A device and method for detecting the current-carrying contact performance of a bushing

Abstract

The application discloses a kind of for bushing current-carrying contact performance detection device and method, it is related to electrical equipment monitoring technical field, including: alternating excitation power supply, for generating excitation signal;Flow increaser, for the excitation signal of alternating excitation power supply generation is amplified;Bushing oil end detection device, for the vibration condition of bushing oil end is detected and obtains first detection signal;Bushing air end detection device, for the vibration condition of bushing air end is detected and obtains second detection signal;Measurement and control terminal, for receiving first detection signal and second detection signal, by first detection signal and second detection signal are analyzed and judge the operating state of bushing.The application can detect the tiny fault such as bushing bending, wiring terminal distortion and elastic current-carrying terminal contact failure by frequency multiplication excitation vibration test method, greatly improve the detection precision, guarantee the safe and stable operation of power system.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical equipment monitoring, in particular to a device and method for detecting the current-carrying contact performance of a bushing, which are used to detect the operating status of a bushing and its elastic current-carrying terminal. Background Art

[0002] In the power system, bushing is a key equipment and its operating status directly affects the safety and stability of the system.

[0003] Traditional bushing inspection methods suffer from low accuracy, inability to monitor in real time, and difficulty detecting subtle faults. For example, existing technologies struggle to accurately detect poor contact between the flexible current-carrying terminals inside the bushing at an early stage. Once a fault develops, it can lead to a serious power outage and significant economic losses.

[0004] Therefore, developing an efficient and accurate casing detection technology is of great practical significance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to solve the deficiencies in the prior art and to design a device and method for detecting the current-carrying contact performance of bushings, so as to realize real-time monitoring of the operating status of bushings, timely discover potential fault hazards, avoid further development of faults, and ensure the safe and stable operation of the power system.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] In a first aspect, the present invention provides a device for detecting current-carrying contact performance of a bushing, comprising:

[0008] AC excitation power supply, used to generate excitation signal;

[0009] A current booster, used to amplify the excitation signal generated by the AC excitation power supply;

[0010] The casing oil end detection device is used to detect the vibration of the casing oil end and obtain a first detection signal;

[0011] The casing air end detection device is used to detect the vibration of the casing air end to obtain a second detection signal;

[0012] a measurement and control terminal, configured to receive the first detection signal and the second detection signal, and determine the operating state of the casing by analyzing the first detection signal and the second detection signal;

[0013] The output end of the AC excitation power supply is connected to the current booster, the output end of the current booster is connected to the casing oil end detection device and the casing air end detection device, and the output ends of the casing oil end detection device and the casing air end detection device are connected to the measurement and control terminal.

[0014] As a further technical solution of the present invention, the casing oil end detection device includes:

[0015] The oil-end current-carrying terminal of the bushing is provided at the oil end of the current-carrying conductor of the bushing and is connected to the oil end of the current-carrying conductor of the bushing;

[0016] The bushing oil end elastic current-carrying terminal is provided between the bushing current-carrying conductor oil end and the bushing oil end current-carrying terminal and is connected to the bushing oil end current-carrying terminal for generating mechanical vibration;

[0017] A first vibration sensor is provided on a first flange at the oil end of the current-carrying conductor of the bushing and is used to detect mechanical vibrations generated by the elastic current-carrying terminal at the oil end of the bushing;

[0018] The output end of the first vibration sensor is connected to the measurement and control terminal, and the current-carrying terminal of the casing oil end is connected to the output end of the current booster.

[0019] As a further technical solution of the present invention, the casing air end detection device includes:

[0020] The air-end current-carrying terminal of the bushing is provided at the air-end of the current-carrying conductor of the bushing and is connected to the air-end of the current-carrying conductor of the bushing;

[0021] The bushing air end elastic current-carrying terminal is arranged between the bushing current-carrying conductor air end and the bushing air end current-carrying terminal and is connected to the bushing air end current-carrying terminal for generating mechanical vibration;

[0022] A second vibration sensor is provided on the second flange of the air end of the current-carrying conductor of the bushing and is used to detect the mechanical vibration generated by the elastic current-carrying terminal of the air end of the bushing;

[0023] The output end of the second vibration sensor is connected to the measurement and control terminal, and the current-carrying terminal at the air end of the bushing is connected to the output end of the current booster.

[0024] Furthermore, the current booster is used to amplify the excitation voltage generated by the AC variable frequency power supply by 100 to 10,000 times, with a transformation ratio of 220:5 and a 1h thermal stability current of 3000A. The heat dissipation method of the current booster is liquid immersion or dry type.

[0025] Furthermore, the AC variable frequency power supply is used to generate a variable frequency excitation signal of 50Hz-1000Hz, with a rated output power of 1600VA and a 1h thermal stability current of 3000A. The heat dissipation method of the AC variable frequency power supply is liquid immersion or dry type.

[0026] In a second aspect, the present invention further provides a method for detecting the current-carrying contact performance of a bushing, comprising the following steps:

[0027] The AC excitation power supply generates an excitation signal;

[0028] The current booster amplifies the excitation signal generated by the AC excitation power supply;

[0029] The casing oil end detection device detects the vibration of the casing oil end to obtain a first detection signal;

[0030] The casing air end detection device detects the vibration of the casing air end to obtain a second detection signal;

[0031] The measurement and control terminal receives the first detection signal and the second detection signal, and determines the operating state of the casing by analyzing the first detection signal and the second detection signal.

[0032] As a further technical solution of the present invention, the casing oil end detection device detects the vibration of the casing oil end to obtain a first detection signal; specifically:

[0033] The current booster provides current to the bushing oil end current-carrying terminal provided at the oil end of the bushing current-carrying conductor;

[0034] The bushing oil end elastic current-carrying terminal, which is arranged between the bushing current-carrying conductor oil end and the bushing oil end current-carrying terminal, generates mechanical vibration under the action of the current in the bushing oil end current-carrying terminal;

[0035] A first vibration sensor provided on a first flange at the oil end of the bushing current-carrying conductor detects mechanical vibration generated by the elastic current-carrying terminal at the oil end of the bushing to obtain a first detection signal.

[0036] As a further technical solution of the present invention, the casing air end detection device detects the vibration of the casing air end to obtain a second detection signal; specifically:

[0037] The current booster provides current to the bushing air end current-carrying terminal provided at the air end of the bushing current-carrying conductor;

[0038] The bushing air end elastic current-carrying terminal, which is arranged between the bushing current-carrying conductor air end and the bushing air end current-carrying terminal, generates mechanical vibration under the action of the current in the bushing air end current-carrying terminal;

[0039] A second vibration sensor disposed on a second flange at the air end of the bushing current-carrying conductor detects mechanical vibration generated by the elastic current-carrying terminal at the air end of the bushing to obtain a second detection signal.

[0040] As a further technical solution of the present invention, the measurement and control terminal receives the first detection signal and the second detection signal, and determines the operating state of the casing by analyzing the first detection signal and the second detection signal, specifically including:

[0041] The measurement and control terminal performs fixed frequency sampling on the first detection signal and the second detection signal;

[0042] Connect the coordinate points corresponding to each sampling moment in sequence to draw a closed trajectory curve;

[0043] The closed trajectory curve is analyzed according to the preset judgment rules to diagnose the casing fault.

[0044] Furthermore, the closed trajectory curve is analyzed according to the preset judgment rules to diagnose the casing fault, specifically:

[0045] When the closed trajectory curve is circular or elliptical, it indicates that the casing is normal;

[0046] When the closed trajectory curve is banana-shaped or outward-shaped, it indicates that the bushing is bent or the terminal is twisted;

[0047] When the closed trajectory curve has multiple loops or intersects, it indicates that the elastic current-carrying terminal has a slight poor contact;

[0048] When the closed trajectory curve track diverges and is partially concave, it indicates that the elastic current-carrying terminal has serious poor contact.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] 1. Based on the principle of frequency-doubled excitation vibration testing, the present invention utilizes an AC variable-frequency power supply to generate a frequency-doubled excitation signal, which is amplified by a current booster. The amplified current passes through elastic current-carrying terminals on the oil and air sides of the casing, causing it to be unevenly distributed, thereby exciting mechanical vibration. A vibration sensor is responsible for collecting these mechanical vibration signals and transmitting them to a measurement and control terminal. The measurement and control terminal analyzes and processes the collected vibration signals. Based on a preset judgment principle, the shape of the vibration trajectory under different frequency maps is analyzed to determine whether the casing is bent, the terminal is twisted, and whether the elastic current-carrying terminals have poor contact.

[0051] 2. The first flange and the second flange are provided to fix and seal the casing oil end detection device and the casing air end detection device to ensure their normal operation.

[0052] 3. This invention utilizes a frequency-doubled excitation vibration test method to detect minor faults such as bent bushings, twisted terminals, and poor contact of elastic current-carrying terminals. Compared to traditional detection methods, this method significantly improves detection accuracy. For example, a minor poor contact of an elastic current-carrying terminal, which may be difficult to detect with traditional methods, can be accurately identified with this invention by analyzing the vibration trajectory.

[0053] 4. The present invention enables real-time monitoring of the bushing's operating status, enabling timely detection of potential faults, preventing them from developing further, and ensuring the safe and stable operation of the power system. For example, if poor contact occurs between the elastic current-carrying terminals during bushing operation, the measurement and control terminal can quickly detect this and issue an early warning.

[0054] 5. The entire testing process is relatively simple to operate, requiring no complex procedures or specialized skills. The control of the AC variable frequency power supply, current booster, and other equipment is all completed by the measurement and control terminal, reducing the operator's work difficulty and labor intensity.

[0055] 6. By timely discovering and handling bushing failures, power accidents caused by bushing failures are reduced, maintenance costs and power outage losses are reduced, and significant economic and social benefits are achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a structural diagram of a device for detecting current-carrying contact performance of a bushing proposed by the present invention;

[0057] Figure 2 This is a flow chart of a method for detecting current-carrying contact performance of a bushing proposed by the present invention;

[0058] As shown in the figure:

[0059] 10-AC excitation power supply, 20-current booster, 30-casing oil-end detection device, 40-casing air-end detection device, 50-measurement and control terminal, 60-casing current-carrying conductor, 70-casing capacitor core; 301-casing oil-end current-carrying terminal, 302-casing oil-end elastic current-carrying terminal, 303-first vibration sensor, 304-first flange; 401-casing air-end current-carrying terminal, 402-casing air-end elastic current-carrying terminal, 403-second vibration sensor, 404-second flange. DETAILED DESCRIPTION

[0060] The specific implementation of the present invention is described below with reference to the accompanying drawings and embodiments:

[0061] It should be noted that the structures, colors, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose that can be achieved by the present invention.

[0062] At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0063] like Figure 1 As shown, the present invention provides a device for detecting the current-carrying contact performance of a bushing, comprising:

[0064] AC excitation power supply 10, used to generate an excitation signal;

[0065] The current booster 20 is used to amplify the excitation signal generated by the AC excitation power supply;

[0066] The casing oil end detection device 30 is used to detect the vibration of the casing oil end and obtain a first detection signal;

[0067] The casing air end detection device 40 is used to detect the vibration of the casing air end and obtain a second detection signal;

[0068] The measurement and control terminal 50 is used to receive the first detection signal and the second detection signal, and determine the operating status of the casing by analyzing the first detection signal and the second detection signal;

[0069] The output end of the AC excitation power supply 10 is connected to the current booster 20, the output end of the current booster 20 is connected to the casing oil end detection device 30 and the casing air end detection device 40, and the output ends of the casing oil end detection device 30 and the casing air end detection device 40 are connected to the measurement and control terminal 50.

[0070] The present invention is based on the principle of frequency-doubled excitation vibration testing. It uses an AC variable-frequency power supply to emit a frequency-doubled excitation signal of 100 Hz to 1000 Hz, and a current booster to amplify the excitation current by 100 to 10,000 times. The amplified current passes through the elastic current-carrying terminals on the oil and air sides of the casing, causing it to be unevenly distributed, thereby exciting mechanical vibration. The vibration sensor is responsible for collecting these mechanical vibration signals and transmitting them to the measurement and control terminal. The measurement and control terminal analyzes and processes the collected vibration signals. According to a preset judgment principle, by analyzing the shape of the vibration trajectory under different frequency maps, it is determined whether the casing is bent, whether the terminal is twisted, and whether the elastic current-carrying terminal has poor contact.

[0071] In the embodiment of the present invention, the casing oil end detection device 30 includes:

[0072] The casing oil end current-carrying terminal 301 is provided at the casing current-carrying conductor oil end and connected to the casing current-carrying conductor oil end;

[0073] The bushing oil end elastic current-carrying terminal 302 is provided between the bushing current-carrying conductor oil end and the bushing oil end current-carrying terminal 301 and is connected to the bushing oil end current-carrying terminal 301 for generating mechanical vibration;

[0074] A first vibration sensor 303 is provided on a first flange 304 at the oil end of the bushing current-carrying conductor and is used to detect mechanical vibrations generated by the elastic current-carrying terminal 302 at the oil end of the bushing;

[0075] The output end of the first vibration sensor 303 is connected to the measurement and control terminal 50 , and the casing oil end current-carrying terminal 301 is connected to the output end of the current booster 20 .

[0076] In the embodiment of the present invention, the casing air end detection device 40 includes:

[0077] The bushing air end current-carrying terminal 401 is provided at the bushing current-carrying conductor air end and connected to the bushing current-carrying conductor air end;

[0078] The bushing air end elastic current-carrying terminal 402 is provided between the bushing current-carrying conductor air end and the bushing air end current-carrying terminal 401 and is connected to the bushing air end current-carrying terminal 401 for generating mechanical vibration;

[0079] A second vibration sensor 403 is provided on the second flange 404 of the air end of the bushing current-carrying conductor and is used to detect the mechanical vibration generated by the elastic current-carrying terminal 402 at the air end of the bushing;

[0080] The output end of the second vibration sensor 403 is connected to the measurement and control terminal 50 , and the air-end current-carrying terminal 301 of the bushing is connected to the output end of the current booster 20 .

[0081] In an embodiment of the present invention, a current booster receives current from an AC variable-frequency power supply and amplifies the excitation voltage generated by the AC variable-frequency power supply by 100 to 10,000 times to meet the current intensity required for detection; the transformation ratio is 220:5, the 1-hour thermal stability current is 3000A, and the heat dissipation method of the current booster is liquid immersion or dry type. The current booster outputs the amplified current to the elastic current-carrying terminal of the bushing and communicates with the measurement and control terminal to accept monitoring and control to ensure normal operation.

[0082] The AC variable-frequency power supply generates a 50Hz-1000Hz variable-frequency excitation signal, providing the excitation source for the entire testing process. It has a rated output power of 1600VA and a 1h thermal stability current of 3000A. It features either liquid-immersion or dry-type cooling. Connected to the current booster, it provides input current and receives control signals from the measurement and control terminal, adjusting the output frequency and power. The AC variable-frequency power supply accurately sets the excitation frequency, ensuring the stability and accuracy of the excitation signal, providing a reliable excitation source for subsequent testing.

[0083] In an embodiment of the present invention, a bushing capacitor core 70 is provided on the outside of the bushing current-carrying conductor 60. The bushing capacitor core is a key component of the bushing and plays an important role in current transmission and electric field distribution. The two ends of the bushing current-carrying conductor are the bushing current-carrying conductor oil end and the bushing current-carrying conductor air end, respectively. A first flange is provided on the outside of the bushing current-carrying conductor oil end for fixing and sealing the oil side of the bushing to ensure its normal operation. A bushing oil-side current-carrying terminal is provided on the oil end of the bushing current-carrying conductor, and a bushing oil-side elastic current-carrying terminal is also provided between the bushing oil-side current-carrying terminal and the bushing current-carrying conductor. The bushing oil-side elastic current-carrying terminal receives the amplified excitation current and generates mechanical vibration under the action of the current. Its vibration state reflects the operating status of the bushing oil side. The bushing oil-side current-carrying terminal connects the bushing oil-side elastic current-carrying terminal with other circuit parts to transmit current.

[0084] A second flange is provided on the outside of the air end of the bushing's current-carrying conductor. This flange, similar to the flange on the oil side of the bushing, secures and seals the air side of the bushing. A bushing air-side current-carrying terminal is provided on the air end of the bushing's current-carrying conductor. An elastic air-side current-carrying terminal is also provided between the terminal and the bushing's current-carrying conductor. Similar to the elastic oil-side current-carrying terminal, this terminal receives current and generates vibration to detect the condition of the bushing's air side. The air-side current-carrying terminal connects the air-side terminal to an external circuit, enabling current transmission.

[0085] In this embodiment of the present invention, a first vibration sensor and a second vibration sensor are respectively mounted on the first and second flanges to accurately capture vibration signals and avoid signal distortion. The outputs of the first and second vibration sensors are connected to a measurement and control terminal. The casing oil-side current-carrying terminals and the casing air-side current-carrying terminals are connected to a current booster, which is connected to the output of an AC variable-frequency power supply. The first and second vibration sensors are used to capture mechanical vibration signals generated by the casing oil-side elastic current-carrying terminals and the casing air-side elastic current-carrying terminals. They have a ±1dB frequency band of 10-1000Hz, a measurement range of 0-20mm / s, a ±3dB frequency band of 0.5-10kHz, and a sensitivity of 100mV / g.

[0086] The measurement and control terminal is responsible for controlling and monitoring the entire testing process. It receives and analyzes signals from the vibration sensor and simultaneously sends control commands to the AC variable-frequency power supply and current booster. It features a measurement frequency band of at least 100 MHz, a range of ±20 V, a memory depth of 128 MS, a frequency adjustment accuracy of 1 Hz, and a current adjustment accuracy of 10 A. The terminal ensures stable and accurate signal transmission, preventing signal loss or interference.

[0087] See also Figure 2 The present invention also provides a method for detecting the current-carrying contact performance of a bushing, comprising:

[0088] Step S1, an AC excitation power supply generates an excitation signal;

[0089] Step S2, the current booster amplifies the excitation signal generated by the AC excitation power supply;

[0090] Step S3: The casing oil end detection device detects the vibration of the casing oil end to obtain a first detection signal;

[0091] Step S4: the casing air end detection device detects the vibration of the casing air end to obtain a second detection signal;

[0092] In step S5, the measurement and control terminal receives the first detection signal and the second detection signal, and determines the operating status of the casing by analyzing the first detection signal and the second detection signal.

[0093] In step S3, the casing oil end detection device detects the vibration of the casing oil end to obtain a first detection signal; specifically:

[0094] The current booster provides current to the bushing oil end current-carrying terminal provided at the oil end of the bushing current-carrying conductor;

[0095] The bushing oil end elastic current-carrying terminal, which is arranged between the bushing current-carrying conductor oil end and the bushing oil end current-carrying terminal, generates mechanical vibration under the action of the current in the bushing oil end current-carrying terminal;

[0096] A first vibration sensor provided on a first flange at the oil end of the bushing current-carrying conductor detects mechanical vibration generated by the elastic current-carrying terminal at the oil end of the bushing to obtain a first detection signal.

[0097] In step S4, the casing air end detection device detects the vibration of the casing air end to obtain a second detection signal; specifically:

[0098] The current booster provides current to the bushing air end current-carrying terminal provided at the air end of the bushing current-carrying conductor;

[0099] The bushing air end elastic current-carrying terminal, which is arranged between the bushing current-carrying conductor air end and the bushing air end current-carrying terminal, generates mechanical vibration under the action of the current in the bushing air end current-carrying terminal;

[0100] A second vibration sensor disposed on a second flange at the air end of the bushing current-carrying conductor detects mechanical vibration generated by the elastic current-carrying terminal at the air end of the bushing to obtain a second detection signal.

[0101] In step S5, the measurement and control terminal receives the first detection signal and the second detection signal, and determines the operating state of the casing by analyzing the first detection signal and the second detection signal, specifically including:

[0102] The measurement and control terminal performs fixed frequency sampling on the first detection signal and the second detection signal;

[0103] Connect the coordinate points corresponding to each sampling moment in sequence to draw a closed trajectory curve;

[0104] The closed trajectory curve is analyzed according to the preset judgment rules to diagnose the casing fault.

[0105] Sampling is done at a fixed time interval, t0, at each frequency f. Coordinates are then constructed using the horizontal axis as the x-axis and the vertical axis as the y-axis. Sampling time t0 ensures sufficient vibration information is captured without excessive data processing. Accurate coordinate construction ensures that the subsequently drawn trajectory curve accurately reflects the vibration conditions.

[0106] Draw a closed trajectory curve: Use the coordinate points (x(t), y(t)) corresponding to each moment as coordinate points and connect them in sequence to form a closed trajectory curve. The key is to ensure the accuracy of the coordinate points and the correct connection order so that the trajectory curve can accurately reflect the changing pattern of vibration.

[0107] The closed trajectory curve is analyzed according to the preset judgment rules to diagnose the casing fault, specifically:

[0108] When the closed trajectory curve is circular or elliptical, it indicates that the bushing is normal;

[0109] When the closed trajectory curve is banana-shaped or outwardly splayed, it indicates that the bushing is bent or the wiring terminal is distorted;

[0110] When the closed trajectory curve has multiple loops or intersects, it indicates that the elastic current-carrying terminal is slightly in poor contact;

[0111] When the closed trajectory curve is divergent or locally concave, it indicates that the elastic current-carrying terminal is in serious poor contact.

[0112] The present application can ensure the reliability of the diagnosis result by accurately identifying the trajectory shape and performing fault diagnosis according to the judgment principle.

[0113] The present application can detect small faults such as bushing bending, wiring terminal distortion, and elastic current-carrying terminal poor contact, and greatly improves the detection accuracy compared with traditional detection methods. For example, for the case of slight poor contact of the elastic current-carrying terminal, the traditional method may be difficult to find, but the present application can accurately judge by analyzing the vibration trajectory.

[0114] The present application can realize real-time monitoring of the operating state of the bushing, timely discover potential fault hazards, avoid further development of the fault, and ensure the safe and stable operation of the power system. For example, during the operation of the bushing, once the elastic current-carrying terminal is in poor contact, the measurement and control terminal can quickly detect and issue a warning.

[0115] The entire detection process is relatively simple to operate and does not require complex operation procedures and professional skills. The control of the alternating frequency power supply, the current booster and other devices is completed by the measurement and control terminal, reducing the work difficulty and labor intensity of the operator.

[0116] By timely discovering and handling the bushing fault, the power accidents caused by the bushing fault are reduced, the maintenance cost and power loss are reduced, and the economic and social benefits are significant.

[0117] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description manner of the specification is only for the sake of clarity, and the person skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be combined to form other embodiments that can be understood by the person skilled in the art.

Claims

1. A device for detecting the current-carrying contact performance of a casing, characterized in that: include: An AC excitation power supply, which is used to generate a variable frequency excitation signal of 50 Hz to 1000 Hz; A current booster, used to amplify the excitation signal generated by the AC excitation power supply; The casing oil end detection device is used to detect the vibration of the casing oil end and obtain a first detection signal; The casing air end detection device is used to detect the vibration of the casing air end to obtain a second detection signal; a measurement and control terminal, configured to receive the first detection signal and the second detection signal, and determine the operating state of the casing by analyzing the first detection signal and the second detection signal; The output end of the AC excitation power supply is connected to the current booster, the output end of the current booster is connected to the casing oil end detection device and the casing air end detection device, and the output ends of the casing oil end detection device and the casing air end detection device are connected to the measurement and control terminal; The casing oil end detection device includes: The oil-end current-carrying terminal of the bushing is provided at the oil end of the current-carrying conductor of the bushing and is connected to the oil end of the current-carrying conductor of the bushing; The bushing oil end elastic current-carrying terminal is provided between the bushing current-carrying conductor oil end and the bushing oil end current-carrying terminal and is connected to the bushing oil end current-carrying terminal for generating mechanical vibration; A first vibration sensor is provided on a first flange at the oil end of the current-carrying conductor of the bushing and is used to detect mechanical vibrations generated by the elastic current-carrying terminal at the oil end of the bushing; The output end of the first vibration sensor is connected to the measurement and control terminal, and the current-carrying terminal of the casing oil end is connected to the output end of the current booster; The casing air end detection device comprises: The air end current-carrying terminal of the bushing is provided at the air end of the current-carrying conductor of the bushing and is connected to the air end of the current-carrying conductor of the bushing; The bushing air end elastic current-carrying terminal is provided between the bushing current-carrying conductor air end and the bushing air end current-carrying terminal and is connected to the bushing air end current-carrying terminal for generating mechanical vibration; A second vibration sensor is provided on the second flange of the air end of the current-carrying conductor of the bushing and is used to detect the mechanical vibration generated by the elastic current-carrying terminal of the air end of the bushing; The output end of the second vibration sensor is connected to the measurement and control terminal, and the current-carrying terminal at the air end of the bushing is connected to the output end of the current booster.

2. The device for detecting the current-carrying contact performance of a bushing according to claim 1, characterized in that: The current booster is used to amplify the excitation voltage generated by the AC variable frequency power supply by 100 to 10,000 times, with a transformation ratio of 220:5 and a 1h thermal stability current of 3,000A. The heat dissipation method of the current booster is liquid immersion or dry type.

3. The device for detecting the current-carrying contact performance of a bushing according to claim 1, characterized in that: The rated output power of the AC excitation power supply is 1600VA, and the 1h thermal stability current is 3000A. The heat dissipation method of the AC excitation power supply is liquid immersion or dry type.

4. A method for detecting the current-carrying contact performance of a casing, characterized in that: A device for detecting current-carrying contact performance of a bushing according to any one of claims 1 to 3 is used, comprising the following steps: The AC excitation power supply generates an excitation signal; The current booster amplifies the excitation signal generated by the AC excitation power supply; The casing oil end detection device detects the vibration of the casing oil end to obtain a first detection signal; The casing air end detection device detects the vibration of the casing air end to obtain a second detection signal; The measurement and control terminal receives the first detection signal and the second detection signal, and determines the operating state of the casing by analyzing the first detection signal and the second detection signal.

5. A method for detecting current-carrying contact performance of a bushing according to claim 4, characterized in that: The casing oil end detection device detects the vibration of the casing oil end to obtain a first detection signal; specifically: The current booster provides current to the bushing oil end current-carrying terminal provided at the oil end of the bushing current-carrying conductor; The bushing oil end elastic current-carrying terminal, which is arranged between the bushing current-carrying conductor oil end and the bushing oil end current-carrying terminal, generates mechanical vibration under the action of the current in the bushing oil end current-carrying terminal; A first vibration sensor provided on a first flange at the oil end of the bushing current-carrying conductor detects mechanical vibration generated by the elastic current-carrying terminal at the oil end of the bushing to obtain a first detection signal.

6. A method for detecting current-carrying contact performance of a bushing according to claim 4, characterized in that: The casing air end detection device detects the vibration of the casing air end to obtain a second detection signal; specifically: The current booster provides current to the bushing air end current-carrying terminal provided at the air end of the bushing current-carrying conductor; The bushing air end elastic current-carrying terminal, which is arranged between the bushing current-carrying conductor air end and the bushing air end current-carrying terminal, generates mechanical vibration under the action of the current in the bushing air end current-carrying terminal; A second vibration sensor disposed on a second flange at the air end of the bushing current-carrying conductor detects mechanical vibration generated by the elastic current-carrying terminal at the air end of the bushing to obtain a second detection signal.

7. A method for detecting current-carrying contact performance of a bushing according to claim 4, characterized in that: The measurement and control terminal receives the first detection signal and the second detection signal, and determines the operating state of the casing by analyzing the first detection signal and the second detection signal, specifically including: The measurement and control terminal performs fixed frequency sampling on the first detection signal and the second detection signal; Connect the coordinate points corresponding to each sampling moment in sequence to draw a closed trajectory curve; The closed trajectory curve is analyzed according to the preset judgment rules to diagnose the casing fault.

8. A method for detecting current-carrying contact performance of a bushing according to claim 7, characterized in that: The closed trajectory curve is analyzed according to the preset judgment rules to diagnose the casing fault, specifically: When the closed trajectory curve is circular or elliptical, it indicates that the casing is normal; When the closed trajectory curve is banana-shaped or outward-shaped, it indicates that the bushing is bent or the terminal is twisted; When the closed trajectory curve has multiple loops or intersects, it indicates that the elastic current-carrying terminal has a slight poor contact; When the closed trajectory curve track diverges and is partially concave, it indicates that the elastic current-carrying terminal has serious poor contact.

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