低压大电流大功率软开关全桥变换器拓扑结构分析

分析研究了低压大电流全桥变换器电路拓扑结构。分别介绍了功率变压器初级移相控制零电压(ZVS)PWM和移相控制零电压零电流(ZVZCS)PWM软开关全桥变换器主电路拓扑结构,以及功率变压器次级适宜采用的不同电路拓扑形式,并对其优缺点进行了对比分析。文中简要说明了在变换器输入级加入功率因数校正环节的必要性。     

基于PWM整流器的高效电动汽车充电机设计

介绍一种用于电动汽车电池充电机的设计实现方法.为满足高功率因数和高效的要求,采用三相PWM整流器和移相全桥变换器两级变换模式.前者基于空间电压矢量PWM直接功率控制（DPC）,实现单位功率因数;后者基于零电压零电流（ZvZCS）控制,实现高效的电能变换.以该方法设计的8 kW的充电机在大部分充电过程中,效率高于84％,输入功率因数高于99.3％.     

通信电源发展综述

本简要介绍通信用整流器发展过程、器件发展对电路的影响、当前电路方案、移相桥的改进、三电平变换器、三相单管及三管功率因数校正、单级整流器等。     

利用谐振电抗器实现单相无源功率因数校正

本文详细描述了一种新型基于谐振电抗器原理的单相无源功率因数校正（PFC）技术，可以适用于各种变频家用电器。在对其工作原理进行较为详细理论分析的基础上，进行了完整的仿真分析和实验研究，指出了这种无源PFC的最佳设计目标参数选择方法，给出了有关仿真与实验的波形和数据，并进行了分析比较。结果表明，这种无源PFC方案的输入谐波电流校正效果良好，直流回路电压利用率最高，而且具有散热处理，安装方便与价格低廉等特点，可以作为较大功率的单相C-DC变换器为后级逆变器-压缩机系统供电。     

高压变频器多重化整流的设计

高压变频器是指输入电源电压在3kV—10kV的大功率变频器。由于其功率大、电压等级高,应用场合重要。所以对其输入谐波、功率因数等要求很高。因此采用移相变压器实现高压变频器的多重化整流,可使高压变频器的输入谐波减小,功率因数提高。     

基于高频交流链接技术的并联谐振变换器

研究一种基于高频交流链接技术的新型并联谐振变换器,给出该变换器的电路拓扑图,并对其工作原理进行理论分析。然后使用Matlab中的Simulink仿真模块对该并联谐振变换器进行了仿真研究,仿真结果表明采用高频交流链接技术的新型并联谐振变换器输入端三相电流与输入端三相电压基本同相,具有高的功率因数和低的谐波含量。该变换器不仅体积小,结构紧凑,电源的功率密度高,同时由于谐波分量较低给电网带来的环境影响小,使整个电网系统供电效率更高。     

大功率高压多重分群移相变压器的研究(下)

大功率高压移相变压器采用多重分群整流,可减小高压变频器输入谐波网侧泄放,提高功率因数.对36脉波多重化分群整流原理、多重化与分群技术、移相技术、高压绝缘等新工艺进行研究和分析,并在多脉冲整流电路的谐渡抑制等方面突破创新,开发了大功率高压多重分群移相变压器.通过用MATLAB软件建立仿真模型,进行仿真与分析,为工程实践提...     

三相三开关部分有源功率因数校正电路的研究

三相交流电源供电的较大功率变频空调日益得到广泛应用,带来了三相整流器的功率校F问题。在简要分析三相单开关部分有源PFC的基础上,根据三相三线制、三相四线制供电方式的不同,提出了两种结合有源PFC技术和无源PFC技术的Buck型混合三相有源部分PFC方案,在对其工作原理进行简要分析和仿真分析的基础上,进行了实验研究,所得结果验证了所提出的三相部分PFC具有电压与电流应力小、效率高、功率因数高、直流平均电压较高的特点,各种负载下交流输入侧的各次谐波电流均满足IEC61000-3-2标准,中等负载以上时输入功率因数高达0.98。     

大功率高压多重分群移相变压器的研究(上)

大功率高压移相变压器采用多重分群整流,可减小高压变频输入谐波网侧泄放,提高功率因数.对36脉波多重化分群整流原理、多重化与分群技术、移相技术、高压绝缘等新工艺进行研究和分析,并在多脉冲整流电路的谐波抑制等方面突破创新,开发了大功率赢压多重分群移相变压器.通过用MATLAB软件建立仿真模型,进行仿真与分析,为工程实践提供...     

三相不控整流器输入LC滤波器的研究

鉴于单相供电的局限性以及三相供电的优越性,目前大功率变频空调领域主要采用三相无源功率因数校正方案。在考虑校正效果以及成本、体积、重量、效率、输出电压等因素情况下,提出并分析了不控整流器采用单级LC滤波器时关键问题,包括混合谐波源等效原理、谐波电流滤波原理、输出直流电压提升原理、整流桥最佳输入线电压波形,并对搭建的最大输...     

A new passive 28-step current shaper for three-phase rectification

A new passive 28-step current shaper for three-phase rectification is proposed in this paper. With a phase-shifting transformer on the AC side and six interphase transformers on the DC side, per-phase input current can be shaped into a 28-step sinusoidal waveform. The total harmonic distortion of AC input currents obtained is 6.53%, lower than one-half of that in a conventional 12-pulse converter. The transformer voltampere rating is also lowered down to one-fifth of that in a 12-pulse converter. A 2 kW experiment is performed to verify the proposed circuit.     

升压变压器低阻抗保护的原理及测试方法

升压变低阻抗保护主要作为发电机—变压器组相间短路的后备保护,逻辑判据中包含相间阻抗、相电流及负序电流三个变量参数,在测试过程中有一定的难度。通过对国电南京自动化股份有限公司生产的GDGT801型数字式发变组保护A柜变压器低阻抗保护的调试和检测,总结出该保护的调试技巧及测试方法,对有类似微机保护装置的发电厂、变电站、电力职业院校及电力培训中心也有一定借鉴意义。     

A high-power-factor, three-phase isolated AC-DC converter using high-frequency current injection

A single-stage, three-phase AC-to-DC converter topology is proposed for high-frequency power supply applications. The principal features of the circuit include continuous current operation of the three AC input inductors, inherent shaping of the input currents, resulting in high power factor, a transformer isolated output, and only two active devices are required, both soft-switched. Resonant conversion techniques are used, and a high power factor is achieved by injecting high-frequency currents into the three-phase rectifier, producing a high frequency modulation of the rectifier input voltages. The current injection principle is explained and the system operation is confirmed by a combination of simulation and experimental results.     

A zero-voltage-switched three-phase interleaved buck converter

This paper proposes a three-phase interleaved buck converter which is composed of three identical paralleled buck converters. The proposed solution has three shunt inductors connected between each other of three basic buck conversion units. With the help of the shunt inductors, the MOSFET parasitic capacitances will resonate to achieve zero-voltage-switching. Furthermore, the decreasing rate of the current through the free-wheeling diodes is limited, and therefore, their reverse-recovery losses can be minimised. The active power switches are controlled by interleaved pulse-width modulation signals to reduce the input and output current ripples. Therefore, the filtering capacitances on the input and output sides can be reduced. The power efficiency is measured to be as high as 98% in experiment with a prototype circuit.     

氧碘化学激光器BHP循环系统对电网干扰的抑制的实验研究

碱性过氧化氢(BHP)溶液需要通过以三相异步电动机为主体的BHP循环系统输送到氧发生器反应混合区和氯气反应的。但是电动机调速装置变频器对电网存在严重干扰。为了抑制变频器对电网的干扰,采用在变频器输入端接入输入电抗器和交流滤波器的方法。并对变频器采用23Hz和50Hz运行时候进行了测量。实验表明采用接入输入电抗器和交流滤波器的方法能很好的抑制变频器对BHP循环系统输入电网的干扰。     

A new high-power-factor three-phase AC-DC converter: analysis,design, and experimentation

This paper proposes a new high-power factor three-phase AC-DC power converter, which is composed of a line interphase transformer (LIT) and two three-phase diode rectifiers, followed by a pulsewidth modulation (PWM) DC-DC boost power converter. The active switch of the boost converter is gated at a constant frequency such that the AC input current is discontinuous. This procedure provides an input current shaping without the third, fifth and seventh harmonics. The currents that flow through the LIT and boost inductors have such a high-switching frequency that ferrite cores with a small size can be utilized. In addition, the output voltage is regulated by PWM to compensate for line voltage variations and load change. Theoretical analysis, design procedure and example, along with experimental results taken from a 6 kW laboratory prototype are given     

传输线变压器相位补偿技术及其应用

传输线变压器是在短波和超短波频段使用广泛的重要器件,根据传输线变压器原理设计制造的器件具有结构紧凑、功率容量大、频带宽、损耗小等优点.该文研究了利用慢波线原理和相位补偿技术克服传输线变压器对于传输线电长度的限制,使其适用频率向s波段以上扩展的方法.文中给出了1:4阻抗变换器电路的传输损耗和高低端输入阻抗理论公式并对其进行了讨论.对所设计的S波段1:4阻抗变换器及功率合成器进行了仿真分析并设计制作了实物.仿真和实测结果表明,利用慢波线原理和相位补偿后的传输线变压器能够适用s波段及以上微波器件.     

Three phase high frequency DC-DC convertor

A three phase system in a high frequency DC-DC convertor is proposed. Potential advantages of such an implementation include smaller magnetic parts, much lower output and input ripple, higher transformer utilisation factor and efficiency, and lower AC voltages for the same DC output voltage. There are also some disadvantages. More switchers and rectifying diodes are required. A three phase transformer and master oscillator at high frequencies are also necessary.<>