| With the rapid development of our economy and the problem of urban traffic jambecomes more seriously, developing urban railway in China is the best solution to theproblems. DC traction supply system is an important part of the urban railway system. TheDC protection and control play the key role in the whole DC traction supply system. Theresearch of protection of DC supply system starts lately, and the development of Chinasubway become quickly, some new problems appear now. When the supply system is out oforder, the action of old protection device becomes slowly and less reliably. These all advancednew requests to the DC protection. So we should develop more reliable and intelligent DCprotection device as quickly as possible.The protection device of subway DC traction supply system is fixed in tractionsubstations. This paper introduced the mode of connection of traction substations. Accordingto the non-linear characteristics of rectifiers, based on MATLAB/Simulink the simulationmodel of24-pulse rectifier is build. Simple models of metro locomotive, supply line and thewhole DC traction supply system also have been built. Then get current simulationwaveforms when the supply system works normally.This paper build the short-circle fault model and the metro locomotive starting model ofsupply system, and get the simulation current waveforms. According to the simulation result,this paper analysis the characteristics of short-circle current and locomotive starting current,and raised that differentiate of the two styles current is the difficulty and emphasis of the DCprotection. Considering the factors, the paper designs the DC feeder protection of subway,analysis the protection principle, whose score is DDL protection, gives the setting principle,and gives the configuration of protection software further.At last, this paper presents the hardware constitution of DC protection device, anddesigns each block originally(such as the design of the block construction, the selection ofchips). |
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