High-sensitivity power line grounding searching instrument

Abstract

The invention discloses a high-sensitivity power line grounding searching instrument which comprises an insulating disc, a plurality of earth return direction detectors are arranged on the insulating disc, current transformers are arranged on the earth return direction detectors respectively, and the current transformers are connected with an alternating current ammeter. The tower grounding current of 20 milliamperes can be detected through the combination of current phase detection and gas generation through grounding current electrolysis, in addition, an earthworm fence is arranged, weak leakage current below 10 milliamperes is detected through the characteristic that earthworms are sensitive to current, whether a fault or an insulation weak point exists in an electric tower or not is sensitively found out, the defects in the prior art are overcome, and the safety of the electric tower is improved. The device has the capability of visually detecting whether the electric power tower is grounded or not.

Description

Technical Field

[0001] The invention relates to the technical field of detection instruments, and in particular to a high-sensitivity power line grounding finder. Background Art

[0002] The difficulty in finding single-phase grounding in the power system has always been a major problem that plagues the operation of distribution networks. Whether it is arc suppression coil grounding or low-resistance grounding, there will be fault points that are difficult to find by conventional inspection methods, resulting in troublesome fault handling, frequent power transmission failures and other serious problems. In response to this problem, some units have developed grounding search instruments based on the fifth harmonic method or signal injection principle.

[0003] Data show that the grounding search equipment of the prior art generally has problems such as inaccurate positioning accuracy, difficulty in finding high-resistance grounding, and dangerousness of injected signals, which greatly limits the promotion and use of the equipment. Some more advanced fault indicators now also have grounding indication functions, but fault indicators cannot be installed densely. For lines with many cable outlet branches or long distances, the help for on-site search is still limited. The most intuitive and effective method for grounding search is to directly detect the grounding current of the pole tower, but the flexible clamp meter of the prior art cannot detect the diameter of the pole, and the detection sensitivity is low, only 0.1A, and cannot detect leakage current of high-resistance grounding or weak insulation points, which is of limited significance for single-phase grounding search. The present invention proposes a new type of power line tower fault test instrument, which overcomes the shortcomings of the prior art and has the ability to intuitively detect whether the power pole tower is grounded.

[0004] Chinese patent document CN107671414A discloses a "comprehensive monitoring system for power line towers". It uses a data acquisition system, a data processing unit, a power module, an information transmission module and a monitoring center server; the data acquisition system includes a temperature sensor, a smoke sensor, a wind sensor, a capacity detector, an inclination sensor, an image acquisition unit and a ground resistance calculation unit; the data processing unit includes a microprocessor and an A / D converter; the system also includes a timer that sends an acquisition signal to the on-site data acquisition unit and the microprocessor at a preset time threshold. The above technical solution collects limited data and cannot sensitively detect whether there is a ground fault in the upper components of the pole. Summary of the invention

[0005] The present invention mainly solves the technical problem that the original technical solution has limited data collection and cannot sensitively detect whether there is a grounding fault in the upper components of the electric pole. It provides a highly sensitive grounding finder for power lines, which combines current phase detection with the electrolysis of grounding current to generate gas, and can detect the grounding current of the pole tower of 20 mA. In addition, an earthworm enclosure is set up to detect weak leakage current below 10 mA by using the current-sensitive characteristics of earthworms, and sensitively find whether there are faults or insulation weak points in the power pole tower, overcoming the shortcomings of the prior art and having the ability to directly detect whether there is grounding in the power pole tower.

[0006] The above technical problem of the present invention is mainly solved by the following technical solution: The present invention includes an insulating disc, and a plurality of earth return direction detectors are provided on the insulating disc. Current transformers are respectively provided on the plurality of earth return direction detectors, and the current transformers are connected to an AC ammeter. By combining current phase detection with the electrolysis of grounding current to generate gas, the grounding current of the pole tower of 20 mA can be detected. In addition, an earthworm enclosure is set up to detect weak leakage current below 10 mA by using the current-sensitive characteristics of earthworms, and sensitively find whether there are faults or insulation weak points in the power pole tower.

[0007] Preferably, the insulating disc is of a disc-shaped structure, and a notch is provided radially from the center to the outer circle of the insulating disc. The insulating disc is of a disc-shaped structure with a diameter of 1 m, ensuring sufficient length to surround the entire electric pole and sensitively detecting whether there is a grounding fault in the upper components of the electric pole.

[0008] Preferably, the width of the notch of the insulating disc is 30 - 50 cm, and an earthworm enclosure is provided at the edge of the notch. When setting up the earthworm enclosure, when detecting problems such as reduced insulation and very small leakage earth current, the present invention proposes to utilize the sensitivity of earthworms to weak earth current. As long as earthworms are placed in the earthworm enclosure, if there is weak grounding current in this pole tower, the earthworms will quickly move away from the pole tower. By using the current-sensitive characteristics of earthworms, weak leakage current below 10 mA can be detected, providing a convenient and feasible solution for further sensitively finding whether there are faults or insulation weak points in the power pole tower.

[0009] Preferably, the earth return direction detector is of a portal structure, and metal probe rods inserted into the ground are provided at both ends. By using the metal probe rods to practice current phase detection, the grounding current of the pole tower of 50 mA can be detected.

[0010] Preferably, there are four earth return direction detectors, which are symmetrically arranged along the radial direction on the outer side of the insulating disc. Four symmetrically arranged detection probes on the insulating disc are used to measure the current direction in the earth soil.

[0011] Preferably, the primary side of the current transformer is directly sleeved into the earth return direction detector. After the same-name terminals of the secondary side of the current transformer are respectively connected in parallel, they are connected to an AC ammeter. By connecting the same-name terminals of the transformer, when in use, as long as the detection disc is sleeved onto the pole tower to be detected, if the current in the earth does not flow into this pole tower, the currents of the four detection probes cancel each other out, and their vector sum is zero, and the AC ammeter has no reading. If they all flow into this pole tower, the current vector sums up, and the AC ammeter can read out the significant grounding current, so as to find out whether the grounding fault occurs in this pole tower.

[0012] Preferably, it further includes a resistance-reducing water injector. There are two resistance-reducing water injectors, which are respectively arranged at both ends of the insulating disc. By injecting the resistance-reducing agent, the soil resistivity of the detection area is further reduced.

[0013] Preferably, it further includes a hydrogen gas sensor. The hydrogen gas sensor is of a soil-insertion type and is arranged on one side of the insulating disc. Through the auxiliary detection of the hydrogen gas sensor, if the grounding is located at this pole tower, the soil current density is concentrated, and hydrogen gas can be collected in the soil. Generally, hydrogen gas can be significantly collected when there is a 50 mA grounding current in the soil. In this way, with the aid of the auxiliary judgment of the hydrogen gas sensor, it can be further determined whether the grounding current flows back to this pole tower.

[0014] The beneficial effects of the present invention are as follows: By combining current phase detection with the electrolysis of grounding current to generate gas, the grounding current of the pole tower of 20 mA can be detected. In addition, an earthworm enclosure is also provided. By utilizing the current-sensitive characteristic of earthworms, the weak leakage current below 10 mA can be detected, and it can sensitively find out whether there are faults or insulation weak points in the power pole tower, overcoming the shortcomings of the prior art and having the ability to directly detect whether there is grounding in the power pole tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the present invention.

[0016] In the figure, 1 is the insulating disc, 2 is the earth return direction detector, 3 is the current transformer, 4 is the AC ammeter, 5 is the resistance-reducing water injector, 6 is the hydrogen gas sensor, and 7 is the earthworm enclosure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The technical solution of the present invention will be further specifically described below through embodiments in combination with the drawings.

[0018] Embodiment: A highly sensitive power line grounding finder in this embodiment, as Figure 1 shown, includes an insulating disc 1, an earth return direction detector 2, a current transformer 3, an AC ammeter 4, a resistance-reducing water injector 5, a hydrogen gas sensor 6, and an earthworm enclosure 7.

[0019] The insulating disc 1 is of a disc-shaped structure with a diameter of 1 meter. It has a notch radially from the center to the outer ring. The width of the notch is between 30 and 50 centimeters. The earthworm enclosure 7 is provided at the edge of the notch. There are four earth return direction detectors 2, each with the same structure, which is a portal structure, and metal probe rods inserted into the ground are provided at both ends. The four earth return direction detectors 2 are symmetrically arranged along the radial direction on the outside of the insulating disc 1. There are four identical current transformers 3, which are respectively arranged on the four earth return direction detectors 2. The primary side of the current transformer 3 is directly sleeved on the earth return direction detector 2. After the secondary side homonymous ends of the four current transformers 3 are respectively paralleled, they are connected to the AC ammeter 4.

[0020] There are two identical resistance-reducing water injectors 5, which are respectively arranged at both ends of the insulating disc 1. The hydrogen sensor 6 is of a soil-insertion type and is arranged on one side of the insulating disc 1.

[0021] The present invention uses four symmetrically arranged detection probes on the insulating disc to measure the direction of the current in the earth soil. Through the connection of the homonymous ends of the transformers, when in use, as long as the detection disc is sleeved on the tower to be detected, if the current in the earth does not flow into this tower, the currents of the four detection probes cancel each other out and their vector sum is zero, and the AC ammeter has no reading. If they all flow into this tower, the current vector sum accumulates, and the AC ammeter can read out a significant grounding current, so as to find out whether a grounding fault occurs in this tower.

[0022] Through the injection of the resistance-reducing agent, the present invention further reduces the soil resistivity of the detection area. Subsequently, through the auxiliary detection of the hydrogen sensor, if the grounding is located on this tower, the soil current density is concentrated, and hydrogen can be collected in the soil. Generally, hydrogen can be significantly collected when there is a 50 mA grounding current in the soil. In this way, with the aid of the auxiliary judgment of the hydrogen sensor, it can be further clarified whether the grounding current flows back to this tower.

[0023] The present invention can very sensitively detect whether there is a grounding current in the power tower and determine whether there is a grounding fault in the line tower. The prior art relies on a flexible clamp meter and cannot have a sufficient length to surround the entire electric pole, so it cannot sensitively detect whether there is a grounding fault in the upper components of the electric pole. The present invention combines current phase detection with the gas generated by the electrolysis of the grounding current and can detect a 50 mA tower grounding current. In addition, the present invention also sets an earthworm enclosure. When the detection encounters problems such as reduced insulation and very small leaked earth current, the present invention proposes to utilize the sensitivity of earthworms to weak earth currents. As long as earthworms are placed in the earthworm enclosure, if there is a weak grounding current in this tower, the earthworms will quickly move away from the tower. Utilizing the current-sensitive characteristics of earthworms, weak leakage currents below 10 mA can be detected, providing a convenient and feasible solution for further sensitively discovering whether there are faults or insulation weak points in the power tower.

Claims

1. A highly sensitive grounding finder for power lines, characterized in that, it includes an insulating disc (1), on which several earth return direction detectors (2) are provided, current transformers (3) are respectively provided on several earth return direction detectors (2), and the current transformers (3) are connected to an AC ammeter (4).

2. The highly sensitive grounding finder for power lines according to claim 1, characterized in that, the insulating disc (1) is of a disc-shaped structure, and a notch is provided radially from the center to the outer circle of the insulating disc (1).

3. The highly sensitive grounding finder for power lines according to claim 2, characterized in that, the width of the notch of the insulating disc (1) is 30 - 50 cm, and an earthworm enclosure (7) is provided at the notch edge.

4. The highly sensitive grounding finder for power lines according to claim 1, characterized in that, the earth return direction detector (2) is of a portal structure, and metal probe rods inserted into the ground are provided at both ends.

5. The highly sensitive grounding finder for power lines according to claim 1 or 4, characterized in that, there are four earth return direction detectors (2), which are symmetrically arranged along the radial direction on the outside of the insulating disc (1).

6. The highly sensitive grounding finder for power lines according to claim 1, characterized in that, the primary side of the current transformer (3) is directly sleeved on the earth return direction detector (2), and the homonymous ends of the secondary sides of the current transformers (3) are respectively paralleled and then connected to the AC ammeter (4).

7. The highly sensitive grounding finder for power lines according to claim 1, characterized in that, it further includes a resistance-reducing water injector (5), and there are two resistance-reducing water injectors (5), which are respectively arranged at both ends of the insulating disc (1).

8. The highly sensitive grounding finder for power lines according to claim 1, characterized in that, it further includes a hydrogen sensor (6), and the hydrogen sensor (6) is of a soil-insertion type and is arranged on one side of the insulating disc (1).

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