On An Equivalent Representation of the Dynamics in District Heating Networks for Combined Electricity-Heat Operation

Improved coordination between power and district heating systems (DHSs) can play a vital role in accommodating more wind power. However, the dynamics of district heating networks (DHNs) have not yet been fully described for large transfer delays, which remains an obstacle for optimal electricity-heat coordination. This paper solves this problem by proposing a uniform framework in the Laplace domain by modeling heat losses and transfer delays from an electrical-analog perspective. Based on this framework, an equivalent representation of DHNs is proposed, showing the explicit "end-to-end" relationship between heat power generation and demand. The model is applied in combined electricity and heat operation, in which the black-box model is provided by DHS operators for power system operators without revealing the detailed network information. A case study of an integrated electricity-heat system demonstrates the effectiveness and simplicity of the proposed model.