Influence of Thermal Characteristics on Optimal Scheduling of Integrated Energy System

Abstract

The complementarity of heat and electricity is the key to an integrated energy system (IES) to improve performance and accommodate renewables. However, the individual, interactive and total effects of thermal inertia, transition delay, and heat loss, the three typical characteristics of thermal processes, are rarely compared. Therefore, a dynamic scheduling model of an IES is innovatively proposed here, where the thermal inertia of heat exchangers is considered via a discrete-time state-space model. A mixed integer linear problem is then solved and eight operation modes are performed to elaborately compare the effect of thermal characteristics. Based on the results of a case study, we found that heat loss increases system operation cost, whereas thermal inertia and transition delay both reduce the cost but with certain fluctuation. When considering heat loss, the interactive effect of thermal characteristics will deteriorate the economy. The reliability of optimal scheduling results is increased when all the three thermal features are considered, though this will burden solution time and increase operation cost.