A transformer bushing partial discharge fault on-line monitoring method and related equipment

Abstract

The present application belongs to the field of on-line monitoring of transformer high-voltage bushing faults, and discloses a transformer bushing partial discharge fault on-line monitoring method and related equipment. The method directly collects the oil level information, gas temperature and pressure in the breathing cavity of the transformer bushing, and then calculates the gas volume, total gas amount, gas production amount and gas production rate, without the need for complex gas component analysis. By comparing the total gas amount, gas production amount and gas production rate with the corresponding preset warning thresholds, timely warning of the transformer bushing partial discharge fault can be realized. Compared with the traditional method relying on gas component analysis, the present method is more direct and efficient, can effectively reflect the internal gas pressure change of the bushing, prevent potential explosion risks, and improve the practicality and response speed of transformer bushing partial discharge fault monitoring. The present method significantly simplifies the monitoring process and improves the real-time monitoring accuracy and reliability.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of online monitoring of transformer high-voltage bushing faults, and particularly relates to a transformer bushing partial discharge fault online monitoring method and related equipment. BACKGROUND

[0002] Most of the transformer bushings of high voltage grade are oil-paper capacitive bushings. When partial discharge occurs due to insulation defects, partial discharge signals will be generated, and characteristic gases will be generated due to the decomposition of oil-paper insulation materials, thereby causing an increase in internal pressure. As the partial discharge develops, the temperature will also rise. Currently, online monitoring of transformer bushing partial discharge faults generally involves direct monitoring of partial discharge signals, pressure, temperature and other indicators, which has the advantage of simple implementation. Meanwhile, there are also applications for online monitoring of characteristic gases under partial discharge faults. Monitoring of fault characteristic gases can directly reflect the partial discharge fault condition of the bushing.

[0003] For online monitoring of bushing discharge fault characteristic gases, oil dissolved gas monitoring or breathing cavity free gas monitoring can be considered. Breathing cavity free gas directly reflects the internal gas pressure of the bushing and determines whether the bushing will explode. Research shows that the gas production and gas production rate of free gas in a low-oil device under partial discharge defects change more obviously than oil dissolved gas. Therefore, monitoring of free gas in the breathing cavity of the bushing has higher sensitivity.

[0004] Currently, the system for online monitoring of transformer bushing breathing cavity gas generally performs component analysis on the gas. For example, Chinese Patent Application Publication No. CN117929654A discloses a transformer bushing free gas detection device and detection method. After the breathing cavity gas is separated into oil and gas, the components are monitored, and the transformer oil is reflowed into the bushing. Therefore, an additional circulating device is needed, and the implementation is complex.

[0005] Currently, there are also monitoring methods based on gas molar density. For example, Chinese Patent Application Publication No. CN112629689A discloses a transformer bushing free gas detection device and detection method. The gas molar density is obtained by monitoring the pressure and temperature. However, it ignores the change of the oil level of the transformer bushing. Even when it is running normally, the oil level changes with the temperature. However, at this time, no characteristic gas is generated, so there is a risk of misjudgment. Moreover, the monitored temperature is the shell temperature, which is different from the temperature in the breathing cavity. The monitoring accuracy needs to be verified.

[0006] It can be seen that the existing transformer bushing fault monitoring method based on gas has the problems of complex monitoring device and low accuracy and reliability due to the need for gas component analysis and the lack of consideration of the change of the oil level of the transformer bushing. SUMMARY

[0007] The present application provides a transformer bushing partial discharge fault online monitoring method and related equipment, which aims at the limitations of the existing transformer bushing partial discharge fault gas monitoring method, on the one hand, it needs to analyze the gas components, resulting in a complex monitoring process, on the other hand, it ignores the method defects caused by the change of the oil level of the transformer bushing, to solve the technical problems of low monitoring reliability and accuracy.

[0008] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0009] A transformer bushing partial discharge fault online monitoring method, comprising:

[0010] Based on the collected oil level information in the transformer bushing breathing cavity, the corresponding gas volume in the transformer bushing breathing cavity is obtained;

[0011] Combined with the gas volume and the collected gas temperature and pressure in the transformer bushing breathing cavity, the total amount of gas in the transformer bushing breathing cavity is calculated, and the gas production rate and the gas production rate in the transformer bushing breathing cavity are calculated based on the total amount of gas;

[0012] The total amount of gas, the preset gas total amount warning threshold, the gas production amount and the preset gas production amount warning threshold, and the gas production rate and the preset gas production rate warning threshold are compared respectively, and the comparison result is obtained; the comparison result is used for early warning of the partial discharge fault of the transformer bushing.

[0013] Further, the transformer bushing breathing cavity based on the collected oil level information in the transformer bushing breathing cavity, comprising:

[0014] The collected oil level information in the transformer bushing breathing cavity is input into the relationship table or relationship fitting curve of the oil level of the transformer bushing and the gas volume in the breathing cavity, to obtain the gas volume in the transformer bushing breathing cavity corresponding to the oil level information.

[0015] Further, the relationship table or relationship fitting curve of the oil level of the transformer bushing and the gas volume in the breathing cavity is obtained based on the actual measurement and calibration of the transformer bushing breathing cavity drawing, and the specific steps are as follows:

[0016] According to the transformer bushing breathing cavity drawing, the corresponding breathing cavity gas volume under different oil levels is measured combined with the preset measurement step length;

[0017] After calibration, a table showing the relationship between transformer bushing oil level and breather gas volume was obtained.

[0018] Based on the data in the table showing the relationship between transformer bushing oil level and breather chamber gas volume, a fitted curve for the relationship between transformer bushing oil level and breather chamber gas volume was obtained.

[0019] Furthermore, the total amount of gas in the transformer bushing breathing chamber is calculated by combining the gas volume with the collected gas temperature and pressure inside the chamber, including:

[0020] Establish a calculation model for the total amount of gas, gas production rate, and gas production rate in the breathing chamber of a transformer bushing;

[0021] The amount of gaseous substance in the transformer bushing breather cavity is obtained based on the gas state equation of the computational model, and the amount of gaseous substance in the transformer bushing breather cavity is taken as the total amount of gas in the transformer bushing breather cavity. The specific formula is as follows:

[0022]

[0023]

[0024] In the formula, This represents the total amount of gas in the transformer bushing's breathing chamber. , These are the gas temperature and pressure inside the transformer bushing breathing chamber, respectively. This refers to the volume of gas inside the transformer bushing's breathing chamber. is the molar gas constant.

[0025] Furthermore, in the calculation of the gas production volume and gas production rate within the transformer bushing breathing chamber based on the total gas volume, the process for obtaining the gas production volume within the transformer bushing breathing chamber is as follows:

[0026] At two different times and The amount of gaseous substance in the breathing chamber of the transformer bushing was calculated. and The increase in the amount of gas in the breathing chamber during the corresponding time period is calculated, and this increase is taken as the gas production in the transformer bushing breathing chamber. The specific formula is as follows:

[0027]

[0028] In the formula, for ~ The increase in the amount of gaseous substances in the respiratory cavity over a period of time; , , respectively are the temperature, pressure and gas volume in the breathing cavity of the transformer bushing at the moment; respectively are the temperature, pressure and gas volume in the breathing cavity of the transformer bushing at the moment.

[0029] Further, in the calculation of the total amount of gas, the gas production rate in the breathing cavity of the transformer bushing is obtained as follows:

[0030] The gas production rate is calculated based on the amount increment of the gas in the breathing cavity, and the specific formula is as follows:

[0031]

[0032] In the formula, is the gas production rate in the breathing cavity of the transformer bushing; is the difference between and .

[0033] Further, the total amount of gas, the preset total amount of gas warning threshold, the gas production amount, the preset gas production amount warning threshold, and the gas production rate, the preset gas production rate warning threshold are compared respectively to obtain the comparison result, including:

[0034] The total amount of gas is compared with the preset total amount of gas warning threshold, and if the total amount of gas is greater than the preset total amount of gas warning threshold, an alarm is issued;

[0035] The gas production amount is compared with the preset gas production amount warning threshold, and if the gas production amount is greater than the preset gas production amount warning threshold, an alarm is issued;

[0036] The gas production rate is compared with the preset gas production rate warning threshold, and if the gas production rate is greater than the preset gas production rate warning threshold, an alarm is issued.

[0037] A transformer bushing partial discharge fault online monitoring system, comprising:

[0038] A first calculation module is configured to obtain the gas volume in the breathing cavity of the transformer bushing based on the collected oil level information in the breathing cavity of the transformer bushing;

[0039] A second calculation module is configured to calculate the total amount of gas in the breathing cavity of the transformer bushing by combining the gas volume and the collected gas temperature and pressure in the breathing cavity of the transformer bushing, and to calculate the gas production amount and the gas production rate in the breathing cavity of the transformer bushing by combining the total amount of gas;

[0040] ​​The fault early warning module is used for comparing the total gas amount with a preset total gas amount early warning threshold, comparing the gas production amount with a preset gas production amount early warning threshold, and comparing the gas production rate with a preset gas production rate early warning threshold, respectively, to obtain a comparison result; and the comparison result is used for early warning of the partial discharge fault of the transformer bushing.

[0041] A transformer bushing partial discharge fault online monitoring device comprises:

[0042] A memory is used for storing a computer program;

[0043] A processor is used for executing the computer program to realize the steps of the transformer bushing partial discharge fault online monitoring method.

[0044] A computer readable storage medium stores a computer program, and the computer program is executed by a processor to realize the steps of the transformer bushing partial discharge fault online monitoring method.

[0045] Compared with the prior art, the present application has the following beneficial effects:

[0046] The present application provides a transformer bushing partial discharge fault online monitoring method, which directly collects the oil level information, gas temperature and pressure in the breathing cavity of the transformer bushing, and then calculates the gas volume, total gas amount, gas production amount and gas production rate, without complex gas component analysis; by comparing the total gas amount, gas production amount and gas production rate with the corresponding preset early warning thresholds, timely early warning of the transformer bushing partial discharge fault can be realized. Compared with the traditional method relying on gas component analysis, the present method is simple to realize, directly monitors the oil level, fully considers the influence of oil level change on gas amount monitoring, improves the accuracy of gas monitoring, is more accurate, direct and efficient, can effectively reflect the internal gas pressure change of the bushing, prevent potential explosion risks, improves the practicality and response speed of the transformer bushing partial discharge fault monitoring, significantly simplifies the monitoring process and improves the real-time monitoring efficiency and accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 A flowchart of a transformer bushing partial discharge fault online monitoring method provided by the present application embodiment is shown;

[0048] Figure 2 A whole flowchart of a transformer bushing partial discharge fault online monitoring method provided by the present application embodiment is shown;

[0049] Figure 3 A structure diagram of a transformer bushing partial discharge fault online monitoring system provided by the present application embodiment is shown;

[0050] Figure 4 This is a schematic diagram showing the oil level when the oil chamber is vertical and tilted, according to an embodiment of the present invention.

[0051] Figure 5 This is a flowchart for obtaining a table or fitting curve showing the relationship between the transformer bushing oil level and the gas volume in the breathing chamber, as provided in an embodiment of the present invention.

[0052] Figure label:

[0053] 1. Oil cavity; 2. Inclination angle; 3. Oil level when tilted; 4. Oil level when vertical. Detailed Implementation

[0054] To further understand the content of this invention, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments are merely illustrative and not limiting of the invention.

[0055] like Figure 2 As shown, this embodiment provides an online monitoring method for partial discharge faults in transformer bushings, including:

[0056] The corresponding gas volume in the transformer bushing breather chamber is obtained based on the collected oil level information in the breather chamber.

[0057] By combining the gas volume with the collected gas temperature and pressure inside the transformer bushing breathing chamber, the total gas volume inside the transformer bushing breathing chamber is calculated. Based on the total gas volume, the gas production rate and gas production rate inside the transformer bushing breathing chamber are calculated.

[0058] The total gas volume is compared with a preset total gas volume warning threshold, the gas production volume is compared with a preset gas production volume warning threshold, and the gas production rate is compared with a preset gas production rate warning threshold to obtain comparison results; the comparison results are used to provide early warning of partial discharge faults in transformer bushings.

[0059] In this embodiment, the oil level and the gas volume of the breathing chamber are measured and calibrated based on the transformer bushing breathing chamber drawing, and the correspondence between the oil level and the gas volume of the breathing chamber is obtained in advance.

[0060] Based on the pre-obtained correspondence between the transformer bushing oil level and the gas volume in the breathing chamber, the corresponding gas volume in the transformer bushing breathing chamber is calculated based on the collected oil level information.

[0061] Preferably, in this invention, the relationship curve between the transformer bushing oil level and the gas volume in the breather chamber needs to be measured and calibrated before the transformer bushing is put into operation. Based on the dimensions of the transformer bushing breather chamber drawing, the corresponding gas volume in the breather chamber at different oil levels is measured and recorded, thereby obtaining a fitted curve of the relationship between the oil level and the gas volume in the breather chamber. Thus, the gas volume in the breather chamber is obtained based on oil level monitoring.

[0062] Preferably, in this invention, by utilizing the relationship curve between the transformer bushing oil level and the gas volume in the breathing chamber, the corresponding gas volume in the breathing chamber can be accurately and quickly obtained from the oil level monitoring data; this method simplifies the gas volume calculation process and improves monitoring efficiency.

[0063] Preferably, in this invention, based on the transformer bushing breather cavity drawing, a table showing the relationship between oil level and gas volume in the breather cavity is obtained by measurement, and a corresponding relationship fitting curve is obtained based on this table, ensuring the accuracy and reliability of the curve. At the same time, this method is simple to implement, reduces experimental costs, and improves the applicability of the relationship curve.

[0064] Preferably, in this invention, a calculation model is established for the total amount of gas, gas production rate and gas production rate in the breathing chamber of the transformer bushing, and the total amount of gas is calculated based on the ideal gas law. This method provides a scientific and accurate calculation basis and ensures the reliability of the monitoring results.

[0065] Preferably, in this invention, the increase in the amount of gas in the breathing chamber, i.e., the gas production, is calculated by collecting gas temperature, pressure, and volume information at different times. This method can reflect the gas changes in the transformer bushing breathing chamber in real time, providing data support for timely fault detection.

[0066] Preferably, in this invention, the gas generation rate is calculated based on the incremental amount of gas in the breathing chamber, which provides an important basis for assessing the severity and development trend of partial discharge faults in transformer bushings; monitoring the gas generation rate helps to detect and handle potential faults in a timely manner.

[0067] Preferably, in this invention, the total gas volume, gas production volume, and gas production rate are compared with a preset warning threshold to achieve early warning of partial discharge faults in transformer bushings; when the monitored value exceeds the warning threshold, the system can automatically issue an alarm to remind maintenance personnel to handle the fault in a timely manner, thereby avoiding the expansion of the fault and the occurrence of accidents.

[0068] This embodiment will be further explained in conjunction with the accompanying drawings:

[0069] like Figure 1 As shown, this embodiment provides an online monitoring method for partial discharge faults in transformer bushings.

[0070] The implementation steps of this method specifically include three aspects: information acquisition and collection, data processing and calculation, and early warning.

[0071] The information acquisition and collection includes acquisition of an oil level-volume relationship curve, i.e., a relationship curve of the transformer bushing oil level and the gas volume in the breathing cavity, and sensor data collection; the data processing and calculation includes calculation of the total gas amount, gas production amount and gas production rate in the transformer bushing breathing cavity; the early warning includes judgment and alarm of the three monitoring values.

[0072] Firstly, before the transformer bushing to be monitored is put into operation, the size information of the transformer bushing breathing cavity is acquired according to the transformer bushing breathing cavity drawing, the corresponding breathing cavity gas volume under different oil levels is measured and calibrated and recorded, and the measurement step can be adjusted according to the accuracy requirement.

[0073] Optionally, the corresponding data of the oil level and the breathing cavity gas volume are stored as a table, the oil level and the breathing cavity gas volume have a one-to-one correspondence relationship, and the table is input into the early warning model.

[0074] Optionally, the corresponding data of the oil level and the breathing cavity gas volume are used to obtain a relationship fitting curve of the oil level and the breathing cavity gas volume . , and the relationship curve is input into the early warning model; wherein, represents the fitting curve function about h.

[0075] Further, the sampling interval of the sensor is set, and the pressure sensor, the temperature sensor and the oil level sensor installed at the transformer bushing oil pillow are used to collect the pressure , temperature and oil level information of the gas in the breathing cavity;

[0076] Further, according to the collected oil level information , it is assumed that the relationship between the oil level and the breathing cavity gas volume is a data table, if the oil level information does not have the oil level data completely corresponding to the table, the oil level data in the table with the smallest difference between the two is selected, which is represented as: , If there is a minimum value when , the breathing cavity gas volume data corresponding to the oil level data in the table is taken as ; represents the minimum value.

[0077] It is assumed that the relationship between the oil level and the breathing cavity gas volume is a fitting curve, based on the relationship curve of the oil level and the breathing cavity gas volume , the breathing cavity gas volume corresponding to the oil level is ;

[0078] According to the monitoring data of the transformer bushing breathing cavity obtained above 、 、 The corresponding total gas amount of substance in the transformer bushing breathing cavity can be calculated by the following formula:

[0079] ;

[0080] Wherein, is the calculated total gas amount of substance, 、 are the gas temperature and pressure in the bushing breathing cavity collected by the sensor respectively; is the obtained volume of the gas part in the bushing breathing cavity; is the molar gas constant, whose value is 8.314 J / (mol·K).

[0081] According to the set sampling time interval, the pressure , temperature and oil level of the gas in the transformer bushing breathing cavity are continuously monitored, and the corresponding total gas amount of substance in the transformer bushing breathing cavity is calculated.

[0082] Further, considering the total gas amount, gas production amount and gas production rate in the transformer bushing breathing cavity as monitoring indexes respectively, the respective pre-warning threshold values 、 and are preset and pre-warning is performed respectively.

[0083] First, considering the total gas amount of substance in the transformer bushing breathing cavity as the monitoring index, the calculated total gas amount of substance in the transformer bushing breathing cavity is compared with the corresponding pre-warning threshold value , and when the following condition is met:

[0084] ;

[0085] It indicates that the bushing has a potential fault, and an alarm is issued. If the condition is not met, no alarm is issued.

[0086] Further, considering the gas production amount as the monitoring index, the total gas amount of substance increment in a period of time needs to be monitored.

[0087] If this is the first collection of the pressure , temperature and oil level three parameter data, and the monitoring values of the three parameters at this time are assumed to be 、 , , based on the relationship curve between oil level and respiratory cavity gas volume , the oil level corresponding to the respiratory cavity gas volume is ;

[0088] The corresponding total gas amount of substance is assigned to , that is:

[0089] ;

[0090] Further wait for the next data collection;

[0091] If it is the i-th collection of three parameter data of pressure , temperature and oil level (i≥2) at this time, assuming that the monitoring values of the three parameters at this time are , , , based on the relationship curve between oil level and respiratory cavity gas volume , the oil level corresponding to the respiratory cavity gas volume is ;

[0092] The corresponding total gas amount of substance is assigned to , that is:

[0093] ;

[0094] Therefore, the value of will be updated continuously as the monitoring progresses;

[0095] Further, the total gas amount of substance in the respiratory cavity of the transformer bushing at the moment and can be calculated to obtain the total gas amount of substance increment in a certain period of time:

[0096] ;

[0097] Further, the calculated total gas amount of substance increment in the respiratory cavity of the transformer bushing is compared with the corresponding warning threshold , and when the following condition is met:

[0098] ;

[0099] At this time, it indicates that the bushing has a potential fault, and an alarm is issued. If it is not met, no alarm is issued.

[0100] Further considering the gas production rate as a monitoring index, the total gas amount increase rate in a period of time needs to be monitored, and the sampling interval is taken as the time interval for calculating the gas production rate, that is, the increase rate between every two total gas amount sampling data is taken as the monitoring index.

[0101] Considering the first case, if the pressure , temperature and oil level three parameter data are collected for the first time, it is assumed that the monitoring values of the three parameters at this time are , , , and the corresponding time is , based on the oil level and respiratory cavity gas volume relationship curve , the respiratory cavity gas volume corresponding to the oil level is ;

[0102] The corresponding total gas amount is assigned to , that is:

[0103] ;

[0104] Further waiting for the second data collection, it is assumed that the monitoring values of the three parameters at this time are , , , and the corresponding time is , based on the oil level and respiratory cavity gas volume relationship curve , the respiratory cavity gas volume corresponding to the oil level is ;

[0105] The corresponding total gas amount is assigned to , that is:

[0106]

[0107] Considering the second case, if the pressure , temperature and oil level three parameter data are collected for the i-th time (i≥3), it is assumed that the monitoring values of the three parameters at this time are , , , based on the oil level and respiratory cavity gas volume relationship curve , the respiratory cavity gas volume corresponding to the oil level is ;

[0108] Then the original is assigned to , the original is assigned to , that is, as the starting point of this monitoring;

[0109] Further, the total gas amount of substance calculated from the monitoring data this time is assigned to , and the corresponding time is , that is:

[0110] ;

[0111] Further, according to the total gas amount of substance in the transformer bushing breathing cavity at the moment and and the corresponding time and , the increase rate of the total gas amount of substance in the time period can be calculated as:

[0112] ;

[0113] Further, the increase rate of the total gas amount of substance in the transformer bushing breathing cavity calculated is compared with the corresponding early warning threshold , and when the following condition is met:

[0114] ;

[0115] At this time, it indicates that the bushing has a potential fault, and an alarm is issued. If it is not met, no alarm is issued.

[0116] It should be noted that and in the two monitoring schemes of gas production amount and gas production rate as monitoring indicators are independent of each other and are only represented by symbols. At the same time, the early warning of the three monitoring indicators of total gas amount, gas production amount and gas production rate is also independent of each other.

[0117] It should also be noted that the monitoring method proposed in the present application involves the conversion of oil level and breathing cavity gas volume, and the oil level and breathing cavity gas volume relationship table or curve is obtained when the bushing is kept vertical. Therefore, when the transformer bushing is kept vertical, the monitoring value of the oil level is accurate, and the corresponding volume value can be obtained according to the oil level and breathing cavity gas volume relationship; but when the transformer bushing is inclined, the oil level monitoring value may be low or high according to the different installation positions of the oil level sensor.

[0118] As Figure 4 ​As shown in the oil cavity 1, the oil level 3 when tilted and the oil level 4 when vertical can be seen; when the oil level sensor is installed in the first installation position, the oil level monitoring value will be low due to tilting away from the oil surface, and the volume obtained from the oil level and the breathing cavity gas volume relationship table or curve will be small; when the oil level sensor is installed in the second installation position, the oil level monitoring value will be high due to tilting close to the oil surface, and the volume obtained from the oil level and the breathing cavity gas volume relationship table or curve will be large. Assuming that the tilt angle 2 is θ, the horizontal distance of the oil level sensor installation position from the center axis is x , then the error of the oil level monitoring is :

[0119] ;

[0120] Assuming that the monitoring value of the oil level is , therefore when the oil level sensor is installed in position 1, the oil level value after error compensation is:

[0121] ;

[0122] When the oil level sensor is installed in position 2, the oil level value after error compensation is :

[0123] ;

[0124] The breathing cavity gas volume corresponding to the oil level value after error compensation is the accurate value.

[0125] Therefore, the method has better accuracy when applied to a vertically installed transformer bushing, and when applied to a tilted transformer bushing, the oil level monitoring value needs to be corrected to compensate for the oil level measurement error caused by tilting.

[0126] As can be seen, the embodiment provides a transformer bushing partial discharge fault online monitoring method, which has the following advantages:

[0127] For the case of transformer bushing partial discharge fault, the monitoring method takes the gas related indicators in the bushing breathing cavity as the monitoring indicators, which can directly reflect the gas production of the bushing partial discharge fault, and the monitoring is direct; especially based on the characteristic gas generated under the bushing partial discharge fault, the calculation method considering the total amount of gas, gas production and gas production rate of the bushing breathing cavity gas temperature, pressure and oil level is proposed, which avoids the component analysis of the breathing cavity gas, and fully considers the influence of oil level on the amount of gas monitoring, which effectively simplifies the monitoring method while ensuring the monitoring accuracy and reliability, and provides ideas for the development of transformer bushing online monitoring device.

[0128] As Figure 2As shown in the figure, this embodiment also provides an online monitoring method for partial discharge faults in transformer bushings, including the following steps:

[0129] The corresponding gas volume in the transformer bushing breather chamber is obtained based on the collected oil level information in the breather chamber.

[0130] By combining the gas volume with the collected gas temperature and pressure inside the transformer bushing breathing chamber, the total gas volume inside the transformer bushing breathing chamber is calculated. Based on the total gas volume, the gas production rate and gas production rate inside the transformer bushing breathing chamber are calculated.

[0131] The total gas volume is compared with a preset total gas volume warning threshold, the gas production volume is compared with a preset gas production volume warning threshold, and the gas production rate is compared with a preset gas production rate warning threshold to obtain comparison results; the comparison results are used to provide early warning of partial discharge faults in transformer bushings.

[0132] Specifically, the method for obtaining the gas volume inside the transformer bushing breathing chamber is as follows:

[0133] The collected oil level information in the transformer bushing breather cavity is input into a table or curve showing the relationship between the transformer bushing oil level and the gas volume in the breather cavity, thus obtaining the gas volume in the transformer bushing breather cavity corresponding to the oil level information.

[0134] Here, similar to Example 1, the table or curve showing the relationship between the transformer bushing oil level and the gas volume in the breathing chamber is obtained by measurement and calibration based on the transformer bushing breathing chamber drawing.

[0135] like Figure 5 As shown, the table or fitted curve illustrating the relationship between transformer bushing oil level and breather chamber gas volume is obtained as follows:

[0136] The table or fitted curve showing the relationship between the transformer bushing oil level and the gas volume in the breather chamber is obtained through actual measurement and calibration based on the transformer bushing breather chamber drawings. The specific steps are as follows:

[0137] Based on the transformer bushing breather cavity drawing, the corresponding gas volume of the breather cavity at different oil levels was obtained by measuring the preset measurement step size.

[0138] After calibration, a table showing the relationship between oil level and gas volume in the breathing chamber was obtained.

[0139] Based on the data in the table showing the relationship between oil level and gas volume in the breathing chamber, a fitted curve for the relationship between oil level and gas volume in the breathing chamber was obtained.

[0140] The process for obtaining the total gas volume in the transformer bushing breathing chamber is as follows:

[0141] A calculation model of total gas amount, gas production amount and gas production rate in the breathing cavity of the transformer bushing is established.

[0142] The gas amount in the breathing cavity of the transformer bushing is obtained based on the equation of state of the calculation model, and the gas amount in the breathing cavity of the transformer bushing is taken as the total gas amount in the breathing cavity of the transformer bushing, and the specific formula is as follows:

[0143]

[0144]

[0145] In the formula, is the total gas amount in the breathing cavity of the transformer bushing; , are the temperature and pressure of the gas in the breathing cavity of the transformer bushing, respectively; is the gas volume in the breathing cavity of the transformer bushing; is the molar gas constant.

[0146] The gas production amount in the breathing cavity of the transformer bushing is obtained as follows:

[0147] The gas amount in the breathing cavity of the transformer bushing is calculated at two time points and , respectively. The gas amount increment in the breathing cavity of the transformer bushing is calculated in the corresponding time period, and the gas amount increment in the breathing cavity of the transformer bushing is taken as the gas production amount in the breathing cavity of the transformer bushing, and the specific formula is as follows:

[0148]

[0149] In the formula, is the gas amount increment in the breathing cavity of the transformer bushing; ~ is the gas amount increment in the breathing cavity of the transformer bushing in the time period; , , are the temperature, pressure and gas volume in the breathing cavity of the transformer bushing at , respectively; , , are the temperature, pressure and gas volume in the breathing cavity of the transformer bushing at , respectively.

[0150] The gas production rate in the breathing cavity of the transformer bushing is obtained as follows:

[0151] The gas production rate is calculated based on the gas amount increment in the breathing cavity, and the specific formula is as follows:

[0152] ​

[0153] In the formula, is the gas production rate in the transformer bushing breathing cavity; is and the difference between them.

[0154] Here, the specific steps of comparing the total gas amount with the preset total gas amount warning threshold, the gas production amount with the preset gas production amount warning threshold, and the gas production rate with the preset gas production rate warning threshold are as follows:

[0155] Compare the total gas amount with the preset total gas amount warning threshold, and if the total gas amount is greater than the preset total gas amount warning threshold, an alarm is issued;

[0156] Compare the gas production amount with the preset gas production amount warning threshold, and if the gas production amount is greater than the preset gas production amount warning threshold, an alarm is issued;

[0157] Compare the gas production rate with the preset gas production rate warning threshold, and if the gas production rate is greater than the preset gas production rate warning threshold, an alarm is issued.

[0158] As shown in Figure 3 , the embodiment also provides a transformer bushing partial discharge fault online monitoring system, comprising: a first calculation module for obtaining the corresponding gas volume in the transformer bushing breathing cavity based on the collected oil level information in the transformer bushing breathing cavity; a second calculation module for calculating the total gas amount in the transformer bushing breathing cavity in combination with the gas volume and the collected gas temperature and pressure in the transformer bushing breathing cavity, and calculating the gas production amount and the gas production rate in the transformer bushing breathing cavity in combination with the total gas amount; a fault warning module for comparing the total gas amount with the preset total gas amount warning threshold, the gas production amount with the preset gas production amount warning threshold, and the gas production rate with the preset gas production rate warning threshold, respectively, to obtain a comparison result; the comparison result is used to warn the partial discharge fault of the transformer bushing.

[0159] The application also provides a device comprising: a memory for storing a computer program; and a processor for executing the computer program to realize the steps of the transformer bushing partial discharge fault online monitoring method.

[0160] The processor implements the steps of the transformer bushing partial discharge fault online monitoring method when executing the computer program, for example: obtaining the gas volume in the transformer bushing breathing cavity based on the collected oil level information in the transformer bushing breathing cavity; combining the gas volume and the collected gas temperature and pressure in the transformer bushing breathing cavity, calculating the total gas amount in the transformer bushing breathing cavity, and combining the total gas amount to calculate the gas production amount and gas production rate in the transformer bushing breathing cavity; comparing the total gas amount with the preset total gas amount warning threshold, comparing the gas production amount with the preset gas production amount warning threshold, and comparing the gas production rate with the preset gas production rate warning threshold, respectively, to obtain a comparison result; and the comparison result is used for early warning of the partial discharge fault of the transformer bushing.

[0161] Alternatively, the processor implements the functions of the modules in the system when executing the computer program, for example: a first calculation module for obtaining the gas volume in the transformer bushing breathing cavity based on the collected oil level information in the transformer bushing breathing cavity; a second calculation module for combining the gas volume and the collected gas temperature and pressure in the transformer bushing breathing cavity, calculating the total gas amount in the transformer bushing breathing cavity, and combining the total gas amount to calculate the gas production amount and gas production rate in the transformer bushing breathing cavity; and a fault warning module for comparing the total gas amount with the preset total gas amount warning threshold, comparing the gas production amount with the preset gas production amount warning threshold, and comparing the gas production rate with the preset gas production rate warning threshold, respectively, to obtain a comparison result; and the comparison result is used for early warning of the partial discharge fault of the transformer bushing.

[0162] For example, the computer program can be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present application. The one or more modules / units can be a series of computer program instruction segments capable of completing a preset function, which are used to describe the execution process of the computer program in the transformer bushing partial discharge fault online monitoring device. For example, the computer program can be divided into a first calculation module, a second calculation module, and a fault warning module; the specific functions of each module are as follows: the first calculation module is used for obtaining the gas volume in the transformer bushing breathing cavity based on the collected oil level information in the transformer bushing breathing cavity; the second calculation module is used for combining the gas volume and the collected gas temperature and pressure in the transformer bushing breathing cavity, calculating the total gas amount in the transformer bushing breathing cavity, and combining the total gas amount to calculate the gas production amount and gas production rate in the transformer bushing breathing cavity; and the fault warning module is used for comparing the total gas amount with the preset total gas amount warning threshold, comparing the gas production amount with the preset gas production amount warning threshold, and comparing the gas production rate with the preset gas production rate warning threshold, respectively, to obtain a comparison result; and the comparison result is used for early warning of the partial discharge fault of the transformer bushing.

[0163] The transformer bushing partial discharge fault on-line monitoring device can be a desktop computer, a notebook computer, a palm computer, a cloud server, and the like. The transformer bushing partial discharge fault on-line monitoring device can include, but is not limited to, a processor and a memory. Those skilled in the art can understand that the above is an example of the transformer bushing partial discharge fault on-line monitoring device, and does not constitute a limitation on the transformer bushing partial discharge fault on-line monitoring device, and can include more components than the above, or combine certain components, or different components, for example, the transformer bushing partial discharge fault on-line monitoring device can also include an input / output device, a network access device, a bus, and the like.

[0164] The processor can be a central processing unit (CPU), and can 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 gates or transistor logic, discrete hardware components, and the like. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor and the like. The processor is a control center of the transformer bushing partial discharge fault on-line monitoring device, and connects various parts of the transformer bushing partial discharge fault on-line monitoring device through various interfaces and lines.

[0165] The memory can be used to store the computer programs and / or modules, and the processor realizes various functions of the transformer bushing partial discharge fault on-line monitoring device by running or executing the computer programs and / or modules stored in the memory, and calling the data stored in the memory.

[0166] The memory can mainly include a program storage area and a data storage area. The program storage area can store an operating system, at least one application required by a function (such as a sound playing function, an image playing function, and the like), and the like. The data storage area can store data created according to use of the mobile phone (such as audio data, a phone book, and the like), and the like. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, for example, a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other volatile solid-state memory devices.

[0167] The application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps of the transformer bushing partial discharge fault online monitoring method.

[0168] The modules / units of the transformer bushing partial discharge fault online monitoring system are stored in a computer readable storage medium if they are realized in the form of software function units and sold or used as independent products.

[0169] Based on the understanding, all or part of the processes of the transformer bushing partial discharge fault online monitoring method can be realized by a computer program to instruct related hardware, the computer program can be stored in a computer readable storage medium, and the computer program can implement the steps of the transformer bushing partial discharge fault online monitoring method when executed by a processor. The computer program includes computer program codes, which can be in the form of source codes, object codes, executable files or preset intermediate forms.

[0170] The computer readable storage medium can include any entity or device, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc. that can carry the computer program codes.

[0171] It should be noted that the content included in the computer readable storage medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to the legislation and patent practice, the computer readable storage medium does not include electric carrier signals and telecommunication signals.

[0172] The above embodiment is only one of the implementation manners of the technical scheme of the application, and the scope of the application claimed by the application is not limited to the above embodiment, but also includes any changes, substitutions and other implementation manners easily thought by those skilled in the art within the technical scope disclosed by the application.

[0173] In summary, the present application provides a transformer bushing partial discharge fault online monitoring method and related equipment, which considers the total amount of gas in the bushing breathing cavity and the gas production, and the total amount of gas and the gas production are obtained based on the monitoring of the gas temperature, pressure and oil level in the breathing cavity. The method considers the simplicity of temperature, pressure and oil level monitoring and the directness of free gas monitoring, and directly considers the monitoring of the total gas in the bushing breathing cavity. Unlike the existing method based on gas component analysis, the complexity of gas component analysis is avoided, and the online monitoring of the gas in the bushing breathing cavity has the advantage of simple implementation.

[0174] Compared with the existing transformer bushing partial discharge fault monitoring measures, the present application has the following advantages:

[0175] The monitoring method can accurately calculate the gas volume, total gas amount, gas production and gas production rate in the breathing cavity by collecting the oil level information, gas temperature and pressure in the transformer bushing breathing cavity, combining the relationship curve of the transformer bushing oil level and the breathing cavity gas volume and the gas state equation. This calculation process is not only scientific and rigorous, but also avoids complex gas component analysis, greatly improving the real-time and accuracy of monitoring. At the same time, the method also realizes the timely early warning of the transformer bushing partial discharge fault by presetting the early warning threshold of the total gas amount, gas production and gas production rate. When the monitoring value exceeds the early warning threshold, the system can automatically issue an alarm, providing valuable time window for the operation and maintenance personnel to timely discover and handle the fault, thereby effectively avoiding the expansion of the fault and the occurrence of accidents, ensuring the safe and stable operation of the power system. In summary, the method not only simplifies the monitoring process and improves the monitoring efficiency, but also significantly enhances the early warning capability of the transformer bushing partial discharge fault, and has important practical value and application prospect.

[0176] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application and not to limit it, although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that the specific embodiments of the present application can be modified or replaced, without departing from the spirit and scope of the present application. Any modification or equivalent replacement, which should be covered within the protection scope of the claims of the present application.

Claims

1. A method for on-line monitoring of partial discharge faults in a transformer bushing, characterized by, The method comprises the following steps: Based on the collected oil level information in the transformer bushing breathing cavity, the corresponding gas volume in the transformer bushing breathing cavity is obtained; Combined with the gas volume, the collected gas temperature and pressure in the transformer bushing breathing cavity, the total gas amount in the transformer bushing breathing cavity is calculated, and the gas production amount and gas production rate in the transformer bushing breathing cavity are calculated combined with the total gas amount; The total gas amount, the preset total gas amount warning threshold, the gas production amount, the preset gas production amount warning threshold, and the gas production rate, the preset gas production rate warning threshold are compared respectively to obtain a comparison result; the comparison result is used for early warning of the partial discharge fault of the transformer bushing; The calculation of the total gas amount in the transformer bushing breathing cavity based on the gas volume and the collected gas temperature and pressure in the transformer bushing breathing cavity comprises: A calculation model of the total gas amount, the gas production amount and the gas production rate in the transformer bushing breathing cavity is established; Based on the gas state equation of the calculation model, the amount of substance of the gas in the transformer bushing breathing cavity is obtained, and the amount of substance of the gas in the transformer bushing breathing cavity is taken as the total gas amount in the transformer bushing breathing cavity, and the specific formula is as follows: wherein is the total amount of gas in the breathing cavity of the transformer bushing; , are the temperature and pressure of the gas in the breathing cavity of the transformer bushing, respectively; is the volume of the gas in the breathing cavity of the transformer bushing; is the molar gas constant.

2. The transformer bushing partial discharge fault on-line monitoring method according to claim 1, characterized in that, The total gas amount in the transformer bushing breathing cavity is obtained based on the collected oil level information in the transformer bushing breathing cavity, which comprises: The collected oil level information in the transformer bushing breathing cavity is input into the relationship table or relationship fitting curve of the transformer bushing oil level and the breathing cavity gas volume to obtain the gas volume in the transformer bushing breathing cavity corresponding to the oil level information.

3. The transformer bushing partial discharge fault on-line monitoring method according to claim 2, characterized in that, The relationship table or relationship fitting curve of the transformer bushing oil level and the breathing cavity gas volume is obtained based on the actual measurement and calibration of the transformer bushing breathing cavity drawing, and the specific steps are as follows: According to the transformer bushing breathing cavity drawing, the corresponding breathing cavity gas volume under different oil levels is measured combined with a preset measurement step length; After calibration, the relationship table of the transformer bushing oil level and the breathing cavity gas volume is obtained; The relationship fitting curve of the transformer bushing oil level and the breathing cavity gas volume is obtained according to the data in the relationship table of the transformer bushing oil level and the breathing cavity gas volume.

4. The transformer bushing partial discharge fault on-line monitoring method according to claim 1, characterized in that, In the calculation of the gas production amount and the gas production rate in the transformer bushing breathing cavity combined with the total gas amount, the gas production amount in the transformer bushing breathing cavity is obtained as follows: at two time instants respectively with The amount of gas substance in the breathing cavity of the transformer bushing is calculated with The amount of gas substance in the breathing cavity of the transformer bushing is calculated In the formula, is ~ The amount of respiratory cavity gas material in the time period is increased; 、 、 are respectively The temperature, pressure and gas volume in the respiratory cavity of the transformer bushing at the moment; 、 、 are respectively The temperature, pressure and gas volume in the respiratory cavity of the transformer bushing at the moment.

5. The transformer bushing partial discharge fault on-line monitoring method according to claim 4, characterized in that, In the calculation of the gas production amount and the gas production rate in the transformer bushing breathing cavity combined with the total gas amount, the gas production rate in the transformer bushing breathing cavity is obtained as follows: The gas production rate is calculated based on the increment of the amount of substance of the breathing cavity gas, and the specific formula is as follows: wherein is the gas production rate within the breathing cavity of the transformer bushing; is is the difference between and 6. The transformer bushing partial discharge fault on-line monitoring method according to claim 1, characterized in that, The total gas amount, the preset total gas amount warning threshold, the gas production amount, the preset gas production amount warning threshold, and the gas production rate, the preset gas production rate warning threshold are compared respectively to obtain a comparison result; the comparison result is used for early warning of the partial discharge fault of the transformer bushing; The total gas amount is compared with the preset total gas amount warning threshold, if the total gas amount is greater than the preset total gas amount warning threshold, an alarm is issued; The gas production amount is compared with the preset gas production amount warning threshold, if the gas production amount is greater than the preset gas production amount warning threshold, an alarm is issued; The gas production rate is compared with a preset gas production rate warning threshold, and if the gas production rate is greater than the preset gas production rate warning threshold, an alarm is issued.

7. A transformer bushing partial discharge fault on-line monitoring system for implementing the steps of the transformer bushing partial discharge fault on-line monitoring method according to any one of claims 1-6, characterized in that, The method comprises the steps of: The first calculation module is configured to obtain the gas volume in the breathing cavity of the transformer bushing based on the collected oil level information in the breathing cavity of the transformer bushing. The second calculation module is configured to obtain the total gas amount in the breathing cavity of the transformer bushing by combining the gas volume and the collected gas temperature and pressure in the breathing cavity of the transformer bushing, and obtain the gas production amount and the gas production rate in the breathing cavity of the transformer bushing by combining the total gas amount. The fault warning module is configured to compare the total gas amount with a preset total gas amount warning threshold, compare the gas production amount with a preset gas production amount warning threshold, and compare the gas production rate with a preset gas production rate warning threshold, respectively, to obtain a comparison result, wherein the comparison result is used to warn the partial discharge fault of the transformer bushing.

8. A partial discharge fault on-line monitoring device for a transformer bushing, characterized by The method comprises the steps of: The memory is configured to store a computer program. The processor is configured to execute the computer program to implement the steps of the transformer bushing partial discharge fault online monitoring method according to any one of claims 1-6.

9. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 8. The computer program is configured to be executed by the processor to implement the steps of the transformer bushing partial discharge fault online monitoring method according to any one of claims 1-6.

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