PLC based peak load control for chemical industries

Chemical processes, employed for manufacturing basic chemicals are highly energy intensive. Due to escalating costs of fossil fuels and capacity addition, the electricity cost has been increasing for the last few decades. Electricity intensive industries find it very difficult to cope up with higher electricity charges particularly with time-of-use (TOU) tariffs implemented by the utilities with the objective of flattening the load curve. Load management programs focusing on reduced electricity use at the time of utility's peak demand, by strategic load shifting, is a viable option for industries to reduce their electricity cost. This paper presents an optimization model and formulation for load management of continuous process industries. The case study of a chemical industry is taken for conducting load management study. The formulation utilizes nonlinear programming technique for minimizing the electricity cost and reducing the peak demand, by rescheduling the loads, satisfying the industry constraints. Development of a generalized graphical user interface (GUI) in Visual Basic for implementing load management actions in industries and testing the GUI with the case study are done. Real time implementation of load management actions using Programmable Logic Controller (PLC) is also investigated.