Vibration analysis and backlash identification of a twin ac drive for a cement kiln

In this paper, a general analysis of a twin ac drive used in the cement industry to produce clinker is presented. The equations of motion of the whole system are presented and thereafter the influence of the elasticity of the shafts and the geared couplings in the resonant frequencies of this five-mass system is investigated. The results are applied to a real kiln installed in a cement plant of TITAN Cement SA in Greece. The electric parts as well as the control strategy are described and a detailed simulation model of the whole electromechanical drive is presented. In addition, the occurrence of backlash (lubrication) phenomena at the mechanical transmission system and the effects of these malfunctions in the electrical equipment are also investigated and the simulation results are presented in this paper. Finally considering the simulation results, the resonance frequency analysis and the general demands of the cement industry operating and improvement guidelines are given to be applied in systems already installed in cement plants.