Study On Traction Load Characteristics,Power Supply Schemes And Economic Performance Of High-speed Railway

With the rapid development of China's high-speed railway,researches on the safety,reliability and economic efficiency of traction power supply system is becoming more and more important.At present,China's high-speed railway traction power supply system generally uses the large-capacity Vx wiring and 2 × 27.5k V AT power supply system,which has a strong power supply capability.However,it is not hard to find that in the early stage of high-speed railway operation,the traffic volume is small,the actual starting density is much less than the starting density considered during design.Therefore,the capacity utilization ratio of traction transformer is low,which affects the economic operation of high-speed railway traction substations.This article relies on the Beijing-Shanghai high-speed railway project "Based on the grid operation diagram traction power supply system of economic operation research" to carry out the work.In this paper,based on the measured traction load data of high-speed railway,the characteristics of traction load are analyzed.First,based on the measured current data,a histogram of the distribution statistics of the feeder current of the traction substation is obtained,and then this paper uses the?distribution to establish the feeder current probability model and tests it by the coefficient,the result shows that the fitting effect is good;At the same time,this paper analyzes the probability density curve of active power when a single train runs at a certain speed limitation;the result shows that the probability density of active power obeys normal distribution function when the train runs at constant speed.Secondly,based on the two different classification conditions of different vehicle density and whether the traction substation is near the station,this paper analyzed the typical load curves of high-speed railway traction transformer under the current driving conditions and compared them with the typical load curve using in the design.Thirdly,based on the measured traction load current data,this paper obtained the train current curves of sixteen marshalling train and eight marshalling train when the trains operating in the power supply interval of Guzhen traction substation to Dayuan home subarea and verified their correctness.Finally,taking the traction transformer temperature rise and life loss as the constraint conditions,and taking the train diagram of Beijing-Shanghai high-speed railway as an example,calculated the capacity of traction transformer in the power supply area.Through the measured current traction loads this article found that the traction transformer capacity utilization of Beijing-Shanghai high-speed railway is low,and there exists a large margin.Therefore,with the objective of optimizing the economic operation of traction substations,the corresponding economic operation optimization plans are proposed.At the same time,based on the measured load data,this article verified each traction substation's negative sequence power,voltage unbalance,and traction transformer temperature rise and life loss under the optimized schemes.Using the Matlab/Simulink software,this article built the simulation model of Beijing-Shanghai high-speed railway traction power supply system,and verified each traction substation's voltage level of the traction network by using the optimized schemes.The results show that under the current traction load conditions,the economic operation optimization schemes mentioned in this paper are feasible.Finally,a brief analysis of the economics of traction substations under the optimized operation schemes was carried out.