Power Flow Analysis Of At Segmentation Power Supply Network

With the development of railway electrification technology and the operation of high-speed, high-power electric locomotives, AT power supply has been adopted by many countries. Practice has proved that it is an advanced power supply not only can effectively weaken the catenary induction effect on adjacent communication lines, but also can adapt to high-speed, high-power electric locomotive running.There are some disadvantages of AT power supply, primarily complex structures, brought some difficulties to the construction and operation maintenance. AT power supply compared with other power supply construction investment cost is higher. Meanwhile, the probability of fault also increased. When the fault occurs, recovery is difficult and construction investment is large. Therefore, strengthening power supply reliability of AT traction network is particularly important.Segmentation power supply technology for AT power supply based on traction segmentation power supply technology and status monitor can achieve subdividing the power supply unit, narrowing the scope of power outages and ensuring the transportation capacity. Study on segmentation power supply technology of AT power supply, mainly includes under the abnormal operation conditions, conductor current distribution, traction impedance, voltage loss calculation and analysis of power supply capacity. When traction fault occurs, switch power supply to the abnormal operation conditions. The fault would be repaired without transport interruption and according to the calculation and analysis results to take measures to ensure the normal operation of trains, such as restrictions on traffic density and limiting current and speed.On the basis of principle and structure of AT power supply, understanding traction segmentation power supply of AT power supply, discussed the traction parameters calculation of AT post fault, and negative feeder fault.It is subdivided into three abnormal operation modes according to the different structure of traction fault. There are AT section post fault, negative feeder of AT segment fault where the trains run, and negative feeder of AT segment fault where the trains not run. Conductor current distribution and traction impedance calculation of single track AT traction, the end of double-track parallel AT traction and all parallel AT traction are discussed. According to the results of fault conditions to calculate voltage loss and make analysis of power supply capacity. By MATLAB/Simulink software platform, with the same traction electrical parameters, model and simulation of AT segmentation power supply power supply is built to prove the validity of mathematical model calculation results. Impedance characteristic curves of normal AT power supply and AT segmentation power supply power supply are programmed to draw and comparatively analyzed. The maximum voltage loss of the end of traction is calculated. Proved segmentation power supply technology for AT power supply is theoretically feasible.