Comprehensive Load-Shedding System

The availability of reliable electrical power supply for petrochemical industries is extremely important not only to maintain continuous production but also from the point of view of overall plant safety. The costs, caused by production losses, due to a partial or a complete blackout easily run up to millions of dollars per blackout. If a proper load-shedding scheme is implemented, it is possible to save a plant from such occurrences. A lack of electrical power can be caused by loss of generation capacity or disconnection from the public power company supply. The load-shedding system ensures the availability of electrical power to all essential and most critical loads in the plant. This is achieved by switching off nonessential loads in the case of a lack of power in the plant electrical network, or parts of the plant electrical network. This paper discusses a comprehensive load-shedding scheme for industrial applications with a background on a similar system implemented at large integrated complexes such as refineries and petrochemical plants.