Field measurement of power quality in steel rolling mills

Power quality is of increasing concern to electric utilities and their customer alike. There is a large growth in the use of loads that can be sensitive to power quality disturbances. Steel rolling mill loads are invariably nonlinear and result in harmonic voltages and current generation. The basic objective of the study undertaken by CPRI was to collect data on the existing levels of harmonic current, voltage and other related parameters in steel rolling mills having induction and arc furnaces, which will help utilities to deal with power quality problems. Induction and arc furnaces produce significant harmonics which lead to additional loading, resulting in a rise of temperature of their transformer. This leads to the deterioration of insulation and a consequent reduction in the life of the transformer. Data collected during these studies have been analysed and presented in this paper