1077-2618/10/$26.00©2010 IEEE BY PETER E. SUTHERLAND, VINICIUS ROUBACH,& LEANDRO MATOS RIANI Large self-generators for controlled load shedding T HIS ARTICLE PROVIDES AN ANALYSIS OF THE SEPARA- tion philosophy for a large steel mill with internal generation, which is transitioning from net power import to net power export after the addition of two new steam turbine generators. Separation from the utility in the case of a fault is determined by the operation of a protective relay system at the point of separation. The plant has a programmable logic con- troller (PLC)-controlled load shedding, which drops blocks of load, based upon measurement of the amount of load and generation in service. With the addition of new generation, alternatives such as generation rejection and fast turbine valv- ing must be evaluated. Digital Object Identifier 10.1109/MIAS.2010.937439 © M.O. STEVENS FROM WIKIMEDIA COMMONS 20 IEEE INDUSTRY APPLICATIONS MAGAZINE SEPT j OCT 2010 WWW.IEEE.ORG/IAS