A method for selecting power supply cables of urban rail transit traction power supply and distribution system

Abstract

The invention discloses a power supply cable type selecting method for an urban track traffic traction power supply and distribution system, and belongs to the field of urban track traffic traction power supply and distribution design. By aiming at the problem of serial and parallel connection resonance caused since the cable charging capacitance is not sufficiently considered in the existing power supply cable design, the invention provides the power supply cable type selecting method by using the public electric network background harmonic voltage and traction rectification machine unit harmonic current frequency distribution as well as the harmonic current amplification factor and the harmonic voltage amplification factor as the basis. The power supply cable type selecting method has the technical scheme that a traction power supply and distribution system equivalent harmonic calculation model and a simplified model of the traction power supply and distribution system equivalent harmonic calculation model are built, and a curve chart, using the harmonic times, the power supply cable length and the power supply cable unit length charging capacitance as the variables, of the harmonic voltage amplification factor and the harmonic current amplification factor is drawn. The power supply cable type selecting method has the advantages that the harmonic serial and parallel connection resonance of the cable charging capacitance is fundamentally avoided, and the guidance significance is realized on the power supply cable design and type selection of other power supply and distribution systems.

Description

technical field [0001] The invention relates to a design method of an urban rail transit traction power supply and distribution system, in particular to a design and type selection method for a power supply cable of an urban rail transit traction power supply and distribution system. Background technique [0002] With the rapid development of urban construction in our country, the pressure on urban traffic is increasing. In order to alleviate the pressure of urban traffic, urban rail transit has developed rapidly and has become the focus of urban construction. The power supply cable in the urban rail transit traction power supply and distribution system undertakes important tasks such as power connection and power transmission. Due to the complexity and particularity of the traction power supply and distribution system of urban rail transit, the power supply cable has become one of the most important components in the traction power supply and distribution system of urban r...

AI Technical Summary

Problems solved by technology

[0004] At present, the design focus of power cables is mostly on cable parameters, such as conductor material, conductor cross-sectional area, conductivity, conductor maximum resistance, minimum insulation resistance, contact resistance, number of cores, insulation level, insulation material, insulation thickness, outer sheath material , sheath thickness, metal shielding, mechanical strength, average diameter, bending radius, arrangement, suppression of induced potential, weight, and path selection, etc., are not aimed at the specificity and complexity of the work of the urban rail transit traction power supply and distribution system. Design and study the charging capacity and cable length of the cable

[0005] At present, in the domestic design methods of power supply cables for urban rail transit traction power supply and distribution systems, only the problem of fundamental wave reactive power transfer caused by the charging capacitance of power supply cables is considered, and the length of power supply cables and unit length are not fully considered in the design. System series and parallel resonance problems caused by charging capacitors

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