A partial discharge diagnostic method, device, and medium for a dc transformer

Abstract

The embodiment of the application provides a partial discharge diagnosis method, equipment and medium of a direct-current transformer, the method comprises the following steps: in the case that a first partial discharge sensor detects a direct-current partial discharge signal, detecting a direct-current partial discharge position according to the first partial discharge sensor and a second partial discharge sensor on a mobile detection model; acquiring gas detection data of the direct-current partial discharge position; and determining a defect type of the direct-current partial discharge position according to the gas detection data and the direct-current partial discharge signal. The positioning of the direct-current partial discharge position is cooperatively completed by the partial discharge sensors arranged on the direct-current transformer and the partial discharge sensors on the mobile robot, which can adapt to various discharge conditions and reduce the installation cost and the detection cost; the defect type of the direct-current partial discharge position can be quickly diagnosed through the gas detection data of the direct-current partial discharge position and the direct-current partial discharge signal, and the defect diagnosis efficiency of the direct-current transformer is high and the detection cost is low.

Description

Technical Field

[0001] This invention relates to, but is not limited to, the field of power detection technology, and particularly to methods, equipment, and media for diagnosing partial discharge in DC transformers. Background Technology

[0002] A DC transformer is a power electronic device used for DC voltage conversion. It achieves the conversion of different DC voltage levels through high-frequency chopping, transformer isolation, and high-frequency rectification. Partial discharge is an electrical phenomenon in DC transformers. It not only indicates the insulation condition of the DC transformer but is also often a precursor to insulation failure. Therefore, timely detection and diagnosis of fault types in the early stages of DC transformer faults are of significant importance for ensuring the safe and reliable operation of DC transformers.

[0003] However, existing technologies are designed for detecting partial discharge in AC transformers, which is insufficient to meet the diagnostic needs of partial discharge in DC transformers. Summary of the Invention

[0004] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0005] The main objective of this invention is to propose a method, device, and medium for diagnosing partial discharge in DC transformers, which can accurately diagnose partial discharge in DC transformers.

[0006] In a first aspect, embodiments of the present invention provide a partial discharge diagnosis method for a DC transformer, applied to a power grid management system. The power grid management system includes a digital twin model of the DC transformer and a mobile detection model corresponding to a mobile robot. Both the DC transformer and the mobile robot are equipped with multiple different types of partial discharge sensors. The method includes:

[0007] When the first partial discharge sensor on the digital twin model detects a DC partial discharge signal, the DC partial discharge position is detected based on the first partial discharge sensor and the second partial discharge sensor on the motion detection model, where both the first partial discharge sensor and the second partial discharge sensor characterize the partial discharge sensor.

[0008] Acquire gas detection data at the DC partial discharge location, wherein the gas detection data indicates the gas type and the content of each gas;

[0009] The defect type at the location of the DC partial discharge is determined based on the gas detection data and the pulse current information, ultra-high frequency spectrum information, and ultrasonic information indicated by the DC partial discharge signal.

[0010] In some optional embodiments, detecting the DC partial discharge location based on the first partial discharge sensor and the second partial discharge sensor on the moving detection model includes:

[0011] In the case where at least two of the first partial discharge sensors receive the DC partial discharge signal at the same first reception time on the digital twin model, a first plane is constructed on the first vertical line of any two first partial discharge sensors with the same first reception time, and the first plane is located in a first direction.

[0012] In the absence of two first partial discharge sensors having equal first reception times on the digital twin model, the first plane is constructed between the second partial discharge sensor and the first partial discharge sensor;

[0013] A second plane is constructed in a second direction by means of the second partial discharge sensor and / or the first partial discharge sensor located in relative positions, and a third plane is constructed in a third direction, wherein the first direction, the second direction and the third direction are perpendicular to each other;

[0014] The location of the DC partial discharge is determined based on the first plane, the second plane, and the third plane.

[0015] In some alternative embodiments, constructing the first plane between the second partial discharge sensor and the first partial discharge sensor includes:

[0016] Configure any one of the first partial discharge sensors as the first target sensor, and obtain the first target position of the first target sensor on the DC transformer;

[0017] The mobile robot is controlled to move along the first direction passing the first target position using the motion detection model, and the real-time position of the mobile robot is obtained.

[0018] Obtain the second reception time of the second partial discharge sensor receiving the DC partial discharge signal at the real-time location;

[0019] When the second receiving time is equal to the first receiving time of the first target sensor, the real-time position is configured as the second target position;

[0020] The first plane is constructed on the second perpendicular line between the first target position and the second target position.

[0021] In some alternative embodiments, the second plane is constructed in a second direction by means of the second partial discharge sensor and / or the first partial discharge sensor located in relative positions:

[0022] If two first partial discharge sensors on the first or second vertical line receive the DC partial discharge signal at the same time, the two first partial discharge sensors with the same receiving time are configured as the second target sensors.

[0023] The second plane is constructed on the third perpendicular line between the two second target sensors;

[0024] If there are no two first partial discharge sensors on the first or second vertical line that receive the DC partial discharge signal at the same time, and there is at least one first partial discharge sensor, then any one of the first partial discharge sensors located on the first or second vertical line shall be configured as the third target sensor.

[0025] The mobile robot is moved along the first or second vertical line, and the position corresponding to the moment when the reception time of the second partial discharge sensor on the mobile robot is equal to the reception time of the third target sensor is configured as the third target position, wherein the third target sensor is not located at the third target position.

[0026] The second plane is constructed on the fourth perpendicular line between the third target location and the third target sensor;

[0027] If the first partial discharge sensor is not present on the first or second vertical line, the mobile robot is moved on the first or second vertical line, and two relative positions with equal reception times of the second partial discharge sensor are configured as the fourth target position.

[0028] The second plane is constructed on the fifth perpendicular line between the two fourth target locations.

[0029] In some alternative embodiments, constructing the third plane upwards includes:

[0030] If two first partial discharge sensors on the third, fourth, or fifth vertical line receive the DC partial discharge signal at the same time, the two first partial discharge sensors with the same receiving time are configured as the fourth target sensor.

[0031] The third plane is constructed on the sixth perpendicular line between the two fourth target sensors;

[0032] If there are no two first partial discharge sensors receiving the DC partial discharge signal at the same time on the third, fourth, or fifth vertical line, and there is at least one first partial discharge sensor, then any one of the first partial discharge sensors located on the third, fourth, or fifth vertical line shall be configured as the fifth target sensor.

[0033] The mobile robot is moved along the third, fourth, or fifth vertical line, and the position corresponding to the moment when the reception time of the second partial discharge sensor on the mobile robot is equal to the reception time of the fifth target sensor is configured as the fifth target position, wherein the fifth target sensor is not located at the fifth target position.

[0034] The third plane is constructed on the seventh perpendicular line between the fifth target location and the fifth target sensor;

[0035] If the first partial discharge sensor is not present on the third, fourth, or fifth vertical line, the mobile robot is moved along the third, fourth, or fifth vertical line to configure two relative positions with equal reception times of the second partial discharge sensor as the sixth target position.

[0036] The third plane is constructed on the eighth perpendicular line between the two sixth target locations.

[0037] In some optional embodiments, determining the DC partial discharge location based on the first plane, the second plane, and the third plane includes:

[0038] Configure the intersecting line between the first plane and the second plane as the target line;

[0039] The intersection of the target line and the third plane is designated as the target point;

[0040] Configure the spatial location of the target point as the DC partial discharge location.

[0041] In some optional embodiments, determining the defect type of the DC partial discharge location based on the gas detection data and the pulse current information, ultra-high frequency spectrum information, and ultrasonic information indicated by the DC partial discharge signal includes:

[0042] When the apparent discharge quantity represented by the pulse current information is less than the first discharge quantity threshold, the variance of the pulse amplitude is less than the first variance threshold, and the pulse repetition rate is greater than the first repetition rate threshold; when the ultra-high frequency spectrum information represents the spectrum being within the first frequency range, the spectral pulse width being less than the first pulse width threshold, and the spectral pulse amplitude being less than the first pulse amplitude threshold; and when the ultrasonic information represents the sound wave amplitude being less than the first sound wave threshold, the sound wave frequency being within the first sound wave frequency range, and the signal duration being less than the first signal time, the discharge type of the DC partial discharge location is configured as corona discharge.

[0043] In the case where the discharge type is corona discharge:

[0044] If the gas detection data indicates that the hydrogen content is between 200 and 500 μL / L, the ratio of methane to organic gas content is between 60% and 80%, the ratio of hydrogen to hydrogen plus organic gas content is between 40% and 60%, and the ratio of ethane to organic gas content is between 10% and 20%, then the defect type of the DC partial discharge location is configured as winding end oil gap electric field distortion.

[0045] If the gas detection data indicates that the hydrogen content is between 100 and 300 μL / L, the ratio of methane to organic gas content is between 50% and 60%, the ratio of hydrogen to hydrogen plus organic gas content is between 50% and 70%, and the ratio of ethane to organic gas content is less than 10%, then the defect type of the DC partial discharge location is configured as poor grounding of the bushing end screen.

[0046] If the gas detection data indicates that the hydrogen content is between 150 and 400 μL / L, the ratio of methane to organic gas content is between 70% and 90%, the ratio of hydrogen to hydrogen plus organic gas content is between 30% and 50%, and the organic gas content is between 100 and 200 μL / L, then the defect type of the DC partial discharge location is configured as having metal burrs on the lead surface.

[0047] In some optional embodiments, the method further includes:

[0048] When the apparent discharge quantity represented by the pulse current information is between the first discharge quantity threshold and the second discharge quantity threshold, the variance of the pulse amplitude is greater than the second variance threshold, and the pulse repetition rate is between the second repetition rate threshold and the first repetition rate threshold, when the ultra-high frequency spectrum information represents the spectrum being in the second frequency range, the spectral pulse width being between the first pulse width threshold and the second pulse width threshold, and the spectrum including energy peaks of multiple frequency bands, and when the ultrasonic information represents the sound wave amplitude being between the first sound wave threshold and the second ultrasonic threshold, the sound wave frequency being in the first sound wave frequency range and the second sound wave frequency range respectively, and the signal duration being between the first signal time and the second signal time, the discharge type of the DC partial discharge location is configured as surface discharge;

[0049] In the case where the discharge type is surface discharge:

[0050] If the gas detection data indicates that the hydrogen content is between 400 and 800 μL / L, the ratio of methane to organic gas content is between 30% and 40%, the ratio of ethylene to organic gas content is between 35% and 45%, the carbon monoxide content is between 200 and 300 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 5 and 8, then the defect type of the DC partial discharge location is configured as winding insulation contamination.

[0051] If the gas detection data indicates that the hydrogen content is between 300 and 500 μL / L, the ratio of methane to organic gas content is between 40% and 50%, the ratio of ethylene to organic gas content is between 25% and 35%, the carbon monoxide content is between 100 and 200 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 8 and 10, then the defect type of the DC partial discharge location is configured as an air gap existing in the inner wall of the bushing.

[0052] If the gas detection data indicates that the hydrogen content is between 350 and 600 μL / L, the ratio of methane to organic gas content is between 35% and 45%, the ratio of ethylene to organic gas content is between 30% and 40%, the carbon monoxide content is between 150 and 250 μL / L, and the ratio of ethane to organic gas content is between 10% and 15%, then the defect type of the DC partial discharge location is configured as lead wire outer insulation layer damage.

[0053] In some optional embodiments, the method further includes:

[0054] When the apparent discharge quantity represented by the pulse current information is between the second discharge quantity threshold and the third discharge quantity threshold, the pulse amplitude exhibits a clustered distribution, and the pulse repetition rate is between the third repetition rate threshold and the second repetition rate threshold; when the ultra-high frequency spectrum information represents the spectrum being within the third frequency range, the spectral pulse width being between the second pulse width threshold and the third pulse width threshold, and the spectral pulse amplitude being greater than the second pulse amplitude threshold; and when the ultrasonic information represents the sound wave amplitude being between the second sound wave threshold and the third ultrasonic wave threshold, the sound wave frequency being within the third sound wave frequency range, and the signal duration being between the second signal time and the third signal time, the discharge type of the DC partial discharge location is configured as spark discharge;

[0055] In the case where the discharge type is spark discharge:

[0056] If the gas detection data indicates that the hydrogen content is between 1000 and 1500 μL / L, the ratio of ethylene to organic gas content is between 40% and 50%, the ratio of acetylene to organic gas content is between 5% and 8%, the carbon monoxide content is between 500 and 600 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 3 and 4, then the defect type of the DC partial discharge location is configured as winding insulation failure.

[0057] If the gas detection data indicates that the hydrogen content is between 800 and 1200 μL / L, the ratio of methane to organic gas content is between 40% and 45%, the ratio of ethylene to organic gas content is between 35% and 40%, the ratio of acetylene to organic gas content is between 3% and 5%, and the carbon monoxide content is between 300 and 400 μL / L, then the defect type of the DC partial discharge location is configured as core insulation failure.

[0058] If the gas detection data indicates that the hydrogen content is between 900 and 1300 μL / L, the ratio of methane to organic gas content is between 30% and 35%, the ratio of ethylene to organic gas content is between 35% and 45%, the ratio of acetylene to organic gas content is between 4% and 7%, and the organic gas content is between 400 and 600 μL / L, then the defect type of the DC partial discharge location is configured as the presence of metal debris in the transformer oil.

[0059] In some optional embodiments, the method further includes:

[0060] When the apparent discharge quantity represented by the pulse current information is greater than the third discharge quantity threshold, the pulse amplitude exhibits a peak-like distribution, and the pulse repetition rate is less than the third repetition rate threshold; when the ultra-high spectrum information represents the spectrum being in the fourth frequency range, the spectrum pulse width being greater than the third pulse width threshold, and the spectrum pulse amplitude variance being less than the third variance threshold; and when the ultrasonic information represents the sound wave amplitude being greater than the third ultrasonic threshold, the sound wave frequency being in the fourth sound wave frequency range, and the signal duration being greater than the third signal time, the discharge type of the DC partial discharge location is configured as arc discharge.

[0061] In the case where the discharge type is arc discharge:

[0062] If the gas detection data indicates that the hydrogen content is between 2000 and 5000 μL / L, the ratio of acetylene to organic gas content is between 30% and 50%, the carbon monoxide content is between 1000 and 2000 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 1 and 2, then the defect type of the DC partial discharge location is configured as winding insulation breakdown.

[0063] If the gas detection data indicates that the hydrogen content is between 1500 and 3000 μL / L, the ratio of acetylene to organic gas content is between 40% and 60%, the carbon monoxide content is between 600 and 1200 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 2 and 3, then the defect type of the DC partial discharge location is configured as lead connector damage.

[0064] If the gas detection data indicates that the hydrogen content is between 1800 and 3500 μL / L, the ratio of acetylene to organic gas content is between 35% and 55%, the ratio of ethane to organic gas content is between 5% and 10%, the carbon monoxide content is between 700 and 1500 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 1.5 and 2.5, then the defect type of the DC partial discharge location is configured as tap changer contact failure.

[0065] In a second aspect, embodiments of the present invention provide a partial discharge diagnostic device for a DC transformer, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the partial discharge diagnostic method for the DC transformer described in the first aspect.

[0066] Thirdly, embodiments of the present invention provide a power grid management system, including the partial discharge diagnostic device for DC transformers mentioned in the second aspect above.

[0067] Fourthly, a computer storage medium stores computer-executable instructions for executing the partial discharge diagnosis method for a DC transformer described in the first aspect.

[0068] The beneficial effects of this invention include: When a DC partial discharge (DMD) signal is detected by a first DMD sensor on a digital twin model, the DC DMD location is detected based on the first DMD sensor and a second DMD sensor on the mobile detection model, both of which characterize the DMD sensor; gas detection data at the DC DMD location is acquired, indicating the gas type and content of each gas; and the defect type at the DC DMD location is determined based on the gas detection data and the pulse current information, ultra-high frequency spectrum information, and ultrasonic information indicated by the DC DMD signal. By coordinating the partial discharge sensors installed on the DC transformer and the mobile robot, the DC DMD location is located, thus adapting to various locations of DC partial discharge on the DC transformer. This also minimizes the number of partial discharge sensors required on the DC transformer, reducing installation and detection costs. Furthermore, the gas detection data and DC DM signal at the DC DM location enable rapid diagnosis of the defect type, facilitating quick processing by personnel. This results in high efficiency and low cost for DC transformer defect diagnosis, making DC partial discharge location and defect diagnosis of DC transformers fast and convenient.

[0069] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0070] Figure 1 This is a flowchart illustrating the steps of a partial discharge diagnosis method for a DC transformer provided in an embodiment of the present invention.

[0071] Figure 2 This is a schematic diagram of locating the DC partial discharge position using a planar method according to an embodiment of the present invention;

[0072] Figure 3 This is a schematic diagram of a controller provided in one embodiment of the present invention.

[0073] Reference numerals: Controller 1000, Processor 1100, Memory 1200. Detailed Implementation

[0074] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0075] It should be noted that although functional modules are divided in the device schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, or the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0076] This application provides a method, device, and medium for diagnosing partial discharge in a DC transformer, which will be described in detail in the following embodiments.

[0077] like Figure 1 As shown, this embodiment of the invention provides a method for diagnosing partial discharge in a DC transformer, including:

[0078] S100, when the first partial discharge sensor on the digital twin model detects a DC partial discharge signal, the DC partial discharge position is detected based on the first partial discharge sensor and the second partial discharge sensor on the motion detection model, wherein both the first partial discharge sensor and the second partial discharge sensor characterize the partial discharge sensor.

[0079] It should be noted that the partial discharge diagnosis method for DC transformers in this application is applied to a power grid management system equipped with a digital twin model of the DC transformer and a corresponding mobile detection model of a mobile robot. The digital twin model of the DC transformer is equipped with multiple vibration wave sensors, ultra-high frequency sensors, temperature and humidity sensors, gas sensors, and partial discharge sensors, etc., meaning that corresponding vibration wave sensors, temperature and humidity sensors, gas sensors, and partial discharge sensors are also installed on the DC transformer itself. Furthermore, the mobile robot and its corresponding mobile detection model are also equipped with multiple different types of partial discharge sensors, thereby enabling the detection of different types of DC partial discharge signals. The location and specific operating status of each sensor can be visually viewed through the digital twin model and the mobile detection model. The mobile robot can be specifically configured as a work robot capable of moving around the DC transformer in various directions, or a drone capable of detecting the DC transformer, etc., without specific limitations.

[0080] Specifically, when the first partial discharge (PD) sensor in the DC transformer digital twin model detects a DC PD signal, it triggers a mobile robot to move the second PD sensor in the detection model, thus accurately locating the DC PD. By combining the body localization of the DC transformer digital twin model with the spatial localization of the mobile robot, three-dimensional precise locking of the DC PD location is achieved, adaptable to multiple installation scenarios for DC transformers. With multiple local locations acquired, their priorities are assigned to determine the processing priority of each local location, which is equivalent to determining the PD level.

[0081] In some optional embodiments, detecting the DC partial discharge location based on the first partial discharge sensor and the second partial discharge sensor on the moving detection model includes:

[0082] S110. In the case that at least two of the first partial discharge sensors receive the DC partial discharge signal at the same first receiving time on the digital twin model, a first plane is constructed on the first vertical line of any two first partial discharge sensors with the same first receiving time, and the first plane is located in a first direction.

[0083] Specifically, if at least two first partial discharge sensors in the digital twin model receive the DC partial discharge signal at exactly the same first reception time, the physical position of the two first partial discharge sensors with exactly the same first reception time is used as a reference. First, a connecting straight line between the two first partial discharge sensors is determined, and then a first plane is built in the first direction. The first plane is perpendicular to the connecting straight line, and the first perpendicular bisector of the connecting straight line is completely within the first plane. That is, the propagation distance of the DC partial discharge signal to the two first partial discharge sensors is equal, and the DC partial discharge position falls on the first plane.

[0084] S120. In the absence of two first partial discharge sensors having the same first reception time on the digital twin model, construct the first plane between the second partial discharge sensor and the first partial discharge sensor.

[0085] Specifically, if no two first partial discharge sensors in the digital twin model receive the DC partial discharge signal at the same first reception time, meaning the distances from the location of partial discharge on the DC transformer to each partial discharge sensor on the DC transformer are all different and unequal, then the second partial discharge sensor on the mobile robot's motion detection model and the first partial discharge sensor on the digital twin model are used as references to construct the first plane in the first direction, thereby locking the spatial range of the DC partial discharge location in the first direction. Specifically, using any one of the first partial discharge sensors as a reference, the first time that the first partial discharge sensor receives the partial discharge signal is calculated, and the mobile robot is synchronously controlled to move to the DC transformer, moving along the second direction perpendicular to the first direction. The movement stops when the time for the second partial discharge sensor on the mobile robot to receive the partial discharge signal is equal to the first time, and the first plane is constructed using the perpendicular bisector between the mobile robot and the selected first partial discharge sensor as a reference.

[0086] S130, A second plane is constructed in a second direction by means of the second partial discharge sensor and / or the first partial discharge sensor located in a relative position, and a third plane is constructed in a third direction, wherein the first direction, the second direction and the third direction are perpendicular to each other;

[0087] Specifically, after constructing the first plane, the construction of the second plane is carried out in the second direction. The second direction is perpendicular to the first direction. The second plane is constructed using a second partial discharge sensor and / or a first partial discharge sensor in relative positions. The construction logic is the same as that of the first plane, based on the sensor's reception characteristics of the DC partial discharge signal and the relative positions between the sensors, ensuring that the DC partial discharge position falls on the second plane. The construction of the third plane continues in the third direction. The third direction is perpendicular to both the first and second directions, achieving the spatial dimension requirement of mutual perpendicularity in the three directions. The third plane is also constructed using a second partial discharge sensor and / or a first partial discharge sensor in relative positions, and the DC partial discharge position falls on this third plane.

[0088] S140. Determine the DC partial discharge location based on the first plane, the second plane, and the third plane.

[0089] Specifically, after the construction of the first, second, and third planes is completed, based on the principles of spatial geometry, the three mutually perpendicular planes will form a unique intersection point in three-dimensional space. This intersection point is the location of the DC partial discharge, thereby achieving precise positioning of the DC partial discharge location.

[0090] In some alternative embodiments, constructing the first plane between the second partial discharge sensor and the first partial discharge sensor includes:

[0091] S121. Configure any one of the first partial discharge sensors as the first target sensor, and obtain the first target position of the first target sensor on the DC transformer;

[0092] Specifically, in the digital twin model, any first partial discharge sensor is selected as the first target sensor, and the physical installation position of the first target sensor in the digital twin model (that is, the corresponding installation position on the DC transformer) is extracted. This position is configured as the first target position, and this position is locked as the reference position on the DC transformer body side.

[0093] It is easy to see that the first partial discharge sensor is a working sensor, and the detection accuracy of each first partial discharge sensor can be determined based on the aging coefficient and interference coefficient of the first partial discharge sensor. Based on the detection accuracy, a corresponding sensor priority order table can be set, and the first sensor with the highest priority in the sensor priority order table can be configured as the first target sensor to improve the detection accuracy.

[0094] S122. Control the mobile robot to move along the first direction passing the first target position through the motion detection model, and obtain the real-time position of the mobile robot;

[0095] Specifically, when there are no two first partial discharge sensors on the DC transformer that receive DC partial discharge signals at equal times in the first direction, the first reception time of one of the first partial discharge sensors in the first direction is used as a reference. A mobile robot equipped with a second partial discharge sensor is controlled to move from its starting position to the DC transformer casing opposite the first partial discharge sensor. The mobile robot then moves along a preset first direction on the DC transformer, continuously and accurately acquiring its real-time spatial position during movement, and simultaneously uploading this real-time position to the power grid management system to complete the recording and storage of the real-time position.

[0096] S123. Obtain the second reception time of the second partial discharge sensor receiving the DC partial discharge signal at the real-time location;

[0097] Specifically, as the mobile robot moves along the first direction, it continuously receives DC partial discharge signals through the second partial discharge sensor. At the same time, it obtains the second reception time of the DC partial discharge signal received by the second partial discharge sensor at each real-time position, and establishes a one-to-one correspondence between the real-time position and the second reception time.

[0098] S124. When the second receiving time is equal to the first receiving time of the first target sensor, the real-time position is configured as the second target position;

[0099] Specifically, the second receiving time is compared in real time with the first receiving time of the DC partial discharge signal received by the first partial discharge sensor on the digital twin model. When the second receiving time at a certain real-time position is found to be exactly equal to the first receiving time, the real-time position is calibrated and configured as the second target position, and the position is locked as the reference position on the mobile robot side.

[0100] S125. Construct the first plane on the second perpendicular line between the first target position and the second target position.

[0101] Specifically, the determined first and second target positions are used as two reference positions. A straight line connecting the two reference positions is determined, and the second perpendicular bisector of the connecting line is obtained. In the first direction, a first plane is constructed with the second perpendicular bisector as the core. The first plane is perpendicular to the straight line connecting the first and second target positions, and the second perpendicular bisector is completely within the first plane. The DC partial discharge position falls on the first plane.

[0102] In some alternative embodiments, the second plane is constructed in a second direction by means of the second partial discharge sensor and / or the first partial discharge sensor located in relative positions:

[0103] S131. If there are two first partial discharge sensors on the first vertical line or the second vertical line that receive the DC partial discharge signal at the same time, the two first partial discharge sensors with the same receiving time shall be configured as the second target sensor.

[0104] S132. Construct the second plane on the third perpendicular line between the two second target sensors;

[0105] Specifically, if two first partial discharge sensors receive DC partial discharge signals at exactly the same time on the constructed first or second perpendicular line, these two first partial discharge sensors with equal receiving times are calibrated and configured as second target sensors. Using the two second target sensors as a reference, the spatial connecting line between them is determined, and the third perpendicular line of the connecting line is accurately obtained. Finally, in the second direction, a second plane is constructed with the third perpendicular line as the core. This second plane is perpendicular to the connecting line of the two second target sensors, and the third perpendicular line is completely within this second plane. The DC partial discharge position falls on this second plane.

[0106] S133. In the case where there are no two first partial discharge sensors receiving the DC partial discharge signal at the same time on the first vertical line or the second vertical line, and there is at least one first partial discharge sensor, any one of the first partial discharge sensors located on the first vertical line or the second vertical line is configured as the third target sensor.

[0107] S134. Move the mobile robot on the first or second vertical line, and configure the position corresponding to the moment when the reception time of the second partial discharge sensor on the mobile robot is equal to the reception time of the third target sensor as the third target position, wherein the third target sensor is not located at the third target position.

[0108] S135. Construct the second plane on the fourth perpendicular line between the third target position and the third target sensor;

[0109] Specifically, if on the constructed first or second vertical line, no two first partial discharge sensors receive DC partial discharge signals at the same time, and there is at least one first partial discharge sensor on the first or second vertical line, then any one first partial discharge sensor is selected from the first or second vertical line, calibrated, and configured as the third target sensor; the mobile robot equipped with the second partial discharge sensor is controlled to move along the first or second vertical line, and the real-time reception time of the DC partial discharge signal received by the second partial discharge sensor during the movement of the mobile robot is simultaneously acquired, and the real-time reception time is compared with the reception time of the DC partial discharge signal received by the third target sensor in real time. When the two reception times are completely equal, the spatial position corresponding to the mobile robot at this time is locked and configured as the third target position, and it is ensured that the third target sensor and the third target sensor are not in the same spatial position.

[0110] Using the installation position of the third target sensor and the position of the third target as two reference points, a straight line connecting the two is determined. The fourth perpendicular bisector of this connecting line is then obtained. In the second direction, a second plane is constructed with the fourth perpendicular bisector as the core. This second plane is perpendicular to the straight line connecting the third target sensor and the position of the third target, and the fourth perpendicular bisector is located within this second plane, which means that the DC partial discharge position falls into the second plane.

[0111] S136. If the first partial discharge sensor is not present on the first or second vertical line, move the mobile robot on the first or second vertical line and configure two relative positions with equal reception times of the second partial discharge sensor as the fourth target position.

[0112] S137. Construct the second plane on the fifth perpendicular line between the two fourth target positions.

[0113] Specifically, if no first partial discharge (PD) sensor is deployed on the constructed first or second perpendicular bisector, a mobile robot equipped with a second PD sensor is controlled to move along the first or second perpendicular bisector. During the movement, the real-time reception time of the DC PD signal received by the second PD sensor is continuously acquired. Two real-time positions of the mobile robot with completely equal reception times of the DC PD signal and in relative positions (the two real-time positions do not overlap spatially) are selected and marked and configured as the fourth target positions. Using the two fourth target positions as a reference, a spatial connecting line is determined between them, and the fifth perpendicular bisector of this connecting line is obtained. In the second direction, a second plane is constructed with the fifth perpendicular bisector as the core. This second plane is perpendicular to the connecting line between the two fourth target positions, and the fifth perpendicular bisector lies within this second plane.

[0114] In some alternative embodiments, constructing the third plane upwards includes:

[0115] S141. If there are two first partial discharge sensors on the third vertical line, the fourth vertical line, or the fifth vertical line that receive the DC partial discharge signal at the same time, the two first partial discharge sensors with the same receiving time shall be configured as the fourth target sensor.

[0116] S142. Construct the third plane on the sixth perpendicular line between the two fourth target sensors;

[0117] Specifically, if two first partial discharge sensors receive DC partial discharge signals at exactly the same time on the constructed third, fourth, or fifth perpendicular line, these two first partial discharge sensors with equal receiving times are calibrated and configured as fourth target sensors. Using the two fourth target sensors as spatial references, a spatial connecting line between them is determined, thereby obtaining a sixth perpendicular line of the connecting line. In the third direction, a third plane is constructed with the sixth perpendicular line as the core. This third plane is perpendicular to the connecting line between the two third target sensors, and the sixth perpendicular line lies within this third plane. The DC partial discharge position falls on this third plane.

[0118] S143. If there are no two first partial discharge sensors receiving the DC partial discharge signal at the same time on the third vertical line, the fourth vertical line, or the fifth vertical line, and there is at least one first partial discharge sensor, then any one of the first partial discharge sensors located on the third vertical line, the fourth vertical line, or the fifth vertical line shall be configured as the fifth target sensor.

[0119] S144. Move the mobile robot along the third, fourth, or fifth vertical line, and configure the position corresponding to the moment when the reception time of the second partial discharge sensor on the mobile robot is equal to the reception time of the fifth target sensor as the fifth target position, wherein the fifth target sensor is not located at the fifth target position.

[0120] S145. Construct the third plane on the seventh perpendicular line between the fifth target position and the fifth target sensor;

[0121] Specifically, if on the constructed third, fourth, or fifth vertical line, no two first partial discharge sensors receive the DC partial discharge signal at the same time, and at least one first partial discharge sensor is deployed on the third, fourth, or fifth vertical line, then any one first partial discharge sensor is selected from the third, fourth, or fifth vertical line, calibrated, and configured as the fifth target sensor; the mobile robot equipped with the second partial discharge sensor is controlled to move along the third, fourth, or fifth vertical line where the fifth target sensor is located, and the real-time reception time of the DC partial discharge signal received by the second partial discharge sensor during the movement of the mobile robot is simultaneously acquired, and the real-time reception time is compared with the reception time of the DC partial discharge signal received by the fourth target sensor in real time. When the two reception times are completely equal, the spatial position corresponding to the mobile robot at this time is locked and configured as the fifth target position, and it is ensured that the physical position of the fifth target sensor does not coincide with the fifth target position.

[0122] Based on the installation position of the fifth target sensor and the position of the fifth target, a straight line connecting the two is determined. The seventh perpendicular bisector of this line is then obtained. In the third direction, a third plane is constructed with the seventh perpendicular bisector as the core. This third plane is perpendicular to the straight line connecting the fifth target sensor and the position of the fifth target, and the seventh perpendicular bisector is completely within this third plane. The DC partial discharge position is obviously also within the third plane.

[0123] S146. If the first partial discharge sensor is not present on the third, fourth, or fifth vertical line, move the mobile robot on the third, fourth, or fifth vertical line and configure the two relative positions with equal reception times of the second partial discharge sensor as the sixth target position.

[0124] S147. Construct the third plane on the eighth perpendicular line between the two sixth target positions.

[0125] Specifically, if no first partial discharge sensor is deployed on the constructed third, fourth, or fifth perpendicular line, the mobile robot equipped with the second partial discharge sensor is controlled to move along the third, fourth, or fifth perpendicular line (the specific perpendicular line is determined by the method of determining the second plane described above). During the movement, the real-time reception time of the DC partial discharge signal received by the second partial discharge sensor is continuously collected and recorded. From all real-time positions, two real-time positions of the mobile robot that meet the condition of having completely equal reception times and being in relative spatial positions are selected, and these two positions are marked and configured as the sixth target positions. Using the two sixth target positions as spatial references, the spatial connecting line between them is determined, and then the eighth perpendicular line of the connecting line is determined. Finally, in the third direction, a third plane is constructed with the eighth perpendicular line as the core. This third plane is perpendicular to the connecting line between the two sixth target positions, and both the eighth perpendicular line and the DC partial discharge position are located within this third plane.

[0126] In some optional embodiments, determining the DC partial discharge location based on the first plane, the second plane, and the third plane includes:

[0127] S151. Configure the intersecting line between the first plane and the second plane as the target line;

[0128] S152. The intersection point of the target line and the third plane is configured as the target point;

[0129] S153. Configure the spatial location of the target point as the DC partial discharge location.

[0130] Specifically, refer to Figure 2 Using the first plane P1 and the second plane P2 that have been constructed as spatial references, find the intersecting line formed by the two planes in three-dimensional space, mark the intersecting line and configure it as the target line. The target line is the common line of the first plane P1 and the second plane P2, and the DC partial discharge position must fall on the target line.

[0131] Using the target straight line and the constructed third plane P3 as spatial references, the unique intersection point formed by the target straight line and the third plane in three-dimensional space is further determined. This intersection point is then calibrated and configured as target point M. The three-dimensional spatial coordinates corresponding to target point M are extracted, and the spatial position of target point M is directly configured as the DC partial discharge location determined in this detection, thus completing the precise locking of the DC partial discharge location.

[0132] S200. Obtain gas detection data at the DC partial discharge location, wherein the gas detection data indicates the gas type and the content of each gas.

[0133] Specifically, based on the determined location of the DC partial discharge, the corresponding physical area and spatial coordinate information of the DC transformer body are matched in the digital twin model of the DC transformer. If the discharge location is inside the transformer (such as in the windings or oil gap), dissolved gas data in the insulating oil of that area are collected using a dissolved gas analysis (DGA) device. If the discharge location is on the surface (such as in the tank weld), gas composition data from the surrounding environment are collected. The collected gas detection data includes the specific type of gas, such as hydrogen, methane, acetylene, and carbon monoxide, as well as the specific content of each gas, commonly expressed in μL / L (ppm, parts per million). Based on the content values ​​of each individual gas, the volume or mass percentage of each gas type in the mixed gas is calculated, completing the accurate statistical analysis of the proportion of each gas type.

[0134] S300. Determine the defect type of the DC partial discharge location based on the gas detection data and the pulse current information, ultra-high frequency spectrum information, and ultrasonic information indicated by the DC partial discharge signal.

[0135] Specifically, pulse current information includes apparent discharge quantity, pulse repetition rate, pulse amplitude distribution, polarity consistency, etc., reflecting the energy level and activity of the discharge; ultra-high frequency spectrum information includes the signal's spectral range, pulse rise time and width, frequency band energy ratio, etc., reflecting the physical characteristics of the discharge channel; ultrasonic information includes the signal's peak amplitude, dominant frequency range, duration, etc., reflecting the mechanical vibration intensity of the discharge.

[0136] Based on the acquired DC partial discharge location gas detection data, the DC partial discharge signals collected by the first and second partial discharge sensors, and combined with the discharge characteristics of DC transformer partial discharge and the component correlation features of decomposition gas, the discharge type and defect type corresponding to the DC partial discharge location are determined through feature extraction, threshold matching, cross-verification, and result judgment.

[0137] In some optional embodiments, the defect type of the DC partial discharge location is determined based on the gas detection data and the pulse current information, ultra-high frequency spectrum information, and ultrasonic information indicated by the DC partial discharge signal, including:

[0138] S311. When the apparent discharge quantity represented by the pulse current information is less than the first discharge quantity threshold, the variance of the pulse amplitude is less than the first variance threshold, and the pulse repetition rate is greater than the first repetition rate threshold; when the ultra-high spectrum information represents the spectrum being in the first frequency range, the spectrum pulse width being less than the first pulse width threshold, and the spectrum pulse amplitude being less than the first pulse amplitude threshold; and when the ultrasonic information represents the sound wave amplitude being less than the first sound wave threshold, the sound wave frequency being in the first sound wave frequency range, and the signal duration being less than the first signal time, the discharge type of the DC partial discharge position is configured as corona discharge.

[0139] Specifically, pulse current information reflects discharge energy and activity, conforming to the characteristics of low energy and high repetition rate of corona discharge. The pulse current information must satisfy the condition that the apparent discharge quantity is less than the first discharge quantity threshold (corona discharge energy is extremely low, and the discharge quantity is significantly small; apparent discharge quantity...). ), the variance of the pulse amplitude is less than the first variance threshold (the amplitude distribution of the corona pulse is uniform and without large fluctuations, which is different from the amplitude dispersion of surface discharge; the specific first variance threshold is set according to the specific detection accuracy), and the pulse repetition rate is greater than the first repetition rate threshold (corona discharge is a continuous low-energy discharge with a high pulse generation frequency; the pulse repetition rate f>100 times / second).

[0140] Ultra-high frequency spectrum information reflects the characteristics of the discharge channel, which is consistent with the characteristics of narrow and weak corona discharge channels. Ultra-high frequency spectrum information needs to meet the following requirements: the spectrum is located in the first frequency range (300-800MHz), the spectrum pulse width is less than the first pulse width threshold (the corona pulse duration is short, less than 5ns, and the signal decays quickly), and the spectrum pulse amplitude is less than the first pulse amplitude threshold (the electromagnetic wave energy generated by corona discharge is weak, and the amplitude is significantly lower than that of spark and arc discharge. The specific first pulse amplitude threshold is determined based on the actual detection data and detection accuracy).

[0141] Ultrasonic information reflects the intensity of discharge vibration, which is consistent with the characteristics of weak vibration and short duration of corona discharge. Ultrasonic information needs to meet the following requirements: the amplitude of the sound wave is less than the first sound wave threshold (the mechanical vibration of corona discharge is weak, the amplitude of the ultrasonic signal is low, less than 60dB), and the frequency of the sound wave is within the first sound wave frequency range (50-100kHz).

[0142] The signal duration is shorter than the first signal duration (the duration of the corona ultrasonic signal is extremely short, less than 10 μs, with no obvious oscillation). After all signal characteristics are met, the discharge type is configured as corona discharge.

[0143] In the case where the discharge type is corona discharge:

[0144] S312. If the gas detection data indicates that the hydrogen content is between 200 and 500 μL / L, the ratio of methane to organic gas content is between 60% and 80%, the ratio of hydrogen to hydrogen plus organic gas content is between 40% and 60%, and the ratio of ethane to organic gas content is between 10% and 20%, then the defect type of the DC partial discharge location is configured as winding end oil gap electric field distortion.

[0145] Specifically, given that corona discharge has been identified, the defect type is matched one by one by comparing the specific ranges of "hydrogen content, methane to organic gas ratio, hydrogen to total hydrocarbon ratio, and ethane percentage / total hydrocarbon content" in the gas detection data. Here, organic gas refers to total hydrocarbon gas, and organic gas content is the content of all hydrocarbon gases.

[0146] Based on gas detection data, hydrogen was detected. The content is 200-500 μL / L (during oil gap corona discharge, oil molecules undergo slight decomposition). The generation rate is moderate to high; the ratio of methane to organic gases ( ) is 60%-80% It is the main hydrocarbon product of oil molecule decomposition, accounting for the majority; the ratio of hydrogen to total hydrogen hydrocarbons ( ): 40%—60% Balanced with total hydrocarbon generation, reflecting the discharge characteristics of oil medium; ethane to organic gas ratio ( The content of ethane is 10%–20% (a relatively high proportion of ethane is a characteristic of more complete oil molecule decomposition due to the concentrated electric field in the oil gap at the winding end). The defect type is configured as electric field distortion in the oil gap at the winding end. The cause of this type of defect is: poor insulation formation at the winding end and uneven oil gap distribution, which leads to local electric field distortion and triggers corona discharge in the oil medium.

[0147] S313. If the gas detection data indicates that the hydrogen content is between 100 and 300 μL / L, the ratio of methane to organic gas content is between 50% and 60%, the ratio of hydrogen to hydrogen plus organic gas content is between 50% and 70%, and the ratio of ethane to organic gas content is less than 10%, then the defect type of the DC partial discharge location is configured as poor grounding of the bushing end screen.

[0148] Specifically, based on gas detection data, the following was obtained: hydrogen. The concentration is 100-300 μL / L (the corona energy at the tip of the end screen is relatively lower). The amount produced is slightly less; the ratio of methane to organic gases ( ) is 50%-60% Still dominant, but accounting for a lower percentage than winding end corona; the ratio of hydrogen to total hydrogen hydrocarbons ( ): 50%—70% A higher proportion reflects the gas generation characteristics of the oil-insulation interface discharge at the end screen; the ratio of ethane to organic gases ( Less than 10% (low ethane production, more concentrated discharge energy at the tip, and low degree of oil molecule decomposition). The defect type is configured as poor grounding of the bushing end screen. Causes of this defect: poor grounding of the bushing end screen and protruding metal tip create a concentrated electric field at the oil-insulation interface, triggering tip corona discharge.

[0149] S314. If the gas detection data indicates that the hydrogen content is between 150 and 400 μL / L, the ratio of methane to organic gas content is between 70% and 90%, the ratio of hydrogen to hydrogen plus organic gas content is between 30% and 50%, and the organic gas content is between 100 and 200 μL / L, then the defect type of the DC partial discharge location is configured as having metal burrs on the lead surface.

[0150] Specifically, based on gas detection data, the following was obtained: hydrogen. The content is 150-400 μL / L (metal burr corona discharge). The amount of formation is between the first two types of defects; the ratio of methane to organic gases ( ) is 70%-90% The proportion is extremely high, which is due to the extremely strong electric field at the tip of the metal burr, preferentially decomposing oil molecules to form the product. Characteristics); the ratio of hydrogen to total hydrogen hydrocarbons ( ) is 30%-50% The proportion is slightly low. Generation is dominant); the content of organic gases ( The concentration is 100-200 μL / L (the total hydrocarbon content is slightly higher, reflecting a more significant decomposition of oil molecules by metal burr discharge). The defect type is configured as metal burrs on the lead surface. Defect cause: Metal burrs and sharp corners on the lead surface create a strong electric field in the oil or at the air-oil interface, triggering corona discharge.

[0151] In some optional embodiments, the method further includes:

[0152] S315. When the apparent discharge quantity represented by the pulse current information is between the first discharge quantity threshold and the second discharge quantity threshold, the variance of the pulse amplitude is greater than the second variance threshold, and the pulse repetition rate is between the second repetition rate threshold and the first repetition rate threshold, when the ultra-high frequency spectrum information represents the spectrum being in the second frequency range, the spectral pulse width being between the first pulse width threshold and the second pulse width threshold, and the spectrum including energy peaks of multiple frequency bands, and when the ultrasonic information represents the sound wave amplitude being between the first sound wave threshold and the second ultrasonic threshold, the sound wave frequency being in the first sound wave frequency range and the second sound wave frequency range respectively, and the signal duration being between the first signal time and the second signal time, the discharge type of the DC partial discharge location is configured as surface discharge.

[0153] Specifically, surface discharge requires the simultaneous fulfillment of pulse current information, ultra-high frequency spectrum information, and ultrasonic information:

[0154] Pulse current information indicates that the apparent discharge quantity is between the first and second discharge quantity thresholds (energy higher than corona discharge, lower than spark discharge, apparent discharge quantity is...). The pulse amplitude variance is greater than the second variance threshold (surface discharge is affected by the redistribution of charge on the insulating surface, resulting in violent fluctuations in pulse amplitude, unlike the uniform amplitude of corona discharge); the pulse repetition rate is between the second repetition rate threshold and the first repetition rate threshold (the discharge frequency is lower than the high frequency of corona discharge but higher than the low frequency of spark discharge; the pulse repetition rate is...). (times / second).

[0155] The ultra-high frequency spectrum information characterizes the spectrum range as being in the second frequency range (200-500MHz); the spectrum pulse width is between the first and second pulse width thresholds (the pulse duration is moderate, 5-15ns, between the narrow pulse of corona discharge and the wide pulse of spark discharge); the spectrum energy characteristics include energy peaks in multiple frequency bands (the discharge channel of surface discharge extends irregularly on the insulating surface, causing electromagnetic waves to form energy peaks in different frequency bands).

[0156] The ultrasonic information characterizes the sound wave amplitude as being between the first and second sound wave thresholds (moderate vibration intensity, 60-80 dB, higher than corona discharge but lower than spark discharge); the sound wave frequency simultaneously covers both the first and second sound wave frequency ranges (50-100 kHz and 200-300 kHz dual dominant frequencies, triggered by multipath vibrations from surface discharge); and the signal duration is between the first and second signal times (moderate signal duration, 10-50 μs, longer than corona discharge but shorter than spark discharge). After satisfying all signal characteristics, the discharge type is configured as surface discharge.

[0157] In the case where the discharge type is surface discharge:

[0158] S316. If the gas detection data indicates that the hydrogen content is between 400 and 800 μL / L, the ratio of methane to organic gas content is between 30% and 40%, the ratio of ethylene to organic gas content is between 35% and 45%, the carbon monoxide content is between 200 and 300 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 5 and 8, then the defect type of the DC partial discharge location is configured as winding insulation contamination.

[0159] Specifically, based on gas detection data, the following was obtained: hydrogen. The content is 400-800 μL / L (water participates in the discharge electrolysis reaction, generating a large amount of...). The content was significantly higher than normal; the ratio of methane to organic gases was also higher than normal. The ethylene-to-total-hydrocarbon ratio is 30%–40%; : 35%-45% (ethylene content is slightly higher than methane, reflecting a deeper degree of oil molecule decomposition); carbon monoxide ( The content of ) is 200-300 μL / L (oil paper insulation generates more due to slight carbonization during discharge). ); carbon dioxide to carbon monoxide ratio ( If the ratio is 5-8 (this range corresponds to mild carbonization of solid insulation, distinct from severe carbonization caused by spark discharge), then the defect type is configured as winding insulation contamination. The cause of the defect is contamination and moisture adsorption on the surface of the winding insulation.

[0160] S317. If the gas detection data indicates that the hydrogen content is between 300 and 500 μL / L, the ratio of methane to organic gas content is between 40% and 50%, the ratio of ethylene to organic gas content is between 25% and 35%, the carbon monoxide content is between 100 and 200 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 8 and 10, then the defect type of the DC partial discharge location is configured as having an air gap in the inner wall of the bushing.

[0161] Specifically, based on gas detection data, the following was obtained: hydrogen. The content is 300-500 μL / L (air gap discharge is mainly due to the decomposition of oil molecules, with little water involvement). The content is lower than that of the contaminated winding insulation type; the ratio of methane to organic gases ( The percentage is 40%–50% (with a higher proportion of methane, characteristic of hydrocarbon products in gas gap discharge); the ratio of ethylene to total hydrocarbons ( : 25%-35% (Ethylene content is lower than in contaminated winding insulation, and the degree of oil molecule decomposition is relatively mild); Carbon monoxide ( The content of ) is 100-200 μL / L (only slight decomposition of epoxy insulation on the inner wall of the bushing). The amount produced is relatively small; the ratio of carbon dioxide to carbon monoxide ( If the value is 8-10, then the defect type is configured as an air gap in the inner wall of the bushing. The cause of the defect is: air gap and impurities at the interface between the inner wall of the epoxy / ceramic bushing and the oil, causing discharge along the oil-insulation interface.

[0162] S318. If the gas detection data indicates that the hydrogen content is between 350 and 600 μL / L, the ratio of methane to organic gas content is between 35% and 45%, the ratio of ethylene to organic gas content is between 30% and 40%, the carbon monoxide content is between 150 and 250 μL / L, and the ratio of ethane to organic gas content is between 10% and 15%, then the defect type of the DC partial discharge location is configured as lead wire outer insulation layer damage.

[0163] Specifically, based on gas detection data, the following was obtained: hydrogen. The content is 350-600 μL / L ( The generation amount is between the first two types of defects and is affected by the three-phase interface discharge characteristics; the ratio of methane to organic gases ( The ethylene content is 35%–45%; the ratio of ethylene to total hydrocarbons ( The content is 30%-40% (methane and ethylene are close in proportion, reflecting the characteristic of oil and insulation decomposition together); carbon monoxide ( The content of ) is 150-250 μL / L (local carbonization at the damaged part of the insulation layer, (Medium production); Ethane to total hydrocarbon ratio ( The concentration of ethane is 10%–15% (a higher ethane content is due to air participating in the discharge reaction). Therefore, the defect type is configured as damage to the lead wire's outer insulation layer. Defect cause: Caused by damage to the lead wire's outer insulation layer, with the discharge occurring along the air-oil-insulation three-phase interface.

[0164] In some optional embodiments, the method further includes:

[0165] S319. When the apparent discharge quantity represented by the pulse current information is between the second discharge quantity threshold and the third discharge quantity threshold, the pulse amplitude exhibits a clustered distribution, and the pulse repetition rate is between the third repetition rate threshold and the second repetition rate threshold; when the ultra-high frequency spectrum information represents the spectrum being within the third frequency range, the spectral pulse width being between the second pulse width threshold and the third pulse width threshold, and the spectral pulse amplitude being greater than the second pulse amplitude threshold; and when the ultrasonic information represents the sound wave amplitude being between the second sound wave threshold and the third ultrasonic wave threshold, the sound wave frequency being within the third sound wave frequency range, and the signal duration being between the second signal time and the third signal time, the discharge type of the DC partial discharge location is configured as spark discharge.

[0166] Specifically, spark discharge requires the simultaneous fulfillment of pulse current information, ultra-high frequency spectrum information, and ultrasonic information:

[0167] Pulse current information indicates that the apparent discharge quantity is between the second and third discharge quantity thresholds (energy higher than surface discharge but lower than arc discharge, corresponding to the core characteristic of medium-energy discharge); the apparent discharge quantity is specifically... The pulse amplitude distribution exhibits a clustered pattern (spark discharge is an intermittent, localized breakdown discharge; pulses appear in groups and clusters, a distinguishing feature from uniform corona pulses and surface-fluctuating pulses); the pulse repetition rate is between the third and second repetition rate thresholds (the discharge frequency is lower than surface discharge but higher than the extremely low frequency of arc discharge, consistent with the intermittent characteristics of medium-energy discharge; the pulse repetition rate is...). (times / second).

[0168] The ultra-high frequency spectrum information characterizes the spectrum range as being in the third frequency range (500-1200MHz, with a frequency band concentration higher than the wide band of surface discharge but lower than the full frequency band of arc discharge); the spectrum pulse width is between the second and third pulse width thresholds (the pulse duration is moderately long, 15-30ns, reflecting a longer duration of the discharge channel than surface discharge); and the spectrum pulse amplitude is greater than the second pulse amplitude threshold (the discharge energy radiation intensity is higher than that of surface discharge, and the ultra-high frequency signal amplitude is more significant).

[0169] The ultrasonic information characterizes the sound wave amplitude as being between the second and third sound wave thresholds (vibration intensity of 80-100 dB, higher than surface discharge but lower than the violent vibration of arc discharge); the sound wave frequency as being within the third sound wave frequency range (100-200 kHz, the characteristic dominant frequency of mechanical vibration when spark discharge breaks down oil dielectric or solid insulation); and the signal duration as being between the second and third signal times (signal duration of 50-200 μs, longer than surface discharge, reflecting the continuous process of discharge energy release). Therefore, the discharge type is configured as spark discharge.

[0170] In the case where the discharge type is spark discharge:

[0171] S320. If the gas detection data indicates that the hydrogen content is between 1000 and 1500 μL / L, the ratio of ethylene to organic gas content is between 40% and 50%, the ratio of acetylene to organic gas content is between 5% and 8%, the carbon monoxide content is between 500 and 600 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 3 and 4, then the defect type of the DC partial discharge location is configured as winding insulation failure.

[0172] Specifically, based on gas detection data, the following was obtained: hydrogen. The content is 1000-1500 μL / L (due to the combined effects of oil paper insulation decomposition and oil molecule ionization, a large amount of...). ); Ethylene to total hydrocarbon ratio ( The content of acetylene to total hydrocarbons is 40%–50% (ethylene accounts for the highest proportion and is a hallmark product of high-temperature decomposition of oil-paper insulation); the ratio of acetylene to total hydrocarbons is ( The content is 5%–8% (the energy of spark discharge is sufficient to generate a small amount of acetylene, which is different from the trace amount of acetylene produced by surface discharge); carbon monoxide ( The content of ) is 500-600 μL / L (for large-area carbonization of oil-paper insulation, (The generation amount is significantly higher than normal); the ratio of carbon dioxide to carbon monoxide is 3-4. Therefore, the defect type is configured as winding insulation damage. Cause of the defect: Aging and localized damage to the inter-turn / inter-pane insulation paper of the windings causes the discharge to directly act on the oil-paper insulation, resulting in severe carbonization of the solid insulation.

[0173] S321. If the gas detection data indicates that the hydrogen content is between 800 and 1200 μL / L, the ratio of methane to organic gas content is between 40% and 45%, the ratio of ethylene to organic gas content is between 35% and 40%, the ratio of acetylene to organic gas content is between 3% and 5%, and the carbon monoxide content is between 300 and 400 μL / L, then the defect type of the DC partial discharge location is configured as core insulation failure.

[0174] Specifically, based on gas detection data, the following was obtained: hydrogen. The content is 800-1200 μL / L (preferential ionization of oil molecules during intermetallic discharge). The content is slightly lower than that of the winding insulation failure type; the ratio of methane to organic gases (total hydrocarbons) is 40%-45% (methane accounts for the highest proportion and is the main product of oil molecule decomposition under metal discharge environment); the ratio of ethylene to total hydrocarbons ( The ethylene content is 35%–40% (the ethylene content is lower than that of the winding insulation failure type, reflecting a lighter degree of solid insulation decomposition); the acetylene to total hydrocarbon ratio ( ) is 3%-5%; carbon monoxide ( The content of ) is 300-400 μL / L (only the iron core insulation sheet is slightly carbonized, (The generation rate is significantly lower than that of the winding insulation failure type). Therefore, the defect type is configured as core insulation failure. Cause of the defect: It is caused by damage to the insulation sheet between the core and the clamping parts, resulting in multi-point grounding. The discharge occurs between metal components, and the damage to the solid insulation is relatively minor.

[0175] S322. If the gas detection data indicates that the hydrogen content is between 900 and 1300 μL / L, the ratio of methane to organic gas content is between 30% and 35%, the ratio of ethylene to organic gas content is between 35% and 45%, the ratio of acetylene to organic gas content is between 4% and 7%, and the organic gas content is between 400 and 600 μL / L, then the defect type of the DC partial discharge location is configured as the presence of metal debris in the transformer oil.

[0176] Specifically, based on gas detection data, the following was obtained: hydrogen. The content is 900-1300 μL / L (oil molecules ionized by a strong electric field at the tip of metal debris). The generation rate is between the first two types of defects; the ratio of methane to organic gases (total hydrocarbons) is 30%–35% (the methane content is slightly lower, reflecting more complete decomposition of oil molecules and the generation of more heavy hydrocarbon gases); the ratio of ethylene to total hydrocarbons ( The acetylene to total hydrocarbon ratio is 35%–45%; The content of organic gases (total hydrocarbons) is 4%–7%; the content of organic gases (total hydrocarbons) is 400–600 μL / L (metal debris discharge has a wide decomposition range on oil molecules, resulting in a high content of organic gases). Therefore, the defect type is configured as the presence of metal debris in the transformer oil. The cause of the defect is: it is triggered by residual metal particles (bolt debris, copper shavings, etc.) in the oil bridging components at different potentials, with the discharge occurring along the tips of the metal debris.

[0177] In some optional embodiments, the method further includes:

[0178] S323. When the apparent discharge quantity represented by the pulse current information is greater than the third discharge quantity threshold, the pulse amplitude exhibits a peak-like distribution, and the pulse repetition rate is less than the third repetition rate threshold; when the ultra-high spectrum information represents the spectrum being in the fourth frequency range, the spectrum pulse width being greater than the third pulse width threshold, and the spectrum pulse amplitude variance being less than the third variance threshold; and when the ultrasonic information represents the sound wave amplitude being greater than the third ultrasonic threshold, the sound wave frequency being in the fourth sound wave frequency range, and the signal duration being greater than the third signal time, the discharge type of the DC partial discharge location is configured as arc discharge.

[0179] Specifically, arc discharge requires the simultaneous fulfillment of pulse current information, ultra-high frequency spectrum information, and ultrasonic information:

[0180] Pulse current information indicates that the apparent discharge quantity is greater than the third discharge quantity threshold (the discharge energy reaches its peak, which is the core threshold characteristic that distinguishes it from medium-energy spark discharge); the apparent discharge quantity is... The pulse amplitude distribution shows a peak-shaped distribution (arc discharge is a violent breakdown discharge of insulating medium, with extremely strong single pulse energy and amplitude far higher than other discharge types, and the waveform has a sharp peak); the pulse repetition rate is less than the third repetition rate threshold (high-energy discharge requires the accumulation of electric field energy, and the pulse generation frequency is extremely low, usually occurring once or at long intervals).

[0181] The ultra-high frequency spectrum information indicates that the spectrum range is located in the fourth frequency range (the full frequency band of 300-2000MHz, covering the characteristic frequency bands of corona and spark discharge, which reflects the stability of the arc discharge channel and the wide range of energy radiation); the spectrum pulse width is greater than the third pulse width threshold (the pulse duration is extremely long, the time corresponding to the spectrum pulse width is >30ns, reflecting that the maintenance time of the arc discharge channel is much longer than other discharge types); the spectrum pulse amplitude variance is less than the third variance threshold (the energy radiation of the arc discharge is stable, and the pulse amplitude fluctuation at different times is very small, which is different from the multi-band amplitude fluctuation of surface discharge).

[0182] The ultrasonic information is characterized by the following characteristics: the sound wave amplitude is greater than the third ultrasonic threshold (vibration intensity > 100 dB, the strongest vibration among all discharge types, as arc discharge causes violent expansion and vibration of the insulating medium); the sound wave frequency is within the fourth sound wave frequency range (a low-frequency band of 20–50 kHz, the characteristic dominant frequency of arc discharge impact vibration); and the signal duration is greater than the third signal time (signal duration > 200 μs, accompanied by multiple oscillations, reflecting the continuous and violent energy release process of high-energy discharge). If all characteristics are met, the discharge type is configured as arc discharge.

[0183] In the case where the discharge type is arc discharge:

[0184] S324. If the gas detection data indicates that the hydrogen content is between 2000 and 5000 μL / L, the ratio of acetylene to organic gas content is between 30% and 50%, the carbon monoxide content is between 1000 and 2000 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 1 and 2, then the defect type of the DC partial discharge location is configured as winding insulation breakdown.

[0185] Specifically, based on gas detection data, the following was obtained: hydrogen. The content is 2000-5000 μL / L (the oil paper insulation and oil molecules are violently ionized and decomposed). Large quantities generated); acetylene to total hydrocarbon ratio ( The percentage is 30%–50% (the energy of the arc discharge is sufficient to generate a large amount of acetylene; this ratio is a core characteristic of arc discharge); carbon monoxide ( The content of ) is 1000-2000μL / L (large-area carbonization and decomposition of winding oil paper insulation, (Large amounts generated); the ratio of carbon dioxide to carbon monoxide is 1-2. Therefore, the defect type is configured as winding insulation breakdown. Defect cause: Caused by complete damage to the winding turn / phase-to-turn insulation, forming a metallic short-circuit path, which directly damages the oil-paper insulation during discharge.

[0186] S325. If the gas detection data indicates that the hydrogen content is between 1500 and 3000 μL / L, the ratio of acetylene to organic gas content is between 40% and 60%, the carbon monoxide content is between 600 and 1200 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 2 and 3, then the defect type of the DC partial discharge location is configured as lead connector damage.

[0187] Specifically, based on gas detection data, the following was obtained: hydrogen. The content is 1500-3000 μL / L ( The content is lower than that of winding insulation breakdown, because discharge mainly occurs at metal joints, and the damage range of oil-paper insulation is small; the ratio of acetylene to total hydrocarbons ( The concentration is 40%–60% (the catalytic effect of the metal arc promotes the large-scale generation of acetylene); carbon monoxide ( The content of ) is 600-1200 μL / L ( The carbon dioxide to carbon monoxide content is below that of winding insulation breakdown, with only slight carbonization of the lead wire outer insulation layer; the carbon dioxide to carbon monoxide ratio is 2-3. Therefore, the defect type is configured as lead wire joint damage. Defect cause: Oxidation, breakage, or poor contact of the lead wire joint leads to intermittent metallic arcing, with the discharge primarily involving the reaction between metal and oil.

[0188] S326. If the gas detection data indicates that the hydrogen content is between 1800 and 3500 μL / L, the ratio of acetylene to organic gas content is between 35% and 55%, the ratio of ethane to organic gas content is between 5% and 10%, the carbon monoxide content is between 700 and 1500 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 1.5 and 2.5, then the defect type of the DC partial discharge location is configured as tap changer contact failure.

[0189] Specifically, based on gas detection data, the following was obtained: hydrogen. The content is 1800-3500 μL / L ( The content is between the first two types of defects, and the gas production fluctuates greatly due to the frequency of switching operations; the acetylene to total hydrocarbon ratio ( The percentage of ethane to total hydrocarbons is 35%–55%; : 5%-10% (the catalytic effect of the contact metal on the decomposition of oil molecules, producing more ethane); carbon monoxide ( The content of ) is 700-1500 μL / L (produced by local carbonization of the insulating parts around the switch contacts). The ratio of carbon dioxide to carbon monoxide is 1.5–2.5. Therefore, the defect type is configured as poor tap changer contact. Cause of the defect: Caused by wear of the tap changer contacts and excessive contact resistance, resulting in an electric arc during tap switching. The discharge is influenced by the catalytic effect of the contact metal.

[0190] In some optional embodiments, corresponding intelligent decision-making information is generated based on the defect type and defect location.

[0191] Specifically, based on the determined location and type of DC partial discharge, and using the intelligent decision analysis engine built into the power grid management system, the system integrates full lifecycle data of DC transformers, power grid operating condition data, maintenance resource data, and a pre-set defect handling rule base. This enables multi-dimensional data linkage analysis, intelligent matching of handling solutions, quantitative assessment of risk levels, and precise generation of maintenance strategies. The final output includes complete intelligent decision information encompassing risk warnings, tiered handling, precise maintenance, and prevention and control optimization. This decision information can directly guide on-site maintenance operations and support power grid dispatch and control. The specific execution process is as follows:

[0192] The system automatically integrates the data obtained from this inspection, including the three-dimensional spatial coordinates of the DC partial discharge location, the specific type of defect and corresponding characteristic parameters. At the same time, it retrieves the DC transformer's factory parameters, years of operation, historical maintenance records, defect cases of the same model of equipment, as well as the current power grid's operating load, voltage level, ambient temperature and humidity, and other operating condition data to form a comprehensive data set covering defects, equipment, power grid, and environment.

[0193] Based on defect type and location as the core criteria, and combined with a pre-set risk assessment model, defects are classified into multiple dimensions for risk assessment: First, inherent risk levels are determined according to defect type, with metal tip discharge and surface discharge having higher risk levels than air gap discharge and floating potential discharge; second, equipment importance risk weights are determined based on defect location; and third, development risk levels are determined based on defect characteristic parameters (discharge amplitude, gas generation rate, and gas content percentage), with higher development risk levels indicating more characteristic parameters exceeding thresholds and more drastic changes. The system integrates these three indicators to classify defect risk levels into four levels: critical, severe, moderate, and minor, simultaneously clarifying the decision-making and handling priorities for each defect, with critical defects receiving priority in generating decision information and triggering alarms.

[0194] The system incorporates a standardized rule library covering various defects in DC transformers. This library pre-stores handling procedures, methods, technical requirements, and acceptance standards for different defect types, risk levels, and locations. Based on the identified defect type and location, the system precisely matches the corresponding handling plan from the rule library: for inherent defects such as equipment manufacturing process defects and assembly errors, it generates a full-process handling plan including disassembly and repair, component replacement, process rectification, and re-inspection and acceptance; for developing defects such as insulation aging and environmental humidity, it generates a tiered handling plan including status tracking, specialized testing, targeted remediation, and operation and maintenance optimization; for minor defects, it generates a conservative handling plan including shortening inspection cycles, real-time monitoring, and operating condition adjustments. All handling plans clearly define specific work content, work processes, technical parameter thresholds, and completion deadlines, ensuring feasibility.

[0195] The system integrates with the power grid dispatch management module and the operation and maintenance resource management module to dynamically optimize the initially generated handling plan, forming intelligent operation and maintenance dispatch information adapted to the actual situation on site: First, based on the current power grid operating load and power supply reliability requirements, the system determines the operation window for defect handling, prioritizing power outage operations during power grid off-peak hours and maintenance windows to avoid affecting the normal power supply of the power grid; Second, based on the allocation of operation and maintenance personnel, the reserve of maintenance equipment, and on-site operating conditions, the system rationally allocates operation and maintenance teams and deploys testing and maintenance tools, clarifying the allocation list and arrival time of operators, tools, and materials; Third, for critical defects that cannot be handled by immediate power outage, the system generates temporary prevention and control strategies, including reducing equipment load, adding real-time monitoring devices, and increasing the frequency of inspections, to avoid power grid failures caused by sudden deterioration of defects.

[0196] Based on the analysis of defect type, location, and cause, the system further delves into the root causes of the defects, generating prevention and optimization suggestions for the entire equipment lifecycle: specific optimization suggestions are generated for each defect. Simultaneously, the system records the defect information, handling plan, and prevention suggestions into the DC transformer archive, forming a closed-loop management system for the entire defect lifecycle, providing data reference for the early warning and handling of similar defects in the future.

[0197] By integrating the aforementioned risk levels, handling plans, operation and maintenance scheduling, and prevention and control optimization, a unified and standardized intelligent decision-making information is generated. This information includes basic defect information, risk level, handling priority, specific handling plan, operation and maintenance scheduling arrangements, and prevention and control optimization. Simultaneously, according to preset push rules, the intelligent decision-making information is pushed to the terminal equipment of the power grid dispatch center, operation and maintenance management department, and field work teams. Critical defects trigger audible and visual alarms and SMS alarms simultaneously, ensuring timely delivery of decision-making information. Furthermore, the intelligent decision-making information will also be synchronously updated to the digital twin model of the DC transformer, visually annotating the defect location, risk level, and handling status in the model, achieving linked management of defect decisions and the digital twin model.

[0198] The beneficial effects of implementing the embodiments of the present invention include: When a DC partial discharge signal is detected by a first partial discharge sensor on a digital twin model of a power grid management system, the present invention detects the DC partial discharge location based on the first partial discharge sensor and a second partial discharge sensor on the mobile detection model, where both the first and second partial discharge sensors characterize the partial discharge sensor; gas detection data at the DC partial discharge location is acquired, indicating the gas type and content of each gas; the defect type at the DC partial discharge location is determined based on the gas detection data and the pulse current information, ultra-high frequency spectrum information, and ultrasonic information indicated by the DC partial discharge signal. By coordinating the partial discharge sensors installed on the DC transformer and the partial discharge sensors on the mobile robot to locate the DC partial discharge location, the invention can adapt to various locations of DC partial discharge on the DC transformer, and can minimize the number of partial discharge sensors deployed on the DC transformer, reducing installation and detection costs; furthermore, the gas detection data and DC partial discharge signal at the DC partial discharge location enable rapid diagnosis of the defect type at the DC partial discharge location, facilitating quick processing by personnel. This results in high efficiency in DC transformer defect diagnosis, low detection costs, and rapid and convenient DC partial discharge location and defect diagnosis of the DC transformer.

[0199] like Figure 3 As shown, Figure 3 A structural block diagram of a controller 1000 according to an embodiment of this application is shown. The components of the controller 1000 include, but are not limited to, a memory 1200 and a processor 1100. The processor 1100 is connected to the memory 1200 via a bus, and the memory 1200 is used to store data.

[0200] The controller 1000 also includes an access device that enables the controller 1000 to communicate via one or more networks. Examples of such networks include a Public Switched Telephone Network (PSTN), a Local Area Network (LAN), a Wide Area Network (WAN), a Personal Area Network (PAN), or a combination of communication networks such as the Internet. The access device may include one or more of any type of wired or wireless network interface (e.g., a Network Interface Card (NIC)), such as an IEEE 802.11 Wireless Local Area Network (WLAN) wireless interface, a Global System for Microwave Access (GSM) interface, or a Wi-Fi interface. MAX interface, Ethernet interface, Universal Serial Bus (USB) interface, Cellular network interface, Bluetooth interface, Near Field Communication (NFC) interface, etc.

[0201] The controller 1000 can be any type of stationary or mobile electronic device, including mobile computers or mobile electronic devices (e.g., tablet computers, personal digital assistants, laptop computers, notebook computers, netbooks, etc.), mobile phones (e.g., smartphones), wearable electronic devices (e.g., smartwatches, smart glasses, etc.) or other types of mobile devices, or stationary electronic devices such as desktop computers or PCs. The controller 1000 can also be a mobile or stationary server.

[0202] The processor 1100 is used to execute computer-executable instructions for a partial discharge diagnostic method for a DC transformer.

[0203] The above is a schematic representation of a computing device according to this embodiment. It should be noted that the technical solution of this computing device and the technical solution of the partial discharge diagnosis method for DC transformers described above belong to the same concept. Details not described in detail in the technical solution of the computing device can be found in the description of the technical solution of the partial discharge diagnosis method for DC transformers described above.

[0204] According to an embodiment of this application, a power grid management system is also provided. This power grid management system is equipped with a controller 1000, or the power grid management system and the controller 1000 are connected via communication, enabling the power grid management system to locate partial discharge sources through the controller 1000. It should be noted that the technical solution of this computing device belongs to the same concept as the technical solution of the aforementioned partial discharge diagnosis method for DC transformers. Details not described in detail in the technical solution of the computing device can be found in the description of the technical solution of the aforementioned partial discharge diagnosis method for DC transformers.

[0205] This application embodiment also provides a storage medium, which is a computer-readable storage medium, storing a computer program that, when executed by a processor, implements the above-described method for diagnosing partial discharge of a DC transformer.

[0206] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof. The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separate, and may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0207] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as processors, such as central processing units, digital signal processors, or microprocessors executing software, or as hardware, or as integrated circuits, such as application-specific integrated circuits. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically include computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0208] The above provides a detailed description of the preferred embodiments of this application. However, this application is not limited to the above-described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A method for diagnosing partial discharge in a DC transformer, characterized in that, The method is applied to a power grid management system, which includes a digital twin model of a DC transformer and a mobile detection model corresponding to a mobile robot. Both the DC transformer and the mobile robot are equipped with multiple different types of partial discharge sensors. When a DC partial discharge signal is detected by a first partial discharge sensor on the digital twin model, the DC partial discharge position is detected based on the first partial discharge sensor and a second partial discharge sensor on the motion detection model, where both the first and second partial discharge sensors characterize the partial discharge sensor. Specifically, this includes: if at least two first partial discharge sensors on the digital twin model receive the DC partial discharge signal at equal first reception times, constructing a first plane on the first perpendicular bisector of any two first partial discharge sensors with equal first reception times, the first plane being located in a first direction; if no two first partial discharge sensors on the digital twin model have equal first reception times, constructing the first plane between the second and first partial discharge sensors; constructing a second plane in a second direction using the second and / or first partial discharge sensors located in relative positions, and constructing a third plane in a third direction, the first, second, and third directions being mutually perpendicular; determining the DC partial discharge position based on the first, second, and third planes. The step of constructing the first plane between the second partial discharge sensor and the first partial discharge sensor includes: configuring any one of the first partial discharge sensors as a first target sensor, and obtaining a first target position of the first target sensor on the DC transformer; controlling the mobile robot to move along a first direction passing through the first target position through the motion detection model, and obtaining the real-time position of the mobile robot; obtaining a second reception time of the second partial discharge sensor receiving the DC partial discharge signal at the real-time position; configuring the real-time position as a second target position when the second reception time is equal to the first reception time of the first target sensor; and constructing the first plane on a second perpendicular line between the first target position and the second target position. Acquire gas detection data at the DC partial discharge location, wherein the gas detection data indicates the gas type and the content of each gas; The defect type at the location of the DC partial discharge is determined based on the gas detection data and the pulse current information, ultra-high frequency spectrum information, and ultrasonic information indicated by the DC partial discharge signal.

2. The partial discharge diagnosis method for a DC transformer according to claim 1, characterized in that, The second plane is constructed in the second direction by means of the second partial discharge sensor and / or the first partial discharge sensor located in relative positions: If two first partial discharge sensors on the first or second vertical line receive the DC partial discharge signal at the same time, the two first partial discharge sensors with the same receiving time are configured as the second target sensors. The second plane is constructed on the third perpendicular line between the two second target sensors; If there are no two first partial discharge sensors on the first or second vertical line that receive the DC partial discharge signal at the same time, and there is at least one first partial discharge sensor, then any one of the first partial discharge sensors located on the first or second vertical line shall be configured as the third target sensor. The mobile robot is moved along the first or second vertical line, and the position corresponding to the moment when the reception time of the second partial discharge sensor on the mobile robot is equal to the reception time of the third target sensor is configured as the third target position, wherein the third target sensor is not located at the third target position. The second plane is constructed on the fourth perpendicular line between the third target location and the third target sensor; If the first partial discharge sensor is not present on the first or second vertical line, the mobile robot is moved on the first or second vertical line, and two relative positions with equal reception times of the second partial discharge sensor are configured as the fourth target position. The second plane is constructed on the fifth perpendicular line between the two fourth target locations.

3. The partial discharge diagnosis method for a DC transformer according to claim 2, characterized in that, The construction of the third plane in the direction of the third party includes: If two first partial discharge sensors on the third, fourth, or fifth vertical line receive the DC partial discharge signal at the same time, the two first partial discharge sensors with the same receiving time are configured as the fourth target sensor. The third plane is constructed on the sixth perpendicular line between the two fourth target sensors; If there are no two first partial discharge sensors receiving the DC partial discharge signal at the same time on the third, fourth, or fifth vertical line, and there is at least one first partial discharge sensor, then any one of the first partial discharge sensors located on the third, fourth, or fifth vertical line shall be configured as the fifth target sensor. The mobile robot is moved along the third, fourth, or fifth vertical line, and the position corresponding to the moment when the reception time of the second partial discharge sensor on the mobile robot is equal to the reception time of the fifth target sensor is configured as the fifth target position, wherein the fifth target sensor is not located at the fifth target position. The third plane is constructed on the seventh perpendicular line between the fifth target location and the fifth target sensor; If the first partial discharge sensor is not present on the third, fourth, or fifth vertical line, the mobile robot is moved along the third, fourth, or fifth vertical line to configure two relative positions with equal reception times of the second partial discharge sensor as the sixth target position. The third plane is constructed on the eighth perpendicular line between the two sixth target locations.

4. The partial discharge diagnosis method for a DC transformer according to claim 1, characterized in that, Determining the DC partial discharge location based on the first plane, the second plane, and the third plane includes: Configure the intersecting line between the first plane and the second plane as the target line; The intersection of the target line and the third plane is designated as the target point; Configure the spatial location of the target point as the DC partial discharge location.

5. The partial discharge diagnosis method for a DC transformer according to claim 1, characterized in that, The defect type for determining the location of the DC partial discharge based on the gas detection data and the pulse current information, ultra-high frequency spectrum information, and ultrasonic information indicated by the DC partial discharge signal includes: When the apparent discharge quantity represented by the pulse current information is less than the first discharge quantity threshold, the variance of the pulse amplitude is less than the first variance threshold, and the pulse repetition rate is greater than the first repetition rate threshold; when the ultra-high frequency spectrum information represents the spectrum being within the first frequency range, the spectral pulse width being less than the first pulse width threshold, and the spectral pulse amplitude being less than the first pulse amplitude threshold; and when the ultrasonic information represents the sound wave amplitude being less than the first sound wave threshold, the sound wave frequency being within the first sound wave frequency range, and the signal duration being less than the first signal time, the discharge type of the DC partial discharge location is configured as corona discharge. In the case where the discharge type is corona discharge: If the gas detection data indicates that the hydrogen content is between 200 and 500 μL / L, the ratio of methane to organic gas content is between 60% and 80%, the ratio of hydrogen to hydrogen plus organic gas content is between 40% and 60%, and the ratio of ethane to organic gas content is between 10% and 20%, then the defect type of the DC partial discharge location is configured as winding end oil gap electric field distortion. If the gas detection data indicates that the hydrogen content is between 100 and 300 μL / L, the ratio of methane to organic gas content is between 50% and 60%, the ratio of hydrogen to hydrogen plus organic gas content is between 50% and 70%, and the ratio of ethane to organic gas content is less than 10%, then the defect type of the DC partial discharge location is configured as poor grounding of the bushing end screen. If the gas detection data indicates that the hydrogen content is between 150 and 400 μL / L, the ratio of methane to organic gas content is between 70% and 90%, the ratio of hydrogen to hydrogen plus organic gas content is between 30% and 50%, and the organic gas content is between 100 and 200 μL / L, then the defect type of the DC partial discharge location is configured as having metal burrs on the lead surface.

6. The partial discharge diagnosis method for a DC transformer according to claim 5, characterized in that, The method further includes: When the apparent discharge quantity represented by the pulse current information is between the first discharge quantity threshold and the second discharge quantity threshold, the variance of the pulse amplitude is greater than the second variance threshold, and the pulse repetition rate is between the second repetition rate threshold and the first repetition rate threshold, when the ultra-high frequency spectrum information represents the spectrum being in the second frequency range, the spectral pulse width being between the first pulse width threshold and the second pulse width threshold, and the spectrum including energy peaks of multiple frequency bands, and when the ultrasonic information represents the sound wave amplitude being between the first sound wave threshold and the second ultrasonic threshold, the sound wave frequency being in the first sound wave frequency range and the second sound wave frequency range respectively, and the signal duration being between the first signal time and the second signal time, the discharge type of the DC partial discharge location is configured as surface discharge; In the case where the discharge type is surface discharge: If the gas detection data indicates that the hydrogen content is between 400 and 800 μL / L, the ratio of methane to organic gas content is between 30% and 40%, the ratio of ethylene to organic gas content is between 35% and 45%, the carbon monoxide content is between 200 and 300 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 5 and 8, then the defect type of the DC partial discharge location is configured as winding insulation contamination. If the gas detection data indicates that the hydrogen content is between 300 and 500 μL / L, the ratio of methane to organic gas content is between 40% and 50%, the ratio of ethylene to organic gas content is between 25% and 35%, the carbon monoxide content is between 100 and 200 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 8 and 10, then the defect type of the DC partial discharge location is configured as an air gap existing in the inner wall of the bushing. If the gas detection data indicates that the hydrogen content is between 350 and 600 μL / L, the ratio of methane to organic gas content is between 35% and 45%, the ratio of ethylene to organic gas content is between 30% and 40%, the carbon monoxide content is between 150 and 250 μL / L, and the ratio of ethane to organic gas content is between 10% and 15%, then the defect type of the DC partial discharge location is configured as lead wire outer insulation layer damage.

7. The partial discharge diagnosis method for a DC transformer according to claim 5, characterized in that, The method further includes: When the apparent discharge quantity represented by the pulse current information is between the second discharge quantity threshold and the third discharge quantity threshold, the pulse amplitude exhibits a clustered distribution, and the pulse repetition rate is between the third repetition rate threshold and the second repetition rate threshold; when the ultra-high frequency spectrum information represents the spectrum being within the third frequency range, the spectral pulse width being between the second pulse width threshold and the third pulse width threshold, and the spectral pulse amplitude being greater than the second pulse amplitude threshold; and when the ultrasonic information represents the sound wave amplitude being between the second sound wave threshold and the third ultrasonic wave threshold, the sound wave frequency being within the third sound wave frequency range, and the signal duration being between the second signal time and the third signal time, the discharge type of the DC partial discharge location is configured as spark discharge; In the case where the discharge type is spark discharge: If the gas detection data indicates that the hydrogen content is between 1000 and 1500 μL / L, the ratio of ethylene to organic gas content is between 40% and 50%, the ratio of acetylene to organic gas content is between 5% and 8%, the carbon monoxide content is between 500 and 600 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 3 and 4, then the defect type of the DC partial discharge location is configured as winding insulation failure. If the gas detection data indicates that the hydrogen content is between 800 and 1200 μL / L, the ratio of methane to organic gas content is between 40% and 45%, the ratio of ethylene to organic gas content is between 35% and 40%, the ratio of acetylene to organic gas content is between 3% and 5%, and the carbon monoxide content is between 300 and 400 μL / L, then the defect type of the DC partial discharge location is configured as core insulation failure. If the gas detection data indicates that the hydrogen content is between 900 and 1300 μL / L, the ratio of methane to organic gas content is between 30% and 35%, the ratio of ethylene to organic gas content is between 35% and 45%, the ratio of acetylene to organic gas content is between 4% and 7%, and the organic gas content is between 400 and 600 μL / L, then the defect type of the DC partial discharge location is configured as the presence of metal debris in the transformer oil.

8. The partial discharge diagnosis method for a DC transformer according to claim 5, characterized in that, The method further includes: When the apparent discharge quantity represented by the pulse current information is greater than the third discharge quantity threshold, the pulse amplitude exhibits a peak-like distribution, and the pulse repetition rate is less than the third repetition rate threshold; when the ultra-high spectrum information represents the spectrum being in the fourth frequency range, the spectrum pulse width being greater than the third pulse width threshold, and the spectrum pulse amplitude variance being less than the third variance threshold; and when the ultrasonic information represents the sound wave amplitude being greater than the third ultrasonic threshold, the sound wave frequency being in the fourth sound wave frequency range, and the signal duration being greater than the third signal time, the discharge type of the DC partial discharge location is configured as arc discharge. In the case where the discharge type is arc discharge: If the gas detection data indicates that the hydrogen content is between 2000 and 5000 μL / L, the ratio of acetylene to organic gas content is between 30% and 50%, the carbon monoxide content is between 1000 and 2000 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 1 and 2, then the defect type of the DC partial discharge location is configured as winding insulation breakdown. If the gas detection data indicates that the hydrogen content is between 1500 and 3000 μL / L, the ratio of acetylene to organic gas content is between 40% and 60%, the carbon monoxide content is between 600 and 1200 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 2 and 3, then the defect type of the DC partial discharge location is configured as lead connector damage. If the gas detection data indicates that the hydrogen content is between 1800 and 3500 μL / L, the ratio of acetylene to organic gas content is between 35% and 55%, the ratio of ethane to organic gas content is between 5% and 10%, the carbon monoxide content is between 700 and 1500 μL / L, and the ratio of carbon dioxide to carbon monoxide content is between 1.5 and 2.5, then the defect type of the DC partial discharge location is configured as tap changer contact failure.

9. A partial discharge diagnostic device for a DC transformer, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the partial discharge diagnosis method for a DC transformer according to any one of claims 1-8.

10. A computer storage medium, characterized in that, The computer storage medium stores computer-executable instructions, which are used to execute the partial discharge diagnosis method for DC transformers according to any one of claims 1-8.

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