改进型零电压转换PWM软开关功率变换器的实现机理分析  

The Analysis of a Novel Zero-Voltage-Transition PWM Soft-Switching Power Converter

作　　者：寇宝泉[1] 张海林[1] 张赫[1] 张鲁[1] 金银锡[1] Kou Baoquan;Zhang Hailin;Zhang He;Zhang Lu;Jin Yinxi(School of Electrical Engineering and Automation Harbin Institute of Technology,Harbin 150001 China)

机构地区：[1]哈尔滨工业大学电气工程及自动化学院,哈尔滨150001

出　　处：《电工技术学报》2017年第14期116-126,共11页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51177023);高等学校博士学科点专项科研基金(20132302110009)资助项目

摘　　要：为改进传统谐振缓冲功率变换器(RSI)应用于高精度场合纹波较大的问题,提出一种改进型零电压转换(ZVT)脉宽调制(PWM)软开关功率变换器。通过LC环节减小输出电流纹波,并采用负载分段实现软开关的方式。轻载下利用交变的滤波电感电流实现主开关器件的零电压开通,重载下通过合理的导通谐振回路实现软开关,同时辅助开关器件实现零电流开关。该拓扑可采用PWM控制,具有效率高、纹波噪声小和开关频率固定的优点。通过分析电路的实现机理,对各工作时区进行解析计算,并给出实现软开关的条件。最后通过实验,在200kHz的开关频率下,验证了电路的有效性。相比于硬开关,效率得到了很大的提升,而相比于RSI在效率上虽有降低,但输出噪声却大幅减小。In order to solve the problems of large current ripple of resonant snubber inverter inhigh-precision application,a novel zero-voltage-transition(ZVT)PWM soft-switching power converterwas proposed.A LC branch is added to reduce the current ripple.In light load condition,the filterinductor current changing polarity is used to achieve zero-voltage switching of the main switches;while in heavy load condition,the properly conducted resonant branch can contribute zero-voltageswitching of the main switches.Meanwhile,the auxiliary switches can work in zero-current switching.This topology has the advantages of high efficiency,low switching current ripple and fixed switchingfrequency.In this paper,detailed circuit operation is described and the main parameters in each periodare calculated.The soft-switching condition is analyzed.A hardware prototype has been designed andtested to verify the validity of this proposed topology with relatively high switching frequency200kHz.Compared with hard-switching power converter in the same condition,the efficiency is improved a lot.However,the efficiency is a little lower than that of RSI,but the output current noise is far lower thanthat of RSI.

关 键 词：零电压转换 脉宽调制 软开关 零电压开关 零电流开关 

分 类 号：TM46[电气工程—电器]