Negative voltage backflow DC supply system for track traffic

Abstract

The invention relates to a negative voltage backflow DC supply system for track traffic. A negative voltage return line and a DC converter implementing negative voltage backflow are added in a conventional DC supply system, the negative voltage return line replaces a walk rail return line in the conventional DC supply system, stray currents of the conventional DC supply system and negative effects caused by overhigh potential of the walk rail relative to the earth can be greatly reduced or eliminated, loss of a supply line can be greatly reduced, and the supply distance of a DC traction substation can be raised. At the same time, the DC converter can be used as an energy storage apparatus for storing regenerative braking energy of a train, the utilization efficiency of the regenerative braking energy in the DC supply system can be raised, and the voltage of the DC supply system for track traffic can be kept stable.

Description

technical field [0001] The invention relates to the technical field of electrified rail transit and power electronic DC conversion, in particular to a rail transit negative voltage return DC power supply system. Background technique [0002] The power supply systems of electrified rail transit in various countries in the world are divided into two modes: DC power supply and AC power supply. Mainline rail transit (also known as large railway) using electrified lines has both DC power supply and AC power supply. Urban rail transit (including subway and light rail, etc.) using electrified lines adopts DC power supply. The DC power supply system of trunk rail transit generally has a power supply voltage of 3000V, and the DC power supply system of urban rail transit generally has a power supply voltage of 1500V or 750V. There are two kinds of voltage systems in the DC power supply system of my country's urban rail transit. In cities such as Beijing and Tianjin that built subwa...

AI Technical Summary

Problems solved by technology

Stray stray currents will electrochemically corrode the running rails, the structural steel bars of the overall ballast bed, the structural steel bars of the tunnel, the bridge steel bars, and the metal equipment along the urban rail line, thereby affecting the service life of the building structures and metal equipment along the urban rail line;

[0006] (2) Since the resistivity of the steel material of the running rail is relatively large, there is a problem that the potential of the running rail to the ground is too high when a large current flows, which easily leads to frequent actions of the potential limiting device of the running rail

However, the energy feedback device (energy feedback grid) involves many practical engineering problems, and the supercapacitor energy storage device occupies too much space

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