A dynamic model of electromagnetic relay including contact bounce

Contact bounce of relays, which is the main cause of electric abrasion and material erosion, is inevitable. Using the mode expansion formalism, this paper presents an analytical investigation of the dynamic behavior of two different reed systems configurations. The model uses dynamic Euler-Bernoulli beam theory for cantilevered beams, includes the driving force from the electromagnetic systems, and takes into account the contact force between moving contact and stationary contact using the Kelvin-Voigt viscoelastic contact model. Analytical results have been complemented by the finite differences simulation of the beam nonlinear partial differential equations and the use of the Runge-Kutta algorithm for the modal equations. The model and simulation can be used as design tools to improve relay performance and reduce contact bounce in future designs.