## 1 Introduction  
In today's world, problems such as energy shortages, environmental pollution, and ecological deterioration are gradually deepening, and the contradiction between energy supply and demand is becoming increasingly prominent. Therefore, it is urgent to improve energy efficiency and promote energy transformation and upgrading [1, 2]. With the widespread use of various renewable energy generation technologies, RIES is of great significance in improving energy utilization efficiency, achieving complementary and coupled operation between various energy sources, and promoting China's energy conservation and emission reduction strategic goals [3]. It will play a more important role in the energy system over time. For the last few years, some scholars from home and abroad have conducted some studies about the RIES system. The Regional Integrated Energy System achieves complementary synergy and scientific scheduling among regional energy sources by organically combining multiple energy sources such as electricity, heat, and cooling with energy demand-side systems. Currently, the Integrated Energy System (IES) takes Combined Heat and Power (CHP) as its core and uses it as a platform to link regional energy sources with energy storage technology [4]. Carbon trading, also known as carbon emissions trading, is a trading mechanism that establishes legal carbon emissions rights and allows emitters to trade them on the market to achieve emission reduction goals. In [5], the actual output of the generator set was used as the standard to allocate the initial carbon emission right for the system for free, and the actual carbon emission is included to calculate the carbon transaction cost, which effectively improves the environmental protection and low carbon of the system but does not consider the user's demand response. In [6], the price elasticity matrix is introduced to describe demand response behavior, and the effectiveness of DR in alleviating the peaking pressure of the system was analyzed, but low carbon was not guaranteed. In [7], the electric load models under DR were built in light of the price elasticity matrix method. Furthermore, based on the fuzziness and delay of the user's thermal perception, the thermal load DR model was established, and it was verified that the model has a great impact on energy efficiency. However, the model did not consider carbon trading, cooling, or gas loads under DR. In [8], an optimal operation model of a multi-energy complementary cogeneration microgrid, including a demand response model on the demand side, is established, but the carbon trading mechanism and the interaction between power energy and gas energy are not considered. In [9], a CCHP microgrid model incorporating integrated demand response and dealing with the randomness of new energy output in the microgrid by scenario method was raised. In [10], the integrated demand response on the residential side based on micro CHP units was studied; however, the two did not consider the carbon trading mechanism and did not connect the CCHP microgrid considering demand response to the bulk power grid. In [11], the total operating cost and wind and light abandoning quantity of the system under different electrical and thermal load comfort levels are compared to achieve multi-energy complementarity, reduce operating costs, and improve new energy consumption on the basis of ensuring user comfort levels. However, the electric load DR only simplified the modeling of interruptible and moveable loads without considering the thermal load DR. In [12], considering the price transmission mechanism of the electricity market and carbon trading market, the electricity generation of renewable energy such as wind and light was converted into emission reduction, and a comprehensive demand-side response scheme of the multi-energy system, including the operation of cold, heat, and power cogeneration units and the control strategy of battery storage, was put forward to realize the economic operation of the multi-energy system in the park.