Abstract: Exploring the flexibility of the heat and electricity coupling integrated energy system（HEC-IES），

reducing system operation costs and promoting renewable energy consumption are hot issues in the field of energy

internet. Thus，a day-ahead optimal scheduling method of the HEC-IES considering the thermal dynamic energy

storage flexibility of heating network was proposed. Firstly，the HEC-IES was modeled and the thermal dynamic

model and equivalent thermal energy storage model of the heating network considering energy storage

characteristics were constructed. On this basis，the flexibility quantification method was proposed to quantify the

flexibility of the HEC-IES. Furthermore，the optimal scheduling model of the HEC-IES considering thermal

dynamic energy storage flexibility of heating network was constructed，where minimizing the system operation cost

was taken as the objective，and the power balance constraints，energy equipment constraints，heating network

constraints and power grid constraints were taken as constraints，then，the optimal system scheduling scheme was

obtained. The effectiveness of the proposed method was verified by case studies. The results show that the optimal

scheduling scheme based on the proposed method can maximize the utilization of system flexibility. By using the

energy storage characteristics of the heating pipe network，the space-time shift of energy supply and demand is

realized，and the forced output of the energy supply equipment is reduced，so as to reduce the operation costs of the system and promote the consumption of renewable energy.

      Key words: integrated energy system（IES）；thermo-electric cooperation；optimization scheduling；flexibility