| Urban traffic is the main artery of urban economy and social development,so it must be maintained the function of high-efficient operation.However,due to the rapid process of urbanization and the increasing number of private cars,some central cities in China have lost their prime balance in the relationship between the supply and demand of transportation resources.The modern urban transit,represented by the metro,can not only relieve the traffic pressure of the city,but also improve the overall image of the city.However,the line characteristic of the short distance between the metro stations and high traffic density,determines that the metro vehicle frequently switches between acceleration of starting and deceleration of braking,and it can consume a large amount of traction power and generate lots of regenerative braking energy.In order to mitigate the reverse violent impact of regenerative energy on the traction power supply system,and to solve practically the problem of the rapid transfer and comprehensive utilization of renewable energy,it is very necessary to properly design the regenerative braking energy absorption scheme.This paper analyzes and compares the existing methods of regenerative braking energy absorption at home and abroad,and analyzes and compares the merit and demerit of each method,and determines the scheme of regenerative braking energy utilization with inverse feedback type.First of all,according to the actual parameters of Shi Jia Zhuang metro vehicle,the paper establishes the basic resistance calculation model and analysis the vehicle braking characteristics.And the renewable energy calculation method is deduced by energy conversion and balance equation,with using example to explain the calculating process of regenerative braking energy and verifying the accuracy of the calculation results,so the related parameters are obtained.In the paper,these provides theoretical foundation for the in-depth design of inverter grid-connected device and parameter settings when modeling.Then,the principle,structure and mathematical model of the subway traction power supply system and the subway traction drive system are researched correspondingly in detail with the vector control based on SVPWM studied detailedly.The simulation model is built in simulink with the simulation analysis carried out on subway single train running at the different speed and multi-train running at the same time in the same power supply interval.Afterwards,according to the above calculation results and simulation analysis,inverter feedback type regenerative braking energy absorption and utilization system is designed.And DC/AC inverter,LCL filter and PLL phase-locked loop module included in the system as well as the control method of the inverter etc have been studied in detail.In addition,the complete simulation model of the traction power supply system,traction drive system and the inverter feedback system is set up,with the whole process of the production and reutilization of regenerative braking energy simulated and analysised.In the end,the urban rail transit experimental platform produced by CRRC YongJi electric co.,LTD is used for many experiments.In this paper,through the analysis of the large amount of experimental data collected,the important conclusions are obtained and the rationality of the designed inverse feedback system is further verified. |
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