Method for distinguishing fault type and direction of AT (auto-transformer) contact network without depending on GPS (global positioning system) time synchronization

Abstract

The invention discloses a method for distinguishing the fault type and direction of a high-speed electrified railway AT (auto-transformer) contact network. The method can ensure the data synchronization of each ranging device on the same power supply arm without depending on the GPS (global positioning system) time synchronization and can judge the fault type and direction based on effective values of T-line and F-line current values without calculating current angles. The distinguishing method is simple and practical, can make accurate judgment on the fault type and the fault direction to enable the conditions of fault points to be more detailed, can effectively shorten the fault removal time for railway power supply maintenance department and is essential to restore power supply in real time. The method provided by the invention is bound to create favorable economic benefit under the background of increasing high-speed rail mileage.

Description

technical field [0001] The invention belongs to the field of AT traction power supply systems for high-speed electrified railways. The invention relates to the discrimination of various short-circuit types and directions of catenary faults of electrified railways using a parallel autotransformer (AT) power supply mode. Background technique [0002] As an important part of the high-speed electrified railway traction power supply system, the electrified railway catenary of AT power supply mode plays a decisive role in the safe and stable operation of railway transportation power supply. Due to the use of pantograph sliding to take current, the catenary failure probability is very high. Catenary line faults can be roughly divided into two types: transient faults and permanent faults. Instantaneous faults can be restored by reclosing the power supply, but the fault point is often a weak point, which needs to be found and dealt with as soon as possible, so as to prevent another...

AI Technical Summary

Problems solved by technology

[0004]Question 1. The principle of suction current ratio is to measure the fault point by using the magnitude of the suction current of the AT autotransformers on both sides of the fault point. The suction current on both sides of the point must be the value at the same moment after the fault, and the data synchronization of each distance measuring device depends on GPS time synchronization.

Regardless of whether a built-in GPS plug-in or an external GPS timing system is used, when the GPS antenna is abnormal, it will inevitably affect the location of the fault point

[0005]Question 2. Since the parameters such as the impedance of the upstream and downstream catenary lines are the same under the AT power supply mode, when a fault occurs, the contact line of the upstream line collected by the substation is (T-line) current IT1 and forward feeder (F-line) current IF1 are equal to the T-line current IT2 and F-line current IF2 of the downlink respectively, so it is impossible to determine whether the fault direction is uplink or downlink, and it is also impossible to determine whether the fault type is a T-line pair Rail (T-R failure) or F line to rail (F-R failure) or T line to F line failure (T-F failure)

[0006] Question 3. Some manufacturers use the current vector difference between the T line and the F line on the uplink and downlink parallel lines on both sides of the fault point. The direction of the fault is determined by the direction of the fault, but because the main wiring of the AT station and the partition station of the high-speed electrified railway is not installed with a current transformer on the upstream and downstream parallel lines (such as figure 1 ), so this method cannot achieve accurate judgment of the fault direction

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