Intelligent electrical load shedding in heavily loaded industrial establishments with a case study

The purpose of a Load Shedding Control System (LSS) is to prevent a dangerous overloading of the generators and/or a general collapse (blackout) of an electric power system due to a generator failure or any contingency which may diminish the capacity of the operational generators below the active power required by the loads. Such a state may create an imbalance in the power supply and thus lead to a frequency decay, voltage collapse and overload on all the power generation units connected to the system. In case the electrical supply is inadequate to meet the demand of the process loads, partial supply to certain areas can be interrupted in order to prevent the failure of the whole electrical system. This process is called load shedding. This is an entirely different concept from a power failure that may occur due to various reasons. Load shedding is an effective method to prevent a total collapse of the electrical supply, which may have a disastrous impact on the continuity of the processes and operations. Unless power imbalances are properly managed, they may cause the entire workflow to collapse until the power to the industrial establishment is restored. The aim of this paper is to discuss the electrical load shedding process of a refinery, which is a heavily loaded industrial establishment, in detail.