Setting calculation optimization method for direct feeding traction network distance protection

Abstract

The invention discloses a setting calculation optimization method for a direct feeding traction network distance protection. A power supply system of a traction network is a single-phase power frequency alternating current system; locomotives obtain current through a contact network T; the current flows back to substations through steel rails R after passing through the locomotives; feeder lines in various traction substations are free of an electrical contact in the traction network in a normal operation; each electric locomotive and each power supply arm obtain electricity from one traction substation; and in a double-track section, two lines of an uplink section I and a downlink section II obtain electricity in the same traction substation, but the middle parts or the tail ends of the lines are respectively independent and are not connected with each other in parallel. The method comprises the steps as follows: (1) the section I, the selectivity of the section I is ensured in priority and setting is carried out according to escape of a short circuit at the tail end of each line; and (2) the section II, setting is carried out on the protection range according to the longest distance in 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

Images