Thermodynamic modeling with experimental validation of the pulsed and periodic operation of a high power resistor

The size and performance demands placed on high power resistors are increasing, in particular for their use in the growing electric vehicle industry. Ceramic composite resistors, which demonstrate high peak temperature limits and high power handling capabilities in low inductance packages, are attractive choices for these applications. A thermodynamic model of one such resistor is presented to better understand their use under repetitive high power stresses and the operating conditions that lead to thermal failure. This model is used to simulate the peak temperatures generated by a series of maximum rated-energy impulses, periodically delivered as to meet the maximum rated average power of the device. To experimentally validate the model, the resistor was subjected to similar voltage stresses and the surface temperatures are compared.