Fault identification and protection method of electrified railway AT traction network

Abstract

Provided is a fault identification and protection method of an electrified railway AT traction network. When network voltage is lower than a specified value, labeling no-load trend symbol values of the near ends and the far ends of a touch net T and a negative feeder F in each self-coupling segment with 0, labeling influent trend symbol values with 1, labeling effluent trend symbol values with -1, if an absolute value of a sum of the trend symbol values of two ends of the touch net T in each self-coupling segment is larger than or equal to 1, or a failure absolute value of a sum of the trend symbol values of two ends of the negative feeder F is larger than or equal to 1, or a failure absolute value of a sum of the trend symbol values of two ends of a touch net T branch and a negative feeder F branch is larger than or equal to 1, respectively judging the touch net T to be in short circuit failure to the ground, or the negative feeder F to be in short circuit failure to the ground, or the touch net T to be in short circuit failure to the negative feeder F, and breaking off all breakers at two ends of each self-coupling segment. Short-circuit reactance calculated according to corresponding voltage and short-circuit current at two ends of each self-coupling segment and the corresponding length of the self-coupling segment determine failure positions.

Description

technical field [0001] The invention relates to a fault discrimination and protection method for an AT traction network of an electrified railway. Background technique [0002] The electrified railway traction power supply system is composed of traction substation and traction network, and the traction network is composed of catenary, train, rail (and ground). The traction network generally adopts a direct power supply method with a simple structure. In order to meet the operation needs of high-power trains on high-speed railways, the traction networks of high-speed railways in Japan, France and my country all adopt autotransformer (AT) power supply mode. In order to further enhance the power supply capacity, my country has also adopted a power supply method in which the uplink and downlink are connected in parallel at the autotransformer (AT) on the nearly 10,000km high-speed railway, which is called the full parallel AT power supply method. However, it must be noted that...

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Problems solved by technology

However, it must be noted that due to the complexity of the power network formed by the AT traction network, the nonlinearity of the traction network reactance-distance characteristics viewed from the traction busbar, the multi-valued nature, and the limitations of existing technologies, the failure of the traction network Finding, locating, removing, and isolating become difficult and inaccurate. At the same time, any fault in the fully parallel AT traction network will cause the entire traction network to be out of service, which greatly reduces the reliability of the already weak traction network. Influence and restrict the good operation of high-speed railway

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