Study On The Optimization Method Of Braking Energy Recycling For Fuel Cell Hybrid Tram

With the development of social economy and urbanization process,the increasing shortage of traditional energy resources such as coal,oil and gas,besides,urban congestion,environmental pollution,ecological deterioration and other problems have gradually intensified,which leads low-carbon environmental,energy conservation and emission reduction to become an important concept pursuing the sustainable development of economy and society.The development and utilization of new energy has become an important way to alleviate the energy crisis.Giving priority to the development of public transport system with rail transit as the backbone is the fundamental way to solve the urban traffic problem.The frequent start-up and break of metro vehicles result in low power utilization and the waste of energy.In order to reduce the waste of braking energy,it is very important to study the optimization method of electric braking energy recovery of fuel cell hybrid tram,which is in line with the direction of urban rail transit technology research in the world,and has significant environmental and social benefits.It also has potential economic value for the broad urban tram market.This paper takes the fuel cell hybrid tram as the research object,and mainly studies the braking control strategy of the tram and its energy recovery optimization method to improve the braking energy recovery rate,the main work is as follows:In order to study the braking control strategy and energy recovery of fuel cell hybrid tram,the topology of power system of fuel cell hybrid tram was designed.According to the power demand of fuel cell hybrid tram under different operating conditions and the energy consumption analysis of tram.The parameter configuration of the dynamical system was determined by the fuel cell response characteristics,super capacitor charging and discharging characteristics.And the simulation model of fuel cell hybrid power system was built.On the basis of the analysis and calculation of the dynamic model of the tram,the vector control method based on the rotor magnetic field directional was studied.Based on the model of fuel cell hybrid power system,according to the requirement of traction/braking power of fuel cell hybrid tram under different operating conditions,combined with the mechanical characteristic curve of traction motor for tram,the braking control strategy of tram was studied,including the distribution of regenerative braking force and friction braking force.Based on the established model of fuel cell hybrid system,taking the braking energy recovery rate as the optimization goal,the SOC of the energy storage device before and after the braking was controlled through optimizing the energy management strategy of the fuel cell hybrid power system,which provides a reliable storage capacity for the recovery of braking energy of the tram,and realizes the improvement of the braking energy recovery rate.We learn from the idea of economic driving mode,according to the braking characteristic curve of vehicle motor,the maximum speed reduction requirement,the braking distance and the ability of super capacitor to absorb braking power,the braking speed curve of a vehicle was optimized.And the braking energy can be recovered as much as possible on the premise of ensuring the vehicle performance,and the braking energy recovery rate is improved.The correctness of the study method was verified by simulation.