| As an important part of traffic transportation sector, urban railway is developing quickly with the rapid development of the social economy. Based on the technical development of DC transit power supply and the requirement of energy efficiency, regenerative braking of train and energy feedback of system have been applied in urban railway, which will have a great effect on regenerative braking utilization, rectifier capacity, transit voltage, rail potential and power quality of AC/DC system. Therefore, discussing the method of the unified AC/DC power flow for dc traction power system with inverter and rectifier is as quite important as combination of train performance simulator are quite important. Based on some successive researches on regenerative braking by resistor, this paper focuses on the calculation of transit power supply for rectifier with inverter.Combined with the principle of inverter-feedback and the power supply system of urban railway, the paper deduces the model of the device of inverter-feedback. It can be described by the voltage, current, and power relations of AC and DC sides. The model of12inverter unit is simplified to two6the pulse of inverter unit in parallel.Based on Newton-Raphson method and the model of six-pulse inverter, the unified AC/DC power flow for dc traction power system is deduced in the paper. With the help of MATLAB, power flow of a6notes and a10nodes test system of hybrid traction power supply is calculated for practical verification. Then the voltage of each node as well as power, firing angle, commutation overlap angle, DC voltage and current is obtained.Finally, on the basis of AC/DC united algorithm of the inverter deduced by Newton Ralph Gibson flow calculation and the existing simulation software, this paper utilizes Unified Modeling Language (UML) to specifically describe the related design about the urban railway power supply simulation system which contains inverter feedback type rectifier. On platform of Visual C++.Net, the urban railway power supply simulation software UrtSim which is based on inverter feedback can be obtained. Using the upgraded UrtSim, an example of urban railway with inverter and rectifier is simulated, and instantaneous voltage of traction nets as well as the power of energy feedback with rectifier is been solved for practical verification. |
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