Development Of The Location Device For The Fault Section Of The Railway 10kV Transmission/automatically Blocked Line

With the development of railway construction in our country, the train speed is becoming more and more fast, but the conventional Transmission/automatically blocked Line management method presented the low level of automation degree and unreliability in power supply, it seriously restricted the railway transportation to high speed and high density. Therefore, railway power supply system needs a new kind of monitoring system, which can find, locate, and isolate the faults of power line safely and reliably.Firstly, according to the characteristic of Transmission/automatically blocked Line, all kinds of faults is analyzed in theory in the paper. The fault characteristic of two phase and three phase short circuit, two phase grounding fault, single phase grounding fault is analyzed in detail. Hereby, an improved fault location theory is established.Secondly, the fault location device based on TMS320LF2407A digital signal processor of TI company is designed. The hardware including digital input, digital output, analog input, interface of CAN bus and RS-485 bus, DS12887 clock module, etc are introduced detailedly. In addition, the example of connection between DSP and slow-speed device is introduced.Thirdly, the main program and subprogram are compiled with assemble language. The protocol of PC to STU and STU to FTU is described. For the process and calculation of sampling data, 32 points are sampled in each periodicity, it gets the phase and amplitude through Fast Fourier Transform. Due to the improved fault location arithmetic ,it is more easier to realize the function program.Finally, in order to validate the theory, an experiment rig which simulates a set of automatically block line is built in our laboratory, in which 10kV line parameters are converted into 380V line's. In our experiments, the single phase grounding fault is tested and analyzed mainly, the stabilization and validity of the new fault location method is proved. The STU is also proved to be safe and reliable by long time's test.