Analysis Of The Transient Process While Locomotive Passing Phase Insulator

Signal-phase AC traction power supply system is applied in electrified railway. Traction substation which obtains power from power system supplies power for overhead contact system by feeders. For the purpose of balancing the triphase load of power system, different phases and sections power supply system is adopted, so phase separation has to been set on the common boundary of different phases. Articulated phase insulators is a passing neutrally mode, which is especially suitable for the operation of high-speed railway. But the over-voltages frequently happen at phase insulator of overhead contact system when the electric locomotive passes. They cause the breakdown of the roof protection gap of the electric locomotive and the burn of neutral line and load-bearing rope, and induce tripping operation of the substation. It causes huge losses for railway interests, and seriously affects the safe operations of electric railway. Therefore, analysis and research of over-voltages of the articulated phase insulator is very important for the safe operation of high-speed railway.In this paper, the modes of passing neutrally phase insulators and the theories of internal overvoltage in power supply system are introduced. Then the transitional course of electric locomotive passing the articulated phase insulator is analyzes theoretically and computes. It comes off the mathematical formula of the voltage of the neutral conductor of the articulated phase insulator in the transitional course of electric locomotive passing. According to the real parameter of the traction substation, overhead contact system and the neutral conductor, the voltage of the neutral conductor in the electric locomotive passing transitional course is computed, and the calculations is analyzed.Secondarily, the Matlab/Simulink software is used to do electromagnetic transient simulation of the voltage of neutral conductor in transient process of the electric locomotive passing the articulated phase insulator. The transient simulation waveforms is gained and analyzed. By testing and verifying the theoretical analysis and calculation. The experiment results indicate the theoretical analysis and the simulations are right. Moreover, a pattern of reducing the over-voltage of the neutral conductor is given. The protect effect is simulated by the Matlab/Simulink, which reaches the conclusion that the protective pattern can reduce the voltage of neutral conductor.Finally, high-speed railway is operating in the present period. The over-voltage of neutral conductor is still existent. The Matlab/Simulink is used to do electromagnetic transient simulation of the voltage of neutral conductor in transient process of high-speed railway.