Insulating surface discharge scanning positioning device and method

Abstract

The invention provides a scanning positioning device and method for insulation surface discharge, and belongs to the field of power equipment state monitoring, and the device comprises an optical conductor, a solar blind avalanche diode, a diode socket substrate, a coding type electric rotating base, a multipath control unit, a signal acquisition and processing unit and a central processor. The central processing unit issues an instruction to the multi-path control unit, and synchronously controls the solar blind avalanche diode, the diode socket substrate and the coding type electric rotating base to start; a discharge photon signal is collected and guided to two solar-blind avalanche diodes, solar-blind ultraviolet band components of an optical signal are converted into a light current signal, then the light current signal is converted into an envelope detection voltage signal, the envelope detection voltage signal is sampled to obtain a light pulse time sequence, and meanwhile, the light pulse time sequence is calculated. Receiving a binary code output by the encoding type electric rotating base and converting the binary code into an angle time sequence; and performing real-time processing on the light pulse time sequence and the angle time sequence to obtain a time sequence, and further calculating to obtain a space direction of discharge.

Description

Technical Field

[0001] The present invention belongs to the field of power equipment status monitoring, and more specifically, relates to a scanning positioning device and method for insulation surface discharge. Background Art

[0002] In the power system, the health of line insulators is crucial to ensure the stable operation of the power system. Once partial discharge occurs on the surface of the insulator, it may lead to a decline in insulation performance and even cause failures and accidents of power equipment. Therefore, effective detection and positioning of discharge on the surface of insulators is an important part of line inspection and operation maintenance. At present, external insulation discharge detection mainly relies on day-blind ultraviolet discharge imaging technology. Although it can realize visual detection of discharge to a certain extent, it still has some limitations and shortcomings. Traditional day-blind ultraviolet discharge imaging technology mainly relies on day-blind ultraviolet optical lens modules to capture and binocularly image the discharge ultraviolet photon signals, but this method requires superposition of ultraviolet channels and visible light channels for two-dimensional imaging, and requires the system to be equipped with complex optical lenses, microchannel plates, optoelectronic imaging sensors and other units. Not only is the cost extremely high, but the entire system is large in size and weight, which is not conducive to large-scale application in scenarios such as drones, robots and station-area online monitoring. Summary of the invention

[0003] In order to solve the deficiencies in the prior art, the present invention provides a scanning positioning device and method for insulating surface discharge.

[0004] The present invention adopts the following technical solution.

[0005] A first aspect of the present invention provides a scanning positioning device for insulating surface discharge, the device comprising:

[0006] Photoconductor, solar-blind avalanche diode, diode socket substrate, coded electric rotating base, multi-channel control unit, signal acquisition and processing unit and central processing unit. The multi-channel control unit is respectively connected with the solar-blind avalanche diode, the diode socket substrate and the coded electric rotating base. The signal acquisition processing unit is respectively connected with the diode socket substrate and the coded electric rotating base. The solar-blind avalanche diode is connected with the diode socket substrate. The diode socket substrate is installed on the coded electric rotating base. The multi-channel control unit synchronously controls the start and stop states of the solar-blind avalanche diode, the diode socket substrate and the coded electric rotating base according to the instructions issued by the central processing unit. The photoconductor is used to collect discharge photon signals and guide them to the solar-blind avalanche diode. The solar-blind avalanche diode converts the solar-blind ultraviolet band component of the optical signal into a photocurrent signal and transmits it to the diode socket substrate. The diode socket substrate converts the photocurrent signal into an envelope detection voltage signal and outputs it to the signal acquisition and processing unit. The signal acquisition and processing unit receives the envelope detection voltage signal for peak sampling to obtain a light pulse time series. At the same time, the signal acquisition and processing unit receives the binary code output by the coded electric rotating base and converts it into an angle time series. The signal acquisition and processing unit transmits and caches the light pulse time series and the angle time series to the register in the central processing unit. The central processing unit performs discharge source directional calculation according to the light pulse time series and the angle time series in the register to obtain the spatial direction of the discharge.

[0007] Optionally, the optical conductor is made of fused quartz material or PMMA material, the material's transmittance in the day-blind ultraviolet band is not less than 85%, the effective horizontal light receiving angle is between 5° and 10°, the effective pitch light receiving angle is not less than 90°, the light loss in the direction of the optical transmission path is not higher than 3%, and after the optical guide is connected to the day-blind avalanche diode, the light guide emission surface area does not exceed the effective light receiving surface of the day-blind avalanche diode.

[0008] Optionally, the solar-blind avalanche diode comprises a first solar-blind avalanche diode and a second solar-blind avalanche diode, wherein the spectral response band of the solar-blind avalanche diode covers 250nm to 280nm, the photon efficiency in the spectral response band is not less than 15%, and the internal photoelectric gain is not less than 1×10 5 A / W, effective light receiving area is not less than 4mm 2 .

[0009] Optionally, the diode socket substrate structure is a dual-plane structure, the angle difference between the normal directions of the two planes is not less than 15°, each plane has a socket connected to a day-blind avalanche diode, which is respectively connected to the first day-blind avalanche diode and the second day-blind avalanche diode, and each socket is connected to an I / V conversion amplification detection circuit at the rear end, which is used to convert the current fast pulse signal output by the day-blind avalanche diode into a voltage signal with a reduced frequency. The voltage signal pulse width is 1 to 2 μs, and the peak value maintains a constant proportional relationship with the peak value of the current fast pulse signal.

[0010] Optionally, the encoded electric rotating base includes a connecting base and an encoded rotating motor, the connecting base is used to fix the diode socket substrate, the bottom of the base is fixedly connected to the central axis of the encoded rotating motor, and each rotation angle of the encoded rotating motor is controlled by a multi-channel control unit, and each rotation angle is not greater than 2°.

[0011] Optionally, each time the encodable rotating motor rotates, the static time T at each angle is:

[0012]

[0013] Among them, n is a positive integer not less than 1. When the scanning and positioning device for insulation surface discharge is used in a fixed position online monitoring scenario, n≥50; f is the AC frequency of the power system where the insulator to be detected is located, and f=50Hz is taken. When the power system where the insulator to be detected is located is a DC system, f=1Hz is taken; the current rotation angle is output to the signal acquisition and processing unit in binary coding form, and is synchronized with the signal acquisition storage time of the day-blind avalanche diode.

[0014] Optionally, the signal acquisition and processing unit is used to receive various photovoltage pulse signals output by the diode socket substrate, and detect the pulse peak and the corresponding time of the peak, form a light pulse time sequence and input it into the internal register of the central processing unit; the signal acquisition and processing unit receives the binary code output by the coded electric rotating base, and converts it into a rotation angle, forms an angle time sequence and inputs it into the internal register of the central processing unit.

[0015] Optionally, the functions of the central processor include: issuing instructions to the multi-channel control units, performing real-time processing on the optical pulse time series and angle time series in the register to obtain the time series, calculating the time series according to a predetermined discharge source orientation calculation step to obtain the discharge source spatial direction.

[0016] The second aspect of the present invention provides a scanning and positioning method for insulating surface discharge. Based on the first aspect of the present invention, a scanning and positioning device for surface discharge is provided, comprising the following steps:

[0017] The central processing unit issues instructions to the multi-channel control unit to synchronously control the start of the solar-blind avalanche diode, the diode socket substrate, and the encoded electric rotary base;

[0018] Collect and guide the discharge photon signals within a limited angle to two solar-blind avalanche diodes, convert the solar-blind ultraviolet band component of the optical signal into a photocurrent signal, and then convert the photocurrent signal into an envelope detection voltage signal. Perform peak sampling on it to obtain the optical pulse time series. At the same time, receive the binary code output by the encoded electric rotary base and convert it into an angle time series;

[0019] Transmit and cache the optical pulse time series and the angle time series to the register in the central processing unit, perform real-time processing on the optical pulse time series and the angle time series in the register to obtain the time series, and perform source orientation calculation on the time series to obtain the spatial direction of the discharge.

[0020] Optionally, the source orientation calculation of the time series in the register includes:

[0021] Read the time series (t, θ1, q1) and (t, θ2, q2) obtained and processed from the two solar-blind avalanche diodes in the register, and form a sequence (θ, q1, q2) with the optical pulse peaks q at the same angle θ;

[0022] Calculate the maximum value Q of the mean square value Q of the optical pulse peaks in θ ∈ [0, 2π] max at the corresponding angle θ max , and the calculation formula for the mean square value Q of the optical pulse peaks is:

[0023]

[0024] Calculate the mean value Q of the mean square value Q of the optical pulse peaks in θ ∈ [0, 2π] av ; Calculate the difference ratio dQ between the maximum value θ max and the mean value Q av :

[0025]

[0026] When dQ ≥ a, it can be determined that at the current t moment, obvious discharge occurs, and the spatial horizontal angle θ of the discharge source PD = θ max ; When dQ < a, it can be determined that the current discharge is not obvious and the discharge positioning result is unreliable. The value of a includes 0.35;

[0027] Calculate the maximum value q of q1 and q2 in θ ∈ [0, 2π] 1,max and q 2,max , and solve the following system of equations:

[0028]

[0029] Where, β is the angle difference between the two planes of the diode socket substrate, β1 and β2 are the angles between the local discharge source and the two planes’ normals, respectively;

[0030] Calculate the local discharge source elevation angle φ PD :

[0031]

[0032] Get the spatial orientation result of the power supply at the current time t (t,θ PD ,φ PD ).

[0033] Compared with the prior art, the beneficial effects of the present invention include at least:

[0034] Simple structure: The present invention does not require a complex two-dimensional imaging system, nor does it require expensive photoelectric conversion devices such as microchannel plates. It has a simple structure and is easy to deploy and maintain.

[0035] Lower cost: Since the reliance on complex optical systems and high-cost devices is reduced, the device cost of the present invention is relatively low, which is conducive to large-scale promotion and application.

[0036] Strong adaptability: The present invention can quickly acquire discharge ultraviolet photon signals at different azimuth angles through a scanning non-planar photoelectric array device, and is not limited by the field of view of traditional imaging methods. It can perform station area scanning over a large range and has a small detection blind area. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of the structure of each unit of a scanning non-planar optoelectronic array device provided according to an embodiment of the present invention;

[0038] Figure 2 is a schematic diagram of the structure of a diode socket substrate provided according to an embodiment of the present invention;

[0039] Figure 3 is a schematic diagram of a method for determining a discharge source spatial pitch angle provided in accordance with an embodiment of the present invention;

[0040] Figure 4 It is a schematic diagram of the spatial orientation result of the discharge source provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0041] 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.

[0042] The present invention proposes a scanning positioning device for insulating surface discharge in embodiment 1, namely a scanning non-planar photoelectric array device. The device is composed of a photoconductor, a solar-blind avalanche diode, a diode array substrate, an encoded electric rotating base, a multi-channel control unit, a signal acquisition and processing unit and a central processing unit. The structure is as follows: Figure 1 As shown, the multi-channel control unit is respectively connected to the day-blind avalanche diode, the diode socket substrate and the encoded electric rotating base, the signal acquisition machine processing unit is respectively connected to the diode socket substrate and the encoded electric rotating base, the day-blind avalanche diode is connected to the diode socket substrate, and the diode socket substrate is installed on the encoded electric rotating base.

[0043] Its main working principle is: the discharge photon signal within a limited angle is collected and guided to the solar-blind avalanche diode through the photoconductor; the solar-blind ultraviolet band component of the light signal is converted into a photocurrent signal through the solar-blind avalanche diode; the photocurrent signal is converted into an envelope detection voltage signal through the diode socket substrate and output to the signal acquisition and processing unit; the envelope detection voltage signal is peak sampled by the signal acquisition and processing unit to obtain the light pulse time series and cache it to the register in the central processing unit; the central processing unit calculates the time series in the register and obtains the spatial direction of the discharge according to the angle feedback information of the encoded electric rotating base; the working state of the above-mentioned solar-blind avalanche diode and the encoded electric rotating base is controlled by the central processing unit through a multi-channel control unit. When the device is in working state, the above-mentioned processes are carried out in real time.

[0044] Specifically, the technical elements of each component unit are as follows:

[0045] Optical conductor: The optical conductor is preferably made of fused quartz or PMMA material. The light transmittance of the material in the solar-blind ultraviolet band is not less than 85%. The effective horizontal light receiving angle should be between 5° and 10°, the effective elevation light receiving angle is not less than 90°, the optical loss in the direction of the optical transmission path is not higher than 3%, and after the optical guide is connected to the solar-blind avalanche diode, the light guide emission surface area does not exceed the effective light receiving surface of the solar-blind avalanche diode;

[0046] Solar-blind avalanche diodes 1 and 2: The spectral response band of solar-blind avalanche diodes covers 250nm to 280nm, the photon efficiency within the spectral response band is not less than 15%, and the internal photoelectric gain is not less than 1×10 5 A / W, effective light receiving area is not less than 4mm 2 ;

[0047] Diode socket substrate: The diode socket substrate structure is a double-plane structure, such as Figure 2 As shown, the angle difference (β) between the two planes in the normal direction should not be less than 15°. Each plane has a socket that can be connected to a solar-blind avalanche diode. The rear end of each socket is connected to an I / V conversion amplifier detection circuit, which can convert the current fast pulse signal output by the solar-blind avalanche diode into a voltage signal with a reduced frequency. The pulse width of the voltage signal is 1 to 2μs, and the peak value should maintain a constant proportional relationship with the peak value of the current fast pulse signal.

[0048] Encoded electric rotating base: The encoded electric rotating base consists of a connecting base and a rotating motor. The connecting base is used to fix the diode socket substrate. The bottom of the base is fixedly connected to the central axis of the encoded rotating motor. The motor's rotation angle is controlled by a multi-channel control unit. Each rotation angle is no more than 2°. The static time T at each angle is set according to the following formula:

[0049]

[0050] Wherein, n is a positive integer not less than 1. When the device is used in a fixed-position online monitoring scenario, it is recommended to take n≥50. f is the AC frequency of the power system where the insulator being tested is located, and f=50 Hz is taken. When the power system where the insulator being tested is located is a DC system, f=1 Hz is taken.

[0051] The current rotation angle (0-2π) is output in binary code form and synchronized with the solar-blind avalanche diode signal acquisition and storage time;

[0052] Multi-channel control unit: The multi-channel control unit receives instructions from the central processing unit and synchronously controls the start and stop states of the solar-blind avalanche diode, the diode socket substrate and the coded electric rotating base according to the instructions;

[0053] Signal acquisition and processing unit: The signal acquisition and processing unit receives the photovoltage pulse signals of each channel output by the diode socket substrate, detects the pulse peak value and the corresponding time of the peak value, forms a light pulse time sequence (t, q) and inputs it into the internal register of the central processing unit; the signal acquisition and processing unit receives the binary code output by the coded electric rotating base, converts it into a rotation angle (0~2π), forms an angle time sequence (t, θ) and inputs it into the internal register of the central processing unit;

[0054] Central Processing Unit: The central processing unit is used to issue instructions to the multi-channel control unit on the one hand, and on the other hand, to process the optical pulse time series (t, q) and angle time series (t, θ) in the register in real time to obtain the time series (t, θ, q), calculate the time series (t, θ, q) according to the predetermined discharge source directional calculation steps, and finally obtain the discharge source spatial direction (t, θ PD ,φ PD ).

[0055] The present invention provides a scanning and positioning method for insulating surface discharge in embodiment 2, based on the scanning and positioning device for insulating surface discharge described in embodiment 1, comprising the following steps:

[0056] The central processor issues instructions to the multi-channel control unit to synchronously control the start-up of the solar-blind avalanche diode, the diode socket substrate and the coded electric rotating base;

[0057] The discharge photon signals within a limited angle are collected and guided to two solar-blind avalanche diodes, the solar-blind ultraviolet band components of the optical signal are converted into photocurrent signals, and then the photocurrent signals are converted into envelope detection voltage signals, and the peak values ​​are sampled to obtain the optical pulse time series. At the same time, the binary code output by the coded electric rotating base is received and converted into an angle time series;

[0058] The light pulse time series and angle time series are transmitted and cached to the register in the central processing unit, the light pulse time series and angle time series in the register are processed in real time to obtain the time series, and the discharge source orientation calculation is performed on the time series to obtain the spatial direction of the discharge.

[0059] In a further preferred but non-limiting embodiment, the discharge source directional calculation of the time series specifically includes:

[0060] Step 1: Read the time series (t,θ1,q1) and (t,θ2,q2) obtained by the solar-blind avalanche diodes 1 and 2 in the register, and form the sequence (θ,q1,q2) of the light pulse peaks (q) at the same angle (θ);

[0061] Step 2: Calculate the peak mean square value of the optical pulse The maximum value Q in θ∈[0,2π] max The corresponding angle θ max ;

[0062] Step 3: Calculate the peak mean square value of the optical pulse The mean Q in θ∈[0,2π] av ;

[0063] Step 4: Calculate the maximum value Q max and mean Qav Difference ratio When dQ ≥ a, it can be determined that at the current time t, obvious discharge occurs currently, and the spatial horizontal angle θ of the discharge source PD = θ max ; when dQ < a, it can be determined that the current discharge is not obvious and the discharge positioning result is unreliable; the value of a is preferably 0.35.

[0064] Step 5: Calculate the maximum value q of q1 and q2 in θ ∈ [0, 2π] 1,max and q 2,max , and solve the following system of equations:

[0065]

[0066] In the formula, β is the angle difference between the normal directions of two planes of the diode socket substrate, and β1 and β2 are the included angles between the partial discharge (PD) source and the normal directions of the two planes, as Figure 3 shown.

[0067] Step 6: Calculate the elevation angle φ of the discharge source according to the following formula PD :

[0068]

[0069] Step 7: Obtain the spatial orientation result (t, θ PD , φ PD ) of the discharge source at the current time t.

[0070] The scanning non-planar optoelectronic array device and method provided by the present invention are very suitable for applications in various scenarios such as unmanned aerial vehicles, robots, and substation online monitoring due to their simple structure, low cost, strong adaptability, and real-time monitoring characteristics. Especially in the field of unmanned aerial vehicle inspection, the device of the present invention can be easily carried on an unmanned aerial vehicle to achieve rapid scanning and discharge detection of power lines, greatly improving the efficiency and accuracy of inspection.

[0071] In order to more clearly introduce the outstanding substantive features of the present invention and the significant progress brought to the prior art, the following introduces an application example of implementing the present invention.

[0072] This application example specifically includes:

[0073] In this embodiment, an artificial simulated discharge source is set at the front end of the device, specifically maintaining about 2 m, at a specific horizontal angle position θ = 25°, and elevation angles φ = 15°, 20°, 25°, 30°, and the discharge intensity is continuously changed.

[0074] The optical conductor of the device is made of fused quartz glass. The minimum transmittance of the material in the solar-blind ultraviolet band (250nm~280nm) is 87.3%, the effective horizontal light receiving angle is 7°, the effective elevation light receiving angle is 115°, and the optical loss in the optical transmission path is 1.76%. The solar-blind avalanche diode has a light quantum efficiency of not less than 16.5% in the 250nm~280nm band, and an internal photoelectric gain of 1.3×10 5 A / W, effective light receiving area is not less than 4.65mm 2 ; The angle difference (β) between the two planes in the normal direction of the diode socket substrate structure is 35°. The pulse width of the voltage pulse signal after transimpedance I / V amplification and detection is 1.45μs, and the peak value should be proportional to the peak value of the current fast pulse signal by 32; The encoding electric rotating base's encoding rotating motor rotates at an angle of 1.0° each time, and the static time T at each angle is 60ms; The signal acquisition uses the AD unit in the STM32 microprocessor to detect the pulse peak value and the corresponding time of the peak value through the ramp algorithm, forming a light pulse time series (t, q) and inputting it into the internal register of the central processing unit; The signal acquisition and processing unit receives the binary code output by the encoding electric rotating base and converts it into a rotation angle (0~2π) with an angle accuracy of 1°;

[0075] The central processing unit adopts the STM32 series single-chip microcomputer, which is used to issue instructions to the multi-channel control unit, and to process the light pulse time series (t, q) and angle time series (t, θ) in the register in real time, read the time series (t, θ1, q1) and (t, θ2, q2) obtained by the day-blind avalanche diodes 1 and 2 in the register, and form the sequence (θ, q1, q2) of the light pulse peaks (q) with the same angle (θ).

[0076] Under the above conditions, the artificial discharge light source calculates the peak mean square value of the light pulse The maximum value Q in θ∈[0,2π] max The range is 30dB~60dB. When it is greater than 60dB (i.e. dQ≥0.82), the corresponding angle is θ max The range is (-12°~26°); at the same time, calculate the pitch angle φ PD =0.5×45°-β1, the result obtained according to different discharge sources is φ PD =12.3°~17.5°,φ PD =17.7°~22.6°,φ PD =23.1°~26.2°,φ PD =26.4°~31.9°.

[0077] Finally, the spatial orientation results of the discharge source (θ PD ,φ PD )like Figure 4 shown.

[0078] The present disclosure may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A scanning and positioning device for insulating surface discharge, characterized in that: The device includes: Photoconductor, solar-blind avalanche diode, diode socket substrate, coded electric rotating base, multi-channel control unit, signal acquisition and processing unit and central processing unit. The multi-channel control unit is respectively connected with the solar-blind avalanche diode, the diode socket substrate and the coded electric rotating base. The signal acquisition processing unit is respectively connected with the diode socket substrate and the coded electric rotating base. The solar-blind avalanche diode is connected with the diode socket substrate. The diode socket substrate is installed on the coded electric rotating base. The multi-channel control unit synchronously controls the start and stop states of the solar-blind avalanche diode, the diode socket substrate and the coded electric rotating base according to the instructions issued by the central processing unit. The photoconductor is used to collect discharge photon signals and guide them to the solar-blind avalanche diode. The solar-blind avalanche diode converts the solar-blind ultraviolet band component of the optical signal into a photocurrent signal and transmits it to the diode socket substrate. The diode socket substrate converts the photocurrent signal into an envelope detection voltage signal and outputs it to the signal acquisition and processing unit. The signal acquisition and processing unit receives the envelope detection voltage signal for peak sampling to obtain a light pulse time series. At the same time, the signal acquisition and processing unit receives the binary code output by the coded electric rotating base and converts it into an angle time series. The signal acquisition and processing unit transmits and caches the light pulse time series and the angle time series to the register in the central processing unit. The central processing unit performs discharge source directional calculation according to the light pulse time series and the angle time series in the register to obtain the spatial direction of the discharge.

2. The scanning and positioning device for insulating surface discharge according to claim 1, characterized in that: The optical conductor is made of fused quartz material or PMMA material, the material has a day-blind ultraviolet band transmittance of not less than 85%, an effective horizontal light receiving angle of 5° to 10°, an effective elevation light receiving angle of not less than 90°, and an optical loss in the direction of the optical transmission path of not more than 3%. After the optical guide is connected to the day-blind avalanche diode, the light guide emission surface area does not exceed the effective light receiving surface of the day-blind avalanche diode.

3. The scanning and positioning device for insulating surface discharge according to claim 1, characterized in that: The solar-blind avalanche diode comprises a first solar-blind avalanche diode and a second solar-blind avalanche diode. The spectral response band of the solar-blind avalanche diode covers 250nm to 280nm, the photon efficiency in the spectral response band is not less than 15%, and the internal photoelectric gain is not less than 1×10 5 A / W, effective light receiving area is not less than 4mm 2 .

4. A scanning and positioning device for insulating surface discharge according to claim 1 or 3, characterized in that: The diode socket substrate structure is a double-plane structure, and the angle difference between the normal directions of the two planes is not less than 15°. Each plane has a socket connected to a day-blind avalanche diode, which is respectively connected to the first day-blind avalanche diode and the second day-blind avalanche diode. The rear end of each socket is connected to an I / V conversion amplification detection circuit, which is used to convert the current fast pulse signal output by the day-blind avalanche diode into a voltage signal with a reduced frequency. The voltage signal pulse width is 1 to 2 μs, and the peak value maintains a constant proportional relationship with the peak value of the current fast pulse signal.

5. The scanning and positioning device for insulating surface discharge according to claim 1, characterized in that: The coded electric rotating base includes a connecting base and a coded rotating motor. The connecting base is used to fix the diode socket substrate. The bottom of the base is fixedly connected to the central axis of the coded rotating motor. The rotation angle of the coded rotating motor is controlled by a multi-channel control unit each time, and the rotation angle is no more than 2° each time.

6. The scanning and positioning device for insulating surface discharge according to claim 5, characterized in that: Each time the encodable rotating motor rotates, the static time T at each angle is: Among them, n is a positive integer not less than 1. When the scanning and positioning device for insulation surface discharge is used in a fixed position online monitoring scenario, n≥50; f is the AC frequency of the power system where the insulator to be detected is located, and f=50Hz is taken. When the power system where the insulator to be detected is located is a DC system, f=1Hz is taken; the current rotation angle is output to the signal acquisition and processing unit in binary coding form, and is synchronized with the signal acquisition storage time of the day-blind avalanche diode.

7. The scanning and positioning device for insulating surface discharge according to claim 1, characterized in that: The signal acquisition and processing unit is used to receive the various photovoltage pulse signals output by the diode socket substrate, and detect the pulse peak value and the corresponding time of the peak value, form a light pulse time sequence and input it into the internal register of the central processing unit; the signal acquisition and processing unit receives the binary code output by the coded electric rotating base, and converts it into a rotation angle, forms an angle time sequence and inputs it into the internal register of the central processing unit.

8. The scanning and positioning device for insulating surface discharge according to claim 1 or 7, characterized in that: The functions of the central processor include: issuing instructions to the multi-channel control units, performing real-time processing on the optical pulse time series and angle time series in the register to obtain the time series, and calculating the time series according to the predetermined discharge source orientation calculation steps to obtain the discharge source spatial direction.

9. A scanning and positioning method for insulating surface discharge, based on a scanning and positioning device for surface discharge according to any one of claims 1 to 8, characterized in that: The steps include: The central processor issues instructions to the multi-channel control unit to synchronously control the start-up of the solar-blind avalanche diode, the diode socket substrate and the coded electric rotating base; The discharge photon signals within a limited angle are collected and guided to two solar-blind avalanche diodes, the solar-blind ultraviolet band components of the optical signal are converted into photocurrent signals, and then the photocurrent signals are converted into envelope detection voltage signals, and the peak values ​​are sampled to obtain the optical pulse time series. At the same time, the binary code output by the coded electric rotating base is received and converted into an angle time series; The light pulse time series and angle time series are transmitted and cached to the register in the central processing unit, the light pulse time series and angle time series in the register are processed in real time to obtain the time series, and the discharge source orientation calculation is performed on the time series to obtain the spatial direction of the discharge.

10. The scanning and positioning method for insulating surface discharge according to claim 9, characterized in that: The discharge source directional calculation of the time series in the register includes: Read the time series (t,θ1,q1) and (t,θ2,q2) obtained and processed by the two solar-blind avalanche diodes in the register, and form the sequence (θ,q1,q2) with the peak values ​​q of the light pulses at the same angle θ; Calculate the maximum value Q of the mean square value Q of the optical pulse peak in θ∈[0,2π] max The corresponding angle θ max , the calculation formula of the peak mean square value Q of the optical pulse is: Calculate the mean value Q of the peak mean square value Q of the optical pulse in θ∈[0,2π] av ; Calculate the maximum value Q max and mean Q av The difference ratio dQ is: When dQ ≥ a, it can be determined that at the current time t, obvious discharge occurs currently, and the spatial horizontal angle θ of the discharge source PD = θ max ; when dQ < a, it can be determined that the current discharge is not obvious and the discharge positioning result is unreliable. The value of a includes 0.35; Calculate the maximum value q of q1 and q2 in θ∈[0,2π] 1,max and q 2,max , and solve the following system of equations: Where, β is the angle difference between the two planes of the diode socket substrate, β1 and β2 are the angles between the local discharge source and the two planes’ normals, respectively; Calculate the local discharge source elevation angle φ PD : Get the spatial orientation result of the power supply at the current time t (t,θ PD ,φ PD ).

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