Research On Hydrogen Power Generation Accessing To Traction Power Supple System

With the gradual increase in the operating mileage of high-speed railways and the increasing mileage of railway electrification in China,the traction power supply system pays huge electricity bills to the power sector every year.Due to the long mileage of the electrified railway line and the numerous stations such as traction substations and section posts along the line,conditions have been created for the access of distributed power stations.As a clean and efficient secondary energy with a wide range of sources,hydrogen energy is the future development direction of the world’s energy.At present,there are self-operated railways of comprehensive energy companies represented by China Energy.Coal transportation mainly relies on self-operated railways.The factories produce a large amount of industrial by-product hydrogen,which can be directly burned to cause waste or be discharged into the atmosphere if it cannot be effectively treated,causing pollution to the environment.It is necessary to consider the use of hydrogen energy for power generation to reduce railway operating costs.In order to realize the control,utilization and consumption of hydrogen energy power generation,increase the proportion of green energy in the energy consumption of the traction power supply system,and save energy and reduce emissions.In this paper,the scheme of hydrogen power generation accessing to the traction power supply system is studied,the connection scheme of the hydrogen energy power generation system is compared and selected,the hydrogen power generation access topology is designed and the adaptability analysis is carried out in terms of power factor,voltage loss and negative sequence.The power generation control strategy based on negative sequence compensation is formulated and verified by simulation.Then the technical and economical analysis of hydrogen power generation mode is carried out.The specific research contents are as follows:First of all,the various access locations and access methods of hydrogen power generation accessing to the traction power supply system are compared.Through the analysis of power flow and power quality control,the optimal installation method and location are selected,and the topology of the hydrogen power generation system accessing to the traction power supply system is proposed.The adaptability analysis of the hydrogen power generation access to the traction power supply system is carried out,the current distribution principle when hydrogen power generation is connected under the Vv transformer,Scott transformer and single-phase transformer traction power supply system is explored,and the power generation control strategy of hydrogen power generation with negative sequence compensation is proposed.A technical scheme for the connection of hydrogen power generation to the traction power supply system is proposed which can reduce the negative sequence.Then,based on MATLAB/Simulink simulation software,the models of the traction power supply system and the hydrogen power generation system are built.The measured data is selected to verify that the connection of the hydrogen power generation system reduces the load power provided by the traction substation,so as to achieve the goal of peak shaving.And the typical operating conditions are selected to simulate the models of hydrogen power generation accessing to the traction substation under three traction transformer schemes,and the feasibility of the control strategy and the effectiveness of the compensation for negative sequence are verified.Secondly,the principles of hydrogen energy strong reaction power generation(gas turbine)and weak reaction power generation(fuel cell)are introduced,and technical analysis is made from the aspects of power,energy conversion rate and environmental protection,and the technical characteristics of the two power generation methods are compared.The economic comparison of the two hydrogen power generation methods is carried out using the levelized cost method(LCOE).Finally,the research contents and shortcomings of this paper are summarized and the future direction is prospected.