Energy Saving Operation Of Urban Rail Train Based On The Use Of Regenerative Braking Energy

In recent years,the construction of rail transit in various cities across the country is in full swing,and the mileage of rail transit continues to grow.On the one hand,the development of rail transit and the promotion of public transport priority strategies can effectively alleviate urban traffic congestion;on the other hand,under the same capacity,the energy consumption of rail transit systems is much lower than other modes of transportation.However,due to the large total transportation volume,the total energy consumption of the urban rail system is still high,and the operating companies have begun to focus on ways and measures to reduce energy consumption.In the total energy consumption of the urban rail system,the traction power supply system has the highest proportion and the energy saving potential is great.By optimizing train operation and reducing traction energy consumption,it helps the urban rail system to achieve energy saving and emission reduction.The energy-saving optimization of the train operation process mainly includes two aspects: one is the optimization of the operation strategy of single trains between stations,and the other is the coordinated optimization of the multi-train operation.Combined with domestic and foreign literature research,this thesis discusses a single train timing energy-saving optimization model and establishes multi-train energy-saving optimization model based on regenerative braking energy utilization.Through the actual operation of Yizhuang line,the case analysis and verification model are carried out.The main work and achievements of this paper are as follows:(1)The dynamic theory of train operation is combed,and the influencing factors of train traction energy consumption are divided according to the attribute dimension.The calculation method of traction energy consumption based on function transformation is proposed.(2)Based on the "four-stage" traction strategy,an energy-saving optimization model for operation of single trains between stations is discussed,and an energy consumption penalty function based on punctuality rate index,stop station accuracy index and speed safety index is constructed,and the cuckoo search algorithm is used to calculate the running strategy of the single train.The case study shows that the energy saving effect is good,and the correctness of the model is also proved.The effects of different technical conditions on energy consumption are further analyzed,including the running time and load conditions between stations.The results show that the traction energy consumption of trains decreases with the increase of running time between stations,and increases with the total weight of trains.(3)The principle and flow process of regenerative braking are analyzed,and the application effects of several common absorption and utilization methods are summarized and compared.Considering the regenerative braking utilization scenario of multi-train operation,it is divided into two scenarios about using regenerative braking energy: two adjacent vehicles and two nonadjacent vehicles.The calculation steps of overlapping time are established.The multi-train operation energy-saving optimization model is established,whose objective function is multi-train traction and braking phase overlap time.The model is compared with the complete knapsack problem,and the greedy algorithm and dynamic programming solution steps are designed.The applicability of the two algorithms is compared.The validity of the model is verified by the case of Beijing Yizhuang Line,and the following conclusions are drawn: 1)When the departure time is equal interval,the overlap time shows multimodality with the change of the departure time interval.The maximum overlap time is 54.88 s,and the equivalent energy is 14.1 kWh,and the interval time is 181 s,and the overlap time accounts for 26.5% of the total braking time.Compared with other literatures,the calculation result is lower,because the paper considers the actual situation of the power supply zone.2)When the departure time is not equal,the departure plan of 25 trains is designed.the overlapping time of the average distribution departure plan is 625 s,and that of the optimized departure plan is 1245 s,which increased by 99.2% compared with average distribution departure plan.The energy saving effect is good.3)The overlap time is not affected by the change of the stop time.The reason is that the traction and the brake phase are shifted without lateral pull-up,which improves the traction and braking duration.(4)The multi-train optimization are analyzed considering disturbances of morning and evening peaks and delay.A multi-train optimization model considering peak peaks is established,and the operation plan of 240 trains is designed.The overlap time of regenerative braking is 7449.7s,accounting for 15% of the total braking time,equivalent to 2390 kwh of regenerative braking energy.The effect is good.A comprehensive analysis of the causes of train delays is carried out,and the adjustment steps for returning the trains to normal operation are proposed.During case analysis,the energy consumption increases by 32% while delayed for 10 s.The delay causes a greater impact on the energy consumption of the operation sections.