## 1 Introduction  
With the acceleration of globalization, global crises such as the novel coronavirus epidemic and the Russia-Ukraine conflict have a huge impact on the energy system. To reduce the dependence on a single energy source, integrated energy systems with diversified energy sources should be constructed. [PERSON] et al. [1] proposed that building a safe, efficient, clean and low-carbon new generation integrated energy system is one of the important means to achieve energy transformation and dual carbon goal. As mentioned in [PERSON] et al. [2] and [PERSON] et al. [3], the two main technological paths are to increase the proportion of renewable energy and to implement various low carbon technologies. Wind power is abundant in north China, northeast China and northwest China. In these three regions, winter heating is generated by thermoelectric units, which are subject to the restriction of \"determining electricity by heat\" of combined heat and power (CHP). When the output of wind power is large, the output adjustment range of thermoelectric units is limited, resulting in a large amount of wind abandonment. [PERSON] et al. [4] proposed that power-to-gas (P2G) has the energy storage characteristics of time-space translation, which provides a solution for wind power absorption and peak shaving and effectively improves the flexibility of the integrated energy system. The research on P2G is mainly focused on the framework of an electric-gas integrated energy system. [PERSON] et al. [5] optimized the sizing and siting of P2G facilities considering the uncertainties of carbon price and carbon tax. A co-optimization scheduling model of the two energy systems considering P2G was proposed by [PERSON] et al. [6]. [PERSON] et al. [7] built the carbon emission flow model which is used to track the emission of P2G. [PERSON] et al. [8] considered gas-fired power and P2G to absorb renewable energy. P2G contributed to optimization as a part of the energy hub considered by [PERSON] et al. [9]. To solve the problem of \"determining electricity by heat\", researchers use heat storage devices and electric boilers for thermoelectric decoupling. [PERSON] et al. [10] proposed a gas storage life reliability model to characterize the performance. The investment cost of the heat storage device at the source side is high and the planned capacity is limited. It is difficult to absorb wind power on a large scale using only a heat storage device. [PERSON] et al. [11] used gas turbines and electricity-to-natural gas facilities to address the uncertainty of renewable energy power generation. However, the low profit of P2G power stations have hindered the development of P2G. In fact, it is easy to understand that the methanation process has strong heat release characteristics from the chemical expression mentioned by [PERSON] et al. [12]. [PERSON] et al. [13] proposed that the electricity-to-methane industrial chain can be incorporated into the heating application to improve efficiency. Considering the exothermic characteristics of P2G methanation reaction and injecting its reaction waste heat into the heat network, the coupling of electric-gas-heat network can be realized, and the economy and energy utilization rate of the system can be further improved. The design of the P2G integrated energy hub (P2G-EH) system is performed with a stochastic dynamic planning method by [PERSON] et al. [14]. [PERSON] et al. [15] proved that P2G technology reduces CO2 emissions by 9.89% through consuming CO2 emitted from the CHP and boiler. [PERSON] et al. [16] used a life cycle assessment methodology to prove that an integrated system will assess the most significant environmental impacts with P2G. A model containing P2G and energy storage was established to enhance the resilience of multi-carrier energy systems integrated with electric-gas-thermal networks by [PERSON] et al. [17].