一种新型零电压零电流开关移相全桥变换器

为了解决传统零电压零电流开关（ZVZCS）PWMDC/DC变换器滞后桥臂零压范围较小、环流损耗大的问题,采用串联双变压器、滞后桥臂带辅助网络和倍压整流电路,提出了一种新型零电压零电流移相全桥变换器.首先分析了变换器在稳态下的各种工作状态,给出了相关计算公式,并制作了一台实验样机进行原理验证.实验结果表明：该变换器能够在较宽的负载范围内实现滞后桥臂的零电压开通,重载下实现零电流开通,从而极大地降低高频电路初级开关损耗和次级电磁干扰.     

ZVZCS三电平逆变弧焊电源

分析了一种新颖的零电压零电流(ZVZCS)开关之电平变换器,以及功率晶体管的驱动电路。分析并试验了它在弧焊电源中应用的可行性,并用Pspice9．2进行仿真,给出了试验与仿真结果。ZVZCS-三电平变换器不仅具有传统软开关脉宽调制(PWM)变换器的优点,还具有其它的优点。变换器的功率开关承受的电压为输入电压的一半,因此,它适合用于有源功率因数校正或输入电压较高的场合。     

MHz-driven snubberless zero-current soft-switching high step-up DC-DC converter with a multi-resonant tank

A novel high step-up DC-DC converter suitable for the power interface of fuel cells (FC) is presented in this paper. The proposed converter features a multi-resonant tank for achieving high-step up ratio under zero current soft switching (ZCS) without any snubber circuits. The simple and minimized-component topology is beneficial for megahertz driving of gallium nitride (GaN) power transistors with effective reductions of switching loss, electromagnetic emission interference (EMI) noise, and ripple-free DC input current. Mode-transitional power stages are described in detail, following that the high step-up principle is revealed by means of frequency-domain analysis. The essential performances of the proposed circuit topology are demonstrated by simulation and experiment of 1.8 MHz-120W prototype whereby effectiveness of the snubberless and multi-resonant topology are verified from the practical point of view.     

一种适合18脉波整流的新型DC/DC变换器

自耦变压器方式的18脉波整流电路采用多相整流技术来提高设备的功率等级、降低谐波,而利用移相自耦变压器可以降低整流器的体积、重量和成本,但不能实现电气隔离.为此,将多脉波整流技术与实现DC/DC变换器软开关相结合,提出了初级采取全桥移相控制策略、次级使用多相整流电路的新型DC/DC变换器电路结构,分析了工作原理和软开关情况,最后进行了仿真和实验.仿真和实验结果表明:理论分析是正确性的,该变换器能实现滞后桥臂开关管的零电压开通和零电流关断.     

一种改进PWM控制半桥ZVS变换器研究

本文分析了一种半桥软开关直流变换器。与传统半桥电路相比,该电路增加了一个由辅助开关管和一个二级管组成的支路。采用一种改进的PWM控制方法。主开关管不仅工作在对称状态,而且能很好地实现软开关。辅助开关开关管在主开关管关闭期间实现ZVS和ZCS导通,辅助开关管不仅为主开关管实现ZVS创造了条件,而且大大减轻了变压器漏感和主开关管结电容之间的振荡。文中详细分析了该变换器的工作原理,仿真和试验研究表明,该变换器具有优良的性能。     

零电压零电流不对称半桥串联混合式直流变换器

提出一种ZVZCS不对称半桥串联混合式直流变换器。该变换器的主开关管的电压应力为输入电压的一半，从而使该变换器非常适合高压输入场合。利用副边的辅助电路在宽负载范围内实现了滞后管的零电流软开关(ZCS)，并克服了以前出现的ZVS半桥串联混合式直流变换器所存在的2个半桥分压不均衡的固有缺点，从而使该类拓扑更加实用。此外，由于实现了ZVZCS，变压器原边环流基本被消除，变换器的效率得到进一步提高。文中详细分析了该变换器的工作原理，阐述了其工作特性，在此基础上设计并制作了1台240W(输出24V/10A)的原理样机，并给出了实验结果。     

一种金卤灯用电子镇流器及其控制方案

提出了一种高性能金属卤化物(MetalHalide,简称MH)灯用电子镇流器的电路拓扑。负载侧输出为低频方波电流,有效克服了MH灯声共振现象。高频开关管实现零电流软开关,提高了工作效率。采用起动和运行阶段不同的控制方法,实现了镇流器与灯特性的配合;给出了其相应的控制策略,并通过实验验证了该方案的有效性和可行性。     

PWM直流变流器中一种新型的零电压零电流转换软开关单元

提出了一种新型的零电压零电流转换(ZVZCT)软开关单元,并基于该开关单元,构造了Buck ZVZCT PWM变流器.该变流器实现了主开关管的零电压零电流开关,辅助开关管的零电流开通、零电压零电流关断,以及续流二极管的零电压零电流关断、零电压开通;不但适合于少子器件,而且适合于多子器件,同时保持PWM控制的特点.同时,该ZVZCT软开关单元可以推广到其它变流器之中,构造出新型ZVZCT PWM变流器族.进行详细的稳态分析、仿真分析和实验验证.实验结果完全验证了理论分析的正确性.     

Zero-current Switching Series Resonant High-voltage DC-DC Converter with Series-connected Primary Windings of Center-tapped Transformer

Abstract—This article proposes a novel zero-current switching series resonant inverter-fed voltage multiplier based high-voltage DC-DC converter. The series resonant inverter in the proposed topology has two power switches (insulated-gate bipolar transistors), two resonant capacitors, and only one high-voltage transformer with center-tapped primary windings. The power switches are connected in the form of a half-bridge network. The leakage inductances of the transformer's primary windings together with resonant capacitors form two series resonant circuits. The series resonant circuits are fed alternately by operating power switches with an interleaved half-switching cycle. The secondary winding of the high-voltage transformer is connected to a voltage multiplier circuit to rectify and boost the voltage. The converter operates in discontinuous conduction mode, and its output voltage is regulated by pulse-frequency modulation. Therefore, all the power switches turn ON and OFF at the zero-current switching condition. The main features of the proposed converter are lower power loss, less cost, and smaller size compared to previously proposed series resonant high-voltage DC-DC converters. The experimental results of a 130-W prototype of the proposed converter are presented both for dynamic and steady-state operation. The results confirm the excellent operation and performance of the converter.     

25kV/2A谐振式恒流充电电源

为 1MJ 电容器储能系统研制了一台输出电压 25kV,输出电流2A的恒流充电电源。该电源采用零电流切换非连续全波谐振原理。串联 LC 谐振电路由接成全桥形式的4只大功率 IGBT 驱动,谐振频率固定为 80kHz,开关工作频率 30-65kHz 可调。谐振产生的非连续正弦形电流经匝比为 1:50 的高压变压器升压至 25kV,经快恢复高压二极管串组成的全桥电路整形为一系列非连续的半正弦状电流脉冲,给 10000μF 高压电容器组充电。最终充电电压和充电电流的大小由微处理器控制,前者正比于充电电流脉冲的总个数,后者则正比于开关工作频率。