Grounding leakage current detecting device for train power supply system

Abstract

The invention discloses a grounding leakage current detecting device for a train power supply system, comprising a current sensor (1) and a leakage current detecting module (2) which are connected with each other. A grounding point (10) of the train power supply system is grounded through the current sensor (1); a protective resistor (3) is connected in parallel outside the current sensor (1); the grounding point (10) of the train power supply system also is grounded through the protective resistor (3). The grounding leakage current detecting device makes the current sensor not influence former protection functions and grounding detection of circuits when the circuits are normal, short-circuiting and open-circuiting through the protector resistor, still has a grounding protection function when the current sensor is invalid and prevents a floating voltage caused by an open circuit from causing harmful effects on power supply circuits, and has the advantages of high measurement precision, good security, good electromagnetic compatibility, simple circuit and low cost.

Description

technical field [0001] The invention relates to the field of electric locomotive power supply safety, in particular to a ground leakage current detection device used in a train power supply system. Background technique [0002] The train power supply system is an important equipment on the electric locomotive. The high-power transformer on the electric locomotive converts the power of the power supply network into an alternating current of about 860 volts, and then converts the alternating current into a DC 600 volts through the half-controlled rectifier bridge of the thyristor. The train power supply system outputs a DC 600-volt power supply to the passenger car power system for use. If there is a leakage problem in the train power supply system, it will affect the equipment on the passenger car and the personal safety of passengers, and affect the safe operation of the train. [0003] The leakage current detection methods of the train power supply system in the prior art m...

AI Technical Summary

Problems solved by technology

After field application, it is found that the active grounding detection method has defects such as cumbersome mechanical actions, many accessories, low reliability, dead zone and easy burning, failure to isolate the power supply circuit from the detection circuit, and poor electromagnetic compatibility.

[0010] In addition, if the connector or the current sensor is faulty when installing the device, the current sensor may be in an open circuit state, which will affect the original voltage division calculation, thereby affecting the grounding protection

At the same time, when the current sensor is in an open circuit state, if the power supply line is isolated from the ground, a floating voltage of several thousand volts may be generated on the power supply line, and the floating voltage of several thousand volts will adversely affect the insulation of the power supply line

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