Efeitos de afundamentos de tensão no processo de laminação industrial

Abstract

The rolling mill process is an important step in the steel industry due to its relationship with the final product, being responsible for the specified size and shape, and operate with high productivity and low cost. Sudden interruptions in the rolling mill process cause delays in production, generate large maintenance expenses and losses of material (scrap).Considering this characteristic, this study examines the susceptibility of DC motors drive of the rolling mill front to disturbances in supply voltage of AC-DC converters of these motors. The methodology used is field data assembly and computer simulation, and has been used the package for calculation of electromagnetic transient time domain - PSCAD. From the assembly data and theoretical studies performed, the system including the electric drive motor of a rolling mill was modeled in PSCAD. Were conducted studies of short-circuit, single line to ground faults, harmonic distortion, susceptibility of the synchronism circuit of the rectifier bridges and evaluating performance of the rolling mill front to disturbances in supply voltage. The results of the work allowed to propose alterations that promote the optimization of the performance of rolling front voltage sags caused by single line to ground faults in other parts of the electrical system. This optimization results in the reduction of non planned stop inthe rolling mill, resulting in increased productivity and reduction in production losses.