Article

# Dynamic model for AC and DC contactors - Simulation and experimental validation

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## Abstract

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.

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... The design and manufacture of electromechanical devices is a highly specialized process subject to many requirements due to the interconnected nature of the electrical, mechanical and thermal designs. Contactors are electromechanical switches employed in applications that require processes of electric circuit "making and breaking", such as starter motors, electric vehicles, heaters, and lighting applications [1]. In the past, the design and development of electromechanical contactors has been based on extremely simple analytic models, supplemented by experience and intuition. ...
... In the definition of the lumped elements, each region where the magnetic flux density B is more or less uniform is represented by an element of a given magnetic reluctance. The relationship between the variables is ,    F (1) where F is the magnetomotive force,  is the magnetic reluctance, and  is the magnetic flux. ...
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... Indeed, contactors are one of the most common discrete electrical components in the current industrial power systems. They are used in such diverse industry applications as rectifiers, motor drives, and uninterruptible power supply systems [41]. In modern machinery applications, such as packaging, pallesting or conveying, it would not be considered unusual to switch three-phase electric motors equipped with ACcontactors each second [42]. ...
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... This effect amid conclusion is the starting point of the contact skip, otherwise called babble. It is an undesirable marvel, which brings about a re-opening of the contacts, creating the ghost of an electric circular segment until the contact makes unquestionably [2]. The curve can bring about extreme contact disintegration, and consequently the electrical life and unwavering quality of the contacts are drastically decreased [3,4]. ...
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