Review of District Energy Network Dynamic Modeling and Coordinate Optimal Operation in Integrated Electricity and Heat Energy Systems

A district energy network with integrated electricity and heat energy systems has a passive heat storage capacity because of its strong thermal inertia. This naturally improves the regulating ability of the electric power system and provides space for the grid-connected consumption of large-scale renewable energy. Under the premise of no additional equipment, the method can achieve the purpose of smoothing the intermittence of renewable energy only through the optimal combined dispatch of heat and power. Therefore, this method has become one of the means with the greatest potential for enhancing power system flexibility and has gradually been given much attention both at home and abroad. However, because of the characteristics of district energy systems, including multi-variable, non-linear, and time delay characteristics, the research has faced several bottlenecks such as incompatibility between power systems and district energy system modeling. There has also been a lack of coordination between the different kinds of energy systems when describing and evaluating the improvements in the regulating ability of district energy networks. This study reviewed the latest research on utilizing the thermal inertia of district energy networks to improve the Science and Technology Foundation of SGCC (Key Technology and Application for the Optimal Configuration and Market-based Interaction of the Regenerative Electric Heating (5400-201914172A-0-0-00)). regulating ability of integrated energy systems based on three aspects. First, heat transportation dynamic modeling of district energy networks was necessary. Second, the modeling of closely related units was a key factor. Third, a combined heat and power dispatch method was eventually established based on the above two factors. In addition, this study compared the advantages and disadvantages of the lumped parameter method, node method, element method, equivalent thermal–electricity analogue circuit method, and other dynamic modeling methods. The key factors affecting the performance of an integrated electricity and heat energy system are summarized, and several suggestions are given for further research.