Development and Experiment of Electromagnetic Pulse Crimping System for Terminal-Wire of Electric Vehicles

Abstract

The safety and reliability of the energy transmission system of electric vehicles (EVs) are decided by the connection reliability of the high-voltage (HV) wire harness and terminals. When the terminal and the HV wire harness are connected by the usual mechanical crimping methods such as hydraulic pressure, there are the edges and corners on the terminal, and gaps between the wire harness and terminal, which are prone to fretting corrosion and threaten the power system. In this work, an electromagnetic pulse crimping (EMPC) system has been designed and developed for joining the Cu wire harness and the Cu terminal of the EV. When the discharge voltage is 13 kV, it can deliver the discharge current of 70 kA peak value, causing the joint of the Cu terminal and the Cu HV wire harness. Scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) were used to analyze the microstructure and element distribution of the joint interface. A good and strong metallurgical bond was obtained at the surface of the Cu HV wire harness, the Cu terminal, and each strand of the Cu HV wire harness. There were a flat interface and a wavy interface between the Cu HV wire harness and the Cu terminal because of the gap on the field shaper.