## 1 Introduction  
With the increased level of integration in the fields of energy, automation, computers, and communications, the micro energy grid attracted the attention of an increasing number of experts and scholars [1; 2; 3], who integrated them into electricity, heating, cooling, and gas grids. The micro energy grid is a micro integrated energy system [4; 5; 6], and a natural extension of the microgrid, which is mainly used in urban communities, industrial and agricultural parks, and rural areas. The micro energy grid is a user-side energy interconnection. By means of information, the power-supply grids for cooling, heating, electricity, and gas in the micro energy grid are coordinated for optimization, in an effort to meet the demands for various energies on the user side, and to achieve comprehensive and efficient utilization of various energies. Photovoltaic (PV) power, wind power, microturbines, and other distributed energies in the form of a micro energy grid accessing a distribution network are becoming increasingly widespread [7]. The micro energy grid is the link between distribution networks and distributed energy, such that the distribution network does not have to manage distributed energies of various types, large quantities, or decentralized access (especially intermittent). Based on the above advantages, many demonstration projects, such as the new Tianjin Eco-city [7], the Golden Concord Group Limited (GCL) Suzhou Industrial Park multi-complementary model [8], and the \"Forest Town\" of Jurong [9], exist in China. Therefore, the coordination of the operation of the distribution network and the micro energy grid, so as to maximize the consumption and utilization of renewable energy, and improve the operating economy, security, and stability of the entire system, is an urgent problem requiring resolution by researchers. Numerous studies in China and abroad focused on the optimal dispatching of the distributed energy's direct access to the distribution network [10; 11; 12; 13; 14; 15; 16; 17; 18; 19]. For example, in Reference [12], a distributed coordinated control framework for a distribution network was proposed to enable reactive power optimization of the distribution network with renewable energy, and to improve the power quality of the system. In Reference [13], an optimal dispatching method for an active distribution network considering the risk of voltage instability was proposed. In Reference [15], a comprehensive optimization algorithm for a distribution network was proposed to enable the simultaneous optimization of renewable energy output, distribution network reconfiguration, and capacitor switching. According to the research reported in the above references, the control variables of the system will feature an increasing amount of distributed renewable energy in the distribution network, which complicates the solution process, and is disadvantageous to the solution of the model. As a result of the continuous development of microgrid technology [20; 21; 22; 23], experts and scholars in China and abroad studied the optimal dispatching problem of renewable energy in the form of microgrid access to a distribution network [24; 25; 26; 27; 28]. For example, Reference [27] considered the various interest demands of the microgrid and the distribution network, established a game relationship model of the two, proposed a cooperative evolutionary game algorithm to solve the above model, and achieved coordinated operation of the microgrid and the distribution network. However, the above studies were based on research on a single electrical energy. Typical situations were not fully considered, such as the dispatching of a micro energy grid comprising cooling, heating, electricity, and gas, and the coordination of the operation of the micro energy grid and the distribution network when the micro energy grid is accessible by the distribution network.