Research On Simulation Software Of Traction Power Supply System In Urban Rail Transit

With the rapid growth of economy, major cities have entered a fast period of urban rail transit construction. China is now the largest market of urban rail transit all over the world. Power supply system in urban rail transit assumes the electricity required for metro to operate. So the security and reliability of power supply system is the guarantee of safe operation for metro. The calculation of power supply system in urban rail transit can test whether the index and performance of the system is reasonable, check the distribution of electrical parameters such as voltages and currents, and provide evidence to design or adjust power supply scheme.Based on the power supply network in urban rail transit, the thesis described the composition of power supply system in urban rail transit, and analyzed the function and basic requirements of each part. Then the thesis put emphasis on several key points, establishing corresponding network models, theoretical calculation and simulation analysis. Taking the model of traction network mixed with power and lighting network under concentration supply system, the thesis made a research on algorithm to calculate power flow for middle-voltage network, and verified by simulation. The next content is about stray current. The thesis did a large number of numerical analysis and simulation on distribution, including different circumstances of rail-to-ground structures, operating modes and whether leakage exists. Then it summarized a series of unified distribution formula and made equivalent simplification of stray current. Started with output characteristics of 24 pulse-wave rectifier, the thesis did research on numerical models and algorithm to calculate power flow for DC traction power supply network. Then it studied hybrid algorithm to calculate power flow for AC and DC hybrid network.At last, based on MATLAB’s GUI platform, the thesis designed each calculation module, and integrated them to develop the simulation software for power calculation of urban rail transit. This software includes AC and DC hybrid calculation module, independent middle-voltage network calculation module, and independent DC traction power network calculation module. The thesis did simulation on each module, and got reasonable results, which demonstrated the reference value of this simulation software.