一种同轴型脉冲功率电缆的设计与试制

Design and Trial-manufacture of a Coaxial Pulsed Power Cable

为满足电热化学炮系统工程化研究需求,开展了一种同轴型脉冲功率电缆设计与试制。根据发射试验获得脉冲电流、内部过电压等数据以及商业大功率电缆使用的经验,分析确定了脉冲功率电缆设计指标;基于同轴型商业大功率电缆开展了脉冲功率电缆结构设计,增加了屏蔽加强层和半导电层。屏蔽加强层能抑制外导体芯线错位产生的强电动力,防止电缆变形和爆裂,提高机械强度,改善电磁屏蔽效果;半导电层有助于消除气隙,平衡内部电场。使用有限元分析ANSYS软件对脉冲功率电缆进行了电磁场和热分析,协助开展了电气强度、机械强度和温升特性等辅助设计。针对脉冲功率电缆推广使用中出现的芯线端部拉长、断股与撕裂等现象,为内导体设计了钢芯以提高其抗拉强度。耐压试验与脉冲放电测试的验证结果表明,脉冲功率电缆在25 k V/5min电压作用下无损坏,在幅值203 k A、半峰值时间大于2 ms脉冲电流作用下无形变,满足系统研制要求。

According to the research requirement of engineering in an electrothermal-chemical gun,a pulsed power cable was designed and developed,which is suitable for coaxial breech transmission system. The index parameters of pulsed power cable are analyzed and determined based on the pulse current and internal overvoltage data obtained from launch tests and the experience of common commercial high power cables. The structure design of pulsed power cable is carried out. Compared with common commercial high power cable,the shielding enhancement and semi-conductive layers are added in pulsed power cable. The strengthening shielding layer is used to improve the mechanical strength,which can restrain the strong electrodynamic force produced by the core dislocation of outer conductor,thus preventing the deformation and burst of cable,and improving the electromagnetic shielding effect. The semi-conductivelayer is used to eliminate the air gap and balance the electric field. The electromagnetic field and thermal analyses of pulsed power cables are carried out by using simulation software,which assists in aided design of electrical strength,mechanical strength and temperature rise characteristics. In view of the breaking and tearing of the inner core end of pulse power cable in other systems,a steel core was designed to improve the tensile strength of inner conductor. Withstand voltage test and pulse discharge test show that the performance of pulsed power cable meets the requirements of the development. It is not damaged under the action of 25 k V/5 min voltage,and is not deformed under the action of pulse current with amplitude of203 k A and half peak time greater than 2 ms.