Application of Protective Relays on a Large Industrial-Utility Tie with Industrial Cogeneration

The recent emphasis on the simultaneous production of electric power and steam within the confines of the industrial plant, often utilizing waste products from the industrial process as fuel, has resulted in renewed interest in the problems of applying protective relaying at the interface between the cogenerating industrial facility and the electric utility. This paper will review the considerations that must be taken into account at the consumer-utility interconnection and will suggest protective practices for these tie points.