Research On The Recovery Device Of Regenerative Braking Energy For Electrical Railway Based On MMC

With the rapid development of electrical railway in transportation system,the speed and density of train have been greatly developed.Therefore,the braking energy has been generated in traction power supply network in quantity by trains.At present,electric locomotives provide traction power for the electrical railway and convert the braking energy into electrical energy by regenerative brake.The braking energy has been charged by power department for the negative sequence and harmonic pollution,which is unfavorable for the efficient operation of the railway department.The recovery device of regenerative braking energy for electrical railway based on MMC has been studied in this paper for recycling the braking energy from 27.5kV traction power supply network to the 10 kV power supply system of the railway efficiently.In writing ideas,firstly,there are three the energy recycling technology that have been presented in this paper: energy consumption,energy storage and energy feedback.And the working principle of recycling methods have been analyzed in detail.The various technical indexes and feasibility have been compared in this paper,and the comparison results show that the recovery device of regenerative braking energy for electrical railway has better development prospect and can stabilized the voltage of traction power supply network well.So,it is important to design an efficient energy recycling device based on the normal energy recycling device.Then,the circuit topology and the working principle of MMC has been analyzed in detail.In this paper,the modulation scheme and the submodule capacitance voltage scheme of MMC has been acquainted deeply.The circuit topology and the operational process of recovery device of regenerative braking energy for electrical railway based on MMC has been studied.According to theories,the parameters of the circuit has been designed.The working principle and the circuit topology of inverter based on MMC in the recovery device of regenerative braking energy for electrical railway have been presented in this paper and there are two strategies that have been analyzed in detail in this paper.Finally,the stability of circuit and validity of strategies have been proved by simulation.Finally,the requirements of grid-connection have been analyzed in conditions in this paper,and the requirements of the grid port have been presented in this paper.Then the presynchronization strategy and the grid-conneted strategy of the recovery device of regenerative braking energy for electrical railway based on the principle of “Sychronverter” have been studyed.Finally,the strategies has been proved by simulation.