Network Protection Scheme Of High Speed Railway Power Supply ARM Based On IEC61850

As an important part of the high-speed railway, reliability of traction power system has a significant impact on the normal operation of railway. Thus, protection scheme removing faults selectively and rapidly is demanded. However, no matter fault occurs on which location of the tracking network, the existing protection scheme would trip both upline and downline to cut off the fault section with a series of protection cooperation. This protection scheme may produce an adverse effect on the power supply and increase the action number of breakers in the normal line, that reduce the life of breaker. Therefore, the current protection would cause some harmful impact on safety and reliability of the traction power supply system.Aiming at the shortcomings of existing protection scheme, a power supply section network protection scheme based on IEC61850is presented in the paper. By installing power direction element, feeder protection device can determine the fault segment by analyzing the power direction information of AT and section post given by GOOSE, and send a tripping signal to referred breaker to cut off the fault segment. As a result, the un-fault segment would operate normally without being affected by the fault trip.Simulation model of all parallel AT power supply mode is built by using MATLAB and the power direction distribution of AT post and section post under different place and different type short circuit fault(T-R, T-F, F-R) in traction network is obtained. Using the power direction information as the standard of fault judging, and cooperating with the protection starting signal, determine the fault section so as to achieve selective isolation of faults.Finally, in order to guarantee the network protection scheme can meet the requirements on time limit, the traction substation network communication is simulated by OPNET software in the paper. Since the condition of the traditional network structure can not meet the requirements, private network which can directly link devices is put forward, and the validity and reliability of the private network is also simulated and verified in the paper.