中文摘要：

针对电力电子变压器（PET）中高压直流母线电容器的可靠性差和成本高的问题,提出一种无高压直流滤波电容的新型PET拓扑.与已有PET拓扑相比,该拓扑采用多脉移相整流技术（MPR）实现输入电流谐波抑制,避免了高压直流母线滤波电容带来的成本和可靠性问题.由于取消了高压直流母线电容,新型PET能够在无充电电阻的条件下实现柔性并网,提高了其一次侧各个直流母线的均压控制效果.通过Matlab/Simulink仿真在电压为6kV、功率为100kVA的样机上进行实验,结果验证了新型PET母线均压、消除谐波和柔性并网等功能的有效性.

英文摘要：

A novel topology of power electronic transformer（PET）with no high voltage direct-current（DC）bus capacitors was investigated,aiming to solve low reliability and high cost problems of high voltage DC bus capacitors in PET.Compared with traditional PET topologies,the harmonic eliminating of input current was implemented by multi-pulse rectifiers（MPR）in the proposed topology,and the problem of cost and reliability caused by high voltage DC bus capacitors were eliminated.Because of the cancellation of high-voltage DC bus capacitors,its flexible grid connection was implemented with no charge resistance,and the voltage balancing control effect of each DC bus was improved.The effectiveness of DC bus voltage balancing,harmonic eliminating and flexible grid connection with the proposed PET was verified by simulation of Matlab/Simulink and experimental results from prototype of 6kV and 100 kVA.