Energy management in Steel rolling plant

Induction machines (IMs) account for a bulk portion of electric energy consumed in industrial applications. The efficiency and power factor of the IMs have been remarkable impact on running cost. In this work, a practical field work data have been taken up as Jindal Steel Plant (JSP) in India, where there were more than 300 Induction Machines ranging from small one HP to large 200 HP. Furthermore, it has been observed that most of IMs had more than required capacity rating, the load sharing between transformers were inadequate, ten large variable speed IMs tripped off sometime due to load fluctuation and, power factor of plant´s electric supply was also poor, hence, all these factors had significant impact on overall energy losses as well as machine´s performances. Therefore, in this work, several techniques/approaches have been suggested in terms of replacing with efficient designed and appropriate capacity rating of Induction Machines as well as Transformers, rescheduling of transformer loads and, improvement of power factor to reduce the overall energy and monetary losses in this Steel Plant. Moreover, the effectiveness of all these proposed approaches have been analyzed in terms of energy and demand saving, payback period of new investment with assumed life time of machines.