Active detection device and method for discharge defect of line insulator

Abstract

The invention provides a line insulator discharge defect active detection device and method, and belongs to the technical field of power transmission line insulation detection, the device comprises a repetition frequency x-ray pulse light source, a solar blind ultraviolet photosensitive detection unit, a switching value counter, an ultrasonic distance measurement unit, an information calculation unit and an execution control unit; the repetition-frequency x-ray pulse light source is used for generating a repetition-frequency x-ray light pulse, and the ultrasonic distance measurement unit is used for obtaining the distance between the solar-blind ultraviolet photosensitive detection unit and a detected insulator; the solar-blind ultraviolet photosensitive detection unit, the switching value counter and the information calculation unit are sequentially connected, the solar-blind ultraviolet photosensitive detection unit is used for detecting insulation discharge ultraviolet photons generated after x-ray excitation, and the switching value counter is used for counting a high-level pulse sequence output by the solar-blind ultraviolet photosensitive detection unit; and the information calculation unit is used for processing the information output by the switching value counter and giving a state judgment result of the detected insulator.

Description

Technical Field

[0001] The present invention relates to the technical field of transmission line insulation detection, and in particular to a device and method for actively detecting discharge defects of line insulators. Background Art

[0002] Sudden short circuits in power transmission lines are a major threat to the safe operation of power grids, and insulator contamination, aging or defects are an important cause of sudden short circuit failures in lines. Insulators bear the dual functions of mechanical support and electrical insulation in the line. When operating in complex atmospheric environments such as ultraviolet radiation, high humidity, dust, salt spray, rain and snow, it is difficult to avoid various defects such as dirt accumulation, aging, and cracking. Once such insulation defects are formed, they will accelerate the insulation failure process. Generally speaking, when aging or defects reach a certain level, abnormal discharge will occur under the action of voltage, so insulation defects can be found with the help of discharge detection technology. However, the local discharge caused by most defects is not continuous and stable. It is hidden, sporadic and random. Even the discharge phenomenon under the operating voltage is not obvious. In recent years, there have been many insulator flashover accidents without obvious early signs of discharge before the fault. Therefore, it is urgent to explore new methods for sensitive and efficient insulator defect detection.

[0003] Traditional insulator defect detection methods mainly include the following: ultrasonic detection, insulator discharge causes rapid thermal expansion and contraction of local media, thereby causing mechanical waves to propagate in different media, and ultrasonic coupling sensors can be used to obtain insulator discharge ultrasonic signals; infrared thermal imaging, when the discharge energy is strong enough and the duration is long enough, the discharge will cause local heating, and infrared thermal imagers can be used to detect abnormal temperature rise, which indirectly reflects the discharge situation; solar-blind ultraviolet imaging, insulator surface discharge will cause light emission in the ultraviolet band, and photon imaging detection using the solar-blind band can effectively detect discharge signals while avoiding sunlight interference. However, the main problems of the above detection methods are: ① The operating voltage of the insulator is generally much lower than the design field strength, and the critical electric field of the discharge of the insulation defect is high, so it is difficult to stimulate stable discharge under a limited electric field; ② At a limited voltage level, the local discharge of the insulation defect often shows strong sporadicity, and its amplitude is lower than the detection threshold; ③ The existing detection methods are all passive detection, and the defect-induced discharge needs to wait for specific conditions, such as the increase in defect size, high humidity environment, material aging, etc., so the discharge signal is difficult to be captured within a limited detection time. Summary of the invention

[0004] The purpose of the present invention is to provide an active discharge detection technology for the rapid detection of line insulator defects. The system uses the principle of short-wave light source to reduce the discharge electric field threshold, transforms passive discharge detection into active detection, shortens the discharge detection time, and improves the discharge activity within the detection cycle. With the help of drones, it can realize rapid, accurate and active detection of various line insulators, thereby improving the detection and maintenance efficiency of line external insulation.

[0005] The present invention adopts the following technical solution.

[0006] A first aspect of the present invention provides a line insulator discharge defect active detection device, the device comprising:

[0007] Heavy-frequency X-ray pulse light source, solar-blind ultraviolet light-sensitive detection unit, switch quantity counter, ultrasonic distance measurement unit, information calculation unit and execution control unit;

[0008] The execution control unit is respectively connected with the repetitive X-ray pulse light source, the solar-blind ultraviolet light-sensitive detection unit, the switch quantity counter, the ultrasonic distance measuring unit and the information calculation unit, and is used to control the start and stop of the work of each component or the output parameters;

[0009] The repetitive frequency x-ray pulse light source is used to generate x-ray light pulses with a repetitive frequency, and the ultrasonic distance measuring unit is used to obtain the distance between the solar-blind ultraviolet light sensitive detection unit and the insulator under test; the solar-blind ultraviolet light sensitive detection unit, the switch quantity counter and the information calculation unit are connected in sequence, the solar-blind ultraviolet light sensitive detection unit is used to detect the ultraviolet photons of insulation discharge generated after the x-ray excitation, the switch quantity counter is used to count the high-level pulse sequence output by the solar-blind ultraviolet light sensitive detection unit, and the information calculation unit is used to process the information output by the switch quantity counter and give the state judgment result of the insulator under test. 2. A line insulator discharge defect active detection device according to claim 1, characterized in that:

[0010] The irradiation angle of the repetitive X-ray pulse light source is not less than 15°, the central wavelength range is 0.5-10nm, the controllable dose range of a single pulse X-ray is 5-15μSv, the controllable range of the pulse half-peak time is 0.5-5μs, and the light pulse repetition frequency is adjustable within 10-50Hz.

[0011] Optionally, the response wavelength range of the day-blind ultraviolet photosensitivity detection unit is 240-280nm, the light quantum efficiency in the day-blind band is not less than 15%, the light pulse response time is less than 200ns, the effective detection angle θ includes at least -30° to +30°, and the photoelectric gain is not less than 60dB.

[0012] Optionally, the solar-blind ultraviolet light-sensitive detection unit outputs a high-level square wave pulse signal after receiving a photon signal, and its pulse width is less than 200ns.

[0013] Optionally, the execution control unit is used to control the start and stop of the heavy-rate X-ray pulse light source and output parameters, the start and stop of the day-blind ultraviolet photosensitivity detection unit, the start and stop of the switch counter and output parameters, and the start and stop of the information calculation unit.

[0014] A second aspect of the present invention provides a method for actively detecting discharge defects of line insulators, based on the device for actively detecting discharge defects of line insulators described in the first aspect of the present invention, comprising the following steps:

[0015] The solar-blind ultraviolet light-sensitive detection unit is turned on by the execution control unit, and the background light pulse when no x-rays are applied is measured to obtain the average discharge frequency within T time, which is recorded as n0;

[0016] Setting a controllable dose R of a single pulse x-ray of a repetition rate x-ray pulse light source by executing a control unit;

[0017] The execution control unit starts the heavy-frequency X-ray pulse light source to irradiate the target area of ​​the line insulator under test;

[0018] The solar-blind ultraviolet light-sensitive detection unit is started immediately after the pulse output of the repetition rate X-ray pulse light source ends by executing the control unit, and the detection frequency is kept consistent with the repetition frequency of the X-ray pulse;

[0019] The switch counter is started by executing the control unit and kept consistent with the working time of the repetitive X-ray pulse light source, and the discharge light pulse frequency in the X-ray pulse interval time Δt is obtained, which is recorded as n;

[0020] The ultrasonic distance measurement unit is started by executing the control unit and kept consistent with the working time of the repetitive X-ray pulse light source to obtain the ultrasonic distance measurement value L in the X-ray pulse interval time Δt;

[0021] The information calculation unit is started by executing the control unit and kept consistent with the working time of the heavy-rate X-ray pulse light source, and the discharge photon excitation intensity S at time t is calculated. The information calculation unit gives a graded evaluation result based on the calculation result of the discharge photon excitation intensity S to obtain the discharge state of the insulator of the tested line.

[0022] Optionally, in the method, a high-frequency X-ray pulse light source is started by executing a control unit to irradiate a target area of ​​the line insulator, and the accumulated X-ray dose is not higher than 10 mSv.

[0023] Optionally, the calculation of the discharge photon excitation intensity S at time t includes the following formula:

[0024]

[0025] Where n(t) is the frequency of X-ray discharge light pulses at time t, n0 is the average discharge frequency of background light pulses within T time when no X-rays are applied, L(t) is the ultrasonic ranging value at time t, R is the controllable dose of a single pulse X-ray of the repetitive X-ray pulse light source, and θ is the effective detection angle of the solar-blind ultraviolet light-sensitive detection unit.

[0026] Optionally, the graded evaluation results given by the information calculation unit include normal, concern, tracking, early warning and alarm.

[0027] Optionally, the information calculation unit provides a graded evaluation result according to the calculation result of the discharge photon excitation intensity S, including:

[0028] Set the effective test value m, input S(t i ), if S(t i )≤0, the output is normal;

[0029] If S(t i )>0, then check whether the data is valid. If |S(t i )-S(t i-1 )|≤m, it is considered valid and enters the next evaluation process. Otherwise, the next data is input and the above process is repeated;

[0030] For S(t i )>0, and S(t i )-S(t i-1 )|≤m, if S(t i )≤a1, then output attention; if a1 <S(t i )≤a2, then output tracking; if a2 <S(t i )≤a3, then output warning; if a3 <S(t i ) then output alarm;

[0031] Among them, a1, a2 and a3 are state thresholds.

[0032] Compared with the prior art, the beneficial effects of the present invention include at least:

[0033] Compared with the existing ultrasonic detection, infrared imaging and ultraviolet imaging detection technologies, the active detection device and method for discharge defects of line insulators proposed in the present invention have the following significant advantages:

[0034] 1) Using drones equipped with this system can quickly cover a large area of ​​power lines, significantly improve detection efficiency, and achieve tower-by-tower detection;

[0035] 2) Using X-ray pulse light source for active irradiation, the traditional passive discharge detection is transformed into active discharge detection, which can effectively stimulate defects to produce stable discharge in a short time, shorten the detection waiting time, and improve the detection efficiency;

[0036] 3) The discharge electric field threshold is lowered by ultraviolet light source, which is not limited by atmospheric environment and operating voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the hardware composition of a solar-blind ultraviolet photon detection device based on an x-ray source;

[0038] Figure 2 It is the start-up sequence when the solar-blind ultraviolet photon detection device based on the x-ray source is working;

[0039] Figure 3 It is a hierarchical evaluation logic based on the discharge photon excitation intensity S;

[0040] Figure 4 It is the actual object and application site of the solar-blind ultraviolet photon detection device based on the X-ray source;

[0041] Figure 5 The logic of graded evaluation according to the discharge photon excitation intensity S. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The described embodiments are only embodiments of a part of the present invention, not all embodiments. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0043] Theoretically, the necessary condition for insulation defects to produce discharge is that the external applied field strength is higher than the critical field strength of defect discharge. Therefore, micro defects are not necessarily accompanied by discharge phenomena. As the operating years increase, potential defects may rapidly develop into sudden insulation failures. Under the irradiation of short-wave external sources such as x-rays, insulation defects can produce stable discharges under lower electric fields, thereby reducing the local discharge field threshold, which is conducive to the rapid and effective detection of defects. Therefore, the present invention proposes an insulator discharge defect detection technology excited by active light sources. The system can be suitable for carrying by drones to actively, quickly and accurately detect line insulator defects.

[0044] The present invention provides a line insulator discharge defect active detection device in embodiment 1, such as Figure 1As shown, the main hardware structure of the device is a solar-blind ultraviolet photon detection device based on an x-ray source, including: a repetitive x-ray pulse light source, a solar-blind ultraviolet photosensitive detection unit, a switch quantity counter, an ultrasonic ranging unit, an information calculation unit and an execution control unit, wherein:

[0045] The execution control unit is respectively connected to the repetitive frequency x-ray pulse light source, the day-blind ultraviolet light sensitive detection unit, the switch quantity counter, the ultrasonic distance measuring unit and the information calculation unit; the day-blind ultraviolet light sensitive detection unit, the switch quantity counter and the information calculation unit are connected in sequence; the execution control unit controls the repetitive frequency x-ray pulse light source to irradiate the insulator to be detected, and within the interval period after the repetitive frequency pulse light source irradiates, the day-blind light sensitive sensor detects the discharge photon signal and transmits it to the switch quantity counter, and the information calculation unit evaluates the strength of the discharge signal through the distance information obtained by the ultrasonic distance measuring unit and the photon counting result obtained by the switch quantity counter. Preferably, the device is a functional load for unmanned aerial vehicle power line patrol, and is used for defect detection and abnormal discharge online detection of various types of line insulators. In a further preferred but non-limiting embodiment, the repetitive frequency x-ray pulse light source is used to generate repetitive frequency x-ray light pulses;

[0046] Specifically, the irradiation angle is not less than 15°, the central wavelength should be within the soft x-ray range (0.5-10nm), the controllable dose range of a single pulse x-ray is 5-15μSv, the controllable range of the pulse half-peak time is 0.5-5μs, and the optical pulse repetition frequency is adjustable within 10-50Hz. The peak optical power output and the optical pulse half-peak time of the above-mentioned pulse light source are both adjusted by the integrated control unit;

[0047] In a further preferred but non-limiting embodiment, the solar-blind ultraviolet photosensitive detection unit is used to detect the insulating discharge ultraviolet photons generated after the excitation of x-rays; its response wavelength range is the ultraviolet solar-blind band (240-280nm), the light quantum efficiency in the solar-blind band is not less than 15%, the light pulse response time is less than 200ns, the effective detection angle θ at least includes from -30° to +30°, and the detection angle is symmetrical with the horizontal line as the symmetry axis, the photoelectric gain is not less than 60dB, and after receiving the photon signal, a high-level square wave pulse signal can be output, and the pulse width is less than 200ns;

[0048] In a further preferred but non-limiting embodiment, the switch counter is used to count the high-level pulse sequence output by the solar-blind ultraviolet light-sensitive detection unit, and output the number of light pulses in the x-ray pulse interval time Δt, recorded as n;

[0049] In a further preferred but non-limiting embodiment, the ultrasonic ranging unit is used to obtain the distance between the solar-blind ultraviolet light-sensitive detection unit and the detection object, and outputs the ultrasonic ranging value L in the x-ray pulse interval time Δt, recorded as L.

[0050] In a further preferred but non-limiting embodiment, the information calculation unit is used to process the output information of the switch quantity counter, calculate the discharge photon excitation intensity according to the calculation steps, and give a state determination result;

[0051] Specifically, the status determination results include normal, attention, tracking, warning and alarm.

[0052] In a further preferred but non-limiting embodiment, the execution control unit is used to control the start and stop of the operation and output parameters of the repetitive X-ray pulse light source, the start and stop of the operation of the day-blind ultraviolet light sensitive detection unit, the start and stop of the operation and output parameters of the switch counter, and the start and stop of the operation of the information calculation unit;

[0053] Preferably, the execution of the command of the execution control unit can be controlled and issued by the host computer.

[0054] The present invention provides a method for actively detecting discharge defects of line insulators in embodiment 2, based on an active detection device for discharge defects of line insulators described in embodiment 1 of the present invention, comprising the following steps:

[0055] The solar-blind ultraviolet light-sensitive detection unit is turned on by the execution control unit, and the background light pulse is measured when no x-rays are applied, and the average discharge frequency within T time is obtained, which is recorded as n0 (unit: s -1 ), preferably, T is rounded as follows:

[0056]

[0057] Where k is an integer greater than zero, and f is the power frequency AC cycle;

[0058] The controllable dose R (unit: μSv) of a single pulse x-ray of the repetition rate x-ray pulse light source is set by the execution control unit;

[0059] The control unit is used to start the heavy-frequency X-ray pulse light source to irradiate the target area of ​​the line insulator, and the cumulative X-ray dose is not higher than 10mSv;

[0060] The solar-blind ultraviolet light-sensitive detection unit is started immediately after the pulse output of the repetition rate X-ray pulse light source ends by executing the control unit, and the detection frequency is kept consistent with the repetition frequency of the X-ray pulse;

[0061] The switch counter is started by executing the control unit and kept consistent with the working time of the repetitive X-ray pulse light source to obtain the discharge light pulse frequency in the X-ray pulse interval time Δt, recorded as n (unit: s -1 );

[0062] The ultrasonic ranging unit is started by executing the control unit and kept consistent with the working time of the repetitive X-ray pulse light source, and the ultrasonic ranging value L in the X-ray pulse interval time Δt is obtained, which is recorded as L (unit: m);

[0063] The startup sequence of the solar-blind ultraviolet photon detection device based on an x-ray source is as follows: Figure 2 shown.

[0064] The information calculation unit is started by executing the control unit and kept consistent with the working time of the repetitive X-ray pulse light source, and the discharge photon excitation intensity S (unit: μSv·s) at time t is calculated according to the following formula: -1 m) to calculate:

[0065]

[0066] Where n(t) is the frequency of X-ray discharge light pulses at time t, n0 is the average discharge frequency of background light pulses within T time when no X-rays are applied, L(t) is the ultrasonic ranging value at time t, R is the controllable dose of a single pulse X-ray of the repetitive X-ray pulse light source, and θ is the effective detection angle of the solar-blind ultraviolet light-sensitive detection unit.

[0067] like Figure 3 As shown, the information calculation unit gives a graded evaluation result according to the calculation result of the discharge photon excitation intensity S according to the following judgment logic:

[0068] Set the effective test value m, input S(t i ), if S(t i )≤0, the output is normal;

[0069] If S(t i )>0, then check whether the data is valid. If |S(t i )-S(t i-1 )|≤m, it is considered valid and enters the next evaluation process. Otherwise, the next data is input and the above process is repeated;

[0070] For S(t i )>0, and S(t i )-S(t i-1 )|≤m, if S(t i )≤a1, then output attention; if a1 <S(t i )≤a2, then output tracking; if a2 <S(t i)≤a3, then output warning; if a3 <S(t i ) then output alarm;

[0071] Wherein, m is a valid check value, preferably, m=100; a1~a3 are state thresholds, whose specific values ​​can be comprehensively given by the insulator type and voltage level, preferably, a1=250, a2=580, a3=1000, unit: μSv·s -1 ·m

[0072] The following is a detailed description of the method embodiments of the present invention so that those skilled in the art can understand the essence and scope of the present invention.

[0073] Applying the hardware structure and working principle of the solar-blind ultraviolet photon detection device based on an x-ray source proposed in the present invention, the following Figure 4 The physical device in a was mounted on a DJI drone gimbal (model: M300 RTK), realizing drone mounting (such as Figure 4 b) and applied it to the defect detection of insulators in 10kV distribution lines (e.g. Figure 4 c), and finally judged that the defect state of the insulator in the video is a warning state (such as Figure 4 d).

[0074] The following further describes how to apply the principle process of the present invention to achieve the above effects:

[0075] The solar-blind ultraviolet light-sensitive detection unit is turned on by the execution control unit, and the background light pulse is measured when no x-rays are applied, and the average discharge frequency n0 within the time T (T = 100 ms) is obtained to be 210 / s;

[0076] The controllable dose of a single pulse X-ray of the repetitive X-ray pulse light source is set by executing the control unit to be R=8μSv, and the pulse width is 2μs;

[0077] The control unit is used to start the repetition rate X-ray pulse light source to irradiate the target area of ​​the line insulator, with a repetition rate of 30 Hz and a cumulative X-ray dose of 3.6 mSv (i.e., a total pulse application duration of 15 s);

[0078] The solar-blind ultraviolet light-sensitive detection unit is started immediately after the pulse output of the repetition rate X-ray pulse light source ends by executing the control unit, and the detection frequency is kept consistent with the repetition frequency of the X-ray pulse;

[0079] By executing the control unit to start the switch counter and keep it consistent with the working time of the repetitive X-ray pulse light source, the discharge light pulse frequency n in the X-ray pulse interval time Δt = 33.331ms is obtained to be 420-480s -1 ;

[0080] The ultrasonic ranging unit is started by the execution control unit, and is kept consistent with the working time of the repetitive frequency X-ray pulse light source, and the ultrasonic ranging value L = 3.1 - 3.3 m in the X-ray pulse interval time Δt is obtained;

[0081] The information calculation unit is started by the execution control unit, and is kept consistent with the working time of the repetitive frequency X-ray pulse light source, and the excitation intensity S of the discharge photons at time t (unit: μSv·s -1 ·m) is calculated according to the following formula:

[0082]

[0083] Based on the calculation result of the excitation intensity S of the discharge photons, a2 < S ≤ a3, according to the judgment logic (such as Figure 5 ), its discharge state is determined as: early warning.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the specific implementation manners of the present invention can still be modified or equivalently replaced, and any modification or equivalent replacement without departing from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A line insulator discharge defect active detection device, characterized in that: The device includes: Heavy-frequency X-ray pulse light source, solar-blind ultraviolet light-sensitive detection unit, switch quantity counter, ultrasonic distance measurement unit, information calculation unit and execution control unit; The execution control unit is respectively connected with the repetitive X-ray pulse light source, the solar-blind ultraviolet light-sensitive detection unit, the switch quantity counter, the ultrasonic distance measuring unit and the information calculation unit, and is used to control the start and stop of the work of each component or the output parameters; The repetitive frequency X-ray pulse light source is used to generate X-ray light pulses with a repetitive frequency, and the ultrasonic ranging unit is used to obtain the distance between the solar-blind ultraviolet photosensitivity detection unit and the insulator under test; the solar-blind ultraviolet photosensitivity detection unit, the switch quantity counter and the information calculation unit are connected in sequence, the solar-blind ultraviolet photosensitivity detection unit is used to detect the ultraviolet photons of insulating discharge generated after the X-ray excitation, the switch quantity counter is used to count the high-level pulse sequence output by the solar-blind ultraviolet photosensitivity detection unit, and the information calculation unit is used to process the information output by the switch quantity counter and give the state judgment result of the insulator under test.

2. The active detection device for discharge defects of line insulators according to claim 1, characterized in that: The irradiation angle of the repetitive X-ray pulse light source is not less than 15°, the central wavelength range is 0.5-10nm, the controllable dose range of a single pulse X-ray is 5-15μSv, the controllable range of the pulse half-peak time is 0.5-5μs, and the light pulse repetition frequency is adjustable within 10-50Hz.

3. The active detection device for discharge defects of line insulators according to claim 1, characterized in that: The response wavelength range of the solar-blind ultraviolet light-sensitive detection unit is 240-280 nm, the light quantum efficiency in the solar-blind band is not less than 15%, the light pulse response time is less than 200 ns, the effective detection angle θ includes at least -30° to +30°, and the photoelectric gain is not less than 60 dB.

4. The active detection device for discharge defects of line insulators according to claim 1, characterized in that: The solar-blind ultraviolet light-sensitive detection unit outputs a high-level square wave pulse signal after receiving the photon signal, and the pulse width thereof is less than 200ns.

5. The active detection device for discharge defects of line insulators according to claim 1, characterized in that: The execution control unit is used to control the start and stop of the operation and output parameters of the repetitive X-ray pulse light source, the start and stop of the operation of the day-blind ultraviolet light sensitive detection unit, the start and stop of the operation and output parameters of the switch counter, and the start and stop of the operation of the information calculation unit.

6. A method for actively detecting discharge defects of line insulators, based on a device for actively detecting discharge defects of line insulators according to any one of claims 1 to 5, characterized in that: The steps include: The solar-blind ultraviolet light-sensitive detection unit is turned on by the execution control unit, and the background light pulse when no x-rays are applied is measured to obtain the average discharge frequency within T time, which is recorded as n0; Setting a controllable dose R of a single pulse x-ray of a repetition rate x-ray pulse light source by executing a control unit; The execution control unit starts the heavy-frequency X-ray pulse light source to irradiate the target area of ​​the line insulator under test; The solar-blind ultraviolet light-sensitive detection unit is started immediately after the pulse output of the repetition rate X-ray pulse light source ends by executing the control unit, and the detection frequency is kept consistent with the repetition frequency of the X-ray pulse; The switch counter is started by executing the control unit and kept consistent with the working time of the repetitive X-ray pulse light source, and the discharge light pulse frequency in the X-ray pulse interval time Δt is obtained, which is recorded as n; The ultrasonic distance measurement unit is started by executing the control unit and kept consistent with the working time of the repetitive X-ray pulse light source to obtain the ultrasonic distance measurement value L in the X-ray pulse interval time Δt; The information calculation unit is started by executing the control unit and kept consistent with the working time of the heavy-rate X-ray pulse light source, and the discharge photon excitation intensity S at time t is calculated. The information calculation unit gives a graded evaluation result based on the calculation result of the discharge photon excitation intensity S to obtain the discharge state of the insulator of the tested line.

7. The method for actively detecting discharge defects of line insulators according to claim 6, characterized in that: In the method, a control unit is executed to start a high-frequency X-ray pulse light source to irradiate a target area of ​​a line insulator, and the accumulated X-ray dose is no higher than 10 mSv.

8. The method for actively detecting discharge defects of line insulators according to claim 6, characterized in that: The calculation of the discharge photon excitation intensity S at time t includes the following formula: Where n(t) is the frequency of X-ray discharge light pulses at time t, n0 is the average discharge frequency of background light pulses within T time when no X-rays are applied, L(t) is the ultrasonic ranging value at time t, R is the controllable dose of a single pulse X-ray of the repetitive X-ray pulse light source, and θ is the effective detection angle of the solar-blind ultraviolet light-sensitive detection unit.

9. The method for actively detecting discharge defects of line insulators according to claim 6, characterized in that: The graded evaluation results given by the information calculation unit include normal, concern, tracking, early warning and alarm.

10. A method for actively detecting discharge defects of line insulators according to claim 8 or 9, characterized in that: The information calculation unit provides a graded evaluation result according to the calculation result of the discharge photon excitation intensity S, including: Set the effective test value m, input S(t i ), if S(t i )≤0, the output is normal; If S(t i )>0, then check whether the data is valid. If |S(t i )-S(t i-1 )|≤m, it is considered valid and enters the next evaluation process. Otherwise, the next data is input and the above process is repeated; For S(t i )>0, and S(t i )-S(t i-1 )|≤m, if S(t i )≤a1, then output attention; if a1 <S(t i )≤a2, then output tracking; if a2 <S(t i )≤a3, then output warning; if a3 <S(t i ) then output alarm; Among them, a1, a2 and a3 are state thresholds.

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