基于辅助充电支路的模块化多电平变换器结构高频纳秒脉冲发生器  

High Frequency Nanosecond Pulse Generator Based on Modular Multilevel Converter Structure with Auxiliary Charging Branch

作　　者：米彦[1] 陈嘉诚 许宁 戴锦炎 Mi Yan;Chen Jiacheng;Xu Ning;Dai Jinyan(State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing University,Chongqing 400044 China)

机构地区：[1]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆400044

出　　处：《电工技术学报》2021年第2期435-444,共10页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51477022);重庆市科委自然科学基金(cstc2016jcyjA0500)资助项目。

摘　　要：高频纳秒脉冲串治疗肿瘤已逐渐成为一种新的医疗手段,但发生器输出高频脉冲串时的开关损耗问题还有待进一步研究。因此该文提出一种基于辅助充电支路的模块化多电平变换器(MMC)拓扑。在MMC模块的一个MOSFET处并联二极管和电阻,为电容提供充电回路,消除充电电流对开关的导通损耗,提高脉冲发生器的稳定性。首先,对该文提出的拓扑结构进行原理介绍;其次,计算硬件参数并利用Pspice对拓扑结构进行仿真验证;最后,研制一台五级模块化的输出装置并进行性能测试。连续输出模式下:前沿20ns,后沿30ns,幅值为4kV;脉冲串输出模式下:最高串内频率1MHz的脉宽100~500ns、幅值0~4kV可调的纳秒脉冲串。开关温升测试表明,在该文测试条件下,RD-MMC相比于MMC的尾切开关温升减少约30%;同时,利用细胞溶液作为负载,测试电压电流波形稳定。该文研制的脉冲发生器为进一步研究高频纳秒脉冲串在生物领域的应用奠定了基础。High-frequency nanosecond pulse trains have gradually developed into a new medical treatment for tumors,but the problem of switching loss when the generator outputs high-frequency pulses trains needs further study.Therefore,this paper proposes a new generator topology based on the modular multilevel converter(MMC)structure with auxiliary charging branch.A diode and a resistor are connected in parallel at a MOSFET of MMC to provide a charging circuit for the capacitor and eliminate the conduction loss of the switch caused by the charging current,thereby improving the stability of the pulse generator.First,the principle of the topology proposed in this paper was introduced.Second,hardware parameters were calculated and Pspice was used to simulate and verify the topology.Finally,a 5-level modular output device was developed and tested.In continuous output mode,the rising time is 20ns,the falling time is 30ns,and the amplitude is 4kV.In pulse train output mode,the pulse width of a pulse train is 100~500ns,the highest frequency is 1MHz,and the amplitude is 0~4kV.The test shows that the RD-MMC can reduce the temperature rise of the tail-cut switch by about 30%compared with MMC under the test conditions.Moreover,using the cell solution as a load,the voltage and current waveforms are stable.The pulse generator developed in this paper lays a foundation for further study on the application of high-frequency nanosecond pulse trains in the biological field.

关 键 词：辅助充电支路模块化多电平变换器 导通损耗 纳秒脉冲串 发生器 

分 类 号：TM832[电气工程—高电压与绝缘技术]