基于变频与中心对称PWM控制的双向DC/DC变换器  

Bidirectional DC/DC Converter Based on Control of Frequency Conversion and Center Symmetric PWM

作　　者：鹿麒 郝瑞祥[1] 王帅 LU Qi;HAO Rui-Xiang;WANG Shuai(Beijing Jiaotong University,Beijing 1QQQ44,China)

机构地区：[1]北京交通大学,电气工程学院,北京100044

出　　处：《电力电子技术》2021年第1期87-90,94,共5页Power Electronics

摘　　要：以在谐振腔并联电感的双向LLC谐振变流器为研究对象,采用变频与中心对称脉宽调制(PWM)混合控制策略,实现变换器正反向工作时的升降压。通过对采用中心对称PWM控制的变换器特性的时域分析,得到变换器的电压增益仅与占空比有关,与变换器的功率大小和传输方向无关,变换器可以自动实现正反向运行的平滑切换。此外,变换器在正向工作时,变压器初级开关管在全负载范围内均可实现零电压开关(ZVS)开通,变换器在反向工作时,变压器次级开关管在全负载范围内均可实现ZVS开通。通过加入变频控制可以减小开关管的关断电流。最后搭建了一台输入75~130 V,输出400 V的1.6 kW实验平台,验证了理论分析的正确性。Taking the bidirectional LLC resonant converter with inductor in parallel in the resonant cavity as the research object,a hybrid control strategy of frequency conversion and center symmetrical pulse width modulation(PWM)is adopted to realize the buck-boost of the converter during forward and reverse direction.By analyzing the characteristics of the central symmetrical PWM control circuit in the time domain,the gain of the converter is only related to the duty cycle and independent of the power level and transmission direction of the converter.The converter can automatically realize the smooth switching of forward and reverse operation.In addition,when the converter works in the forward direction,the switches on the primary side of the transformer can be turned on at zero voltage switching(ZVS)in the full load range.When the converter works in the reverse direction,the switches on the secondary side of the transformer can be turned on at ZVS in the full load range.Variable frequency control can reduce the turn-off current of the switch.Finally,a 1.6 kW experimental platform with input 75~130 V and output 400 V is built which verifies the correctness of the control strategy proposed.

关 键 词：变换器 脉宽调制 零电压开关 

分 类 号：TM46[电气工程—电器]