On the Real-Time Quantification of Flexibility Provided by District Heating Networks Considering Dynamic Temperature Distribution

Abstract

District heating networks (DHNs) can provide electrical power systems (EPSs) flexibility by utilizing heat storage abilities. There are three challenges to the real-time quantification of the flexibility offered by the DHN. First, the balance between the heat supply and consumption in the long term must be considered. Second, the robustness and economy of the quantified result must be guaranteed. Third, the reliable dynamic temperature distribution in the DHN must be obtained. Thus, this paper designs a flexibility-providing mechanism for the DHN to interact with the EPS, consisting of the service period and the recovery period. The real-time quantification of the flexibility of the DHN is formulated as an optimization problem, where both flexibility revenue and the operation cost increase in the CHP units are considered. A novel thermal dynamic state estimation (TDSE) model with a bad data filtering process is proposed, which is used to provide the dynamic temperature distribution to support the real-time quantification of the flexibility. Numerical results verified that the proposed real-time quantification model has advantages in ensuring the benefits of the DHN. The performance of the TDSE in providing data support for flexibility quantification is also verified. Finally, key factors impacting the quantified flexibility are exploited by simulations.