Study On The Relay Protection Scheme Of The New-Type Cable Traction Power Supply Technology Of Electrfied Railway

In our country, the unilateral power supply is used in electrified railway, so there are neutral sections on the export of the traction substation and the section post. The realization of the superiority of electrified railway is restricted by the neutral sections. They also have a negative effect on the exertion of the locomotive power and system reliability. Even the auto-passing neutral section technology is adopted, the neutral sections are still the weak link of the whole system. Studies show that the new-type cable traction power supply technology can extend the power supply distance effectively. It also reduces the interface to the power grid and the neutral sections. So it is suitable for the operation of high-speed railway and heavy haul railway.Firstly, a relay protection scheme was set for the main traction substation. The structure and the working principle of the combined co-phase power supply were analyzed. Also, a relay protection scheme was set separately for the main traction substation. Then a cooperation scheme was set for the main traction substation.Secondly, a relay protection scheme was set for the cable traction network. The structure and the working principle of the cable traction network were analyzed. The working principle of fault power flow symbol value method based on distributed protection method was introduced in detail. It was easily to establish the measurement and control system of the cable traction network.Thirdly, the relay protection of new-type cable traction power supply was simulated. The simulation model of new-type cable traction power supply system and measurement and control system were built on Matlab/Simulink platform. It was proved to be true and feasible that active power differential protection. It provides total protection to the co-phase compensation devices. Finally, typical fault conditions were simulated in the cable traction network. It was also proved to be true and feasible that measurement and control system of cable traction network.