Optimization Operation Strategy For Microgrid With CCHP Systems In High-speed Railway Stations

High-speed railway stations are one of the shining business cards showing the rapid economic development momentum of China to the world.With the increasing expansion of the scale of high-speed railway stations,the problems of economy,energy consumption and environmental protection are also becoming more and more prominent.Introducing the microgrid with CCHP systems into high-speed railway stations can not only provide cold,heat and electricity for the users inside the stations,guarantee the safety of power supply and the stable operation of high-speed railway stations,but also achieve good economic,energy saving and environmental protection benefits.This paper focuses on the optimization operation strategy for microgrid with CCHP systems in high-speed railway stations,and the main work is summarized as follows:(1)Research on the composition of the microgrid with CCHP systems in high-speed railway stations.Establish the probability density distribution model of fans and photovoltaics from the perspective of the "source" layer to realize the utilization of the environment and scenery resources around the high-speed railway stations,and establish gas turbines,fuel cells,gas boilers,sewage source heat pumps,waste heat boilers,heat exchangers,and absorption the model of a type refrigerator and an electric refrigerator to solve the multi-energy complementarity problem of the co-supply system.From the perspective of the "network" layer,establish a two-way interactive network relationship between the microgrid and the grid to ensure that the cogeneration system is friendly to the Internet.From the perspective of the "load" layer,a load model that obeys the normal distribution is established to consider the impact of load randomness on the operation of the microgrid.(2)Research is carried out on the cooperative optimization of the "source-network-load" operation of the microgrid with CCHP systems in high-speed railway stations.In order to analyze the influence of the operation strategies of "Following the Electric Load" and "Following the Thermal Load" on the economic operation of the microgrid,a collaborative optimization model of microgrid "source-network-load" based on stochastic programming was established.Probability density function fitting and Scenario Generation and Reduction Techniques are used to characterize the uncertainty of new energy and load,and are embedded in the optimization model in the form of discrete probability scenarios.An Improved Q-Learning Optimization Algorithm is proposed to optimize system energy.Comparing the two operating strategies and the economic efficiency of the system before and after the algorithm is improved,it is concluded that the total annual cost of "Following the Thermal Load" under the networked operation mode is 41.32% less than that of "Following the Electric Load",and the single-day operating cost ratio of the improved algorithm if there is no improvement,it will be reduced by 4000 yuan.The economic operation of the system has been realized,indicating that the operation strategy of "Following the Thermal Load" is more suitable for network operation,and improving the Q-Learning Optimization Algorithm has a better effect in economic optimization.(3)Research is carried out on the coordinated optimization operation of the "source-network-load-storage" microgrid with CCHP systems in high-speed railway stations.In order to analyze the impact of energy storage on the operation of microgrid,a microgrid "source-network-load-storage" collaborative optimization model based on double-layer stochastic chance constrained programming is established.An Improved Multi-Objective Universal Gravitation Search Algorithm is proposed,combined with Monte Carlo simulation technology and stochastic power flow calculation method to solve the optimization model.Comparing the results of the "source-network-load" coordinated operation of the sub-supply system and the microgrid,the total annual cost was reduced by 22.3% and 18.63%,and the energy consumption was reduced by 17.24% and 9.63% respectively,and both voltage deviation and active power loss were both significantly reduced.Realize the optimal system economy and energy saving,with minimum voltage deviation and active power loss.It is verified that the improved algorithm is better than the optimization effect when it is not improved.(4)Research is carried out on the cooperative optimization of the "source-network-load-storage-vehicle" coordinated operation of the microgrid with CCHP systems in high-speed railway stations.In order to analyze the impact of EV on microgrid operation,a microgrid "source-network-load-storage-vehicle" collaborative optimization model based on double-layer stochastic fuzzy chance constrained programming is established.The Improved Multi-Objective Universal Gravitation Search Algorithm is used,combined with the expected value random fuzzy simulation technology and the random fuzzy power flow calculation method based on credibility theory to solve the optimization model.Comparing the situation of not considering EV and only considering EV charging,it is found that the system indicators are better when not considering,and after considering the optimization control of EV charging/discharging is more economical,energy-saving and environmentally friendly the performance is good,and the system voltage deviation and active network loss are greatly reduced,and the system indicators are optimized.