CN115078924A - System and method for judging transformer defects by combining dissolved gas in oil and iron core grounding current - Google Patents
System and method for judging transformer defects by combining dissolved gas in oil and iron core grounding current Download PDFInfo
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- CN115078924A CN115078924A CN202210629884.1A CN202210629884A CN115078924A CN 115078924 A CN115078924 A CN 115078924A CN 202210629884 A CN202210629884 A CN 202210629884A CN 115078924 A CN115078924 A CN 115078924A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
- G01R31/1263—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation
Abstract
The invention discloses a system and a method for judging transformer defects by combining dissolved gas in oil and iron core grounding current, which relate to the field of transformer fault detection and comprise the following steps: the on-line analysis device for the gas dissolved in the oil, the grounding flat iron, the iron core grounding current monitoring on-line sensor, the iron core grounding current on-line monitor and the data processing and analysis system; the online analysis device for the dissolved gas in the oil is used for online analysis of the dissolved gas in the oil in the transformer, the iron core grounding current online monitor is used for online monitoring of the iron core grounding current of the transformer, and finally the monitoring results of the dissolved gas in the oil and the iron core grounding current are combined to judge whether defects exist. The invention has the advantages that the detection of oil dissolved gas in the transformer is combined with the detection of the grounding current of the on-line iron core, the defects of latent partial discharge, insulation and the like in the transformer equipment are accurately pre-judged, and the hidden danger of the equipment is effectively killed in the sprouting stage in time.
Description
Technical Field
The invention belongs to the technical field of transformer fault detection, relates to a system and a method for judging transformer defects by combining dissolved gas in oil with iron core grounding current, and particularly relates to a system and a method for judging transformer defects by combining online analysis of dissolved gas in oil with iron core grounding current.
Background
With the increasing of the power consumption, the transformer of the transformer substation is used more and more. Partial discharge of parts in transformer equipment is one of main defects in the operation process of high-voltage electrical equipment, and not only can the insulation strength of the equipment be influenced, but also unplanned power failure can be caused, and the safety of a power grid is influenced. Therefore, it is very important to monitor whether or not there is a defect due to partial discharge of the transformer device.
In the power industry, aiming at whether partial discharge exists in the transformer, dissolved gas in oil is mainly analyzed, and offline high-frequency and iron core grounding current live detection is mainly adopted, so that whether discharge exists in equipment is judged; partial transformer substations are provided with online dissolved gas analysis devices in oil, but whether partial discharge exists or not is considered from the aspect of chemical quantity, so that the situations of one side and inaccurate test are inevitable, and other means do not exist for mutual verification. The existing detection method is difficult to accurately predict the latent partial discharge in the transformer equipment, cannot timely and effectively kill the hidden trouble of the equipment at the sprouting stage, and particularly has no defect diagnosis technology for combining the analysis of dissolved gas in oil and the grounding current of an iron core.
Disclosure of Invention
The invention aims to solve at least one technical problem in the prior art and provides a system and a method for judging the defects of a transformer by combining dissolved gas in oil and iron core grounding current.
The technical solution of the invention is as follows:
the invention provides a system for judging the defects of a transformer by combining dissolved gas in oil and iron core grounding current, which comprises:
the online analysis device for the dissolved gas in the oil is connected with transformer equipment and used for online analysis of the content of the dissolved gas in the insulating oil in the transformer equipment, the online analysis device for the dissolved gas in the oil is provided with an oil inlet and an oil return port, the oil inlet is connected with the transformer equipment through a sample inlet pipe, the sample inlet pipe is provided with an oil taking valve, the oil return port is connected with the transformer equipment through a sample return pipe, and the sample return pipe is provided with an oil return valve;
the grounding flat iron is connected with a grounding down lead of the transformer equipment;
the iron core grounding current monitoring online sensor is connected with a grounding down lead of the transformer equipment and is connected with the grounding flat iron;
the iron core grounding current on-line monitor is connected with the iron core grounding current monitoring on-line sensor and is used for on-line monitoring of iron core grounding current of transformer equipment;
and the data processing and analyzing system is connected with the online analyzing device for the gas dissolved in the oil and the online monitor for the iron core grounding current and is used for carrying out combined processing and analysis on the monitoring results of the online analyzing device for the gas dissolved in the oil and the online monitor for the iron core grounding current.
Preferably, the on-line analysis device for the dissolved gas in the oil is used for carrying out on-line analysis on the content of at least one of carbon monoxide, carbon dioxide, methane, ethane, ethylene, acetylene and hydrogen in the insulating oil in the transformer equipment.
Preferably, the data processing and analyzing system is capable of receiving the content data of the dissolved gas in the insulating oil transmitted by the online analyzing device for the dissolved gas in the oil and the iron core grounding current data transmitted by the online monitor for the iron core grounding current, and calculating and comparing the received content data of the dissolved gas in the insulating oil with historical data;
when the data processing and analyzing system monitors that the grounding current of the iron core exceeds a set threshold value, the acetylene content in the insulating oil exceeds the set threshold value, and the relative growth rate of carbon monoxide and carbon dioxide in the insulating oil exceeds the set threshold value, judging that the transformer equipment has an insulation defect;
when the data processing and analyzing system monitors that the grounding current of the iron core exceeds a set threshold value, the acetylene content in the insulating oil exceeds the set threshold value, and the relative growth rate of the acetylene and the hydrogen in the insulating oil exceeds the set threshold value, judging that the transformer equipment has a discharge defect;
more preferably, when the iron core grounding current value monitored by the data processing and analyzing system is higher than 1000mA, the acetylene content monitored by the online analyzing device for the gas dissolved in the oil is more than 0.1 muL/L, and the relative growth rate of the gas of carbon monoxide and carbon dioxide is more than 100%/month, the transformer equipment is judged to have insulation defects;
and when the iron core grounding current value monitored by the data processing and analyzing system is higher than 3000mA, the acetylene content monitored by the online analyzing device for the gas dissolved in the oil is more than 1.0 mu L/L, and the relative growth rate of the gas of the acetylene and the hydrogen is more than 100%/month, judging that the transformer equipment has a discharge defect.
The invention provides a method for judging the defects of a transformer by combining dissolved gas in oil and iron core grounding current, which comprises the following steps:
s1, sampling the insulating oil in the transformer equipment, and carrying out online analysis on the content of dissolved gases such as carbon monoxide, carbon dioxide, methane, ethane, ethylene, acetylene and hydrogen in the insulating oil to obtain the content data of the dissolved gases in the insulating oil; preferably, the insulating oil in the transformer equipment is sampled by an online analysis device for the dissolved gas in the oil, the dissolved gas in the insulating oil is analyzed online, the content of carbon monoxide, carbon dioxide, methane, ethane, ethylene, acetylene and hydrogen in the insulating oil is analyzed online, and the analysis data is transmitted to a data processing and analyzing system; after the online analysis is finished, opening an oil return valve, and returning the insulating oil to the transformer equipment;
s2, carrying out on-line monitoring on the iron core grounding current of the transformer equipment to obtain iron core grounding current data; preferably, the iron core grounding current of the transformer equipment is monitored on line through an iron core grounding current on-line monitor and an iron core grounding current monitoring on-line sensor, and monitoring data are transmitted to a data processing and analyzing system;
s3, comparing and calculating the obtained content data of the dissolved gas in the insulating oil with historical data to obtain relative gas increase rate data; preferably, the analysis data of the on-line analysis device for the dissolved gas in the oil and the monitoring data of the on-line monitor for the grounding current of the iron core are combined, processed and analyzed through a data processing and analyzing system, and whether the transformer equipment has discharge defects and insulation defects is judged.
When the iron core grounding current data exceed a set threshold value, the acetylene content data in the insulating oil exceed the set threshold value, and the gas relative growth rate data of carbon monoxide and carbon dioxide in the insulating oil exceed the set threshold value, judging that the transformer equipment has an insulation defect;
when the grounding current data of the iron core exceeds a set threshold value, the acetylene content data in the insulating oil exceeds the set threshold value, and the relative gas growth rate data of acetylene and hydrogen in the insulating oil exceeds the set threshold value, judging that the transformer equipment has a discharge defect;
wherein the gas relative growth rate is 100% × (C) 2 -C 1 )/(C 1 ×Δt)
In the formula: the relative growth rate of gas, in%/month;
C 2 -the concentration of dissolved gas in the oil obtained from the second sampling analysis in μ L/L;
C 1 -the concentration of dissolved gases in the oil obtained from the first sampling analysis in μ L/L;
Δ t — the running time of the transformer in two sampling intervals, in months.
Preferably, the method for determining the insulation defect in step S3 is:
when the data processing and analyzing system monitors that the value of the iron core grounding current transmitted by the iron core grounding current on-line monitor is higher than 1000mA, and monitors that the content of acetylene in insulating oil transmitted by the on-line analysis device for the gas dissolved in the oil is higher than 0.1 muL/L, and the relative growth rate of the gas of carbon monoxide and carbon dioxide in the insulating oil is higher than 100%/month, the insulating oil is judged to be an insulating defect;
wherein the gas relative growth rate is 100% × (C) 2 -C 1 )/(C 1 ×Δt)
In the formula: the relative growth rate of gas, in%/month;
C 2 -the concentration of dissolved gas in the oil obtained from the second sampling analysis in μ L/L;
C 1 -the concentration of dissolved gas in the oil obtained from the first sampling analysis in μ L/L;
Δ t — the running time of the transformer in months in the twice-sampling interval.
Preferably, the method for determining the discharge defect in step S3 is:
when the data processing and analyzing system monitors that the value of the iron core grounding current transmitted by the iron core grounding current on-line monitor is higher than 3000mA, and monitors that the content of acetylene in insulating oil transmitted by the on-line analysis device for the gas dissolved in the oil is higher than 1.0 muL/L, and the relative growth rate of the gas of acetylene and hydrogen in the insulating oil is higher than 100%/month, the discharging defect is judged;
wherein the gas relative growth rate (%/month) × (C) is 100% × ( 2 -C 1 )/(C 1 ×Δt)
In the formula: c 2 -the concentration of dissolved gas in the oil, μ L/L, obtained from the second sampling analysis;
C 1 -the concentration of dissolved gas in the oil, μ L/L, obtained from the first sampling analysis;
Δ t — the running time of the transformer in the two sampling interval, month.
The principle of judging the defects of the transformer is that oil in transformer equipment is used as an insulating and cooling medium, an online analyzer for dissolved gas in the oil analyzes according to a set monitoring period, specifically, the insulating oil in the transformer equipment is sampled, then the dissolved gas in the oil is analyzed online, and the total number of analysis items is 7, namely the contents of carbon monoxide, carbon dioxide, methane, ethane, ethylene, acetylene and hydrogen in the oil; carrying out on-line monitoring on the grounding current of the iron core of the transformer equipment; then, the analysis result of the gas dissolved in the oil is combined with the on-line monitoring result of the grounding current of the iron core, and whether the potential discharge and insulation trends exist in the transformer equipment is comprehensively judged, so that the method is different from the conventional high-frequency on-line monitoring, oil chromatography laboratory detection and iron core grounding current live detection of the transformer.
The invention has at least one of the following beneficial effects:
1. the device comprises an online analysis device for the dissolved gas in the oil, an online monitor for the iron core grounding current and a data processing and analysis system, wherein the online analysis device for the dissolved gas in the oil can analyze the dissolved gas in the insulating oil in the transformer equipment, the online monitor for the iron core grounding current can monitor the iron core grounding current of the transformer on line, and the data processing and analysis system combines the gas analysis result with the online monitoring result for the iron core grounding current, so that the defects of latent local discharge, insulation and the like in the transformer equipment can be monitored.
2. According to the method for judging the defects of the transformer equipment, the insulating oil in the transformer is sampled, the dissolved gas is analyzed on line, the detection result is combined with the on-line iron core grounding current analysis result, the defects of latent partial discharge, insulation and the like in the transformer equipment are accurately pre-judged, and the hidden equipment danger is effectively killed at the sprouting stage in time.
3. The invention is suitable for transformer electrical equipment taking oil as an insulating and cooling medium, and can monitor partial discharge, insulation defects and the like of the transformer equipment in real time.
Drawings
FIG. 1 is a schematic structural view of the present invention;
the following are marked in the figure: 1 is a transformer device; 2 is an oil extraction valve; 3 is an on-line analysis device for dissolved gas in oil; 4 is a return valve; 5, an iron core grounding current monitoring on-line sensor; 6 is a grounding flat iron; 7 is iron core grounding current on-line monitor; and 8, a data processing and analyzing system.
Detailed Description
The present invention will be described in further detail with reference to the following examples, but the present invention is not limited to the following examples.
In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.
Example 1
Fig. 1 is a schematic diagram of a system for determining a transformer defect by combining a dissolved gas in oil and an iron core grounding current in this embodiment, which includes an oil extraction valve 2, a dissolved gas online analysis device 3, an oil return valve 4, an iron core grounding current monitoring online sensor 5, a grounding flat iron 6, an iron core grounding current online monitor 7, and a data processing and analysis system 8.
The online analysis device 3 for the gas dissolved in the oil is connected with the oil-filled transformer equipment 1, and is used for performing online analysis on the content of the gas dissolved in the insulating oil in the transformer equipment 1, namely, the data of the content of carbon monoxide, carbon dioxide, methane, ethane, ethylene, acetylene and hydrogen in the insulating oil, and transmitting the monitored data to the data processing and analysis system 8. The online analysis device 3 for the dissolved gas in the oil is provided with an oil inlet and an oil return port, the oil inlet is connected with the transformer equipment 1 through a sampling pipe, an oil taking valve 2 and a sampling pump are arranged on the sampling pipe, the oil taking valve 2 and the sampling pump are opened, and the oil in the transformer equipment 1 is pumped into the online analysis device 3 for the dissolved gas in the oil through the sampling pump; the oil return port is connected with the transformer equipment 1 through a sample return pipe, an oil return valve 4 is arranged on the sample return pipe, and after oil sample analysis is completed, oil is pumped back into the transformer through a sampling pump. The on-line analysis device 3 for gas dissolved in oil in the embodiment is installed in a fixed box with an air conditioner.
The grounding flat iron 6 is connected with a grounding down lead of the transformer equipment 1; the iron core grounding current monitoring on-line sensor 5 is fixed on a grounding down lead of the transformer equipment 1, the iron core grounding current monitoring on-line sensor 5 is connected with a grounding flat iron 6, and the iron core grounding current monitoring on-line sensor 5 can monitor the iron core grounding current of the transformer equipment 1 on line and transmit the iron core grounding current to an iron core grounding current on-line monitor 7; the iron core grounding current on-line monitor 7 is connected with the iron core grounding current monitoring on-line sensor 5 and is used for on-line monitoring of the iron core grounding current of the transformer equipment 1.
The data processing and analyzing system 8 is connected with the data output port of the on-line analyzing device 3 for the gas dissolved in the oil and the data output port of the on-line monitoring instrument 7 for the iron core grounding current, and is used for combining, processing and analyzing the monitoring results of the on-line analyzing device 3 for the gas dissolved in the oil and the on-line monitoring instrument 7 for the iron core grounding current, and an expert diagnosis system for judging the defects of the transformer equipment by combining the analysis data of the on-line analyzing device for the gas dissolved in the oil and the analysis data of the on-line iron core grounding current is arranged on the monitoring data processing and analyzing system 8, so that the latent partial discharge, the insulation defects and the like in the transformer equipment 1 can be accurately pre-judged, and the real-time monitoring can be realized. Specifically, the data processing and analyzing system 8 can receive the data of the content of the dissolved gas in the insulating oil in the transformer equipment 1 transmitted by the online analyzing device 3 for the dissolved gas in the oil, i.e. the carbon monoxide, carbon dioxide, methane, ethane, ethylene, acetylene and hydrogen content of the insulating oil, and receives the data of the iron core grounding current of the transformer equipment 1 transmitted by the iron core grounding current on-line monitor 7, storing the data, calculating and comparing the received data of the content of the dissolved gas in the insulating oil with stored historical data, when the grounding current of the iron core of the transformer equipment 1 exceeds a set threshold value and the acetylene content monitored by the on-line analysis device of the dissolved gas in the oil exceeds the set threshold value, and the relative increase rate of the content of other gases exceeds the set threshold, the transformer device 1 is judged to have insulation defect or discharge defect.
Specifically, when the data processing and analyzing system 8 receives that the numerical value monitored by the iron core grounding current on-line monitor 7 is higher than 1000mA, receives that the acetylene content monitored by the oil dissolved gas on-line analyzing device 3 is more than 0.1 muL/L, and simultaneously calculates and compares that the gas relative growth rate of carbon monoxide and carbon dioxide in the oil is more than 100%/month, the insulation defect is judged;
when the data processing and analyzing system 8 receives that the numerical value monitored by the iron core grounding current on-line monitor 7 is higher than 3000mA, receives that the acetylene content monitored by the on-line analyzing device for the dissolved gas in the oil is more than 1.0 muL/L, and simultaneously calculates and compares that the gas relative growth rate of acetylene and hydrogen is more than 100%/month, the discharge defect is judged;
wherein the gas relative growth rate is 100% × (C) 2 -C 1 )/(C 1 ×Δt)
In the formula: the relative growth rate of gas, in%/month;
C 2 -the concentration of dissolved gases in the oil obtained from the second sampling analysis in μ L/L;
C 1 -the concentration of dissolved gas in the oil obtained from the first sampling analysis in μ L/L;
Δ t — the running time of the transformer in two sampling intervals, in months.
Example 2
The method for judging the defects of the transformer by adopting the system in the embodiment 1 comprises the following steps:
s1, opening the oil taking valve 2, sampling the insulating oil in the transformer equipment 1 through the online analysis device 3 for the gas dissolved in the oil, wherein the sampling comprises online analysis of the content of carbon monoxide, carbon dioxide, methane, ethane, ethylene, acetylene and hydrogen in the insulating oil, and transmitting the analysis data to the data processing and analysis system 8; after the on-line analysis is finished, opening an oil return valve 4 and returning the insulating oil to the transformer equipment 1;
s2, carrying out online monitoring on the iron core grounding current of the transformer equipment 1 through the iron core grounding current online monitor 7 and the iron core grounding current monitoring online sensor 5, and transmitting the monitoring data to the data processing and analyzing system 8;
and S3, the data processing and analyzing system 8 receives the analysis data of the on-line analysis device 3 for the dissolved gas in the oil and the monitoring data of the on-line monitor 7 for the iron core grounding current, and combines and analyzes the analysis data and the monitoring data to judge whether the transformer equipment 1 has discharge defects and insulation defects.
Specifically, when the method for judging partial discharge of the transformer equipment by combining the analysis of the online analysis device 3 for the dissolved gas in the oil and the analysis of the online monitor 7 for the grounding current of the iron core is used in the field, if the online analysis device for the dissolved gas in the oil or the online analysis device for the grounding current of the iron core monitors suspicious signals, the method can be used for judging whether the equipment in the transformer has partial discharge or judging the type of the defect according to the following steps.
(1) When the numerical value monitored by the iron core grounding current online monitor 7 is higher than 1000mA, the acetylene content monitored by the online analysis device 3 for the gas dissolved in the oil is more than 0.1 mu L/L, and the gas relative growth rate of carbon monoxide and carbon dioxide is more than 100%/month, the insulation defect is judged;
wherein the gas relative growth rate (%/month) × (C) is 100% × ( 2 -C 1 )/(C 1 ×Δt)
In the formula: c 2 -the concentration of dissolved gas in the oil, μ L/L, obtained from the second sampling analysis;
C 1 -the concentration of dissolved gas in the oil, μ L/L, obtained from the first sampling analysis;
Δ t — the running time of the transformer in the two sampling interval, month.
Taking a certain actually-operated 220kV transformer as an example, wherein between 12 months in 2018 and 12 months in 2019, the grounding current monitoring data of the transformer core is shown in table 1, and the monitoring data of the gas dissolved in the oil is shown in table 2:
TABLE 1 grounding current of transformer core
| Monitoring time | Iron core grounding current (mA) |
| 12 months in 2018 | 10.6 |
| 06 months in 2019 | 10.8 |
| 12 months and 1 day in 2019 | 1112 |
| 12 months and 3 days in 2019 | 1236 |
TABLE 2 dissolved gas in oil
From the data in table 1, it is understood that the value monitored by the iron core grounding current on-line monitor 7 in 2019, 12 months and 1 days is 1112mA and more than 1000mA, and the data in table 2 can calculate that in 2019, 06 months to 12 months and 1 days, the acetylene content monitored by the on-line analysis device 3 for the gas dissolved in the oil is increased from 0 μ L/L to 0.2 μ L/L, and the gas relative increase rates of carbon monoxide and carbon dioxide are 115.4%/month and 111.3%/month respectively and are both more than 100%/month.
And comprehensively judging that the transformer has insulation defects.
(2) When the numerical value monitored by the iron core grounding current online monitor 7 is higher than 3000mA, the acetylene content monitored by the online analysis device for the gas dissolved in the oil is more than 1.0 muL/L, and the gas relative growth rate of acetylene and hydrogen is more than 100%/month, the iron core grounding current online monitor is judged to be a discharge defect;
wherein the gas relative growth rate (%/month) × (C) is 100% × ( 2 -C 1 )/(C 1 ×Δt)
In the formula: c 2 -the concentration of dissolved gas in the oil, μ L/L, obtained from the second sampling analysis;
C 1 -the concentration of dissolved gas in the oil, μ L/L, obtained from the first sampling analysis;
Δ t — the running time of the transformer in the two sampling interval, month.
Taking a certain actually-operated 220kV transformer as an example, wherein between 2019 and 2020 and 12 months, the monitoring data of the grounding current of the transformer core is shown in table 3, and the monitoring data of the gas dissolved in the oil is shown in table 4:
TABLE 3 grounding current of transformer core
| Monitoring time | Iron core grounding current (mA) |
| 06 months in 2019 | 10.9 |
| 06 months in 2020 | 11.4 |
| 12 and 5 days in 2020 | 3460 |
| 12 and 6 days in 2020 | 3630 |
TABLE 4 dissolved gas in oil
From the data in table 3, it can be seen that the value monitored by the iron core grounding current on-line monitor 7 is 3460mA and larger than 3000mA at 12 months and 5 days in 2020, and that the data in table 4 can be used to calculate the value from 06 months to 12 months and 5 days in 2020, the acetylene content monitored by the on-line analysis device 3 for the gas dissolved in oil is increased from 0 μ L/L to 1.2 μ L/L, and the gas relative increase rate of hydrogen is 117.3%/month and larger than 100%/month.
And comprehensively judging that the transformer has a discharge defect.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.
Claims (10)
1. System for judging transformer defects by combining dissolved gas in oil with iron core grounding current is characterized by comprising:
the online analysis device (3) for the dissolved gas in the oil, which is connected with the transformer equipment (1), is used for online analysis of the content of the dissolved gas in the insulating oil in the transformer equipment (1), the online analysis device (3) for the dissolved gas in the oil is provided with an oil inlet and an oil return port, the oil inlet is connected with the transformer equipment (1) through a sample inlet pipe, the sample inlet pipe is provided with an oil taking valve (2), the oil return port is connected with the transformer equipment (1) through a sample return pipe, and the sample return pipe is provided with an oil return valve (4);
the grounding flat iron (6) is connected with a grounding down lead of the transformer equipment (1);
the iron core grounding current monitoring on-line sensor (5) is connected with a grounding down lead of the transformer equipment (1), and the iron core grounding current monitoring on-line sensor (5) is connected with a grounding flat iron (6);
the iron core grounding current on-line monitor (7) is connected with the iron core grounding current monitoring on-line sensor (5) and is used for on-line monitoring of the iron core grounding current of the transformer equipment (1);
and the data processing and analyzing system (8) is connected with the online analyzing device (3) for the gas dissolved in the oil and the online monitor (7) for the iron core grounding current, is used for carrying out combined processing and analysis on the monitoring results of the online analyzing device (3) for the gas dissolved in the oil and the online monitor (7) for the iron core grounding current, and judges whether the transformer equipment (1) has defects or not.
2. The system for judging the defects of the transformer by combining the dissolved gas in the oil with the grounding current of the iron core according to claim 1, wherein the online analyzing device (3) for the dissolved gas in the oil is used for online analyzing the content of at least one of carbon monoxide, carbon dioxide, methane, ethane, ethylene, acetylene and hydrogen in the insulating oil in the transformer equipment (1).
3. The system for judging the defects of the transformer by combining the dissolved gas in the oil and the grounding current of the iron core according to claim 2,
the data processing and analyzing system (8) is used for receiving the content data of the dissolved gas in the insulating oil transmitted by the online analyzing device (3) for the dissolved gas in the oil and the iron core grounding current data transmitted by the online monitoring instrument (7) for the iron core grounding current, and comparing and calculating the received content data of the dissolved gas in the insulating oil with historical data to obtain the relative increase rate data of the gas;
wherein the gas relative growth rate is 100% × (C) 2 -C 1 )/(C 1 ×Δt)
In the formula: the relative growth rate of gas, in%/month;
C 2 -the concentration of dissolved gas in the oil obtained from the second sampling analysis in μ L/L;
C 1 -the concentration of dissolved gas in the oil obtained from the first sampling analysis in μ L/L;
Δ t — the running time of the transformer in the two sampling time interval, in months;
when the data processing and analyzing system (8) monitors that the grounding current of the iron core exceeds a set threshold value, the acetylene content in the insulating oil exceeds the set threshold value, and the relative growth rate of carbon monoxide and carbon dioxide in the insulating oil exceeds the set threshold value, the transformer equipment (1) is judged to have insulation defects;
when the data processing and analyzing system (8) monitors that the grounding current of the iron core exceeds a set threshold value, the acetylene content in the insulating oil exceeds the set threshold value, and the relative growth rate of the acetylene and the hydrogen in the insulating oil exceeds the set threshold value, the transformer equipment (1) is judged to have a discharge defect.
4. The system for judging the defects of the transformer by combining the dissolved gas in the oil and the grounding current of the iron core according to claim 3,
when the data processing and analyzing system (8) monitors that the value of the iron core grounding current transmitted by the iron core grounding current on-line monitor (7) is higher than 1000mA, and monitors that the content of acetylene in insulating oil transmitted by the on-line analysis device (3) for dissolved gas in the oil is higher than 0.1 muL/L, and the relative growth rate of carbon monoxide and carbon dioxide in the insulating oil is higher than 100%/month, the insulating oil is judged to be an insulating defect;
when the data processing and analyzing system (8) monitors that the value of the iron core grounding current transmitted by the iron core grounding current on-line monitor (7) is higher than 3000mA, and monitors that the content of acetylene in insulating oil transmitted by the dissolved gas on-line analyzing device (3) in the oil is higher than 1.0 muL/L, and the relative growth rate of acetylene and hydrogen in the insulating oil is higher than 100%/month, the discharge defect is judged.
5. The method for judging the defects of the transformer by combining the dissolved gas in the oil and the grounding current of the iron core is characterized by comprising the following steps of:
s1, sampling the insulating oil in the transformer equipment (1), and carrying out online analysis on the content of dissolved gases, namely carbon monoxide, carbon dioxide, methane, ethane, ethylene, acetylene and hydrogen in the insulating oil to obtain the content data of the dissolved gases in the insulating oil;
s2, carrying out on-line monitoring on the iron core grounding current of the transformer equipment (1) to obtain iron core grounding current data;
s3, comparing and calculating the obtained content data of the dissolved gas in the insulating oil with historical data to obtain relative gas increase rate data;
when the iron core grounding current data exceed a set threshold value, the acetylene content data in the insulating oil exceed the set threshold value, and the gas relative growth rate data of carbon monoxide and carbon dioxide in the insulating oil exceed the set threshold value, judging that the transformer equipment (1) has an insulation defect;
when the grounding current data of the iron core exceeds a set threshold value, the acetylene content data in the insulating oil exceeds the set threshold value, and the relative gas growth rate data of acetylene and hydrogen in the insulating oil exceeds the set threshold value, judging that the transformer equipment (1) has a discharge defect;
wherein the gas relative growth rate is 100% × (C) 2 -C 1 )/(C 1 ×Δt)
In the formula: the relative growth rate of gas, in%/month;
C 2 -the concentration of dissolved gases in the oil obtained from the second sampling analysis in μ L/L;
C 1 -the concentration of dissolved gas in the oil obtained from the first sampling analysis in μ L/L;
Δ t — the running time of the transformer in two sampling intervals, in months.
6. The method for determining the transformer defect by combining the dissolved gas in oil with the core grounding current according to claim 5, wherein in step S1, the insulating oil in the transformer equipment (1) is sampled by the online analyzing device (3) for the dissolved gas in oil connected with the transformer equipment (1), the dissolved gas in the insulating oil is analyzed online, including the content of carbon monoxide, carbon dioxide, methane, ethane, ethylene, acetylene and hydrogen in the insulating oil, and the analysis data is transmitted to the data processing and analyzing system (8); and after the online analysis is finished, opening the oil return valve (4) and returning the insulating oil to the transformer equipment (1).
7. The method for determining the transformer defect by combining the dissolved gas in the oil with the core grounding current according to claim 5, wherein in step S2, the core grounding current of the transformer device (1) is monitored on line by the core grounding current on-line monitor (7) and the core grounding current on-line sensor (5) connected to the grounding down-lead of the transformer device (1), and the monitored data is transmitted to the data processing and analyzing system (8).
8. The method for determining the transformer fault by combining the dissolved gas in oil with the core grounding current according to claim 5, wherein in step S3, the analysis data of the online analyzer (3) for the dissolved gas in oil and the monitoring data of the online monitor (7) for the core grounding current are combined and analyzed by a data processing and analyzing system (8) to determine whether the transformer equipment (1) has the discharge fault and the insulation fault.
9. The method for determining the transformer defect by combining the dissolved gas in the oil and the core grounding current according to claim 5, wherein the method for determining the insulation defect in the step S3 is as follows:
when the data processing and analyzing system (8) monitors that the numerical value of the iron core grounding current transmitted by the iron core grounding current online monitor (7) is higher than 1000mA, and monitors that the content of acetylene in insulating oil transmitted by the online analyzing device (3) for dissolved gas in the oil is higher than 0.1 muL/L, and the relative growth rate of carbon monoxide and carbon dioxide in the insulating oil is higher than 100%/month, the insulating oil is judged to be an insulating defect;
wherein the gas relative growth rate is 100% × (C) 2 -C 1 )/(C 1 ×Δt)
In the formula: the relative growth rate of gas, in%/month;
C 2 -the concentration of dissolved gas in the oil obtained from the second sampling analysis in μ L/L;
C 1 first samplingAnalyzing the concentration of the dissolved gas in the obtained oil, wherein the unit is mu L/L;
Δ t — the running time of the transformer in two sampling intervals, in months.
10. The method for determining the transformer defect by combining the dissolved gas in the oil and the core grounding current according to claim 5, wherein the method for determining the discharge defect in the step S3 is:
when the data processing and analyzing system (8) monitors that the value of the iron core grounding current transmitted by the iron core grounding current on-line monitor (7) is higher than 3000mA, and monitors that the content of acetylene in insulating oil transmitted by the on-line analyzing device (3) for dissolved gas in the oil is higher than 1.0 muL/L, and the relative growth rate of acetylene and hydrogen in the insulating oil is higher than 100%/month, the discharging defect is judged;
wherein the gas relative growth rate (%/month) is 100% × (C) 2 -C 1 )/(C 1 ×Δt)
In the formula: c 2 -the concentration of dissolved gas in the oil, μ L/L, obtained from the second sampling analysis;
C 1 -the concentration of dissolved gas in the oil, μ L/L, obtained from the first sampling analysis;
Δ t — the running time of the transformer in the two sampling interval, month.
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| CN117110587A (en) * | 2023-10-25 | 2023-11-24 | 国网四川省电力公司超高压分公司 | Method and system for on-line monitoring abnormality alarm of dissolved gas in oil |
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| CN117110587B (en) * | 2023-10-25 | 2024-01-23 | 国网四川省电力公司超高压分公司 | Method and system for on-line monitoring abnormality alarm of dissolved gas in oil |
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