–DC converter and low-dropout regulator (LDO) without output capacitor. The switch capacitor DC–DC converter has variable conversion ratios and synchronous controller that lets the DC–DC converter to switch among five different conversion ratios to prevent output voltage drop and LDO regulator efficiency reduction. For all ranges of output current (0–10 mA), the voltage regulator is compensated and is stable. Voltage regulator stabilisation does not need the off-chip capacitor. In addition, a novel adaptive biasing frequency compensation method for low dropout voltage regulator is proposed in this paper. This method provides essential minimum current for compensation and reduces the quiescent current more effectively. The power receiver was designed in a 180-nm industrial CMOS technology, and the voltage range of the input is from 0.8 to 2 V, while the voltage range of the output is from 1.2 to 1.75 V, with a maximum load current of 10 mA, the unregulated efficiency of 79.2%, and the regulated efficiency of 64.4%.     

UC3863控制的并联谐振电源

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。     

NLCC controller for SEPIC-based micro-wind energy conversion system

The growth of the power industry is gaining greater momentum as the usage of the non-conventional energy sources that include fuel, solar, and wind energies, increases. Wind energy conversion systems (WECSs) are gaining more popularity and are expected to be able to control the power at the output. This paper describes the current control (CC), non-linear carrier charge control (NLCCC), and fuzzy logic control (FLC) applied to the single-ended primary inductor converter (SEPIC)-based WECS. The current controller has an inherent overcurrent protection with better line noise rejection. The pulses for the switch of the SEPIC are obtained by comparing the current flowing through it with the virtual current reference. FLC is also investigated for the micro-wind energy conversion system (μWECS), since it improves the damping characteristics of WECS over a wide range of operating points. This cannot attain the unity power factor rectification. In this paper, NLCCC is proposed for high-power factor rectifier-based SEPIC in continuous conduction mode (CCM) for μWECS. The proposed converter provides an output voltage with low input current ripple due to the presence of the inductor at the input side. By comparing the signal proportional to the integral of switch current with a periodic non-linear carrier wave, the duty ratio of the converter switch is determined for the NLCC controller. By selecting the shape of the periodic non-linear carrier wave the input-line current can be made to follow the input-line voltage. This work employs a parabolic carrier waveform generator. The output voltage is regulated for changes in the wind speed. The results obtained prove the effectiveness of the NLCC controller in improving the power factor.     

Design of a single-switch high-power-factor regulator with near-zero output current ripple

The characteristics of a novel single-switch high-power-factor regulator with low output current ripple are studied. By employing a modified-boost converter cell as the input stage and a double-ended forward converter cell as the output stage, a high power factor and near-zero output current ripple are achieved. This regulator also eliminates the need for an extra clamping switch to recycle the transformer leakage energy and to reduce the switch voltage stress. The analysis, design, simulation, and experimental results are reported to verify the operation and performance of the proposed regulator.     

A zero-voltage transition boost converter using a zero-voltage switching auxiliary circuit

A soft switching boost converter with zero-voltage transition (ZVT) main switch using zero-voltage switching (ZVS) auxiliary switches is proposed. Various operating intervals of the converter are presented and analyzed. Design considerations are discussed. A design example with experimental results obtained from a 300-W, 250-kHz, 300-V output DC-DC converter is presented. A modified gating scheme to utilize the auxiliary switch in the main power processing is discussed. A 600-W, 100-kHz, 380 V output, 90-250 V AC, power factor corrected, AC-to-DC, boost converter with the modified gating scheme is presented. Results show that the main switch maintains ZVT while auxiliary switches retain ZVS for the complete specified line and load conditions. Parasitic oscillations existing in the converters proposed in the literature are completely removed.     

星用基于UC1845多路输出双管反激开关电源设计

为了解决航天器DC/DC变换器高压输入多路输出时,开关管电压应力以及多路输出稳定度问题,设计了一种基于UC1845的多路输出双管反激开关电源。主电路采用双管反激式变换器,使主开关管上的电压应力仅为输入电压Vin,满足航天器高可靠性的应用需求;同时电路采用磁隔离反馈稳压控制,通过一个反馈控制量实现多路输出,输出端配合应用低压差三端稳压器,各路输出负载稳定度优于±1%。控制电路采用电流型控制器UC1845,其具有电压调整率高、负载调整率高和瞬态响应快等优点。实验结果表明,该电源安全可靠、稳定性好、纹波小、效率高,达到了设计要求。     

中大功率单相功率因数校正器的设计与实现

采用有源功率因数校正技术(active power factor correction,APFC)设计并实现了一款高功率因数、高效率、低谐波、低噪声的"绿色"功率因数校正装置.1700 W样机实验结果表明:所设计的功率因数校正装置能在165～275 V AC宽电压范围内,得到稳定的直流电压输出;输入交流电流能很好的跟踪...