Optimal operation for integrated energy system considering thermal inertia of district heating network and buildings

The use of wind power is often restricted by the strong interdependence between the electricity generation and thermal energy generation of combined heat and power units (CHP), especially during winter, when CHP operates according to the heat-led mode. Considering the strong temporal and spatial correlations between wind power and thermal demand, the heating system can provide margins for wind power accommodation from the perspective of overall energy consumption. This paper proposes an optimal operation model for an integrated energy system (IES) combining the thermal inertia of a district heating network (DHN) and buildings to enhance the absorption of wind power. The temperature dynamics and transmission delay in DHN and the thermal storage capacity of buildings are studied to exploit the heating system as an option for managing the dispatch of wind power. The proposed model is a mixed integer non-linear programming model and can be solved by general commercial optimization software. To illustrate the effectiveness of the proposed model, a real heating system (having 24 nodes and 50 pipelines) in Jilin Province is used in the case study. The simulation results demonstrate the benefits of the proposed model in terms of operational economics and wind power utilization.