三电平串联谐振变换器内外管均压方法  

Voltage Balancing Method for Inner and Outer Switches of Three-level Series Resonant Converter

作　　者：王伟 李彬彬[2] 宋昕哲 杨冬梅 周少泽 韦徵 WANG Wei;LI Binbin;SONG Xinzhe;YANG Dongmei;ZHOU Shaoze;WEI Zheng(NARI Group Corporation(State Grid Electric Power Research Institute),Nanjing 211106,China;School of Electrical Engineering and Automation,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]南瑞集团有限公司(国网电力科学研究院有限公司),江苏省南京市211106 [2]哈尔滨工业大学电气工程及自动化学院,黑龙江省哈尔滨市150001

出　　处：《电力系统自动化》2024年第23期188-196,共9页Automation of Electric Power Systems

基　　金：黑龙江省优秀青年科学基金资助项目(YQ2023E019);国电南瑞科技股份有限公司科技项目(2022081101069)。

摘　　要：三电平串联谐振变换器凭借其三电平半桥结构,具有显著减少功率模块数目进而降低成本的优势,被广泛应用于直流变压器。然而,当三电平串联谐振变换器工作在功率反向传输模式时,换流过程中内外管结电容充电电流不一致会导致开关器件不均压,器件存在过压损坏风险。针对该问题,文中分析了功率反向传输模式下三电平内外管不均压的产生机理,据此提出了在内管两端并联辅助电容的无源均压方法,给出了辅助电容的参数设计方法。进一步,提出了控制内外管时序的有源均压方法,推导得出了内外管时序设计依据。最后,通过75 kW实验平台验证了理论分析的正确性及所提方法的可行性。With a three-level half-bridge structure,the three-level series resonant converter(TL-SRC)has the advantage of significantly reducing the number of power modules and thus reducing the cost,so it is widely used in DC transformers.However,when the TL-SRC operates in the power reverse transmission mode,the inconsistent charging current of the junction capacitors of the inner and outer switches may cause a voltage imbalance of the switching devices,which brings the risk of overvoltage damage to the devices.To solve this problem,this paper analyzes the mechanism of voltage imbalance of the three-level inner and outer switches in the power reverse transmission mode.Based on the mechanism,a passive voltage balancing method with parallel auxiliary capacitors at both ends of the inner switch is proposed,and the parameter design method of auxiliary capacitors is given.Further,an active voltage balancing method for controlling the timing of the inner and outer switches is proposed,and the basis for designing the timing of the inner and outer switches is derived.Finally,the correctness of the theoretical analysis and the feasibility of the proposed method are verified on a 75 kW experimental platform.

关 键 词：直流变压器 三电平串联谐振变换器 功率反向传输 内外管 不均压 无源均压 有源均压 

分 类 号：TM46[电气工程—电器]