Dynamic model for AC and DC contactors – Simulation and experimental validation

Electromagnetic contactors have a non-linear behavior due to the magnetic force. This paper develops a robust and low time-consuming parametric model to describe the dynamic behavior of both AC and DC contactors. The proposed model solves simultaneously the mechanic, electric and magnetic coupled differential equations that govern its dynamic response. This model takes into account the fringing flux, an effect that greatly influences the dynamic behavior. In case of AC contactors, the model deals with the shading rings. First, the electric and magnetic equations of an AC contactor – which are more complex due to the effect of the shading rings – are introduced. After that, by simplifying this set of equations, the ones of a DC contactor are derived. Conversely, mechanical equations are the same for both, AC and DC powered contactors. Data from simulations carried out by applying the presented parametric model are compared with experimental data, being demonstrated its accuracy and effectiveness.