| With the networked,high-density,and high-speed development of electrified rail transit,the demand for electricity in the rail transit system has sharply increased.As the main source of electricity in China is fossil energy generation,electrified rail transit remains one of the key areas of carbon emissions.Therefore,in order to support the realization of the vision of "carbon neutrality",while ensuring its own safe and reliable power supply,electrified rail transit urgently needs to achieve low-carbon,green,efficient and highly elastic development of its own energy consumption structure,and vigorously promote the application of new energy.Given the above background,this article proposes a method for planning the optical storage capacity of rail transit self consistent energy systems considering extreme weather effects.Analyzed the basic structure and traction load characteristics of the self consistent energy system in rail transit,and studied the photovoltaic output model and hybrid energy storage system characteristics.The self consistent energy system for rail transit proposed in this article mainly consists of a public power grid,photovoltaic power generation devices,all vanadium flow batteries,supercapacitors,and an electrified railway traction power supply system,forming an integrated power supply system of"source network vehicle storage" for electrified railways.The introduction of photovoltaic new energy and energy storage increases the controllability and flexibility of system trends,promoting the absorption of regenerative braking energy and new energy in traction systems;And both can provide short-term emergency power supply capability for traction trains in case of external power grid failure.Subsequently,a simplified photovoltaic power generation system model and a hybrid energy storage system composed of all vanadium flow batteries and supercapacitors were introduced,and the advantages and characteristics of hybrid energy storage were analyzed.Finally,the traction load characteristics were studied.We have established a traction load reduction model and a rail transit self consistent energy system optical storage capacity planning model considering extreme weather effects.Considering the occurrence of disconnection faults in the transmission system under extreme weather conditions,a traction load reduction model was established to obtain the maximum transmission power between the transmission system and the rail transit self consistent energy system under extreme weather conditions.On this basis,considering both normal operation and extreme weather conditions,a light storage configuration planning model was constructed with the goal of minimizing the sum of investment cost and operating cost for the self consistent energy system of rail transit.Next,for the objective function containing max function and the constraint containing continuous variables multiplied by 0-1 variables,linearization is carried out based on the large M method by introducing auxiliary variables.Then set five typical planning configuration scenarios,and verify the progressiveness of the model and the advantages of photovoltaic and hybrid energy storage configuration by comparing each scenario.A light storage capacity planning model for self consistent energy systems in rail transit considering battery cycle life has been proposed.Considering the equivalent battery cycle life loss under different discharge depths and calculating the actual service life of the battery,a two-layer optical storage capacity planning model is constructed.The outer layer is the optical storage capacity configuration model of the rail transit self consistent energy system;The inner layer is a self consistent energy system operation and scheduling model for rail transit.Based on the improved particle swarm optimization algorithm,the bi-level programming model was optimized and iteratively solved,and the necessity of considering cycle life for battery energy storage was verified through case analysis. |
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