Aplicação de inversores de frequência como uma alternativa para sistemas de elevação de carga do tipo pontes rolantes.

Abstract

In this paper a study about the replacement of wound-rotor motor for squirrel-cage rotor, operating through electronic motor drives such as variable-frequency drive and softstarter for application in overhead crane is approached. It also outlines the basic concepts about the operation of power electronics equipment, in a way to explain its use for torque, starting current and speed control. It will also describe the use of electric machines for overhead crane, where it is necessary a high starting torque for moving the load, and how resistive load banks were widely used, along with wound-rotor motor, to reach a reasonable torque control. Also, a brief historic evolution about the usage of electric machines for industrial purposes is shown, more specifically in cases where it is necessary a good speed and torque control over the load, showing how the electronic advance can increase the efficiency, lower the costs maintenance-related, and operate with a refined and precise control over the load. It also shows a brief study about VFD parameters with induction motors, where it is necessary the speed or torque control over the load.