Direct power supply mode traction network distance protection setting calculation optimization method

Abstract

The invention discloses a direct power supply mode traction network distance protection setting calculation optimization method. A power supply system of a traction network is a working frequency single-phase alternating-current system, locomotives take current from a contact network T, and current flows back to power substations through steel rails R after flowing through the locomotives. During normal running, feeds of all the traction substations are free of electric contact in the traction network, and each electric locomotive and each power supply arm take electricity from only one traction substation. In each double-track section, two lines of the uplink section I and the downlink section II take electricity in the same traction substation and are independent and not connected in parallel in the middles or at the tail ends of the lines. The method includes the steps that firstly, on each section I, flexibility of a distance section I is ensured preferentially, and setting is conducted according to the insurance of the total track length; secondly, on each section II, setting is conducted on the protection range according to the longest distance under various power supply modes.

Description

technical field [0001] The invention relates to the technical field of safety of traction power supply systems of electrified railways, in particular to a calculation optimization method for distance protection setting calculation of traction network in direct power supply mode. Background technique [0002] The safety of the electrified railway traction power supply system is an important prerequisite to ensure the normal operation of the train, especially the complex structure of the traction network, frequent failures, and no backup, the correct action of relay protection is particularly important. Distance protection is the main protection of the towing net. The direct power supply method with return line is the most commonly used power supply method adopted by ordinary speed railways in my country. There are many operating forms under this power supply method. The current mainstream fixed value scheme needs to be aimed at different power supply forms, and the feeder dis...

AI Technical Summary

Problems solved by technology

[0005] When the power supply mode changes, artificially switch the fixed value range, which undoubtedly increases the complexity of the operation of the on-duty personnel and possible accidents, resulting in an increase in the probability of incorrect action of the protection

Secondly, in the case of normal power supply or unprotected cross-region power supply, setting two-stage protection will not realize the selectivity of upper and lower levels, but will lose the quickness of 15% of the end of the line.

Finally, in the actual specific protection schemes, some schemes directly use a set of fixed impedances, and do not adopt different measurement impedances for different power supply forms under the direct power supply mode.

In the scheme of measuring impedance with different units, the basis of unit measurement impedance is different, and the fixed value is different, so the actual range of protection is also different.

[0006] There are various operation forms under the direct power supply mode with return line. At present, the mainstream setting scheme needs to design multiple sets of setting values ​​for the distance protection of traction network feeder for different power supply forms. When the power supply form changes, artificially switch the setting This will undoubtedly increase the complexity of the operation of the on-duty personnel and the possible accidents, resulting in an increase in the probability of incorrect action of the protection

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