Reconfiguration of District Heating Network for Operational Flexibility Enhancement in Power System Unit Commitment

Massive adoptions of combined heat and power (CHP) units necessitate the coordinated operation of the power system and district heating system (DHS). Exploiting the reconfigurable property of district heating networks (DHNs) provides a potentially cost-effective solution to enhance the flexibility of the power system by readjusting the configuration for heat supply, which has not been addressed in the literature. To address this issue, a unit commitment considering combined electricity and reconfigurable heating network (UC-CERHN) is proposed in this paper to coordinate the day-ahead scheduling of power system and DHS. The DHS is formulated as a nonlinear and mixed-integer model considering the reconfigurable DHN. To make the commitment problem tractable, an auxiliary heat quantity variable is introduced, and the DHS model is reformatted to a linear energy flow model by approximation of heat loss, where the computational burdens are significantly reduced. Extensive case studies are presented to validate the effectiveness and accuracy of the approximated model and illustrate the potential benefits of the proposed method with respect to congestion management and wind power accommodation.