Converter transformer partial discharge online monitoring and early warning method and system based on ultrahigh frequency method
Patent Information
- Application Number
- CN202510251039.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2025-02-28
- Filing Date
- 2025-03-04
- Publication Date
- 2025-07-01
Smart Images
Figure CN120233192A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of on-line monitoring of power transmission and transformation equipment, and more specifically, to a method and system for on-line monitoring and early warning of partial discharge in a converter transformer based on the ultra-high frequency method. Background Art
[0002] The UHV converter transformer is the core equipment of the new energy supply and consumption system. When a fault occurs inside the converter transformer, if it cannot act in time, the converter transformer body may be damaged due to the internal fault pressure shock, and even cause explosion and fire accidents. The situation that the hidden dangers of the converter transformer affect the safe and stable operation of the DC is very serious. At present, the current differential protection and mechanical gas protection of the converter transformer cannot fully ensure the safe and stable operation of the converter transformer body, and it is also difficult to achieve sensitive and reliable detection in the stage of slight faults or serious defects of the converter transformer. Therefore, it is particularly urgent to strengthen the comprehensive perception and intelligent analysis of the state of the converter transformer equipment.
[0003] Condition monitoring is an effective technical means for early warning of latent defects in converter transformers. The current condition monitoring and diagnosis of converter transformers mainly rely on oil chromatography devices and partial discharge devices. The on-line oil chromatography monitoring device mainly includes a highly reliable oil chromatography device, a single hydrogen device, and a single acetylene device. However, due to the fact that the time for the oil inlet and return, degassing, detection and other links of the device cannot be compressed or omitted, the detection period of the current UHV in-service oil chromatography on-line monitoring device is 2h, and the early warning ability for sudden faults is insufficient. Summary of the Invention
[0004] In view of the above problems, the present invention proposes a method for on-line monitoring and early warning of partial discharge in a converter transformer based on the ultra-high frequency method, including:
[0005] On-line monitoring is carried out on the target converter transformer based on an ultra-high frequency sensor, and the ultra-high frequency signal of the whole process from the start of typical defect discharge to breakdown of the target converter transformer is obtained;
[0006] The characteristic parameters in the ultra-high frequency signal are extracted, and based on the pre-established early warning strategy, a partial discharge early warning of the converter transformer is issued according to the characteristic parameters.
[0007] Optionally, the pre-established early warning strategy includes:
[0008] Obtain the characteristic laws of each stage of the defect discharge of the converter transformer, and formulate an early warning strategy based on the characteristic laws.
[0009] Optionally, obtaining the characteristic laws of each stage of the defect discharge of the converter transformer includes:
[0010] Set a typical defect model inside the full-scale converter transformer model, and simulate the converter transformer by the boosting method. For the typical defect from the initial discharge to the arc breakdown process, obtain the simulation test data. Based on the simulation test data, obtain the characteristic laws of each stage of the defect discharge of the converter transformer.
[0011] Optionally, the typical defect model includes:
[0012] Oil-paper insulation discharge model and oil-gap insulation discharge model.
[0013] Optionally, the process of the typical defect from the initial discharge to the arc breakdown includes:
[0014] Discharge initiation stage, discharge development stage, and discharge severity until breakdown stage.
[0015] Optionally, the characteristic laws include:
[0016] The characteristic laws of the average value of the PD signal amplitude, the discharge pulse frequency, and the amplitude change rate during the discharge development process.
[0017] Optionally, the early warning strategy includes: PD early warning logic;
[0018] The PD early warning logic includes:
[0019] When during the discharge development process, there is a characteristic law of two-step sudden changes in the amplitude, and any two of the three characteristic parameters of the average value of the amplitude, the discharge pulse frequency, and the amplitude change rate exceed the limit value, issue a PD early warning.
[0020] On the other hand, the present invention also proposes an on-line monitoring and early warning system for PD of a converter transformer based on the UHF method, including:
[0021] An on-line monitoring unit, used to perform on-line monitoring on the target converter transformer based on UHF sensors, and obtain the UHF signals of the whole process from the initial discharge to the breakdown of the typical defects of the target converter transformer;
[0022] An early warning unit, used to extract the characteristic parameters from the UHF signals, and based on the pre-established early warning strategy, issue a PD early warning for the converter transformer according to the characteristic parameters.
[0023] Optionally, the pre-established early warning strategy includes:
[0024] Obtain the characteristic laws of each stage of the defect discharge of the converter transformer, and formulate an early warning strategy based on the characteristic laws.
[0025] Optionally, obtaining the characteristic laws of each stage of the defect discharge of the converter transformer includes:
[0026] Set up a typical defect model inside the full-scale converter transformer model, and simulate the converter transformer by the step-up method for the process of the typical defect from initial discharge to arc breakdown to obtain simulation test data. Based on the simulation test data, obtain the characteristic laws of each stage of the defect discharge of the converter transformer.
[0027] Optionally, the typical defect model includes:
[0028] Oil-paper insulation discharge model and oil-gap insulation discharge model.
[0029] Optionally, the process of the typical defect from initial discharge to arc breakdown includes:
[0030] Discharge initiation stage, discharge development stage, and discharge severity until breakdown stage.
[0031] Optionally, the characteristic laws include:
[0032] The characteristic laws of the average value of the partial discharge signal amplitude, the discharge pulse frequency, and the amplitude change rate during the discharge development process.
[0033] Optionally, the early warning strategy includes: partial discharge early warning logic;
[0034] The partial discharge early warning logic includes:
[0035] When during the discharge development process, there is a characteristic law of two stepwise mutations in the amplitude, and any two of the three characteristic parameters of the average value of the amplitude, the discharge pulse frequency, and the amplitude change rate exceed the limit value, issue a partial discharge early warning.
[0036] On the other hand, the present invention also provides a computing device, including: one or more processors;
[0037] The processor is used to execute one or more programs;
[0038] When the one or more programs are executed by the one or more processors, the method as described above is implemented.
[0039] On the other hand, the present invention also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed, the method as described above is implemented.
[0040] Compared with the prior art, the beneficial effects of the present invention are:
[0041] The present invention provides an on-line monitoring and early warning method for partial discharge of a converter transformer based on the ultra-high frequency method, including: on-line monitoring of a target converter transformer based on an ultra-high frequency sensor, and obtaining ultra-high frequency signals of the whole process from the start of typical defect discharge to breakdown of the target converter transformer; extracting characteristic parameters from the ultra-high frequency signals, and issuing a partial discharge early warning for the converter transformer based on the characteristic parameters according to a pre-established early warning strategy. The present invention can realize early warning of internal discharge of a converter transformer. Description of the Drawings
[0042] Figure 1 It is a flowchart of the method of the present invention;
[0043] Figure 2 It is a schematic diagram of the installation position of an in-built ultra-high frequency sensor of a converter transformer in an embodiment of the method of the present invention
[0044] Figure 3 It is a schematic diagram of the average discharge amplitude of an ultra-high frequency signal in an embodiment of the method of the present invention;
[0045] Figure 4 It is a schematic diagram of the discharge frequency of an ultra-high frequency signal in an embodiment of the method of the present invention;
[0046] Figure 5 It is a schematic diagram of the "double mutation + two out of three" early warning strategy in an embodiment of the method of the present invention;
[0047] Figure 6 It is a structural diagram of the system of the present invention. Detailed Embodiments
[0048] Now, exemplary embodiments of the present invention will be introduced with reference to the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely, and to fully convey the scope of the present invention to those skilled in the art. The terms in the exemplary embodiments shown in the drawings are not limitations on the present invention. In the drawings, the same units / components use the same reference numerals.
[0049] Unless otherwise specified, the terms (including scientific and technical terms) used herein have the ordinary meaning understood by those skilled in the art. In addition, it can be understood that the terms defined in the commonly used dictionary should be understood as having a consistent meaning with the context of the relevant field, and should not be understood as idealized or overly formal meanings.
[0050] Embodiment 1:
[0051] The present invention proposes an on-line monitoring and early warning method for partial discharge of a converter transformer based on the ultra-high frequency method, as Figure 1 shown, including:
[0052] Step 1: Conduct on-line monitoring of the target converter transformer based on UHF sensors, and obtain the UHF signals of the whole process from the initiation to breakdown of typical defects in the target converter transformer.
[0053] Step 2: Extract the characteristic parameters from the UHF signals, and issue a partial discharge warning for the converter transformer based on the pre-established warning strategy according to the characteristic parameters.
[0054] Among them, the pre-established warning strategy includes:
[0055] Obtain the characteristic laws of each stage of the defective discharge of the converter transformer, and formulate a warning strategy based on the characteristic laws.
[0056] Among them, obtaining the characteristic laws of each stage of the defective discharge of the converter transformer includes:
[0057] Set a typical defect model inside the prototype converter transformer model, and simulate the converter transformer by the boosting method. The typical defect goes through the process from the initial discharge to the arc breakdown to obtain the simulation test data. Based on the simulation test data, obtain the characteristic laws of each stage of the defective discharge of the converter transformer.
[0058] Among them, the typical defect model includes:
[0059] Oil-paper insulation discharge model and oil-gap insulation discharge model.
[0060] Among them, the process of the typical defect from the initial discharge to the arc breakdown includes:
[0061] Initial discharge stage, discharge development stage, and discharge severity until breakdown stage.
[0062] Among them, the characteristic laws include:
[0063] The characteristic laws of the average value of the amplitude of the partial discharge signal, the discharge pulse frequency, and the amplitude change rate during the discharge development process.
[0064] Among them, the warning strategy includes: partial discharge warning logic;
[0065] The partial discharge warning logic includes:
[0066] When, during the discharge development process, there is a characteristic law of two-step sudden changes in the amplitude, and any two of the three characteristic parameters of the average value of the amplitude, the discharge pulse frequency, and the amplitude change rate exceed the limit value, issue a partial discharge warning.
[0067] In the present invention, a defect model is set inside a full-scale converter transformer, and a partial discharge test is carried out by the step-up method. The signals of the whole process from the start of defect discharge to breakdown are collected by an in-built ultra-high frequency sensor. According to the discharge test data of the full-scale transformer, the characteristic laws of the partial discharge signals with the development of defects are summarized, and an early warning strategy is formulated in combination with the discharge laws.
[0068] The internal defects of the converter transformer are divided into two categories: oil-paper insulation discharge and oil-gap insulation discharge. The development path of oil-paper insulation discharge includes the breakdown of oil insulation and the breakdown / cross-talk of paper insulation. The breakdown path of oil-gap insulation discharge only includes the breakdown of oil insulation.
[0069] The step-up method is the stepwise voltage increase method. First, the test voltage is increased to 0.2 times the rated voltage to obtain background partial discharge signals / noise signals; then the voltage is increased at 5% intervals, and each voltage is maintained for 10 minutes. When a discharge higher than 1000 pC occurs (judged by the partial discharge detector), record the partial discharge inception voltage; gradually increase the test voltage according to the stepwise voltage increase method until a single discharge above 10000 pC occurs, and keep this voltage constant until breakdown occurs.
[0070] The ultra-high frequency sensor for collecting the internal partial discharge signals of the converter transformer is installed on the long axis plane of the full-scale transformer. The in-built ultra-high frequency sensor is integrated with the flange and connected to the tank body, with high detection sensitivity. The in-built ultra-high frequency sensor can sense ultra-high frequency electromagnetic pulse signals in the range of 300 - 1500 MHz. When detecting the peak value of the transient electric field intensity of 3 mV / m in GTEM, the signal-to-noise ratio should not be less than 2 times (or 6 dB), and the dynamic range should not be less than 40 dB.
[0071] The ultra-high frequency characteristic parameters during the development process of the partial discharge signals include the average amplitude value, amplitude change rate, and discharge pulse frequency. Further, for the average amplitude value, since the step-like jump of the amplitude will cause a large increase in the average amplitude, the amplitude fluctuation after the amplitude jump should be considered when designing the upper limit value of the average amplitude; for the amplitude change rate, when calculating the partial discharge amplitude change rate, the slopes of multiple step lengths (considering intervals of 1 point, 5 points, and 10 points) should be considered, and different upper limit values of the slopes should be set according to different step lengths; the setting of the upper limit values of the characteristic parameters should be gradually iteratively optimized according to the test results to improve the sensitivity and reliability of the partial discharge signal detection.
[0072] The whole process from the start of defect discharge to breakdown includes: the discharge inception stage, the discharge development stage, the severe discharge stage until breakdown.
[0073] At different development stages of the defect, the UHF partial discharge signal shows an obvious step-like development law. For the oil-paper discharge process, in the initial stage of discharge, the UHF signal shows a step-like upward jump, with a relatively large amplitude change rate and an increase in pulse frequency at this time. In the discharge development stage, the amplitude of the UHF signal is maintained at a relatively high level and fluctuates within a small range, and the average value of the UHF signal amplitude increases significantly at this time. In the severe discharge stage, the amplitude of the UHF signal of the oil-paper discharge will show a step-like mutation again. For the oil-gap discharge process, the UHF signal fluctuates within a small range in the initial stage and the development stage of discharge, and the amplitude is relatively stable. In the severe discharge stage, the amplitude of the UHF signal shows a step-like mutation once.
[0074] According to the characteristic law that the average amplitude, discharge pulse frequency, and amplitude change rate of the partial discharge signal generally show an increasing trend during the discharge development process, the proposed early warning strategy designs a partial discharge early warning logic of "double mutation + two out of three".
[0075] "Double mutation" refers to the characteristic law that the amplitude shows two step-like mutations during the discharge development process. Each time a mutation occurs in the partial discharge signal, it is necessary to judge whether the second mutation will occur within the subsequent 30 s, and both positive and negative mutations of the amplitude need to be considered; "two out of three" means that any two of the three characteristic parameters of the average amplitude, discharge pulse frequency, and amplitude change rate exceed the limit value.
[0076] In this embodiment, the UHF sensor for receiving the internal partial discharge signal of the converter transformer is installed on the long-axis plane of the full-scale transformer, as Figure 2 shown. The internal defect of the converter transformer is tip discharge, the tip electrode is the high-voltage electrode, and the low-voltage electrode is cardboard. The discharge process belongs to oil-paper insulation discharge. The rated voltage of the full-scale transformer is 110 kV, and the phase voltage is 63.5 kV. The step-up voltage method is adopted during the voltage application process. First, it is raised to 12.7 kV (0.2 times the rated voltage) to obtain the background partial discharge signal / noise signal; then it is raised step by step at a 5% interval, and each voltage is maintained for 10 min. When a discharge higher than 1000 pC occurs (judged by the partial discharge detector), record the partial discharge inception voltage; gradually increase the test voltage until a single discharge above 10000 pC occurs, and keep this voltage constant until breakdown occurs. The average amplitude of the UHF partial discharge signal monitored by the built-in UHF sensor during the voltage increase process is as Figure 3 shown, and the UHF partial discharge pulse frequency is as Figure 4 shown.
[0077] Specifically, according to Figure 3 、 Figure 4Analysis of the discharge test data of a full-scale transformer shows that the partial discharge signal exhibits a three-stage characteristic of "mutation - maintenance - mutation" as the defect develops. At the initial stage of discharge, the UHF signal shows a stepwise upward jump, with a relatively large amplitude change rate and an increase in pulse frequency at this time. During the discharge development stage, the UHF signal amplitude is maintained at a relatively high level and fluctuates within a small range, and the average value of the UHF signal amplitude increases significantly at this time. In the severe discharge stage, the UHF signal amplitude of oil-paper discharge will show a stepwise mutation again.
[0078] Furthermore, according to the experimental law that the average amplitude value, discharge pulse frequency, and amplitude change rate of the partial discharge signal generally show an increasing trend during the discharge development process, a detection and confirmation logic for the occurrence of partial discharge of "double mutation + two out of three" is designed, as Figure 5 shown.
[0079] Specifically, the amplitude startup criterion is that the maximum amplitude value of the detected partial discharge signal is greater than the set threshold. This threshold value should be set with high sensitivity but should be able to avoid the amplitude of background noise. After the amplitude is greater than the startup value, a time window is started, and the characteristic values of the average amplitude value, discharge pulse frequency, and amplitude change rate are extracted. Among them, when two of the two characteristic values of "average amplitude value" and "amplitude change rate" exceed the limit, the "two out of three" logic is satisfied.
[0080] Specifically, when the partial discharge signal undergoes 1 mutation and the second mutation is detected within the subsequent 30 s, the "double mutation" logic is satisfied.
[0081] Based on Figure 4 the "double mutation + two out of three" early warning logic, when two of the three characteristic values have exceeded the limit or the amplitude shows a double mutation characteristic, it is determined that insulation breakdown is imminent, and a protection tripping operation is performed.
[0082] Embodiment 2:
[0083] The present invention also proposes an on-line monitoring and early warning system 200 for partial discharge of a converter transformer based on the UHF method, as Figure 6 shown, including:
[0084] An on-line monitoring unit 201, configured to perform on-line monitoring on a target converter transformer based on a UHF sensor, and obtain UHF signals of the entire process from the start of discharge to breakdown of typical defects of the target converter transformer;
[0085] An early warning unit 202, configured to extract characteristic parameters from the UHF signals, and based on a pre-established early warning strategy, issue an early warning of partial discharge of the converter transformer according to the characteristic parameters.
[0086] Among them, the pre-established early warning strategy includes:
[0087] Obtain the characteristic laws of each stage of the defect discharge of the converter transformer, and formulate an early warning strategy based on the characteristic laws.
[0088] Among them, obtaining the characteristic laws of each stage of the defect discharge of the converter transformer includes:
[0089] Setting a typical defect model inside the prototype converter transformer model, simulating the converter transformer by the boosting method, and obtaining simulation test data from the starting discharge to the arc breakdown process of the typical defect. Based on the simulation test data, obtaining the characteristic laws of each stage of the defect discharge of the converter transformer.
[0090] Among them, the typical defect model includes:
[0091] Oil-paper insulation discharge model and oil-gap insulation discharge model.
[0092] Among them, the process from the starting discharge to the arc breakdown of the typical defect includes:
[0093] Discharge starting stage, discharge developing stage, and discharge severe until breakdown stage.
[0094] Among them, the characteristic laws include:
[0095] The characteristic laws of the average value of the partial discharge signal amplitude, the discharge pulse frequency, and the amplitude change rate during the discharge development process.
[0096] Among them, the early warning strategy includes: partial discharge early warning logic;
[0097] The partial discharge early warning logic includes:
[0098] When during the discharge development process, there is a characteristic law of two stepwise mutations in the amplitude, and any two of the three characteristic parameters of the average value of the amplitude, the discharge pulse frequency, and the amplitude change rate exceed the limit values, a partial discharge early warning is issued.
[0099] The present invention uses an in-built ultra-high frequency sensor to receive the electrical signals generated by the partial discharge inside the converter transformer, extracts the characteristic parameters of "average value of the amplitude, discharge pulse frequency, amplitude change rate" that characterize the whole process of the occurrence, development, and breakdown of different types of partial discharges. According to the "double mutation + two out of three" logical judgment, the development of the fault discharge can be analyzed quickly and reliably, and the fault discharge stage can be accurately obtained before the internal fault insulation breakdown of the converter transformer. When the early warning strategy determines that two of the three characteristic values have exceeded the limit or there is a double mutation characteristic in the amplitude, it is determined that the insulation breakdown is about to occur, and a protection tripping action is performed. The present invention gives full play to the advantages of high detection sensitivity and strong anti-interference ability of the in-built ultra-high frequency sensor, and can realize the early warning of the internal discharge of the converter transformer.
[0100] Example 3:
[0101] Based on the same inventive concept, the present invention also provides a computer device, which includes a processor and a memory. The memory is used to store a computer program, and the computer program includes program instructions. The processor is used to execute the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function, so as to implement the steps of the method in the above embodiments.
[0102] Embodiment 4:
[0103] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory). The computer-readable storage medium is a memory device in a computer device and is used to store programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and, of course, the extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, and the operating system of the terminal is stored in this storage space. And, one or more instructions suitable for being loaded and executed by the processor are also stored in this storage space. These instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The one or more instructions stored in the computer-readable storage medium can be loaded and executed by the processor to implement the steps of the method in the above embodiments.
[0104] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The solutions in the embodiments of the present invention can be implemented in various computer languages. For example, object-oriented programming languages such as Java and interpreted scripting languages such as JavaScript, etc.
[0105] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for realizing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.
[0106] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing devices to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device that realizes the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.
[0107] These computer program instructions can also be loaded onto a computer or other programmable data processing devices, such that a series of operation steps are executed on the computer or other programmable devices to generate a computer-implemented process, so that the instructions executed on the computer or other programmable devices provide steps for realizing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.
[0108] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concepts. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.
[0109] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.
Claims
1. A method for online monitoring and early warning of partial discharge of converter transformer based on ultra-high frequency method, characterized in that: include: Performing online monitoring of the target converter transformer based on a UHF sensor, and obtaining UHF signals of the entire process from the initiation of discharge to breakdown of a typical defect of the target converter transformer; Characteristic parameters in the UHF signal are extracted, and based on a pre-established early warning strategy and the characteristic parameters, a partial discharge early warning of the converter transformer is issued.
2. The method for online monitoring and early warning of partial discharge of converter transformer according to claim 1 is characterized in that: Develop an early warning strategy in advance, including: The characteristic laws of each stage of defective discharge of the converter transformer are obtained, and an early warning strategy is formulated based on the characteristic laws.
3. The method for online monitoring and early warning of partial discharge of converter transformer according to claim 1 is characterized in that: The method of obtaining characteristic rules of each stage of defective discharge of converter transformer includes: A typical defect model is set up inside the real converter transformer model, and the converter transformer is simulated by the boost method. The typical defect process from initial discharge to arc breakdown is obtained to obtain simulation test data. Based on the simulation test data, the characteristic laws of each stage of converter transformer defect discharge are obtained.
4. The method for online monitoring and early warning of partial discharge of converter transformer according to claim 3 is characterized in that: The typical defect model includes: Oil-paper insulation discharge model and oil-gap insulation discharge model.
5. The method for online monitoring and early warning of partial discharge of converter transformer according to claim 3 is characterized in that: The typical defects from the initial discharge to the arc breakdown process include: The discharge initial stage, discharge development stage and discharge severe until breakdown stage.
6. The method for online monitoring and early warning of partial discharge of converter transformer according to claim 1, characterized in that: The characteristic laws include: The characteristic laws of the average amplitude value, discharge pulse frequency and amplitude change rate of the partial discharge signal during the discharge development process.
7. The method for online monitoring and early warning of partial discharge of converter transformer according to claim 1, characterized in that: The early warning strategy includes: partial discharge early warning logic; The partial discharge warning logic includes: When the amplitude shows two step-like mutation characteristics during the discharge process, and any two of the three characteristic parameters, namely the amplitude average value, the discharge pulse frequency and the amplitude change rate, exceed the limit value, a partial discharge warning is issued.
8. An online monitoring and early warning system for partial discharge of converter transformer based on ultra-high frequency method, characterized in that: include: An online monitoring unit, used for online monitoring of a target converter transformer based on a UHF sensor, and obtaining UHF signals of the entire process from the initiation of discharge to breakdown of a typical defect of the target converter transformer; The early warning unit is used to extract characteristic parameters from the ultra-high frequency signal, and based on a pre-established early warning strategy and the characteristic parameters, issue a partial discharge early warning of the converter transformer.
9. The converter transformer partial discharge online monitoring and early warning system according to claim 1 is characterized in that: Develop an early warning strategy in advance, including: The characteristic laws of each stage of defective discharge of the converter transformer are obtained, and an early warning strategy is formulated based on the characteristic laws.
10. The converter transformer partial discharge online monitoring and early warning system according to claim 8, characterized in that: The method of obtaining characteristic rules of each stage of defective discharge of converter transformer includes: A typical defect model is set up inside the real converter transformer model, and the converter transformer is simulated by the boost method. The typical defect process from initial discharge to arc breakdown is obtained to obtain simulation test data. Based on the simulation test data, the characteristic laws of each stage of converter transformer defect discharge are obtained.
11. The converter transformer partial discharge online monitoring and early warning system according to claim 10, characterized in that: The typical defect model includes: Oil-paper insulation discharge model and oil-gap insulation discharge model.
12. The converter transformer partial discharge online monitoring and early warning system according to claim 10, characterized in that: The typical defects from the initial discharge to the arc breakdown process include: The discharge initial stage, discharge development stage and discharge severe until breakdown stage.
13. The converter transformer partial discharge online monitoring and early warning system according to claim 8, characterized in that: The characteristic laws include: The characteristic laws of the average amplitude value, discharge pulse frequency and amplitude change rate of the partial discharge signal during the discharge development process.
14. The converter transformer partial discharge online monitoring and early warning system according to claim 8, characterized in that: The early warning strategy includes: partial discharge early warning logic; The partial discharge warning logic includes: When the amplitude shows two step-like mutations during the discharge process, and any two of the three characteristic parameters, namely the amplitude average value, the discharge pulse frequency and the amplitude change rate, exceed the limit value, a partial discharge warning is issued.
15. A computer device, characterized in that: include: one or more processors; a processor for executing one or more programs; When the one or more programs are executed by the one or more processors, the method according to any one of claims 1 to 7 is implemented.
16. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the method according to any one of claims 1 to 7 is implemented.