脉冲负载两级式DC-DC拓扑与控制策略研究  

Research on Topology and Control Strategy for Pulsed Load Two-Stage DC-DC Power Supply

作　　者：张森 曹轩[2] 谭云飞 赵志宏 ZHANG Seng;CAO Xuan;TAN Yunfei;ZHAO Zhihong(Power Science Research Institute of State Grid Jiangsu Electric Power Co.,Ltd.,Nanjing 210000,China;Nanjing University of Science and Technology,Nanjing 210000,China)

机构地区：[1]国网江苏省电力有限公司电力科学研究院,江苏南京210000 [2]南京理工大学,江苏南京210096

出　　处：《电器与能效管理技术》2024年第5期20-29,共10页Electrical & Energy Management Technology

摘　　要：为满足脉冲负载直流变换器高功率密度和高动态响应性能的要求,研究了一种应用于脉冲负载的两级式直流变换器。选用滤波电感更小、系统环路带宽更高的三电平同步整流Buck变换器作为前级变换器,选用DCX-LLC谐振变换器作为后级变换器,其相对闭环控制LLC在动态响应及效率方面更具优势。然后提出优化TL-Buck开关管电压应力的软起动策略,解决了软起动阶段飞跨电容电压在完成充电后降到很低的问题。最后,通过仿真和实验验证了所提两级式直流变换器闭环及软起动控制策略能优化前级TL-Buck起动时开关管电压应力。In order to meet the requirements of high power density and high dynamic response performance of pulse-load DC converter,a two-stage DC converter applied to pulsed load is studied.Among them,the three-level synchronous rectifier buck converter with smaller filter inductance and higher system loop bandwidth is selected as the pre-stage converter,and the DCX(DC Transformer)-LLC resonant converter is selected as the post-stage converter,which has more advantages in dynamic response and efficiency than the closed-loop control LLC.Then,a soft-start strategy to optimize the voltage stress problem of TL(Three Level)-Buck switch is proposed,which solves the problem that the flying capacitor voltage drops to a very low level after charging in the soft-start stage.Finally,the proposed closed-loop and soft-start control strategies of two-stage DC converters are verified by simulation and experiments,and it is determined that the soft-start strategy can optimize the voltage stress of the switch during the start-up of the pre-stage TL-Buck.

关 键 词：脉冲负载直流变换器 脉冲功率平衡 两级式架构 快速动态响应 

分 类 号：TM46[电气工程—电器]