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为实现一种结构简单、高效、高频、低的电压应力、易于控制的软开关变换器.提出了一种新型无源软开关变换器.它通过采用简单的无源辅助谐振网络实现了开关管的软开关,开关管电压电流应力小,解决了输出二极管反向恢复问题.特别适用于以IGBT(Insulated Gate Bipolar Transistor)作为开关器件的高电压大功率场合.该文以其在Boost变换器的应用为例分析了它的工作原理,软开关实现条件,给出了谐振参数的设计方法,该软开关设计思想可以推广到其他基本的DC-DC变换器中.制作了一个使用IGBT的5kW~20kHz的实验样机,通过实验验证了该变换器的有效性. 相似文献
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提出一种新型的零电压零电流转换(ZCZVT)的正激拓扑。拓扑工作频率为300kHz,能实现主开关管的零电压开通(ZVS)和零电流关断(ZCS),同时辅助开关管也能实现零电流关断(ZCS),且变压器的磁通复位不需要辅助绕组。文章进行了拓扑的稳态分析,并且讨论了谐振电路的参数设计。最后,在研制一台48V输入、12V/100W输出样机的基础上,实验验证这种新型正激ZCZVT PWM DC-DC变换器的软开关特性。 相似文献
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文章研究了一种采用无源辅助电路的零电压开关移相全桥变换器,它是在传统全桥拓扑上加入了由电容和电感组成的无源辅助电路,从而可以在整个输入电压和全负载范围内实现原边所有开关管的零电压开关。文中详细分析了该变换器的工作原理及其特性,并对辅助电路参数进行了设计。在此基础上,设计完成了一台1.2kW(50V/24A),开关频率为100kHz的样机,实验结果验证了该变换器的优越性。 相似文献
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详细分析了一种基于PWM变换器的新型无源无损软开关,并给出了其最优化设计步骤。通过一台满载输出功率为900w的带有该无源无损软开关的Boost变换器验证了其开关管实现零电流开通和零电压关断,并与传统的Boost变换器比较,验证其具有较高的效率。 相似文献
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提出一种新型零电压零电流(ZVZCS)飞跨电容型不对称PWM半桥三电平变换器,该变换器原边开关器件的电压应力为输入电压的一半;所有开关器件在较宽负载范围内实现软开关,其中超前管实现ZVS开通,ZCS关断;滞后管实现ZCS开通,ZVS关断,从而降低开关损耗;副边采用容性整流,在续流阶段将原边电流降至0,使得开关器件的电流分布更加均衡并减小飞跨电容的电流应力;与此同时,消除二极管反向恢复损耗。文中讨论了电路的结构、工作原理和基础特性,为证明理论正确性,搭建一台500W实验样机来验证。 相似文献
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Bor-Ren Lin Chien-Lan Huang Jin-Fa Wan 《Industrial Electronics, IEEE Transactions on》2008,55(4):1586-1594
A soft-switching converter is presented in this paper to achieve a zero-voltage-switching (ZVS) turn on for all switches. Two half-bridge converters with asymmetric pulsewidth-modulation scheme are connected in parallel to control the output voltage at the desired value and achieve load-current sharing. Based on the output capacitance of power switches and the resonant inductance, including the external inductance and the transformer leakage inductance, the resonance can be achieved at the transition interval of power switches. Therefore, the ZVS turn on of power switches can be realized. The peak voltage of the power switches is limited to input dc voltage. The center-tapped rectifier is adopted at the transformer secondary side to achieve a full-wave rectification. Operation principles, steady-state analysis, and design equations of the proposed converter are discussed in detail. Finally, experimental results based on a 240-W prototype are provided to verify the performance and the feasibility of the proposed converter. 相似文献
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一种新型的零电压零电流三电平变换器的研究 总被引:1,自引:0,他引:1
针对采用IGBT的软开关三电平变换器中IGBT关断过程存在的电流拖尾现象,以及基本三电平拓扑变压器次级存在的电压过冲和电压振荡现象,提出了改进型ZVZCS三电平结构。该结构在基于拓扑的三电平桥臂侧和两电平桥臂侧分别加入了一个无源辅助网络,三电平桥臂侧的辅助变压器在续流阶段为主变压器初级电流回零提供了条件,两电平桥臂的谐振电感和箍位二极管有效地抑制了主变压器次级电压的过冲现象。详细分析了改进拓扑的工作原理、工作模态,以及辅助网络的工作特点,并研制了实验样机,验证了理论分析的正确性以及改进拓扑的可行性。 相似文献
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作为中小功率发电系统重要环节的三相逆变器的开关频率增大时,开关损耗也显著增大,不利于节能。为实现中小功率三相逆变器的高频化和节能化,提出了一种三相零电压开关谐振极逆变器拓扑结构.当桥臂上的辅助谐振电路处于工作状态时,开关器件并联的电容的电压能周期性变化到零,使开关器件完成零电压软切换,这有利于高频金属氧化物半导体场效应晶体管(Metal Oxide Semiconductor Field Effect Transistor,MOSFET)作为逆变器的开关器件.分析了电路的工作流程,实验结果表明开关器件处于零电压软切换.因此,该拓扑结构对于研发高性能的中小功率三相逆变器具有参考价值. 相似文献
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ABSTRACTIn the paper, the novel topology of the resonant DC link three-level soft-switching inverter is proposed to reduce switching losses and improve the efficiency of three-level inverter at high switching frequency. Symmetrical auxiliary resonant circuits are set in the DC link of three-level hard-switching inverter. Moreover, the terminal voltage of the resonant capacitors between the DC buses periodically drops to zero via the resonance of auxiliary circuits. Furthermore, under such condition, the main switches of the three-level inverter would be operated, in order to achieve zero-voltage switching. Based on the equivalent circuits in different operating modes, the paper analyses the working process of the soft-switching inverter in detail. In addition, a 3 kW laboratory prototype of resonant DC link three-phase three-level soft-switching inverter is built. The experimental results show that the main switches and auxiliary switches of the inverter are operated under soft-switching conditions, and the efficiency is significantly improved compared with the three-level hard-switching inverter. Therefore, the proposed topology can effectively reduce switching losses and prove to be more practical in engineering. 相似文献
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Novel zero-voltage and zero-current-switching (ZVZCS) full-bridge PWM converter using coupled output inductor 总被引:2,自引:0,他引:2
Hang-Seok Choi Jung-Won Kim Bo Hyung Cho 《Power Electronics, IEEE Transactions on》2002,17(5):641-648
A novel zero-voltage and zero-current-switching (ZVZCS) full-bridge pulse-width-modulated (PWM) converter is proposed to improve the previously proposed ZVZCS full-bridge PWM converters. By employing a simple auxiliary circuit with neither lossy components nor active switches, soft-switching of the primary switches is achieved. The proposed converter has many advantages such as simple auxiliary circuit, high efficiency, low voltage stress of the rectifier diode and self-adjustment of the circulating current, which make the proposed converter attractive for the high voltage and high power applications. The principles of operation and design considerations are presented and verified on the 4 kW experimental converter operating at 80 kHz. 相似文献
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A simplified three-phase zero-current-transition inverter with three auxiliary switches 总被引:2,自引:0,他引:2
Most existing three-phase soft-switching inverters with fewer than six auxiliary switches have fundamental drawbacks in performance. There exist a few soft-switching inverters with six auxiliary switches that can potentially achieve desirable performance, but are penalized with the high cost and large size associated with the auxiliary switches. This paper proposes a zero-current-transition (ZCT) inverter topology that requires only three auxiliary switches. Each phase of the proposed circuit employs one auxiliary switch and one LC resonant tank to assist switching transitions. With considerable reduction in device count, cost, and size, the proposed topology realizes zero-current turn-off for all main switches and auxiliary switches, and provides soft commutation for all diodes. Meanwhile, it requires no modification to normal pulsewidth modulated (PWM) algorithms. The operation principles, design and control guidelines, and an analysis using the state-plane technique are presented. Based on the proposed topology, a 50-kW three-phase prototype inverter has been developed for electric vehicle propulsions, and tested to the full power level with a closed-loop induction motor drive system. Experimental results on the 50-kW prototype are provided to verify the proposed concept in high-power AC adjustable speed drive applications. 相似文献
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为改善逆变器的运行效率,提出了一种节能型三相谐振直流环节软开关逆变电路,在直流环节增设了辅助电路.当主开关需要切换时,提前使辅助电路进入谐振状态,将直流环节电压变化到零,保证主开关完成零电压软切换,并且辅助开关也能完成软切换.通过控制辅助开关切换的间隔时间来调节直流环节电压保持为零的时间,使逆变器能根据需要来调整脉宽调制策略.详细说明了电路的工作过程.实验结果表明逆变器主开关和辅助开关能完成软切换.因此,该拓扑结构对于研发高性能谐振直流环节逆变器具有借鉴意义. 相似文献
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光伏发电系统中DC-DC变换器的作用是使太阳能光伏电池电压达到光伏系统逆变环节的直流母线电压的要求。其中,全桥结构具有功率开关管电压应力小、变压器利用率高、容易实现软开关的特点,现将标准的全桥DC-DC变换器重新设计成串联形式,用计算机仿真来评估其工作状况,结果表明,开关的工作峰值电流被显著地减小了,减少了损耗并提高了... 相似文献