基于推挽电路的大功率直流电源设计

基于PWM控制的推挽式DC-DC直流升压电路的系统结构,设计了一款2 k W大功率直流升压变换器。该推挽拓扑结构采用2组高频变压器并联的升压方式,用1组驱动信号同时驱动2个开关管,转换效率高,对器件的参数要求不高。最后研制出了额定直流48 V输入,直流310 V输出,2 k W功率的DC/DC变换器。通过实验证明该变换器具有较高的效率与实用价值。     

一种次级LC谐振变换器的建模与参数设计

提出一种LC谐振型推挽直流变换器拓扑。初级采用桥型推挽结构,次级采用倍压结构,主要利用变压器漏感和倍压电容构成的LC谐振来传递能量。该变换器能实现初级开关管和次级二极管的零电流开关,有效抑制开关管的最高承受电压。针对电路输入输出特性,采用基波分析法建立相应的电压增益模型,反映谐振品质因数、漏感系数及频率比对电压增益的影响。根据电压增益模型设计了一款22~28 V输入/360 V输出/额定负载650 W的样机的电路参数,实验验证了电路的可行性和电压增益模型的有效性。     

基于电流馈电推挽式变换拓扑的变换器电源设计

以提高变换器电源的效率和可靠性为目标,设计了基于电流馈电推挽式变换拓扑的变换器电源。为使变换器电源具备开关管以零电压开关方式通断、开关频率恒定等理想特性,采用电压型推挽全桥逆变器,设计属于电流馈电推挽式变换拓扑结构的变换器电源装置主回路。选择DSSK60-015A全波整流二极管作为变换器电源主回路硬件;通过反馈控制电路调控电压波动时控制端流变化;根据变压器电感、匝数、线径等特性设计变压器绕制结构,完成变换器电源变压过程;设计保护电路,保证电源可靠工作。实验结果表明,所设计的变换器电源的输出电压、电流误差范围均在2%内,开关管实现了零压开通,变换器电源功率因数均保持在0.96以上,且效率高达95%。     

推挽正激式准单级高频环节光伏并网逆变器

分析研究了推挽正激式高频环节光伏并网逆变器的电路拓扑、开路电压法与变步长扰动观察法相结合的双模式最大功率点跟踪(MPPT)控制、输入电压外环和输出电流内环的双环PWM控制策略,给出了关键电路参数设计准则。该电路拓扑是由推挽正激式直流变换器和极性反转逆变桥级联构成,属于准单级电路结构。DC 1 kVA 48 V/220 V 50 Hz光伏并网逆变器样机的设计、仿真与实验结果表明,该光伏并网逆变器具有高频电气隔离、准单级功率变换、MPPT准确、极性反转逆变桥功率开关电压应力低且为零电压零电流开关(ZVZCS)、变换效率高、并网电流质量高等优点,在中小容量光伏并网逆变场合具有重要应用价值。     

一种双变压器串联谐振软开关推挽电路

针对输出电压与输入电压之比较高的推挽变换器,提出一种双变压器串联谐振软开关推挽电路,以提高其效率。两个推挽变换器的变压器次级串联,并且实现串联谐振软开关。给出了其电路构成及工作原理,推导分析了该电路的工作过程。在此基础上,对该电路与单变压器串联谐振软开关推挽电路作了比较研究。最后研制了12V输入、360V输出、200W功率的DC/DC变换器。通过实验证明,该电路具有较高的效率。     

新型坦克炮控系统软开关升压电源

在某新型坦克炮控系统中采用升压变换电源实现了装甲车辆26～270V的电压变换,但这种硬开关推挽式升压电源存在着电磁干扰严重、效率低的缺点.为改善坦克内部的电磁环境,进一步提高电源效率和可靠性,设计并成功研制了一种新型ZCT推挽正激软开关升压电源.通过在推挽变压器的二次侧引入辅助谐振电路,实现主开关管的零电流关断,彻底消除了因变压器漏感而产生的关断尖峰电压.在分析ZCT推挽正激主电路工作原理的基础上,给出了电路关键参数计算公式;通过试验波形和效率曲线分析,进一步验证了该新颖ZCT推挽正激升压电源具有的高效率、低电磁干扰的优点.     

一种高频变压器多级式拓扑的微型逆变器设计

针对绝缘型多级式拓扑逆变器转换效率低、滤波困难等问题,设计了一种高频变压器多级式拓扑的微型逆变器.阐述了系统的组成及原理,前级采用了基于SG3525的推挽式逆变电路,后级采用了全桥逆变电路,逆变控制技术采用了SPWM波脉冲调制技术,其控制系统由AT89S52单片机实现.同时采用了HER508整流二级管构建全桥整流电路,采用二阶LC滤波电路对输出电流进行滤波.实验数据表明:该系统输出波形为50 Hz的正弦波;测得2路PWM波的死区时间为5 μs;逆变器逆变效率随负载的变大而变大,其峰值效率可达88.67％.     

一种新型推挽式三电平逆变器的分析与仿真

提出了由多电平逆变器、高频变压器、输出周波变换器等构成的推挽式高频隔离三电平逆变器电路拓扑,具有电路简洁、两级功率变换、双向功率流、高频电气隔离,该变换器的功率开关管两端为三电平电压波,降低了开关管的电压应力,能够将不稳定的高压直流电变换成稳定的正弦交流电。分析了该逆变器的工作模式、稳态原理与电压瞬时值反馈控制策略,给出了逆变器外特性公式,与传统的二电平逆变器进行比较,可以得出该逆变器可以减小滤波电感、并能降低主开关管电压应力等结论,通过仿真证实了该逆变器的正确性和先进性。     

准单级单向Buck直流变换器型高频链并网逆变器

提出准单级单向Buck直流变换器型高频链并网逆变器电路结构与拓扑族。其电路结构是由单向隔离Buck直流变换器和极性反转逆变桥级联构成;其拓扑族包括推挽正激式、双管正激式、并联交错双管正激式、半桥式和全桥式电路。深入分析研究类逆变器的电路拓扑、电流瞬时值控制策略、稳态原理特性和关键电路参数设计准则。以推挽正激式拓扑为例,设计并研制出1kW48VDC/220V50HzAC并网逆变器样机。研究结果表明,此类逆变器具有高频电气隔离、电路结构简洁、准单级功率变换、变换效率高、极性反转逆变桥功率开关电压应力低且为ZVZCS、并网电流质量高等优点。     

ZVS三管推挽直流变换器

提出一种采用3个开关管的推挽式(three-transistors Push-Pull,TTPP)变换器,仅需要在传统推挽变换器的输入电源和变压器两个原边绕组中点间插入一个辅助开关管Q3.两个主管驱动信号μgs1和μgs2与传统推挽变换器中开关管的驱动信号相反;除去死区时间,辅管驱动信号μgs3是两个主管驱动信号μgs1和μgs2的与非关系.用等效电路的方法结合解析方程,分析电路各个工作模态的工作原理和主要开关波形.指出主管可在宽负载范围下实现零电压开通(zero voltage switching,zvS),且主管关断电流是传统推挽电路中的一半值.辅管在大负载或加大漏感情况下可以实现ZVS开通,辅管的额定电压是主管的一半,等于输入电压.讨论软开关的实现问题.提出控制芯片及其驱动电路的设计方法,完成一台800 W、开关频率为83.3 kHz的原理样机,实验结果验证了该变换器工作原理的有效性.     

LLC resonant DC–DC converter with series‐connected primary windings of transformer

This paper proposes a zero‐voltage switching (ZVS) LLC resonant step up DC–DC converter with series‐connected primary windings of the transformer. The series resonant inverter in the proposed topology has two power switches (MOSFETs), two resonant capacitors, two resonant inductors, and only one transformer with center‐tapped primary windings. The power switches are connected in the form of a half‐bridge network. Resonant capacitors and inductors along with the primary windings of the transformer form two series resonant circuits. The series resonant circuits are fed alternately by operating the power switches with an interleaved half switching cycle. The secondary winding of transformer is connected to a bridge rectifier circuit to rectify the output voltage. The converter operates within a narrow frequency range below the resonance frequency to achieve ZVS, and its output power is regulated by pulse frequency modulation. The converter has lower conduction and switching losses and therefore higher efficiency. The experimental results of a 500‐W prototype of proposed converter are presented. The results confirm the good operation and performance of the converter. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

基于新型双开关逆变器的感应加热电源研究

为解决传统感应加热电源桥式逆变器控制策略复杂,开关损耗大以及输出谐波分量大的问题,提出了一种新颖的双开关逆变器。该逆变器仅含两个开关器件,采用推挽式(push-pull)互补导通控制方式,并利用LC串联谐振实现电路的能量交换,以达到简化电路拓扑,改善输出波形,减少谐波分量的目的。对双开关逆变器的工作原理进行了详细分析和PSPICE仿真,在此基础上设计了一台1kW/25kHz的实验样机。仿真和实验结果证明:与传统桥式逆变器相比,新型逆变器具有更优良的性能。     

A Symmetry Correcting Pulsewidth Modulator for Power Conditioning Applications

A wide variety of power converters is of the transformer-coupled push-pull type and uses pulsewidth modulation for output regulation. In designing and operating such converters, serious complications usually arise as a result of unsymmetrical switching of the two power transistors. Caused by small parameter dissymmetries of these transistors, asymmetrical switching normally drives the transformer into saturation. Resulting excessive saturation currents reduce efficiency and put a severe strain on the power transistors, which can eventually cause circuit failure. This paper presents a new pulsewidth modulator circuit which can be advantageously utilized in the design of such converters, and which can effectively cope with the aforementioned symmetry problem. Symmetry correction is accomplished by monitoring the two primary currents and by providing proper feedback of the integrated difference between these two currents.     

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.     

Development of a high-efficiency inverter without audible noise

The proposed inverter combines two methods which can significantly decrease the on-state and switching losses. The first method, using a current transformer and a single transistor, makes possible the reduction of the on-state loss to less than one-third of the usual Darlington transistor. The second method, using an auxiliary commutation IGBT in parallel with the transistor, makes possible zero-voltage switching, resulting in no switching loss. To realize higher inverter efficiency, a snubber and its loss recovery circuit are employed. Three-phase inverters were fabricated experimentally to evaluate our idea. Device volume and weight can be decreased to one-third those of a conventional three-phase inverter, and an efficiency of 98.0% from 5 kW to 20 kW is obtained at a switching frequency of 16 kHz. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120(1): 62–69, 1997     

提高脉冲逆变器开关频率的技术——最佳基极驱动电流和抗饱和电路的设计

大功率晶体管逆变器在当代高性能的逆变器装置中显示了其突出的优点,其中提高其开关运行的频率是至关重要的。本文介绍的提高功率晶体管开关频率的措施,经实践证明可使功率晶体管在20kHz的开关频率下带负载可靠地运行。     

Series resonant high‐voltage DC–DC converter with reduced component count

This paper proposes a novel zero‐current‐switching series resonant high‐voltage DC–DC converter with reduced component count. The series resonant inverter in the proposed topology has two power switches (insulated‐gate bipolar transistors, IGBTs), two resonant capacitors, and only one high‐voltage transformer (HVT) 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 the resonant capacitors form two series resonant circuits. The series resonant circuits are fed alternately by operating the power switches with interleaved half switching cycle. The secondary winding of the HVT is connected to a bridge rectifier circuit to rectify the secondary voltage. The converter operates in the discontinuous conduction mode (DCM) 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 its lower core loss, lower cost, and smaller size compared to previously proposed double series resonant high voltage DC–DC converters. The experimental results of a 130‐W prototype of the proposed converter are presented. The results confirm the excellent operation and performance of the converter. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

一种模块化48脉冲大功率PWM逆变器

多脉冲逆变器通过移相变压器原副边移相角度的精确设计,可以在工频开关方式下,实现交流侧阶梯波输出,经过滤波得到高质量的正弦波形,但工频开关方式使其输出调压困难,而且随着脉冲数的提高,逆变器连接的变压器结构复杂,多个绕组之间的匝比难以兼顾,因此实际应用中多脉冲逆变器的通道数多在4以下。提出一种只有两个规格移相变压器结构的模块化48脉冲大功率PWM逆变器,该逆变器具有8个通道的三相逆变器和对应移相变压器组成,且每个三相逆变器采用低频PWM调制策略,实现输出电压调节。构建了一台8通道48脉冲的PWM逆变器样机,在各种运行状态下的输出波形以及相关测试数据验证了所提出的模块化多脉冲逆变器在输出波形、开关频率以及输出调节特性等方面的优势。     

并网独立双模式控制高性能逆变器设计与实现

本文设计并实现了一种小型的用于分布式发电系统的功率调节系统。高性能，高可靠性，高功率密度是功率变换装置的基本要求。传统的并网逆变器输出采用工频变压器，体积重量大，成本高。本文采用高频隔离的逆变器，消除了输出端的工频变压器。传统的桥式逆变电路存在桥臂直通问题，本文将双降压式逆变器用于并网发电场合，提高了可靠性，提高了效率。半周期调制方式的采用减小了器件的开关损耗，以及功率场效应管的导通损耗。以往的文献对并网逆变器的分析侧重于单独工作模式或者并网模式，较少涉及到独立工作和并网工作切换过程的分析。本文分析了双模式运行的逆变器的切换过程。采用TMS320F240DSP芯片实现数字锁相同步，实现并网和独立控制的逻辑和基准切换。在此基础上实现了一个500VA的实验样机证明了方案的可行性。