Electric Locomotive Passing Articulated Phase Insulator Overvoltage Analysis And Protection

The overhead contact system of electric railway is a special single phase powernet work. It must setting phase insulator each 30km, which insulate two different phase. Articulated phase insulator is a new type phase insulator, it is especially suitable for the electric locomotive running in highspeed. But the over-voltages frequently happen at phase insulator of overhead contact system when the electric locomotive runs. They cause the roof protection gap discharge of the electric locomotive and induce tripping operation of the substation. It seriously affects the electric railway's safe oprations; there is an urgent need for electric locomotive passing the articulated phase insulator transient process overvoltage research.In the paper, it first introduces the present research conditions of the overvoltage at articulated phase insulator when the electric locomotive passing. Then it analyzes theoretically and computes the transitional course of electric locomotive passing the articulated phase insulator. It comes off the mathematical formula of the voltage of the the articulated phase insulator's neutral conductor 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 paper also does engineering compute of the voltage of the neutral conductor in the electric locomotive passing transitional course and analyzes the copute result.Secondarily, the paper simply introduces the function of the PSCAD/EMTDC software. It uses the PSCAD/EMTDC to do electromagnetic transisent simulation of the voltage of neutral conductor in the transisentional course of the electric locomotive passing the articulated phase insulator , gains the transisent simulation waveforms and analyzes them,then tests and verifies the theoretical analysis and compute. The experimental results indicate the theoretical analysis and the simulations are right for the transitional course of electric locomotive passing the articulated phase insulator.Finally, the paper presents several measures of reducing the over voltage of the neutral conductor in the transisental course of the electric locomotive passing the articulated phase insulator, including the RC protective installation and MOA protective pattern, then uses the PSCAD/EMTDC to build model and simulate the protect effect of the RC protective installation and MOA protective pattern. Finally reaches the conclusion that the two protective patterns both can decrease the overvoltage of the neutral conductor.