HEML换向过程的续流回路设计

The Continuous Current Circuit Design for Commutation Process in Helical Electromagnetic Launcher

利用PSpice电路仿真软件建立了螺旋线圈型电磁发射器(Helical electromagnetic launcher,HEML)换向过程的等效电路模型,分析了换向过程中后换向匝断开时的能量转化情况,并在此基础上针对HEML设计了2种续流方案;结果表明:换向结束之后,后换向匝仍有大量的能量剩余,容易造成匝间电弧放电;通过将二极管反接在后换向匝两端可以将后换向匝中剩余能量释放,有效抑制匝间电弧的产生;利用二极管将后换向匝与激励区连接可以将后换向匝中剩余能量前馈到激励区,以此抑制匝间电弧的产生,并且提高换向过程能量转换效率。

The equivalent network of commutation process in helical electromagnetic launcher （HEML） is established in Pspice and the energy transformation in back commutation turns is analyzed. Then two con- tinuous current circuit solutions for HEML are developed. The results show that the back commutation turns still remain considerable energy after commutation which can easily result in interturn arcs; connect- ing two pins of the back commutation turn with fly-wheel diode reversely, the dump energy in back commu- tation turn can be gradually released and the interturn arc can be suppressed effectively; connecting the back commutation turn with the excitation area by fly-wheel diode, the dump energy in back commutation turn can be transferred to the excitation area, that can suppress the interturn arc and increase the efficiency of energy transformation in commutation.