Online backflow cable breakage monitoring device

Abstract

The utility model discloses an on-line backflow cable breakage monitoring device, and relates to the technical field of backflow cable monitoring. The device comprises a laser, an optical isolator, an optical circulator, a sensing optical cable, an optical reflector and an optical detector. The laser emits a light source of a narrow-linewidth monochromatic light beam and is used for generating laser; the optical isolator allows optical signals to be transmitted in one direction, high isolation is provided for reverse optical signals, the optical isolator is used between the laser device and the transmission optical fiber, reflected light can be prevented from returning to the laser device, and therefore the working state of the laser device is kept stable, and system noise is reduced. The optical circulator controls the transmission direction of an optical signal, and the optical signal is unidirectionally transmitted to a second port through a first port of the optical circulator; the optical circulator and the optical reflector are combined to form a single optical signal transmission path, whether a backflow cable is broken or not can be judged by detecting whether reverse light exists in the sensing optical cable on line, and the device has the advantages of being simple in structure, passive in front end and free of false alarm.

Description

Technical Field

[0001] The utility model relates to the technical field of return cable monitoring, in particular to an online return cable break monitoring device. Background Art

[0002] With the rapid development of the national economy, my country's demand for electric energy continues to grow. The country has vigorously strengthened the construction of power infrastructure, and power cables have also been laid and applied on a large scale.

[0003] As an important component of power cables, return cables are used to introduce short-circuit current into the ground when a cable fails. They have the functions of reducing the induced voltage of the sheath, suppressing electrical interference, balancing current distribution, and maintaining the integrity of the cable structure. They play an important role in the safe and stable operation of the power grid system. However, due to the high recycling value, small zero-sequence current, and low theft risk of return cables, they have become the main target of criminals who steal cables.

[0004] At present, the existing return cable monitoring devices include magnetic ring induction monitoring devices, optical fiber vibration monitoring devices and other systems. However, magnetic ring induction monitoring devices and optical fiber vibration monitoring devices still have some defects:

[0005] 1. The magnetic ring induction monitoring device detects the zero-sequence current in the return cable online through the magnetic ring inductance at the front end, and determines whether the return cable is broken by the presence or absence of current. However, its front-end active sensor has the problems of short life cycle and high maintenance cost;

[0006] 2. The optical fiber vibration monitoring device uses the sensor optical cable to monitor the vibration information generated by digging, touching, knocking, cutting, etc. near the return cable online to determine whether theft has occurred, but it has the problems of high false alarm rate and high price. Utility Model Content

[0007] In order to solve the problems of short life cycle and high maintenance cost of magnetic ring induction monitoring devices and high false alarm rate and high price of optical fiber vibration monitoring devices; the purpose of the utility model is to provide an online return cable break monitoring device.

[0008] In order to solve the above technical problems, the utility model adopts the following technical solutions: an online return cable disconnection monitoring device, the online return cable disconnection monitoring device is composed of a laser, an optical isolator, an optical circulator, a sensor optical cable, an optical reflector and a light detector;

[0009] The laser emits a light source with a narrow line width and a monochromatic light beam, and is used to generate laser light;

[0010] The optical isolator allows the optical signal to be transmitted in one direction, while providing high isolation for the reverse optical signal. The use of the optical isolator between the laser and the transmission optical fiber can suppress the reflected light from returning to the laser, thereby maintaining the stability of the laser working state and reducing system noise.

[0011] The optical circulator controls the transmission direction of the optical signal, the optical signal is unidirectionally transmitted to the second port through the first port of the optical circulator, and the reverse light in the sensor optical cable is unidirectionally transmitted to the third port through the second port of the optical circulator;

[0012] The light reflector totally reflects the incident light back to the sensing optical cable;

[0013] The photodetector receives the reflected light signal and converts it into an electrical signal.

[0014] Preferably, the sensing optical cable is a transmission medium for incident light and reflected light, and is bundled together with a return cable.

[0015] Preferably, if the return cable is a single cable, it is bundled together with the sensing optical cable; if the return cable is a composite cable, the optical cable contained therein is used as the sensing optical cable.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] In the utility model, a single optical signal transmission path is formed by combining an optical circulator and an optical reflector, and the presence of reverse light in the sensing optical cable can be detected online to determine whether the return cable is broken. It has the advantages of simple structure, passive front end and no false alarm. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of the working process of the utility model.

[0020] In the figure: 1, first port; 2, second port; 3, third port. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] Example: Figure 1 As shown, the utility model provides an online return cable disconnection monitoring device, which is composed of a laser, an optical isolator, an optical circulator, a sensor optical cable, an optical reflector and a light detector;

[0023] Laser is a light source that emits a narrow line width, monochromatic beam and is used to generate laser light;

[0024] The optical isolator allows the optical signal to be transmitted in one direction, while providing high isolation for the reverse optical signal. Using an optical isolator between the laser and the transmission fiber can suppress the reflected light from returning to the laser, thereby maintaining the stability of the laser's working state and reducing system noise.

[0025] The optical circulator controls the transmission direction of the optical signal. The optical signal is unidirectionally transmitted to the second port 2 through the first port 1 of the optical circulator, and the reverse light in the sensor optical cable is unidirectionally transmitted to the third port 3 through the second port 2 of the optical circulator.

[0026] The optical reflector totally reflects the incident light back to the sensing optical cable;

[0027] The photodetector receives the reflected light signal and converts it into an electrical signal.

[0028] The sensing optical cable is the transmission medium for incident light and reflected light and is bundled together with the return cable.

[0029] If the return cable is a single cable, it is bundled together with the sensing optical cable. If the return cable is a composite cable, the optical cable contained therein is used as the sensing optical cable.

[0030] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. An online return cable disconnection monitoring device, characterized in that: The online return cable disconnection monitoring device is composed of a laser, an optical isolator, an optical circulator, a sensor optical cable, an optical reflector and a light detector; The laser emits a light source with a narrow line width and a monochromatic light beam, and is used to generate laser light; The optical isolator allows the optical signal to be transmitted in one direction, while providing high isolation for the reverse optical signal. The use of the optical isolator between the laser and the transmission optical fiber can suppress the reflected light from returning to the laser, thereby maintaining the stability of the laser working state and reducing system noise. The optical circulator controls the transmission direction of the optical signal, the optical signal is unidirectionally transmitted to the second port (2) through the first port (1) of the optical circulator, and the reverse light in the sensor optical cable is unidirectionally transmitted to the third port (3) through the second port (2) of the optical circulator; The light reflector totally reflects the incident light back to the sensing optical cable; The photodetector receives the reflected light signal and converts it into an electrical signal.

2. An online return cable disconnection monitoring device as claimed in claim 1, characterized in that: The sensor optical cable is a transmission medium for incident light and reflected light and is bundled together with the return cable.

3. An online return cable disconnection monitoring device as claimed in claim 2, characterized in that: If the return cable is a single cable, it is bundled together with the sensing optical cable. If the return cable is a composite cable, the optical cable contained therein is used as the sensing optical cable.

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