Estimations of compatibility of supercapacitors for use as power sources for resistance welding guns

Supercapacitors offer potential for several kilojoules of energy to be proved in a small package with limited charge voltage (few volts). A preliminary examination of supercapacitors suggests that both the voltages used and retainable energies are well matched for resistance spot welding applications. Utilization of supercapacitors as resistance welding power supplies offers significant weight reduction over conventional (transformer and power supply) approaches, with subsequent economic advantages. In this work, some preliminary analyses have been done to assess the potential for using supercapacitors as resistance welding power supplies. This was done by integrating two separate analyses: one to assess the inductive response of specific weld gun designs and the second to define the current response of supercapacitors matched with that inductance. Results demonstrated potential for achieving desired currents and pulse widths with the proper selection of supercapacitor type and arrangement as well as secondary gun configuration. These analyses were further used to understand implications of system design on overall deliverable current capability. While the results described here only describe potential, some recommendations are made for next steps advancing supercapacitor-based resistance spot weld gun technology.