三电平单元电力电子变压器容错运行技术  

Fault-tolerant Operation Technology for Three-level Cell Power Electronic Transformer

作　　者：祝琳 李楚杉[1,2] 卢倚平 杨欢[1] 李武华[1] ZHU Lin;LI Chushan;LU Yiping;YANG Huan;LI Wuhua(College of Electrical Engineering,Zhejiang University,Hangzhou 310027,China;University of Illinois at Urbana-Champaign Institute,Zhejiang University,Haining 314400,China)

机构地区：[1]浙江大学电气工程学院,浙江省杭州市310027 [2]浙江大学伊利诺伊大学厄巴纳香槟校区联合学院,浙江省海宁市314400

出　　处：《电力系统自动化》2023年第11期144-154,共11页Automation of Electric Power Systems

基　　金：国家重点研发计划资助项目(2022YFE0101900);国家自然科学基金高铁联合基金重点项目(U1834205);浙江省自然科学基金重点项目(LZ22E070002)。

摘　　要：基于三电平单元的电力电子变压器具有功率模块少、功率密度高等优点,在数据中心不间断电源、铁路配电系统、超级充电站等场景中应用前景广阔。然而,电力电子变压器中开关器件多,器件故障引发的故障模块切除动作将导致系统容量损失,易引发系统失稳、故障越界等问题。针对该问题,文中提出了一种基于故障模块、故障相与非故障相协同的三电平容错运行技术。首先,采用开关组合列举法分析了不同故障类型下三电平单元H桥的共性故障结果,并基于部分器件旁路实现了故障模块重构和容错运行。其次,提出了相内协同控制策略,实现了故障模块电容电压的稳定与均压控制,并通过相间协同控制实现线电压平衡,共同保障电路正常运行。最后,针对不同故障结果提出具体的容错控制方法,并通过仿真验证了所提容错方法的有效性。仿真结果证明了容错控制下电力电子变压器能稳定运行。The power electronic transformer(PET)based on the three-level cell has the advantages of few power modules and high power density,which has broad application prospects in the scenarios of uninterruptible power supplies in data centers,railway power distribution systems and super-charging stations.However,there are many switching devices in PET,and the faulty module removal action triggered by the device fault will lead to the loss of system capacity,which can easily lead to system instability,fault expansion and other problems.To address this problem,this paper proposes a fault-tolerant operation technology based on cooperation among faulty modules,faulty phase and non-fault phase.First,the common fault results of three-level cell H-bridge with different fault types are analyzed by using the switch combination enumeration method,and faulty module reconfiguration and fault-tolerant operation are realized based on partial device bypass.Secondly,the in-phase coordinated control strategy is proposed to realize the capacitor voltage stability and equalization of the faulty module,and the line voltage balance is achieved through the inter-phase coordinated control,which ensures the normal operation of the circuit.Finally,specific fault-tolerant control methods are proposed for different fault results and the effectiveness of the proposed fault-tolerant methods is verified by simulation.The simulation results prove that the PET can operate stably with fault-tolerant control.

关 键 词：电力电子变压器 三电平变换器 级联型H桥 容错控制 协同控制 故障模块重构 

分 类 号：TM41[电气工程—电器]