Research On Regenerative Braking Process Of CRH2EMU

EMUs are constructed by motor cars and trailer cars,and generally not disintegrated until overhaul. Dated from the earliest French DMUs into actual use, EMU has been born for nearly50years. Because of its safety, comfortable, convenience and other features,EMUs have been widely used in the world in the past50years. After the16th National Congress of Communist Party of China, Our country’s high-speed railway has won a golden developing opportunity to achieve leapfrog development.This paper researchs on the regenerative braking of CRH2typed EMU,which ordered by the Ministry of Railway in China from the Kawasaki Heavy Industries in Japan and re-designed by our own railway engineers during the sixth national railway speed-up.This paper introduces the general structure of the EMUs and describes the brake operation status-quo of the EMUs both in and abroad. Analyzes of several common methods of braking principles and introduces their advantages and disadvantages also.On top of that,this paper aims to the regenerative braking system of the CRH2typed EMUs,makes a deep study of the three-level rectifier’s transient direct current control principle and the three-level inverter’s space vector pulse width modulation principle and also the traction motor’s vectos control principle.The CRH2typed EMUs adopt regenerative braking as their electric braking method.Durning the braking, the three-phase alternating current which comes from the traction motor is turned into direct current when it goes through the three-level inverter,then the direct current goes through the DC link,and turned into single-phase alternating current by the three-level rectifier at last,single-phase alternating current is sended to the train power grid. Regenerative braking is the only kind of braking which sends energy back to the power grid,compared to the tradition air brake methods,the regenerative braking doesn’t have the wear of the components,the energy which is senged back can be re-used by other trains,so it becomes to the major method of braking for the AC-DC-AC transmission EMUs.After have make a deeply research on the CRH2typed EMU’s break control system,a regenerative braking system simulation model has been build by myself on the software environment of Matlab. The model has been run and obtained the Current waveform voltage waveform during the breaking.