Optimization Method Of Energy-Saving Operation Strategy For High-speed Trains

Reducing operation energy consumption of high-speed trains is of great significance for improving the competitiveness and achieving sustainable operations for high-speed railways.The optimization of energy-saving operation for high-speed trains is studied.Firstly,considering the characteristics of trains that need to be coasted in neutral phase insulator area,an energy-saving operation optimization model of single train in single interstation is constructed.Then,given the fact that interstation running time has a significant impact on train operation energy consumption,a multi-interstation energy-saving operation optimization model whose arrival time of non-hub station can be fine-tuned for high-speed trains is formulated.Finally,considering the influence of the preceding vehicle on the maximum allowable speed of the rear vehicle,a high-speed train multi-section tracking running energy-saving operation optimization method is proposed.Finally,considering the influence of the forward train on the maximum allowable speed of the rear train,an energy-saving operation optimization model of for high-speed trains in multi-interstation is proposed.Moreover,based on the train operation optimization model,the influence of the line design and operation plan on the train operation energy consumption is quantitatively analyzed.The main research contents and conclusions are as follows:(1)Considering the influence of the neutral phase insulator on the operation of high-speed trains,the single interstation energy-saving operation method that meets the actual operation constraints is studied for high-speed trains.Firstly,according to the characteristics of speed limit and line conditions,the interstation is divided into multiple sub-sections.Train control strategies in different types of sub-sections are analyzed,and energy-saving operation optimization model considering the practical constraints such as the train must be coasted in neutral phase insulator area and so on for high-speed train is constructed.Secondly,Based on the idea of the optimal control theory,"train energy-saving operation strategy consists of four kinds of operation conditions:traction,cruising,coasting and braking",the genetic algorithm is designed to solve the above model to obtain the optimal sequence of working conditions and conversion position.Finally,the analysis of the case under different types of line conditions shows that the high-speed train single interstation energy-saving control method proposed in this paper is always better than the driver's conventional control method.When the line ramp is steep,the energy saving rate exceeds 5%.The sensitivity analysis of the line parameters found that neutral phase insulator is set in the constant speed area to facilitate the train energy-saving operation compared to the neutral phase insulator in the acceleration area and the deceleration area.(2)Considering the delay distribution of train leaving the station,the collaborative optimization method of train running time adjustment and control scheme is studied,and the train operation energy consumption is reduced as much as possible while meeting the arrival time of the hub station.Firstly,a multi-interstation energy-saving operation random chance constraint model for high-speed trains with dynamic adjustment of running time is constructed.Besides considering the control constraint of neutral phase insulator,the consistency of the arrival time of the hub station and the arrival time of the timetable is increased.The arrival time of the non-hub station can be dynamically adjusted within a certain time range.A three-layer chromosome coding genetic algorithm is designed for this model.In the algorithm,the first layer solves the train running time in each interstation;the second layer solves the train running time of each sub-section type in each interstation;the third layer solves the energy-saving operation speed trajectory of the train after fine-tuning running time in each sub-section.The case study shows that when there are random delays of leaving the station,the,cooperative optimization method of train running time adjustment and control scheme"can reduce the train energy consumption by 6.7%compared with the"single interstation energy-saving operation method of non-adjustable interstation running time".The energy saving rate is more than 10%compared with the "traction coasting control method"that has been proposed in previous studies.(3)In view of the characteristics that the train energy-saving operation is affected by the forward train when the headway is small,the multi-interstation tracking running energy-saving operation problem of high-speed trains considering the automatic train protection(ATP)under the mobile blocked system is studied.Firstly,the principle of ATP control of high-speed trains and its calculation method of protection curves are expounded,and the energy-saving operation model of multi-interstation tracking running with ATP speed limit and running time fine-tuning for high-speed train is constructed.In the model,in addition to considering neutral phase insulator,hub station and non-hub station to the time constraints,ATP speed limit,section tracking interval and station tracking interval constraints are also considered.Then,using the chromosome coding method:in matrix form,a multi-interstation train tracking running energy-saving operation scheme is designed.The case study shows that compared with the traditional method of the rear train control scheme without considering the influence of the forward train,the high-speed train multi-interstation tracking running energy-saving control method proposed in this paper can reduce 4.3%energy consumption of the trains in whole operation line in the case of constant running time.(4)Based on the operation method proposed in the previous section,the influences of factors such as target speed,interstation running time,station spacing,stopping schedule,full load rate and so on train running energy consumption are quantitatively analyzed.When the target speed is constant,the train consumption per unit distance increases with the negative power reduction relationship.When the station spacing is longer than 100km,the unit consumption change rate is less than 0.01.When the target speed is set to speed grades of 160km/h,200km/h,250km/h,300km/h and 350km/h,and when target speed is increased by one speed grade,the increase in train running energy consumption is much greater than the decrease in train running time and the growth rate of energy consumption is close to three times the rate of running time reduction rate.The full load rate at high target speed has a greater impact on train energy consumption than at low target speed.When the target speed is 350km/h,with the increase of the full load rate,when the full load rate is smaller than 40%,the unit consumption of person kilometer decreases sharply,and when the full load rate is greater than 40%,the unit consumption of person kilometer is slowly reduced.The impact of the stopping schedule on the energy consumption of trains is mainly reflected the number of stopping.Each time the train stops,the operating unit consumption increases by about 0.6 kWh/km.