The serious power quality problem is likely caused by the large scale-integration of nonlinear pollution load due to the power quality problem not considered in advance in the planning stage of large projects. In this paper

a kind of high speed rail load integration method which is suitable for the main network at planning stage is proposed at such condition as the interest of railway department and power network

the power quality index as constraint condition of both parties and the investment cost of substation bay of main power network. The load probability flow analysis model of high speed rail is established with combination of the uncertainty probability model of traction load of high speed rail and with the use of Monte Carlo and DC power flow methods. As for the load feature of high speed rail and the power quality index of both parties as constraint condition

the chance planning constraint model of high speed rail to the power network with minimum investment as objective is established and the planning model is solved by LDIW-PSO algorithm. Finally

real example of the planning scheme of the line to the power network at certain practical high speed rail construction project is performed. It is shown by the simulation result that some 110 k V substations with shorter power supply distance and bigger short circuit capacity can meet the power supply requirement of high speed rail.