Research On Optimal Design Of High-speed Railway Of Traction Power Supply System

Because the high-speed railway lines are designed according to the long-term transport volume,and the transport volume is small in the early and medium term of the line operation,the equipment utilization rate of the whole traction power supply system is relatively low,mainly concentrated in the low capacity utilization of the traction transformer in the traction substation.Through the optimal allocation of the capacity,quantity and location of the equipment in the whole line of the traction power supply system,the energy consumption of the whole line can be reduced and the utilization rate of the equipment can be improved.Therefore,this thesis takes the high-speed railway traction power supply system as the research object,and mainly carries out the following aspects of research,including the basic structure of the traction power supply system,load process calculation,design scheme optimization and so on.The details are as follows:(1)The structure of the traction power supply system is analyzed,and based on the transformation relationship of the electrical quantity at the port of the traction substation,a unified mathematical model of the traction substation is derived,which is suitable for all kinds of connection modes of the traction transformer.According to the traction calculation theory,the power of the whole train line is obtained.Based on the unified chain network model of the traction network,the simulation operation of the load process of the traction power supply system is realized,and finally the power flow distribution of the traction power supply system is obtained.(2)Taking the traction power supply system of high-speed railway as the research object,the external power supply line,equipment investment,capital construction and operation and maintenance expenses of the traction power supply system are analyzed.The power loss of the traction network and the capacity utilization rate of the traction transformer are studied,and the multi-objective optimization scheme of the traction power supply system is put forward.(3)In order to realize the accuracy requirements of the optimal design of the traction power supply system,this thesis adopts both the four-dimensional visualization algorithm and the NSGA-? algorithm to optimize the design of the traction power supply system.Taking the investment cost,operation and maintenance cost and active power loss of the traction power supply system as the objective function and the catenary-to-ground voltage as the constraint,the traction power supply system is optimized according to the design code of railway electric traction power supply.(4)Finally,based on the multi-objective optimization method of traction power supply system proposed in this thesis,a high-speed railway traction power supply system is selected as an example for optimization design,and compared with other optimization design methods.The results show that the optimization results designed in this thesis can not only meet the constraints,but also reduce the investment cost and line active power loss,which verifies the feasibility of this method.