Method and system for evaluating insulation health state of mixed insulation oil paper system

Abstract

The invention discloses a method and system for evaluating the insulation health state of a mixed insulating oil paper system, and relates to the technical field of transformer state evaluation, and the method comprises the steps: determining the partial discharge characteristic parameters of the mixed insulating oil paper system according to a standard and a test result, and carrying out the per-unit processing of the partial discharge characteristic parameters; different health states of the mixed insulation oil paper system are divided according to test results, and insulation health state grades of the oil paper system corresponding to the different states are formulated; based on the insulation health state grade of the oil paper system, the partial discharge characteristic parameter per unit value and the radar map, constructing an insulation health state evaluation model of the mixed insulation oil oil paper system; and the health state is determined by inputting actual mixed insulating oil paper system partial discharge characteristic parameters into the evaluation model, and the accuracy of the evaluation model is verified. The method for evaluating the insulation health state of the mixed insulation oil paper system provides technical support for accurately and effectively evaluating the insulation health state of the mixed insulation oil paper system.

Description

Technical Field

[0001] The invention relates to the field of transformer status assessment, and in particular to a method and system for assessing the insulation health status of a mixed insulating oil-paper system. Background Art

[0002] As the core component of oil-immersed transformers, the insulating oil-paper system is of great significance for the stable operation of transformers and the normal development of society. Mineral oil has been used in transformer oil-paper systems for about a century due to its excellent insulation performance. However, due to its low flash point and ignition point, non-renewable and poor biodegradability, it can no longer meet the higher requirements for liquid dielectric safety, fire protection and green environmental protection in the future. Natural ester is an environmentally friendly liquid dielectric with high biodegradability, excellent fire resistance and a wide source of raw materials. It can effectively delay the aging process of the oil-paper system, but it needs to be refined and modified to overcome the shortcomings of easy moisture absorption, high acid value and poor antioxidant performance, and then be applied to the oil-paper system. Synthetic ester, as a new type of carboxylic acid insulating oil, has the advantages of high ignition point, easy degradation and good antioxidant performance, but due to its high production cost, it has not been widely used in the oil-paper system.

[0003] The mixed insulating oil made of mineral oil, natural ester and synthetic ester in a certain proportion has excellent physical, chemical and electrical properties. Its main parameters meet the IEC 60296-2012 mineral oil standard. It can effectively overcome the problems of difficult degradation of mineral oil, easy oxidation of natural ester and high application cost of synthetic ester. It has become a good substitute for liquid dielectrics used in insulating oil-paper system. At present, 10kV, 35kV and 110kV transformers using this insulating oil-paper system have been put into operation in Henan, Sichuan and Chongqing.

[0004] During the long-term operation of oil-immersed transformers, the insulating oil-paper system will produce irreversible degradation under the action of electrical stress, resulting in the degradation of transformer insulation performance or even failure, which seriously threatens the operation safety of the transformer and even the entire power system. Therefore, it is crucial to timely evaluate the insulation health status of the oil-paper system, discover its abnormal state and formulate reasonable maintenance measures to ensure the safety of the entire power grid. Since the degradation process of the insulating oil-paper system is relatively complex, it is necessary to carefully select characteristic parameters that can effectively reflect its state in order to accurately evaluate its actual insulation health status. Domestic and foreign standards and test results show that partial discharge characteristic parameters are one of the most effective characteristic parameters reflecting the insulation health status of the insulating oil-paper system. At present, most of the insulation health status assessment models of the oil-paper system use too many characteristic parameters, and there are problems such as redundant evaluation indicators and complex and lengthy evaluation processes. In addition, the current insulation health status assessment models of the oil-paper system are mostly based on the mineral oil-paper system, and there is a lack of health status assessment models for the mixed insulating oil-paper system.

[0005] In view of the above problems, the present invention selects the maximum discharge amount, average discharge amount and discharge pulse number, three local discharge characteristic parameters that best reflect the health status of the mixed insulating oil-paper system, based on the test results, to establish a mixed oil-paper system health status assessment model. The present invention provides a mixed insulating oil-paper system health status assessment method, which includes five aspects: determining the local discharge characteristic parameters of the mixed insulating oil-paper system according to the standards and test results, and normalizing the local discharge characteristic parameters; dividing the insulation health status level of the oil-paper system; constructing a mixed insulating oil-paper system insulation health status assessment model based on the radar chart; determining its health status by inputting the actual mixed insulating oil-paper system local discharge characteristic parameters into the assessment model; and finally verifying the accuracy of the assessment model. It is applicable to the field of transformer status assessment. Summary of the invention

[0006] In view of the above-mentioned problems, the present invention is proposed.

[0007] Therefore, the problem to be solved by the present invention is: how to solve the problems that most of the current oil-paper system insulation health status assessment models use too many characteristic parameters, there are redundant evaluation indicators, and the assessment process is complicated and lengthy.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for evaluating the insulation health status of a hybrid insulating oil-paper system, comprising: determining the local discharge characteristic parameters of the hybrid insulating oil-paper system according to standards and test results, and normalizing the local discharge characteristic parameters; dividing the hybrid insulating oil-paper system into different health states according to the test results, and formulating the insulation health state level of the oil-paper system corresponding to different states; constructing an insulation health state evaluation model for the hybrid insulating oil-paper system based on the insulation health state level of the oil-paper system, the local discharge characteristic parameter normalized value and the radar chart; determining the health state by inputting the actual local discharge characteristic parameters of the hybrid insulating oil-paper system into the evaluation model, and verifying the accuracy of the evaluation model.

[0009] As a preferred scheme of the insulation health status assessment method of a hybrid insulating oil-paper system described in the present invention, wherein: the local discharge characteristic parameters include the maximum discharge amount, the average discharge amount and the number of discharge pulses; the change of the local discharge characteristic parameters of the hybrid insulating oil-paper system with the external applied voltage under three different oil gap distances is obtained.

[0010] As a preferred solution of the insulation health status assessment method of a hybrid insulating oil-paper system described in the present invention, the standardization process includes the maximum discharge capacity Q max , average discharge capacity Q mean The three local discharge characteristic parameters, namely, the number of discharge pulses N, are normalized and expressed as follows:

[0011]

[0012]

[0013] Among them, Q max is the maximum discharge capacity actually measured, Q max0 is the maximum discharge capacity reference value, Q* max is the maximum discharge capacity per unit value, Q mean is the actual measured average discharge capacity, Q mean0 is the average discharge capacity reference value, Q* mean is the per-unit value of the average discharge capacity, N is the actual number of discharge pulses, N0 is the reference value of the discharge pulse number, and N* is the per-unit value of the discharge pulse number.

[0014] As a preferred solution of the insulation health status assessment method of a hybrid insulating oil-paper system described in the present invention, the insulation health status level of the oil-paper system includes the maximum discharge capacity Q obtained according to the calculated three partial discharge characteristic parameter standard values. max , average discharge capacity Q mean The per-unit value variation curves of the discharge pulse number N are plotted, and the per-unit value ranges of the three partial discharge characteristic parameters are divided into normal, abnormal and severe types according to the curve variation trends.

[0015] As a preferred solution of the insulation health status assessment method of a hybrid insulating oil-paper system described in the present invention, wherein: the insulation health status level of the oil-paper system also includes obtaining a maximum discharge amount low threshold, a maximum discharge amount high threshold, an average discharge amount low threshold, an average discharge amount high threshold, a discharge pulse number low threshold and a discharge pulse number high threshold according to the per-unit value change curve; for the maximum discharge amount per-unit value Q* max , if Q* max If Q* is greater than or equal to 0 and less than or equal to the maximum discharge low threshold, the health status level is normal. max If Q* is greater than the maximum discharge capacity low threshold and less than or equal to the maximum discharge capacity high threshold, the health status level is abnormal. max If the discharge capacity is greater than the high threshold value, the health status level is severe; for the average discharge capacity per unit value Q* mean , if Q* mean If Q* is greater than or equal to 0 and less than or equal to the average discharge low threshold, the health status level is normal. mean If the average discharge amount is greater than the low threshold and less than or equal to the high threshold, the health status level is abnormal. meanIf it is greater than the high threshold of the average discharge amount, the health status level is serious; for the actual number of discharge pulses N, if N is greater than or equal to 0 and less than or equal to the low threshold of the number of discharge pulses, the health status level is normal; if N is greater than the low threshold of the number of discharge pulses and less than or equal to the high threshold of the number of discharge pulses, the health status level is abnormal; if N is greater than the high threshold of the number of discharge pulses, the health status level is serious.

[0016] As a preferred solution of the insulation health status assessment method of a hybrid insulating oil-paper system described in the present invention, the insulation health status assessment model of the hybrid insulating oil-paper system includes dividing the insulation health status range according to different per-unit values ​​of partial discharge characteristic parameters, constructing a hybrid insulating oil-paper system health status assessment model, and judging the area proportion of the health status triangle in different state regions in the assessment model by inputting per-unit values ​​of three partial discharge characteristic parameters, namely, maximum discharge amount, average discharge amount and number of discharge pulses, and the area with the largest proportion is the insulation health status of the hybrid insulating oil-paper system at this time.

[0017] As a preferred embodiment of the method for evaluating the insulation health status of a hybrid insulating oil-paper system according to the present invention, the input of the actual local discharge characteristic parameter of the hybrid insulating oil-paper system includes inputting the local discharge characteristic parameter value of the actual transformer hybrid insulating oil-paper system, performing per-unit processing, and inputting the per-unit value of the local discharge characteristic parameter into the hybrid insulating oil-paper system insulation health status evaluation model to obtain an evaluation result.

[0018] Another object of the present invention is to provide a system for evaluating the insulation health status of a mixed insulating oil-paper system, which can solve the problem of evaluating the insulation health status of a mixed insulating oil-paper system by constructing an insulation health status evaluation system.

[0019] In order to solve the above technical problems, the present invention provides the following technical solutions: a hybrid insulating oil-paper system insulation health status assessment system, comprising a characteristic parameter determination processing module, a health status level determination module, a model construction module and an assessment module; the characteristic parameter determination processing module is used to determine the local discharge characteristic parameters of the hybrid insulating oil-paper system according to the standard and the test results, and to perform per-unit processing on the local discharge characteristic parameters; the health status level determination module is used to divide the hybrid insulating oil-paper system into different health states according to the test results, and formulate the insulation health state level of the oil-paper system corresponding to different states; the model construction module is used to construct an insulation health state assessment model of the hybrid insulating oil-paper system based on the insulation health state level of the oil-paper system, the per-unit value of the local discharge characteristic parameters and the radar chart; the assessment module is used to determine the health state by inputting the actual local discharge characteristic parameters of the hybrid insulating oil-paper system into the assessment model, and to verify the accuracy of the assessment model.

[0020] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the above-mentioned method for evaluating the insulation health status of a hybrid insulating oil-paper system are implemented.

[0021] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the above-mentioned method for evaluating the insulation health status of a hybrid insulating oil-paper system.

[0022] The beneficial effects of the present invention are as follows: a hybrid insulating oil-paper system insulation health status assessment method provided by the present invention combines three local discharge characteristic parameters, namely, maximum discharge amount, average discharge amount and discharge pulse number, to provide a hybrid insulating oil-paper system insulation health status assessment method, including the selection and per-unit of characteristic parameters, the division of insulation health status levels, the construction of a hybrid insulating oil-paper insulation system insulation health status assessment model based on the oil-paper system health status level classification, the per-unit value of local discharge characteristic parameters and the radar chart, and finally the accuracy of the hybrid insulating oil-paper system insulation health status assessment model is verified, so as to provide technical support for accurately and effectively evaluating the insulation health status of the hybrid insulating oil-paper system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0024] Figure 1 A flow chart of a method for evaluating the insulation health status of a hybrid insulating oil-paper system provided in accordance with the first embodiment of the present invention.

[0025] Figure 2 A graph showing the variation of maximum discharge capacity with external applied voltage for a method for evaluating insulation health status of a hybrid insulating oil-paper system provided in the first embodiment of the present invention.

[0026] Figure 3 A graph showing changes in average discharge capacity versus applied voltage for a method for evaluating insulation health status of a hybrid insulating oil-paper system provided in accordance with the first embodiment of the present invention.

[0027] Figure 4 A graph showing the variation of discharge pulse number with external applied voltage for a method for evaluating insulation health status of a hybrid insulating oil-paper system provided in the first embodiment of the present invention.

[0028] Figure 5A maximum discharge capacity per unit value variation curve diagram of a hybrid insulating oil-paper system insulation health status assessment method provided in the first embodiment of the present invention.

[0029] Figure 6 This is a curve diagram of average discharge capacity variation of a method for evaluating insulation health status of a hybrid insulating oil-paper system provided by the first embodiment of the present invention.

[0030] Figure 7 A discharge pulse number variation curve diagram of a hybrid insulating oil-paper system insulation health status assessment method provided in the first embodiment of the present invention.

[0031] Figure 8 A mixed insulating oil-paper system health status assessment model diagram of a mixed insulating oil-paper system insulation health status assessment method provided by the first embodiment of the present invention.

[0032] Fig. 9 This is a diagram of the evaluation results of a method for evaluating the insulation health status of a hybrid insulating oil-paper system provided in the first embodiment of the present invention.

[0033] Fig.10 A structural diagram of an insulation health status assessment system for a hybrid insulating oil-paper system provided in accordance with a second embodiment of the present invention.

[0034] Fig.11 This is a diagram of insulation health status assessment results of a normal oil-paper system 1 of a method for assessing insulation health status of a hybrid insulating oil-paper system provided by a third embodiment of the present invention.

[0035] Fig.12 This is a diagram of insulation health status assessment results of abnormal oil-paper system 2 of a method for assessing insulation health status of a mixed insulating oil-paper system provided by the third embodiment of the present invention.

[0036] Fig.13 This is a diagram of the insulation health status assessment result of a severe oil-paper system 3 of a mixed insulating oil-paper system insulation health status assessment method provided by the third embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0038] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0039] Example 1, reference Figures 1 to 9 , which is the first embodiment of the present invention, and provides a method for evaluating the insulation health status of a hybrid insulating oil-oil-paper system, comprising: determining the local discharge characteristic parameters of the hybrid insulating oil-oil-paper system according to the standards and test results, and normalizing the local discharge characteristic parameters; dividing the hybrid insulating oil-oil-paper system into different health states according to the test results, and formulating the insulation health state level of the oil-paper system corresponding to different states; constructing an insulation health state evaluation model for the hybrid insulating oil-oil-paper system based on the insulation health state level of the oil-paper system, the local discharge characteristic parameter normalized value and the radar chart; determining the health state by inputting the actual local discharge characteristic parameters of the hybrid insulating oil-oil-paper system into the evaluation model, and verifying the accuracy of the evaluation model.

[0040] The present invention provides a method for evaluating the insulation health status of a hybrid insulating oil-paper system. The three local discharge characteristic parameters of maximum discharge, average discharge and discharge pulse number are jointly analyzed, and the insulation health status of the hybrid insulating oil-paper system is evaluated based on the per-unit value method and radar chart, which is applicable to the field of transformer status evaluation. It mainly includes the following five steps: First, according to domestic and international standards and test results, the local discharge characteristic parameters used to judge the insulation health status of the hybrid insulating oil-paper system are selected, and the local discharge characteristic parameters are per-unit processed according to the per-unit formula; the hybrid insulating oil-paper system is divided into different health states according to the test results, and the corresponding levels of different states are formulated. Based on the insulation health status level of the oil-paper system, the per-unit value of the local discharge characteristic parameters and the radar chart, a hybrid insulating oil-paper system insulation health status evaluation model is constructed; the actual local discharge characteristic parameters of the hybrid oil-paper system are input to obtain its insulation health status triangle and determine its insulation health status; the accuracy of the health status evaluation model is verified to determine the patent significance of the present invention. Figure 1 shown.

[0041] Step 1: According to relevant domestic and international standards and related experimental studies, three partial discharge characteristic parameters, namely maximum discharge, average discharge and discharge pulse number, are selected as the insulation health status assessment parameters of the hybrid insulating oil-paper system. Based on the per-unit formula, the per-unit values ​​of the three partial discharge characteristic parameters, namely maximum discharge, average discharge and discharge pulse number, are obtained to comprehensively reflect the insulation health status of the oil-paper system under different oil gaps.

[0042] Step 2: According to the partial discharge phenomenon of the mixed oil-paper system at different stages, its insulation health status level is divided into normal, abnormal and severe.

[0043] Step 3: Based on the insulation health status level, per-unit value of partial discharge characteristic parameters and radar chart of the mixed insulating oil-paper system, an insulation health status assessment model for the mixed insulating oil-paper system is constructed.

[0044] Step 4: Input the actual local discharge characteristic parameters of the mixed oil-paper system to obtain its health status triangle, analyze its proportion in different areas of the evaluation model, and determine its health status.

[0045] Step 5: By inputting the per-unit values ​​of the local discharge characteristic parameters of the actual mixed insulating oil-paper system under different insulation health conditions, the accuracy of the evaluation model is verified to determine the patent significance of the present invention.

[0046] S1. Parameter selection and processing method for characterizing the insulation health status of mixed insulating oil-paper system.

[0047] Since the degradation process of the hybrid insulating oil-paper system is relatively complex, it is necessary to carefully select characteristic parameters that can effectively reflect its state in order to accurately evaluate its actual insulation health state. Therefore, in order to more objectively and comprehensively evaluate and analyze the insulation health state of the hybrid oil-paper system, the partial discharge characteristic parameters that can effectively reflect the insulation health state of the oil-paper system are selected to analyze and study them, which is conducive to timely grasping the health status and insulation safety status of the hybrid oil-paper insulation composite system.

[0048] In order to more conveniently, comprehensively and truly reflect the health status of the oil-paper system, characteristic parameters whose test results are easy to obtain and whose effect of reflecting the health status of insulation is significant should be selected as much as possible. Based on the above selection principles, refer to the national standards and relevant test results related to transformer insulation testing, and select the maximum discharge capacity Q max , average discharge capacity Q mean The three local discharge characteristic parameters of the mixed insulating oil-paper system are analyzed and feature extracted to jointly build an insulation health status assessment model for the oil-paper system. The changes of the local discharge characteristic parameters of the mixed insulating oil-paper system with the external applied voltage at three different oil gap distances are shown in Figure 2. Figure 2 , Figure 3 and Figure 4 shown.

[0049] It can be seen from the figure that at the same oil gap distance, Q max , Q mean Both Q and N increase with the increase of applied voltage. max , Q mean and N both show a decreasing trend with the increase of oil gap distance. However, the above partial discharge characteristic parameters do not reflect the corresponding stages of different insulation health states of the mixed insulating oil-paper system, and cannot comprehensively reflect the insulation health state of the oil-paper system under different oil gaps, and they need to be normalized.

[0050] According to formula (1)-formula (3), the maximum discharge capacity Q max , average discharge capacity Q meanThe three local discharge characteristic parameters, namely, the number of discharge pulses N, are normalized:

[0051]

[0052] Among them, Q max Indicates the actual maximum discharge capacity, Q max0 Indicates the maximum discharge capacity reference value, Q* max Indicates the maximum discharge capacity per unit value. mean Indicates the actual measured average discharge capacity, Q mean0 Indicates the average discharge capacity reference value, Q* mean Indicates the average discharge capacity per unit value. N indicates the actual number of discharge pulses, N0 indicates the reference value of the discharge pulse number, and N* indicates the per unit value of the discharge pulse number. According to the standards GB / T 1094.3-2017, Q / GDW 10169-2016 and test results, Q max0 Take 500pC, Q mean0 Take 300pC and N0 as 12.

[0053] According to the calculated values ​​of the three partial discharge characteristic parameters, the maximum discharge capacity Q is obtained. max , average discharge capacity Q mean The variation curve of the discharge pulse number N per unit value is as follows: Figure 5 , Figure 6 and Figure 7 As shown in the figure, the per-unit value ranges of the three partial discharge characteristic parameters are divided into normal, abnormal and severe types according to the changing trends of the curves.

[0054] S2. Construction of insulation health status classification and evaluation model for mixed insulating oil-paper system.

[0055] Combined with the partial discharge test phenomena of the mixed insulating oil-paper system at three oil gap distances of 0mm, 5mm and 10mm, according to GB / T 1094.3-2017 "Power transformers - Part 3: Insulation level, insulation test and external insulation air gap" and Q / GDW 10169-2016 "Guidelines for condition assessment of oil-immersed transformers (reactors)", different thresholds are set to divide the insulation health status level of the oil-paper system into normal, abnormal and severe.

[0056] according to Figure 5 , Figure 6 and Figure 7 The maximum discharge capacity shown is Q* max , Average discharge capacity per unit value Q* mean The variation curve of the per-unit value N* of the discharge pulse number is shown in Table 1, and the insulation health status division range of the three per-unit values ​​of partial discharge characteristic parameters is obtained.

[0057] Table 1 Different partial discharge characteristic parameter standard value insulation health status classification range

[0058]

[0059]

[0060] According to the insulation health status classification range table of different partial discharge characteristic parameter per unit value shown in Table 1, the health status assessment model of the mixed insulation oil-paper system is constructed as follows: Figure 8 By inputting the normalized maximum discharge capacity, average discharge capacity and discharge pulse number of three partial discharge characteristic parameter values, the area proportion of the health triangle in different state areas in the evaluation model is determined. The area with the largest proportion is the insulation health state of the mixed insulating oil-paper system at this time.

[0061] S3. Calculate the insulation health status of the mixed insulating oil-paper system.

[0062] First, input the partial discharge characteristic parameter values ​​of the actual transformer mixed insulation oil-paper system, which are: Q max =50pC, Q mean =38pC, N0=120.

[0063] After normalizing it, we can get: Q* max =0.9, Q* mean =0.87, N*=9.

[0064] The partial discharge characteristic parameter standard value is input into the insulation health status assessment model of the mixed insulating oil-paper system, and the assessment results are as follows: Fig. 9 shown.

[0065] It can be seen from the figure that the insulation health status triangle of the oil-paper system is completely in the healthy area of ​​the assessment model, so its insulation health status assessment result is healthy, which is consistent with the actual state.

[0066] Based on the problems that the characteristic parameters used in the current insulation health status assessment model of the insulating oil-paper system are strictly required, the engineering application is limited, the evaluation process is long and complicated, and the research on the insulation health status assessment model of the mixed insulating oil-paper system is basically blank, in order to achieve accurate assessment of the insulation health status of the mixed insulating oil-paper system, the present invention combines three local discharge characteristic parameters of maximum discharge capacity, average discharge capacity and discharge pulse number to provide a hybrid insulating oil-paper system insulation health status assessment method, including the selection and per-unit of characteristic parameters, the division of insulation health status levels, the construction of the insulation health status assessment model of the mixed insulating oil-paper system based on the oil-paper system health status level classification, the per-unit value of the local discharge characteristic parameters and the radar chart, and finally the accuracy of the mixed oil-paper system insulation health status assessment model is verified, so as to provide technical support for accurately and effectively evaluating the insulation health status of the mixed insulating oil-paper system.

[0067] Example 2, reference Fig.10 , which is the second embodiment of the present invention, is different from the previous embodiment in that it provides a hybrid insulating oil-paper system insulation health status assessment system, including: a characteristic parameter determination processing module, a health status level determination module, a model construction module and an assessment module.

[0068] The characteristic parameter determination processing module is used to determine the partial discharge characteristic parameters of the mixed insulating oil-paper system according to the standards and test results, and to perform standardization processing on the partial discharge characteristic parameters.

[0069] The health status level determination module is used to classify the mixed insulating oil-paper system into different health states according to the test results, and to formulate the insulation health status levels of the oil-paper system corresponding to different states.

[0070] The model building module is used to construct an insulation health status assessment model for a hybrid insulating oil-paper system based on the insulation health status level of the oil-paper system, the per-unit value of partial discharge characteristic parameters and the radar chart.

[0071] The evaluation module is used to determine the health status and verify the accuracy of the evaluation model by inputting the partial discharge characteristic parameters of the actual mixed insulating oil-paper system into the evaluation model.

[0072] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0073] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0074] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0075] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0076] Example 3, reference Figure 11 to Figure 13 The third embodiment of the present invention is different from the first two embodiments in that it is used to verify the technical effects adopted in the present invention in order to verify the real effects of the method.

[0077] By inputting the partial discharge characteristic parameter standard values ​​of three actual mixed insulating oil-paper systems with different insulation health states as shown in Table 2, the accuracy of the insulation health state assessment model of the oil-paper system is verified, and the assessment results are as follows: Fig.11 , Fig.12 and Fig.13 shown.

[0078] Table 2 Actual transformer partial discharge characteristic parameter values ​​and per unit values

[0079]

[0080] Depend on Fig. 9 It can be seen that the health triangle of the normal oil-paper system 1 is completely in the normal area, and the evaluation result is normal, which is the same as its actual state; the health triangle of the abnormal oil-paper system 2 is completely in the abnormal area, and the evaluation result is abnormal, which is the same as its actual state; the health triangle of the severe oil-paper system 2 is between the abnormal and severe areas, but most of it is in the severe area, and the evaluation result is severe, which is the same as its actual state. From the verification results, it can be seen that the established model can intuitively and effectively evaluate the three insulation health states of normal, abnormal and severe of the mixed insulating oil-paper system at different oil gap distances, and can maintain high accuracy without complex algorithms.

[0081] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for evaluating the insulation health status of a mixed insulating oil-paper system, characterized in that: include, Determine the partial discharge characteristic parameters of the mixed insulating oil-paper system according to the standards and test results, and perform standardization on the partial discharge characteristic parameters; According to the test results, the mixed insulating oil-paper system is divided into different health states, and the insulation health state level of the oil-paper system corresponding to different states is formulated; Based on the insulation health status level of the oil-paper system, the per-unit value of the partial discharge characteristic parameters and the radar chart, an insulation health status assessment model for the hybrid insulating oil-paper system is constructed. By inputting the partial discharge characteristic parameters of the actual mixed insulating oil-paper system into the evaluation model, the health status is determined and the accuracy of the evaluation model is verified.

2. The method for evaluating the insulation health status of a hybrid insulating oil-paper system according to claim 1, characterized in that: The local discharge characteristic parameters include maximum discharge amount, average discharge amount and discharge pulse number; The variation of partial discharge characteristic parameters of the mixed insulating oil-paper system with external applied voltage under three different oil gap distances was obtained.

3. A method for evaluating the insulation health status of a hybrid insulating oil-paper system according to claim 2, characterized in that: The normalization process includes the maximum discharge capacity Q max , average discharge capacity Q mean The three local discharge characteristic parameters, namely, the number of discharge pulses N, are normalized and expressed as: Among them, Q max is the maximum discharge capacity actually measured, Q max0 is the maximum discharge capacity reference value, Q* max is the maximum discharge capacity per unit value, Q mean is the actual measured average discharge capacity, Q mean0 is the average discharge capacity reference value, Q* mean is the per-unit value of the average discharge capacity, N is the actual number of discharge pulses, N0 is the reference value of the discharge pulse number, and N* is the per-unit value of the discharge pulse number.

4. A method for evaluating the insulation health status of a hybrid insulating oil-paper system according to claim 3, characterized in that: The oil-paper system insulation health status level includes the maximum discharge capacity Q obtained according to the calculated three partial discharge characteristic parameter standard values. max , average discharge capacity Q mean The per-unit value variation curves of the discharge pulse number N are plotted, and the per-unit value ranges of the three partial discharge characteristic parameters are divided into normal, abnormal and severe types according to the curve variation trends.

5. The method for evaluating the insulation health status of a hybrid insulating oil-paper system according to claim 4, characterized in that: The oil-paper system insulation health status level also includes obtaining a maximum discharge amount low threshold, a maximum discharge amount high threshold, an average discharge amount low threshold, an average discharge amount high threshold, a discharge pulse number low threshold and a discharge pulse number high threshold according to the per-unit value change curve; For the maximum discharge capacity per unit value Q* max , if Q* max If Q* is greater than or equal to 0 and less than or equal to the maximum discharge low threshold, the health status level is normal. max If Q* is greater than the maximum discharge capacity low threshold and less than or equal to the maximum discharge capacity high threshold, the health status level is abnormal. max If it is greater than the maximum discharge high threshold, the health status level is severe; For the average discharge capacity per unit value Q* mean , if Q* mean If Q* is greater than or equal to 0 and less than or equal to the average discharge low threshold, the health status level is normal. mean If the average discharge amount is greater than the low threshold and less than or equal to the high threshold, the health status level is abnormal. mean If it is greater than the average discharge high threshold, the health status level is severe; For the actual number of discharge pulses N, if N is greater than or equal to 0 and less than or equal to the low threshold of the number of discharge pulses, the health status level is normal; if N is greater than the low threshold of the number of discharge pulses and less than or equal to the high threshold of the number of discharge pulses, the health status level is abnormal; if N is greater than the high threshold of the number of discharge pulses, the health status level is serious.

6. A method for evaluating the insulation health status of a hybrid insulating oil-paper system according to claim 5, characterized in that: The insulation health status assessment model of the hybrid insulating oil-paper system includes dividing the insulation health status range according to different per-unit values ​​of partial discharge characteristic parameters, constructing the health status assessment model of the hybrid insulating oil-paper system, and judging the area proportions of the health status triangle in different state regions in the assessment model by inputting per-unit values ​​of three partial discharge characteristic parameters, namely, maximum discharge capacity, average discharge capacity and number of discharge pulses, and the area with the largest proportion is the insulation health status of the hybrid insulating oil-paper system at this time.

7. A method for evaluating the insulation health status of a hybrid insulating oil-paper system according to claim 6, characterized in that: The input of the actual mixed insulating oil-paper system partial discharge characteristic parameter comprises inputting the actual transformer mixed insulating oil-paper system partial discharge characteristic parameter value, performing per-unit processing, and inputting the per-unit value of the partial discharge characteristic parameter into the mixed insulating oil-paper system insulation health status assessment model to obtain an assessment result.

8. A system using the method for evaluating the insulation health status of a hybrid insulating oil-paper system as claimed in any one of claims 1 to 7, characterized in that: It includes a characteristic parameter determination processing module, a health status level determination module, a model building module and an evaluation module; The characteristic parameter determination processing module is used to determine the partial discharge characteristic parameters of the mixed insulating oil-paper system according to the standards and test results, and to perform standardization processing on the partial discharge characteristic parameters; The health status level determination module is used to classify different health states of the mixed insulating oil-paper system according to the test results, and formulate insulation health status levels of the oil-paper system corresponding to different states; The model building module is used to build an insulation health status assessment model for a hybrid insulating oil-paper system based on the insulation health status level of the oil-paper system, the per-unit value of the partial discharge characteristic parameter and the radar chart; The evaluation module is used to determine the health status and verify the accuracy of the evaluation model by inputting the actual local discharge characteristic parameters of the mixed insulating oil-paper system into the evaluation model.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of a method for evaluating the insulation health status of a hybrid insulating oil-paper system according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of a method for evaluating the insulation health status of a hybrid insulating oil-paper system according to any one of claims 1 to 7 are implemented.

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