AT traction network short circuit fault distance measurement method

Abstract

The invention provides an AT traction network short circuit fault distance measurement method. The method comprises the steps: A, a current sensor is arranged on each auxiliary?connection line CPWn between a protection line and a steel rail; in the case of short circuit, a central controlling and processing unit acquires at once current In of all auxiliary?connection lines measured by the current sensors, the largest auxiliary?connection line current Ik and the second largest auxiliary?connection line current Ik' are found out, k'=k+ / -1, and the central controlling and processing unit determines the section between the auxiliary?connection line CPWk and the CPWk' to be the section where a short circuit fault happens; B, the distance X between the short circuit fault position and the auxiliary?connection line CPWk where the largest auxiliary?connection line current Ik is located is found out, in the formula shown in the description, D is the distance between the auxiliary?connection line CPWk and the CPWk'; and finally the distance between the fault and the traction substation can be obtained. According to the method provided by the invention, the traction network short circuit fault position in high speed railway full parallel AT power supply?mode can be quickly and accurately measured, timely maintenance is facilitated, and loss expansion and accident happening can be more effectively avoided.

Description

Technical field [0001] The invention relates to an AT traction network fault location method. Background technique [0002] Railway traction power supply systems mostly use AT power supply, and the power supply loop is mainly composed of contact wires, locomotives, steel rails, and protection wires. On the basis of AT power supply, high-speed railway has developed into a fully parallel AT power supply mode. This power supply mode connects the uplink and downlink lines in parallel at the AT location. The power supply distance is longer, the power supply is larger, and the line structure is more complicated. The fault location device of the power supply system and its automation function put forward higher requirements, requiring better selectivity, higher reliability, faster action speed, fault identification, judgment, and faster recovery time. [0003] At present, the fault location methods for the all-parallel AT power supply mode of China's high-speed railways include "AT neutr...

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Problems solved by technology

[0003] At present, there are fault location methods for the fully parallel AT power supply mode of my country's high-speed railways, such as "AT neutral point suction current ratio", "section uplink current ratio" and "horizontal line current ratio". The fault location principle of the fault location method is affected by the main transformer leakage reactance, AT leakage reactance, and earth leakage. The fault location only considers the short-circuit current or impedance of an AT section (10-15km) as the basic measurement unit, low ranging accuracy and large error

On the other hand, the traditional full-parallel AT power supply mode fault location method does not consider the influence and function of the protection line current on fault location. The position of the protection line on the pillar is relatively close to the positive feeder line and contact line. Under the influence of factors such as damage and trees, it is easy to cause a short-circuit fault between the positive feeder and the protection line. However, this type of fault location is not considered in the existing fault location schemes, resulting in catenary-protection line faults and positive feeder- The protection line fault cannot realize the fault location, which reduces the safety and reliability of the traction power supply system

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