Cyber/physical interplay in the real-time scheduling for peak load optimization of electric loads

Real-time scheduling is an attractive option to co-ordinate a set of electric loads, with the goal of optimizing the aggregated peak load of power used by loads, for example in the field of Cyber-Physical Energy Systems (CPES) made by, e.g., household appliances or industrial loads. This paper contributes a novel study of the interplay between cyber and physical components in the coordination of electric loads where real-time scheduling is leveraged in both the cyber and physical domain. In particular, the relationship will be derived between the schedule enforced on electric loads (i.e., the physical components) and the one associated to processing tasks (i.e., the cyber components) that are executed by a computer to handle the loads. Power loads will be scheduled using a combination of two-dimensional bin-packing and optimal multi-processor real-time scheduling to coordinate their activation. The scheduling pattern of power loads influences the timing of processing tasks that are dedicated to the activation/deactivation of loads. The relationship between the two aspects is formally derived. Numerical simulations and experiments confirm the good performance of the proposed peak load minimization method.