高压电力电缆导体连接管的电磁脉冲成形研究

Research on Electromagnetic Pulse Forming of Conductor Connecting Pipe of High Voltage Power Cable

电力电缆中间接头制作中,用液压钳压接的导体连接管易存在压接不紧密、表面有毛刺、压接面之间有杂质等缺陷,会导致接头的接触电阻大或产生局部放电,进而对接头造成破坏。而电磁脉冲成形技术具有压接紧密、无压痕等优点。因此,通过仿真获得了成形线圈和集磁器设计的优选规律,并据此搭建了一套电磁成形设备,对GT–G–70型号的铜连接管与铝绞线的电磁压接进行了研究。研究结果表明:使用电磁脉冲成形技术压接的铜连接管从外观上看,表面光滑均匀、无毛刺;从横截面看,铜管紧密包覆在铝绞线上,并使铝绞线的线芯之间也紧密贴合;从压接界面的SEM图像上看,存在类似于固相焊接的微波状连接界面的界面形貌。综上所述,使用电磁脉冲成形技术压接的铜连接管在表面光滑度和压接紧密度上都比用液压钳压接的效果好。

In the production of power cable intermediate joint, the conductor connecting pipe crimped by hydraulic pliers is easy to have defects such as tight crimping, burrs on the surface, impurities between crimping surfaces, etc., which will lead to large contact resistance or partial discharge of the joint, and then damage the joint. The electromagnetic pulse forming technology has the advantages of tight crimping and no indentation. Therefore, the optimal design rules of forming coil and magnetic collector are obtained by simulation, and a set of electromagnetic forming equipment is built based on it. The electromagnetic crimping of GT–G–70 copper connecting pipe and aluminum strand is studied. The results show that the surface of the copper pipe crimped by electromagnetic pulse forming technology is smooth without burrs from the appearance;the copper pipe is tightly wrapped on the aluminum strand from the cross-section, and the core of the aluminum strand is also tightly bonded;from the SEM image of the crimping interface, there is the interface morphology similar to the microwave connection interface of solid-phase welding. To sum up, the copper joint pipe crimped by electromagnetic pulse forming technology has better surface smoothness and crimping tightness than that by hydraulic tong.