Track electric potential limiting device and control method thereof

Abstract

The invention discloses a track electric potential limiting device and a control method thereof. The track electric potential limiting device consists of a voltage limiting circuit, a protection circuit, a multi-point voltage monitoring unit, a splitter, a shunt, a current monitoring unit, a PLC control system unit and a working state display instrument. The core part of the voltage limiting circuit is a combination switch; the multi-point voltage monitoring unit detects the voltage between the track and the ground at multiple points along the track in real time; the PLC control system unit performs data processing of the detected voltages and controls the action of the combination switch in the voltage limiting circuit by using a fuzzy control method; the current monitoring unit is used for monitoring a current flowing between the track and a grounded bus and controls the combination switch to turn off automatically; the protection circuit is used for eliminating an instantaneous high voltage generated when the combination switch is turned on and off; and the working state display instrument displays the working state parameters in real time. The device and the method have the advantages that: a multi-point monitoring mode is adopted; the test accuracy of the system is improved; the hazards caused by overhigh track electric potential are eliminated; the response is made in time and safety; and the reliability is high.

Description

technical field [0001] The invention relates to a track potential limiting device and a control method thereof, which are particularly suitable for limiting excessively high track potential by adopting a multi-point monitoring method in subway and light rail systems, so as to prevent passengers getting on and off the train from being hurt. Background technique [0002] In order to prevent the harm of stray currents, it is necessary to ensure a sufficiently large ballast bed resistance. Therefore, in the subway DC traction power supply system, the rails are installed insulated from the ground, thus forming independent protection grounds (station grounds) and track grounds (traction grounds). The return current when the train is running may cause the track to generate an abnormally high voltage to the earth. When some faults occur, such as metal contact short circuit between catenary and rail, metal contact fault between catenary and overhead ground wire, frame leakage fault o...

AI Technical Summary

Problems solved by technology

[0004](1) The measurement accuracy is low, which may easily cause the malfunction of the track potential limiting device;

[0005] (2) There is a certain time delay in monitoring and control, and there is no advance prediction function. cause harm;

[0006](3) The track potential in a section is not considered, and it is not enough to tell whether the track potential in a section exceeds the safety of the human body by simply monitoring the track potential at a certain point on the track Ultimate voltage

[0007] The basis for the action closure of the track potential limiting device is whether the track potential exceeds the safe voltage of the human body. It is complex, and each parameter has the characteristics of nonlinearity and strong coupling, so it is difficult to establish an accurate mathematical model of the process, and it is difficult to guarantee the control accuracy of the general conventional control method

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