The Modelling, Simulation and Experimental Testing of Vertical Vibrations in an Elevator System with 1:1 Roping Configuration

Vertical vibrations affect passenger comfort during an elevator travel. In this work the results of a study to investigate the vertical vibrations caused by torque ripple generated at the drive system and transmitted through the suspension ropes to the car is presented. The acceleration response at the suspended masses and at the drive machine end in a laboratory rig are measured during the system travel. The machine torque ripple and the radial forces generated at the machine air-gap between the stator and the rotor are computed using the Finite Element Method simulation with the software FLUX. The torque ripple excitation is then accounted for in a non-stationary lumped-parameter model of an elevator system with 1:1 roping configuration. The model accommodates the dynamics and control of the drive system. The model is implemented in the MATLAB/Simulink computational environment and the dynamic response of the system during travel is determined through numerical simulation. Both computer simulation and experimental results demonstrate that the vibration generated at the machine is transmitted to the elevator car becoming magnified if the excitation frequency is close to the natural frequencies of the system.