Protection Device Design For Metro Feeder

With the rapid development of Chinese economy and urbanization, urban rail transit has been more widely used. Metro power system, as an important part of urban rail transport system, is responsible for the power supply of metro electric passenger cars. The reliability and security of metro power system is a significant guarantee for urban rail transit system. At present, research and development of metro feeder protection device is still in initial stage in our country. The dependence of protection unit abroad causes the metro growth paid a high price. Thus, developing a high reliability, high intelligence metro feeder protection device has a great practical significance and broad market prospect.The structure of subway feeder power supply system is briefly introduced in this article, and the types of fault that may occur in metro feeder are analyzed. Based on the analysis, the desired configuration of protection and control function in metro feeder is selected, and all these protection principles are analyzed.Combined with metro feeder protection principles, detailed design scheme of metro feeder protection device hardware system are given in the article. According to achieved functions, the metro feeder protection hardware system are divided into data acquisition unit, isolation amplifier unit, A/D conversion unit, and data processing and fault determination unit. The function of each unit is described in detail, the appropriate elements are selected, and the design scheme is given. On this basis, the overall block diagram and circuit board of metro feeder protection device hardware part are completed.The software development platform, CCES, and the software design principles are briefly introduced in the paper. According to the required functions of metro feeder protection device, the software part is devised as initialization module, data sampling module, protection module, control module and display module. All these modules are analyzed, and the program flow diagrams are given.Finally, the test platform is built, and the protection device is tested in a variety of situations contained locomotive starting and fault operation. The effectiveness of the protection device is certified by the test.