Research On Regenerative Braking Energy Utilization System Of Electrified Railway

As the main artery of the national economy,the electrified railway has an indispensable role in promoting social development.However,the rapid development of China’s railways has brought increasingly serious energy consumption problems.In order to achieve energy saving in traction power supply systems,it can be considered to make full use of train regenerative braking energy to reduce traction load power consumption.Traction load is a single-phase asymmetric load.The regenerative braking energy generated by the train has a strong impact and contains a negative sequence component.If the remaining regenerative braking energy in the power supply section is directly fed back to the power grid,power quality and electrical equipment will are adversely affected.For this reason,this article studies the regenerative braking energy utilization technology of electrified railways.The main contents include:(1)By analyzing the measured data,the characteristics of the regenerative braking energy of the electrified railway are summarized,and the difficulties in recycling the regenerative braking energy are analyzed.Study the topology and working principle of the hybrid energy storage regenerative braking energy utilization system,and propose a two-layer system control framework composed of a decision layer and an execution layer(2)The main circuit parameter calculation method and converter control strategy of the regenerative braking energy utilization system are studied.Focus on discussing the calculation method of connecting the transformer,connecting the reactor,and the DC side capacitance parameter,analyzing the working principle and parameter design ideas of the bidirectional half-bridge DC / DC structure.According to the application scenarios and requirements of the system,the control strategies of back-to-back converters and DC converters are studied.Simulation cases prove the correctness and effectiveness of parameter calculation methods and control strategies.(3)Study the energy comprehensive management strategy of the regenerative braking energy utilization system.Put forward the regenerative braking energy management strategy based on the load state,determine the size and direction of the power flow of the system in different states,and solve the problem of the system’s multiple working mode switching.A hybrid energy storage power distribution strategy based on the super-capacitor intermediate regulation voltage is proposed,so that the hybrid energy storage can cope with sudden power changes and also increase the life of the battery to meet the operating needs of the system.Finally,a simulation case verifies that the system works in different jobs Stable operation in all modes.(4)Establish the economic analysis model of the regenerative braking energy utilization system in the whole life cycle.Combined with the comprehensive management strategy of regenerative braking energy proposed in this paper and using PSO to solve the model,the optimal rated power,rated capacity and maximum economic benefit of the hybrid energy storage system are determined;The verification through the measured data shows that after the system is installed in a traction substation,there will be considerable benefits within the planned period of time,and it also proves the effectiveness of the proposed comprehensive energy management strategy.Finally,the work of this paper is summarized,and the shortcomings of this study have prospected.