Circuit Modeling of Contact Arc and Contact Bounce in a Transient Electromagnetic Compatibility Test

Automotive electronic/electrical systems are required to operate as designed while exposed to transient electromagnetic compatibility (EMC) tests. An example of such an EMC test is the CI 220 test, in which pulse voltages produced by switch contact arcing and contact bounce during switching of an inductive load are employed. Apposite but simple modeling is thereby desirable for the EMC engineer to evaluate at the early design phase and avoid failures in advance. In this work, an easy-to-implement circuit model simulating both contacts arcing and contact bounce phenomenon is derived and implemented in LTspice., in which arc behavior parameters, as well as bounce time, are extracted from the experimental measurement results using a home-made pulse generator. Experimental validation of this developed circuit model under three different loads is also demonstrated.