Contribution of electrical parameters on the dynamical behaviour of a nonlinear electromagnetic damper

Abstract

This study explores the dynamical behaviour of electromechanical systems used as vibration absorber. A nonlinear system is considered, with the nonlinearity coming from Duffing-type stiffness. The mathematical modelling uses a Lagrangian approach, both for the mechanical components and the electromagnetic components of a RLC circuit. The coupling of the mechanical and electromagnetic subsystems is accomplished by a moving coil, permanent magnet transducer. The models were motivated by suspension systems used in automotive industry, resulting in a simplified model of a quarter-car suspension system. The influence of the parameters on the RLC circuit was investigated, and it was observed that they are highly responsible for the behaviour of the resulting mechanical damping effect. The correlation of the mechanical damping with the electrical resistance and capacitance was performed, and stability analysis was performed based on eigenvalues and root locus of a simplified linear system. The dynamical behaviour of the nonlinear model was observed for varying levels of capacitance, at four values of the excitation frequency. The results show that the system has a wide range of dynamical responses, and indicates that the capacitance of the electrical subsystem can be used as a control parameter.