An integrated lightning arrester for monitoring

Abstract

The present invention discloses an integrated monitoring lightning arrester, which includes a lightning arrester outer casing and lightning arrester resistor chips arranged therein, and further includes a pressure sensor and a sealing performance monitoring module. The pressure sensor is arranged between the lightning arrester outer casing and the lightning arrester resistor chips, and the pressure sensor is electrically connected to the sealing performance monitoring module. It can accurately monitor key state variables such as the internal sealing performance, resistive current and phase angle of the lightning arrester, reflect the operation state of the lightning arrester in real time, which has great significance for preventing the further expansion and development of lightning arrester faults, correctly guiding its maintenance work and ensuring the safety of the power grid; moreover, it can replace the power-off test and live detection of the lightning arrester, saving a large amount of manpower and material resources.

Description

Technical Field

[0001] The present invention relates to the field of power equipment, and in particular to a monitoring integrated lightning arrester. Background Art

[0002] A lightning arrester can release the energy of lightning or switching overvoltage, protect electrical equipment from instantaneous overvoltage hazards, and can also interrupt the follow current to prevent system ground short-circuit faults. When the overvoltage value reaches the specified operating voltage, the lightning arrester immediately operates, conducts charges, limits the overvoltage amplitude, and protects the equipment insulation from breakdown; after the voltage value returns to normal, the lightning arrester quickly returns to its original state to ensure normal power supply of the system. The reliable operation of the lightning arrester plays a very important role in ensuring the safe operation of the power system. Therefore, the detection of the operating state of the lightning arrester is crucial. At present, the methods for detecting the operating state of lightning arresters mainly include outage tests, live detection, and online monitoring of the total current. Outage tests can indeed well detect the defects of lightning arresters, but power outages are time-consuming and laborious and affect residents' electricity consumption; the live detection methods mainly include infrared temperature measurement and resistive current detection. The defects of lightning arresters belong to voltage heating defects, and the temperature change is small, generally not exceeding 1-2K. It often requires very experienced professionals to detect through infrared temperature measurement; for the resistive current live detection method, its measurement results are easily affected by factors such as ambient temperature and humidity, electromagnetic interference, and external insulation contamination; for the online monitoring method of the total current, the sensitivity to the defects of lightning arresters is low, and only when the defects of the lightning arrester are serious can a large difference be shown. Therefore, there is currently no lightning arrester defect detection method that can ensure both accurate measurement results and convenience. Summary of the Invention

[0003] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a monitoring integrated lightning arrester to realize real-time monitoring of the operating state of the lightning arrester, prevent the further expansion and development of lightning arrester failures, so as to correctly guide its maintenance work and prevent power grid accidents.

[0004] A monitoring integrated lightning arrester includes a lightning arrester outer casing and lightning arrester resistor discs arranged therein, and further includes a pressure sensor and a sealing performance monitoring module. The pressure sensor is arranged between the lightning arrester outer casing and the lightning arrester resistor discs, and the pressure sensor is electrically connected to the sealing performance monitoring module.

[0005] The above solution first proposed a method for real-time monitoring of the sealing performance of lightning arresters. More than 85% of the defects of lightning arresters are caused by internal moisture discharge due to poor sealing. Under normal circumstances, the inside of the lightning arrester is slightly positively pressurized. A pressure sensor is used to monitor the internal pressure. If the internal pressure is equal to the atmospheric pressure, it indicates that the internal sealing performance of the lightning arrester has failed. By setting a pressure sensor inside the outer casing of the lightning arrester, the internal sealing performance of the lightning arrester can be accurately and real-time monitored, preventing the further expansion and development of lightning arrester failures, so as to correctly guide its maintenance work, prevent power grid accidents, without the need for power-off tests, which is convenient and fast and will not affect residents' electricity use.

[0006] Furthermore, it also includes a leakage current sensor and a current monitoring module. The leakage current sensor is arranged inside the outer casing of the lightning arrester and at the bottom end of the lightning arrester resistor chip, and the leakage current sensor is electrically connected to the current monitoring module; the current monitoring module is also used to access a voltage reference signal, and based on the voltage reference signal and the total current signal transmitted by the leakage current sensor, obtain and display the real-time resistive current; wherein, the voltage reference signal is the secondary winding voltage signal of a voltage transformer in the same phase as this integrated monitoring lightning arrester.

[0007] For the first time, the leakage current monitoring of the lightning arrester is integrated with the lightning arrester design. The leakage current sensor is placed at the inner bottom end of the lightning arrester to directly monitor the leakage current flowing through the lightning arrester resistor chip, successfully solving the problems affected by factors such as environmental temperature and humidity, electromagnetic interference, and external insulation pollution, and the measurement result has high accuracy.

[0008] Furthermore, the current monitoring module is also used to obtain and display the real-time phase angle based on the voltage reference signal and the total current signal transmitted by the leakage current sensor.

[0009] Furthermore, the current monitoring module is also used to display the real-time total current according to the total current signal transmitted by the leakage current sensor.

[0010] Furthermore, the leakage current sensor is a Rogowski coil.

[0011] Furthermore, it also includes an epoxy resin board with a two-way plug on the outer casing of the lightning arrester. Both between the pressure sensor and the epoxy resin board with a two-way plug and between the epoxy resin board with a two-way plug and the sealing performance monitoring module are connected through pressure transmission lines; both between the leakage current sensor and the epoxy resin board with a two-way plug and between the epoxy resin board with a two-way plug and the current monitoring module are connected through current transmission lines. The epoxy resin board with a two-way plug ensures the sealing of the lightning arrester while transmitting the pressure signal and the current signal to the outside of the outer casing of the lightning arrester.

[0012] Further, the epoxy resin board with a two-way plug includes an epoxy resin board and a metal connecting piece. The metal connecting piece is embedded in the epoxy resin board. Two jacks communicating with the metal connecting piece are respectively opened on both sides of the epoxy resin board, and the jacks opened on both sides of the epoxy resin board are staggered with each other. The staggered arrangement of the jacks can prevent the jacks on both sides from being conducted, resulting in the inability to ensure the sealing performance of the lightning arrester.

[0013] Further, both the pressure transmission line and the current transmission line are double-shielded lines.

[0014] Further, it further includes a discharge counter. The input end of the discharge counter is connected to the flange provided at one end of the lightning arrester outer casing, and the output end of the discharge counter is grounded. The discharge counter is used to record and display the discharge times of the integrated monitoring lightning arrester.

[0015] Further, the acquisition range of the pressure sensor is 0.1 - 0.2 Mpa, and the acquisition range of the leakage current sensor is 0 - 5 mA.

[0016] Compared with the prior art, an integrated monitoring lightning arrester proposed by the present invention has the following advantages:

[0017] (1) For the first time, a real-time monitoring method for the sealing performance of a lightning arrester is proposed. More than 85% of the defects of the lightning arrester are caused by internal moisture discharge due to poor sealing. Under normal circumstances, the inside of the lightning arrester is slightly positively pressurized. A pressure sensor is used to monitor the internal pressure. If the internal pressure is equal to the atmospheric pressure, it indicates that the internal sealing performance of the lightning arrester fails. By setting a pressure sensor inside the lightning arrester outer casing, the internal sealing performance of the lightning arrester can be accurately and real-time monitored.

[0018] (2) For the first time, the leakage current monitoring of the lightning arrester is integrated with the lightning arrester design. The leakage current sensor is placed at the inner bottom end of the lightning arrester to directly monitor the leakage current flowing through the lightning arrester resistor disc, successfully solving the problems affected by factors such as environmental temperature and humidity, electromagnetic interference, and external insulation pollution, and the measurement result has high accuracy.

[0019] (3) Accurately and real-time monitor key state variables such as the internal sealing performance, resistive current, and phase angle of the lightning arrester, and real-time reflect the operating state of the lightning arrester, which has great significance for preventing the further expansion and development of lightning arrester failures, correctly guiding its maintenance work, and ensuring the safety of the power grid.

[0020] (4) By using the integrated monitoring lightning arrester proposed by the present invention, the power-off test and live detection of the lightning arrester can be replaced, saving a large amount of manpower and material resources. Description of the Drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Figure 1 is a schematic structural diagram of an integrated monitoring lightning arrester provided by an embodiment of the present invention;

[0023] Figure 2 is a cross-sectional view of an epoxy resin board with a two-way plug.

[0024] In the figure, 1 - lightning arrester resistor chip, 2 - lightning arrester outer casing, 3 - leakage current sensor, 4 - pressure sensor, 5 - epoxy resin board with a two-way plug, 6 - current transmission line, 7 - pressure transmission line, 8 - sealing performance monitoring module, 9 - current monitoring module, 10 - discharge counter, 11 - voltage reference signal, 12 - epoxy resin board, 13 - jack, 14 - metal connecting piece. Detailed implementation manners

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will describe the technical solutions of the present invention in detail. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other implementation manners obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present invention.

[0026] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", "center", "longitudinal", "transverse", "vertical", "horizontal", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0027] Such as Figure 1 、 Figure 2As shown in the figure, an embodiment of the present invention provides an integrated monitoring lightning arrester, which includes a lightning arrester outer casing 2 and lightning arrester resistor chips 1 arranged therein. It further includes a pressure sensor 4 and a sealing performance monitoring module 8. The pressure sensor 4 is arranged between the lightning arrester outer casing 2 and the lightning arrester resistor chips 1, and the pressure sensor 4 is electrically connected to the sealing performance monitoring module 8. The sealing performance monitoring module 8 is used to display the pressure state inside the lightning arrester outer casing 2.

[0028] The solution of the above embodiment first proposes a method for real-time monitoring of the sealing performance of a lightning arrester. More than 85% of the defects of the lightning arrester are caused by poor sealing, resulting in internal moisture discharge. Under normal circumstances, the inside of the lightning arrester is slightly positively pressurized. The pressure sensor 4 is used to monitor the internal pressure. If the internal pressure is equal to the atmospheric pressure, it indicates that the internal sealing performance of the lightning arrester has failed. By arranging the pressure sensor 4 inside the lightning arrester outer casing 2, the internal sealing performance of the lightning arrester can be accurately and real-time monitored, preventing the further expansion and development of lightning arrester failures, so as to correctly guide its maintenance work, prevent power grid accidents, without the need for power-off tests, which is convenient and fast and will not affect residents' electricity consumption.

[0029] In this embodiment, it further includes a leakage current sensor 3 and a current monitoring module 9. The leakage current sensor 3 is arranged inside the lightning arrester outer casing 2 and at the bottom end of the lightning arrester resistor chips 1, and the leakage current sensor 3 is electrically connected to the current monitoring module 9. The current monitoring module 9 is further used to access a voltage reference signal 11, and based on the voltage reference signal 11 and the full current signal transmitted by the leakage current sensor 3, obtain and display the real-time resistive current and phase angle. Among them, the voltage reference signal 11 is the voltage signal of the secondary winding of a voltage transformer in the same phase as this integrated monitoring lightning arrester. The leakage current sensor 3 is selected as a Rogowski coil. For the first time, the leakage current monitoring of the lightning arrester is integrated with the lightning arrester design. The leakage current sensor 3 is placed at the inner bottom end of the lightning arrester to directly monitor the leakage current flowing through the lightning arrester resistor chips 1, successfully solving the problem of being affected by factors such as environmental temperature and humidity, electromagnetic interference, and external insulation pollution, and the measurement result has high accuracy. After the current monitoring module 9 receives the full current signal transmitted by the leakage current sensor 3 and the voltage signal of the secondary winding of the voltage transformer in the same phase, it calculates and extracts the fundamental current signal of the full current and the fundamental voltage signal through FFT (Fast Fourier Transform). The phase difference between the voltage and the fundamental current signal of the full current is the phase angle signal, and thus the phase angle can be obtained. The resistive current is the fundamental current signal of the full current multiplied by the cosine value of the phase angle.

[0030] Optionally, the current monitoring module 9 is further used to display the real-time full current according to the full current signal transmitted by the leakage current sensor 3.

[0031] In a specific implementation, it also includes an epoxy resin plate 5 with a bidirectional plug head disposed on the arrester jacket 2, the pressure sensor 4 and the epoxy resin plate 5 with a bidirectional plug head, and the epoxy resin plate 5 with a bidirectional plug head and the sealing performance monitoring module 8 are connected through a pressure transmission line 7; the leakage current sensor 3 and the epoxy resin plate 5 with a bidirectional plug head, and the epoxy resin plate 5 with a bidirectional plug head and the current monitoring module 9 are connected through a current transmission line 6. The epoxy resin plate 5 with a bidirectional plug head ensures the sealing of the arrester while ensuring that the pressure signal and the current signal are transmitted to the outside of the arrester jacket 2.

[0032] Specifically, Figure 2 As shown, the epoxy resin board 5 with a bidirectional plug head includes an epoxy resin board 12 and a metal connecting piece 14, wherein the metal connecting piece 14 is embedded in the epoxy resin board 12, and two jacks 13 connected to the metal connecting piece 14 are respectively provided on both sides of the epoxy resin board 12, and the jacks 13 provided on both sides of the epoxy resin board 12 are staggered. The jacks 13 are staggered to avoid the jacks 13 on both sides being connected, which makes it impossible to ensure the sealing of the arrester.

[0033] Optionally, a discharge counter meter 10 is also included, the input end of the discharge counter meter 10 is connected to a flange arranged at one end of the arrester jacket 2, and the output end of the discharge counter meter 10 is grounded. The discharge counter meter 10 is used to record and display the number of discharges (actions) of the monitoring integrated arrester. In this embodiment, the display range is 1 to 100 times.

[0034] In this embodiment, the pressure transmission line 7 and the current transmission line 6 are both double-shielded wires; the acquisition range of the pressure sensor 4 is 0.1-0.2Mpa, and the accuracy is 0.002Mpa; the acquisition range of the leakage current sensor 3 is 0-5mA, and the accuracy is 0.01mA. The sealing performance monitoring module 8 displays the internal pressure of the arrester collected and transmitted by the pressure sensor 4, and the display range is 0.1-0.2Mpa. The resistive current display range of the current monitoring module 9 is 10-1000μA, the phase angle display range is 45-90°, and the full current display range is 10-3000μA. In addition, it is explained that the lightning arrester resistor 1: a metal oxide resistor with nonlinear volt-ampere characteristics composed of a porcelain body, metal electrodes on both end surfaces and a side insulating layer. It exhibits high resistance under normal power frequency voltage and low resistance when subjected to overvoltage, thereby limiting the overvoltage between the lightning arrester terminals; the lightning arrester jacket 2: an external insulating component of the lightning arrester used to provide creepage distance, mechanical strength and protect internal components from environmental influences.

[0035] The monitoring integrated arrester provided in the above embodiment has the following advantages:

[0036] (1) The real-time monitoring method for the sealing performance of arresters is proposed for the first time. More than 85% of the defects of arresters are caused by internal moisture discharge due to poor sealing. Under normal conditions, the internal pressure of the arrester is slightly positive, 0.13 - 0.15 Mpa. A pressure sensor is used to monitor the internal pressure. If the internal pressure is equal to the atmospheric pressure, it indicates that the internal sealing performance of the arrester has failed. By setting a pressure sensor inside the arrester jacket, the internal sealing performance of the arrester can be accurately and real-time monitored.

[0037] (2) The leakage current monitoring of the arrester and the integrated design of the arrester are carried out for the first time. The leakage current sensor is placed at the inner bottom end of the arrester to directly monitor the leakage current flowing through the arrester resistor chips, successfully solving the problems affected by factors such as environmental temperature and humidity, electromagnetic interference, and external insulation pollution. Experiments show that the measurement accuracy is as high as 99%.

[0038] (3) Accurately and real-time monitor key state variables such as the internal sealing performance, resistive current, and phase angle of the arrester, and reflect the operating state of the arrester in real time, which is of great significance for preventing the further expansion and development of arrester faults, correctly guiding its maintenance work, and ensuring the safety of the power grid.

[0039] (4) By using the integrated monitoring arrester proposed in this invention, the power-off test and live detection of the arrester can be replaced, saving a large amount of manpower and material resources.

[0040] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. An integrated lightning arrester for monitoring, comprising a lightning arrester outer sheath and lightning arrester resistor chips arranged therein, characterized in that, It also includes a pressure sensor and a sealing performance monitoring module. The pressure sensor is arranged between the arrester outer casing and the arrester resistor disc, and the pressure sensor is electrically connected to the sealing performance monitoring module; It also includes a leakage current sensor and a current monitoring module. The leakage current sensor is arranged inside the arrester outer casing and at the bottom end of the arrester resistor disc, and the leakage current sensor is electrically connected to the current monitoring module; The current monitoring module is also used to access a voltage reference signal, and obtain and display the real-time resistive current based on the voltage reference signal and the total current signal transmitted by the leakage current sensor; The voltage reference signal is the secondary winding voltage signal of a voltage transformer in the same phase as this integrated monitoring arrester; It also includes an epoxy resin board with a two-way plug on the arrester outer casing. Both between the pressure sensor and the epoxy resin board with a two-way plug and between the epoxy resin board with a two-way plug and the sealing performance monitoring module are connected through pressure transmission lines; Both between the leakage current sensor and the epoxy resin board with a two-way plug and between the epoxy resin board with a two-way plug and the current monitoring module are connected through current transmission lines; The epoxy resin board with a two-way plug includes an epoxy resin board and a metal connecting piece. The metal connecting piece is embedded in the epoxy resin board. Two jacks communicating with the metal connecting piece are respectively opened on both sides of the epoxy resin board, and the jacks opened on both sides of the epoxy resin board are staggered with each other.

2. The integrated monitoring lightning arrester according to claim 1, characterized in that, The current monitoring module is also used to obtain and display the real-time phase angle based on the voltage reference signal and the total current signal transmitted by the leakage current sensor.

3. The integrated monitoring lightning arrester according to claim 2, characterized in that, The current monitoring module is also used to display the real-time total current according to the total current signal transmitted by the leakage current sensor.

4. The integrated monitoring lightning arrester according to any one of claims 1 to 3, characterized in that, The leakage current sensor is a Rogowski coil.

5. The integrated monitoring lightning arrester according to claim 1, characterized in that, Both the pressure transmission line and the current transmission line are double-shielded lines.

6. The integrated monitoring lightning arrester according to claim 1, characterized in that, It also includes a discharge counter. The input end of the discharge counter is connected to a flange arranged at one end of the arrester outer casing, the output end of the discharge counter is grounded, and the discharge counter is used to record and display the discharge times of this integrated monitoring arrester.

7. The integrated monitoring lightning arrester according to claim 1, characterized in that, The acquisition range of the pressure sensor is 0.1~0.2 Mpa, and the acquisition range of the leakage current sensor is 0~5 mA.

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