Rail Transit Negative Voltage Backflow DC Power Supply System

Abstract

The invention relates to a rail transit negative voltage return DC power supply system. On the basis of the traditional DC power supply system, a negative voltage return line and a DC converter for realizing negative voltage return are added, and the negative voltage return line is used to replace the traditional DC power supply system. The return line of the running rail can greatly reduce or eliminate the stray stray currents in the traditional DC power supply system, and the negative impact of the running rail on the ground potential is too high, which can greatly reduce the loss of the power supply line and increase the DC traction substation. At the same time, the DC converter can also be used as an energy storage device for the regenerative braking energy of the train to improve the utilization efficiency of the regenerative braking energy of the DC power supply system and maintain the voltage stability of the rail transit DC power supply system.

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. The main rail transit (also known as large railway) that adopts electrified lines has both DC power supply and AC power supply. Urban rail transit using electrified lines (including subways and light rails, etc.) uses DC power supply. For the DC power supply system of main rail transit, the power supply voltage is generally 3000V, and for the DC power supply system of urban rail transit, the power supply voltage is generally 1500V or 750V. There are two voltage systems in the DC power supply system of urban rail transit in my country. In cities where subways were built in the early days, su...

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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