Multi-Train Coordination For Regenerative Braking Energy Usage Based On Real-Time Regulation

The booming development of urban rail transit provides an efficient solution to relieve the traffic jam.However,it also brings unneglected problem of energy consumption.Using regenerative braking energy through multi-train coordination is an efficient way of energy saving.The widely-used method to optimize timetable is able to achieve energy-saving effect to some extent,but when random interferences occur,the static optimization is obviously unsatisfied.In order to reduce tractive energy consumption and decrease operation costs,this thesis studies on multi-train coordination via carrying out real-time regulation on the timetable to increase matching number between traction trains and braking trains.The main research contents are as follows.Firstly,a method to make use of the regenerative braking energy based on regulating dwell time in real time is proposed.An energy-saving single-objective model and a bi-objective model considering energy saving and punctuality are built,taking dwell time adjustment as the decision variable.The piecewise quadratic fitting of the nonlinear objective function is used to simplify the optimization problem,and the Lagrange multiplier method is applied to solve the optimal adjustment.As a result,the matching rate between traction trains and braking trains can be enhanced by dwell time regulation according to the optimal solution.Secondly,a method to use regenerative braking energy through regulating running time and dwell time in real time is studied and two strategies are proposed.Energy saving is taken as the optimal object and a bi-optimization model is established in first strategy.One of the bi-optimization model is selected to regulate running time or dwell time according to designated regulations in each matching.On account that the real-time feature of the above method needs to be improved,the second strategy that absorb regenerative braking energy considering punctuality is proposed.Energy saving and punctuality are taken as two objects,running time and dwell time are regulated at the same time.Particle swarm optimization is applied to find optimal adjustments under different weighting factors.Simulations on above methods that coordinate multi trains via real-time regulation are implemented based on data of Beijing Metro Line 4,and the efficiency of algorithms is verified.Comparing the simulation results of each methods,it's obvious that the comprehensive regulation on running time and dwell time has larger improvement space and higher matching efficiency.Finally,a train real-time regulation simulation software is designed on the basis of object-oriented C#and SQL Server database according to 8 power supply sections of Beijing Metro Line 4.The software realizes various functions,including train operation simulation,real-time display of operation information,train timetable display before and after optimization,speed-time curves display and so on.All modules cooperate with each other to realize the simulation on train energy-saving operation.