## 1 Introduction  
With the development of the economy, people pursue a higher quality of life. The living environment, such as shopping centers, hospitals, office buildings, and residential communities, needs an air condition system for refrigeration in the summer and heating in the winter [1, 2]. In terms of energy efficiency and environmental protection, relying solely on commercial electric power is not so economical and environment friendly because of the low electric generation efficiency and high environmental cost. Combining the cooling, heating, and power (CCHP) system has the potential of decreasing energy consumption and pollutant emissions by generating electricity locally and recycling the waste heat for cooling and heating [3, 4, 5]. A CCHP system can achieve efficiency higher than 90%; however, because of the regional, seasonal, and diurnal variations, the system's configurations and especially the operating strategies need to be studied further to meet the requirements and achieve a better operating economy [6, 7]. [PERSON] et al. [8] and [PERSON] et al. [9] studied an efficient algorithm for the operation and control of the CCHP system. [PERSON] and [PERSON] [10] and [PERSON] et al. [11] proposed a novel thermal storage strategy for a CCHP system, which can receive 3.79% and 20.22% annually in total costs. [PERSON] et al. [12] analyzed the influence of building type and climate zone on the performance of the CCHP system, which proved that a heat storage tank or gas-fired boiler is required. The above studies prove that the current CCHP system is limited by the so-called heat-electricity ratio. Once the system is constructed, the power generation unit (PGU), either a turbine or an internal combustion engine, cannot change the rate of the generation and the exhaust heat easily without adding extra-devices. Therefore, most CCHP systems need to add devices to store the excess heat or add a gas-fired auxiliary boiler to supplement the heat shortage. Thus, those CCHP systems should be optimally designed and controlled to minimize the system's construction cost and operating energy consumption. Currently, the research on the cogeneration of gas-fired internal combustion engine mainly focuses on the selection of system configuration and the optimization of operating conditions. These two factors directly determine the economic benefits and energy saving and environmental protection performance of the cogeneration system. [PERSON] et al. [13] evaluated the combined cooling, heating, and power generation system with a gas internal combustion engine, gas turbine, Stirling machine, and molten carbonate fuel cell as the prime movers from the three aspects of system economy, energy saving, and environmental-protection ability. The decision method shows that when the internal combustion engine is used as the prime mover, the overall performance of the system is better in terms of energy saving effect, carbon emission reduction, and annual cost saving. Taking a hospital in Italy as an example, [PERSON] et al. [14] established a dynamic simulation network of the energy system of the cogeneration system and studied the optimal system capacity under the premise of long-term uncertainties in energy demand. The cogeneration system uses natural gas internal combustion engine as the driving energy. The author's model calculates the energy-saving performance of the internal combustion engine in the power range from 600 kw to 1600 kw. [PERSON] et al. [15] took a six-story hotel in Shanghai as the research object; established a linear optimization model of the combined cooling, heating, and power system; and analyzed the economic performance and environmental performance of the four different configurations of the combined supply system. They determined the type and capacity of the optimal drive machine for the system. [PERSON] of Shandong University [16] carried out Simulink modeling for the combined cooling, heating, and power-generation system based on natural gas internal combustion engines.