Method for performing condition monitoring and active protection of oil-filled transformer, recording medium, and system

Abstract

The present invention relates to the technical field of power transmission and distribution monitoring. Disclosed are a method for performing condition monitoring and active protection of an oil-filled transformer. Combustible gas content data of measuring points in a tested oil-filled transformer is acquired by means of a plurality of channels, it is determined whether an internal fault has occurred, and tripping protection is performed, increasing the reliability of operation of the oil-filled transformer. Further provided are a non-transient readable recording medium storing a program for performing condition monitoring and active protection of an oil-filled transformer, and a data processing system comprising the medium. The program can be called by means of a processing circuit to execute the method above, thus the present invention is suitable for being popularized and used in device state detection in the power industry.

Description

A method, recording medium and system for monitoring and actively protecting oil-filled transformer status Technical Field

[0001] The present invention belongs to the technical field of power transmission and distribution monitoring, and specifically discloses a method for state monitoring and active protection of an oil-filled transformer, a non-transient readable recording medium and a system. Background Art

[0002] Currently, power transformer protection primarily includes gas protection, differential protection, and current quick-break protection. These protections effectively respond to and trigger tripping for common faults that can persist for months or even years, such as internal transformer bushing grounding and interturn short circuits. However, large oil-filled equipment like UHV transformers and converter transformers, with their large capacity, high arc voltage, and high arc energy, can easily develop into penetrating discharges and trigger deflagrations within tens of minutes. For example, in 2018, a UHV converter transformer in Hami, Xinjiang, experienced a faulty explosion that spread rapidly, resulting in direct equipment losses exceeding 300 million yuan and significant economic losses. These rapidly developing faults develop rapidly, and the fault gas takes a long time to circulate to the protective device installation port, making conventional gas protection unable to respond in a timely manner. Furthermore, as the internal fault develops, the external current signal remains unchanged, rendering conventional protection methods and devices ineffective.

[0003] Current relay protection methods rely on "passive protection" after a fault has occurred. Its application in large-scale oil-filled equipment is primarily limited by its slow protection speed and inability to respond before a fault breaks down. To address practical engineering applications, numerous researchers have conducted research on online monitoring technologies, such as oil chromatography and monohydrogen, and applied them to assist in decision-making regarding the status of large-scale oil-filled equipment. However, oil chromatography monitoring devices have a detection cycle of hours (gas chromatography: 2 hours, photoacoustic spectroscopy: 4 hours), making them ineffective against rapidly developing faults (tens of minutes). Monohydrogen discharge devices, on the other hand, lack reliability, resulting in numerous false alarms caused by abnormal jumps. Furthermore, under certain fault conditions, the monohydrogen content does not significantly increase, leading to missed alarms.

[0004] Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a method for monitoring the state of an oil-filled transformer and actively protecting the transformer, comprising the following steps:

[0006] Perform self-inspections on the oil chromatograph, single hydrogen, and single acetylene monitoring devices. Set the monitoring data obtained from abnormal detection items as invalid, and set the remaining monitoring data as valid. Only valid monitoring data will be used for subsequent fault determination.

[0007] The monitoring data includes the content of various gas components contained in the transformer oil collected from the upper and middle parts of the oil-filled transformer body and the upper, middle and lower parts of the riser, as measured by the oil chromatography monitoring device, the hydrogen content of the transformer oil in the upper part of the oil-filled transformer body and the upper part of the riser, as measured by the single hydrogen monitoring device, and the acetylene content measured by the single acetylene monitoring device;

[0008] The total hydrocarbon content is calculated based on the content of each gas component; the growth rate of the acetylene content is calculated based on the acetylene content; the sampling period, risk threshold and fault judgment criteria of various monitoring data are set, and trip protection is initiated when it is determined that a fault has occurred.

[0009] Preferably, the sampling period is set as follows: single acetylene monitoring data sampling period <30min, single hydrogen monitoring data sampling period <10min, oil chromatography monitoring data sampling period <30min.

[0010] Preferably, the hydrogen content is used as the first criterion in the criterion. If the hydrogen content exceeds the set risk threshold of the hydrogen content, the transformer is determined to have reached the risk range; if the hydrogen content is within the set threshold, the acetylene content or the growth rate is used as the second criterion. If either of the two exceeds the risk threshold set for acetylene, the transformer is determined to have reached the risk range; otherwise, the total hydrocarbon content is used as the third criterion. Only when the total hydrocarbon content exceeds the set risk threshold of the total hydrocarbon content is the transformer considered to have reached the risk range.

[0011] Furthermore, if the hydrogen content obtained through more than half of the sampling points in any monitoring device is greater than the set hydrogen content risk threshold, it is determined that a fault has occurred.

[0012] Furthermore, if any one of the acetylene growth rate every 2 hours, every 4 hours, daily growth rate, and weekly growth rate exceeds the risk threshold set for acetylene, a fault is determined to have occurred.

[0013] Preferably, if the monitoring data measured by the oil chromatography monitoring device are all invalid, at least one piece of monitoring data in the single hydrogen monitoring device and the single acetylene monitoring device is valid, if the obtained hydrogen content exceeds the set risk threshold of the hydrogen content and the acetylene content exceeds the set risk threshold of the acetylene content for two consecutive cycles, it is determined that the fault is established.

[0014] Furthermore, if the monitoring data measured by the oil chromatography monitoring device and the single hydrogen monitoring device are both invalid and the obtained acetylene content exceeds the set acetylene content risk threshold for two consecutive cycles, retesting is initiated.

[0015] Furthermore, it also includes a screening process for transformer oil sampling at any location. Offline sampling is better than repeated sampling, and repeated sampling is better than online sampling. Only the monitoring data obtained by the optimal sampling is taken within a sampling cycle.

[0016] Another embodiment of the present invention is to provide a non-transitory readable recording medium for storing one or more programs containing multiple instructions. When the instructions are executed, the processing circuit will perform the steps included in the above-mentioned method for monitoring the condition and actively protecting the oil-filled transformer.

[0017] Another embodiment of the present invention provides a data processing system comprising a processing circuit and a memory electrically coupled thereto, wherein the memory is configured to store at least one program, wherein the program includes a plurality of instructions, and the processing circuit executes the steps included in the aforementioned method for condition monitoring and active protection of an oil-filled transformer by running the program.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] By obtaining combustible gas content data at each measuring point in the tested oil-filled transformer through multiple channels, it is possible to determine whether an internal fault has occurred and perform protective tripping. This avoids the one-sidedness of obtaining data through a single channel, provides the possibility of setting multiple combinations of judgment criteria, and at the same time, can obtain the risk status of the oil-filled transformer in a relatively short time and take necessary protective actions, thereby improving the operational reliability of the oil-filled transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1 is a flow chart of a method according to an embodiment of the present invention;

[0021] FIG2 is a schematic diagram of sampling positions in an embodiment of the present invention. DETAILED DESCRIPTION

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be described below in conjunction with the accompanying drawings. The described embodiments are part of the embodiments of the present invention, but not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without making any innovative efforts shall fall within the scope of protection of the present invention.

[0023] The main steps of an embodiment of a method for monitoring the state of an oil-filled transformer and actively protecting the transformer are shown in Figure 1. Specifically, an embodiment of the present invention provides a method for monitoring the state of an oil-filled transformer and actively protecting the transformer, comprising the following steps:

[0024] Perform self-inspections on the oil chromatograph, single hydrogen, and single acetylene monitoring devices. Set the monitoring data obtained from abnormal detection items as invalid, and set the remaining monitoring data as valid. Only valid monitoring data will be used for subsequent fault determination.

[0025] The monitoring data includes the content of various gas components contained in the transformer oil collected from the upper and middle parts of the oil-filled transformer body and the upper, middle and lower parts of the riser, as measured by the oil chromatography monitoring device, the hydrogen content of the transformer oil in the upper part of the oil-filled transformer body and the upper part of the riser, as measured by the single hydrogen monitoring device, and the acetylene content measured by the single acetylene monitoring device;

[0026] The total hydrocarbon content is calculated based on the content of each gas component; the growth rate of the acetylene content is calculated based on the acetylene content; the sampling period, risk threshold and fault judgment criteria of various monitoring data are set, and trip protection is initiated when it is determined that a fault has occurred.

[0027] Preferably, the sampling period is set as follows: single acetylene monitoring data sampling period <30min, single hydrogen monitoring data sampling period <10min, oil chromatography monitoring data sampling period <30min.

[0028] Preferably, the hydrogen content is used as the first criterion in the criterion. If the hydrogen content exceeds the set risk threshold of the hydrogen content, the transformer is determined to have reached the risk range; if the hydrogen content is within the set threshold, the acetylene content or the growth rate is used as the second criterion. If either of the two exceeds the risk threshold set for acetylene, the transformer is determined to have reached the risk range; otherwise, the total hydrocarbon content is used as the third criterion. Only when the total hydrocarbon content exceeds the set risk threshold of the total hydrocarbon content is the transformer considered to have reached the risk range.

[0029] Furthermore, if the hydrogen content obtained through more than half of the sampling points in any monitoring device is greater than the set hydrogen content risk threshold, it is determined that a fault has occurred.

[0030] Furthermore, if any one of the acetylene growth rate every 2 hours, every 4 hours, daily growth rate, and weekly growth rate exceeds the risk threshold set for acetylene, a fault is determined to have occurred.

[0031] Preferably, if the monitoring data measured by the oil chromatography monitoring device are all invalid, at least one piece of monitoring data in the single hydrogen monitoring device and the single acetylene monitoring device is valid, if the obtained hydrogen content exceeds the set risk threshold of the hydrogen content and the acetylene content exceeds the set risk threshold of the acetylene content for two consecutive cycles, it is determined that the fault is established.

[0032] Furthermore, if the monitoring data measured by the oil chromatography monitoring device and the single hydrogen monitoring device are both invalid and the obtained acetylene content exceeds the set acetylene content risk threshold for two consecutive cycles, retesting is initiated.

[0033] Furthermore, it also includes a screening process for transformer oil sampling at any location. Offline sampling is better than repeated sampling, and repeated sampling is better than online sampling. Only the monitoring data obtained by the optimal sampling is taken within a sampling cycle.

[0034] In a preferred embodiment of the present application, the implementation of the above embodiment depends on a device for defect identification and active protection of oil-filled equipment, which includes a multi-gas characteristic signal monitoring module, a self-test module, a comprehensive diagnosis module, and a trip protection module.

[0035] The multi-gas characteristic signal monitoring module is used to obtain the gas signal of the large oil-filled equipment under test. The sampling points of the signal on the transformer and ancillary facilities are shown in Figure 2. The gas signal includes the oil chromatogram monitoring signal of the upper part of the large oil-filled equipment body, the single hydrogen monitoring signal, the single acetylene monitoring signal, the oil chromatogram monitoring signal of the middle part of the body, the oil chromatogram monitoring signal of the upper part of the riser, the single hydrogen monitoring signal, the single acetylene monitoring signal, the oil chromatogram monitoring signal of the middle part of the riser, and the oil chromatogram monitoring signal of the lower part of the riser;

[0036] The self-test module is used to detect abnormalities in the multi-gas characteristic signal monitoring module. The detection items include abnormal operation of the monitoring device, abnormal oil sampling, abnormal oil discharge, abnormal control module, gas source pressure alarm, abnormal degassing, abnormal oil and gas module air pressure, abnormal oil and gas module temperature control, abnormal chromatography module temperature control, abnormal gas detector, abnormal operation of spectral device, abnormal circuit, abnormal baseline, abnormal spectrum, abnormal background, etc. The specific details are shown in the table below.

[0037] The comprehensive diagnosis module is used to perform comprehensive analysis and diagnosis on the gas signals in the multi-gas characteristic signal monitoring module, determine the state of the oil-filled transformer and generate a report. If there is an internal fault in the state of the oil-filled transformer, a trip protection command is issued to the trip protection module.

[0038] The trip protection module is used to perform trip protection on the oil-filled transformer. When the comprehensive diagnosis module issues a trip protection command, the trip protection module controls the circuit breaker operating mechanisms on both sides of the oil-filled transformer to trip, thereby cutting off the protected oil-filled transformer.

[0039] In the above technical solution, the oil chromatography monitoring sampling period in the multi-gas characteristic signal monitoring module is <30 minutes, the single hydrogen monitoring sampling period is <10 minutes, and the single acetylene monitoring sampling period is <30 minutes.

[0040] In the above technical solution, optionally, the gas signal monitoring device in the multi-gas characteristic signal monitoring module may include any available oil chromatography monitoring device such as gas chromatography type, photoacoustic spectroscopy type, laser spectroscopy type, infrared absorption spectroscopy type, etc.

[0041] In the above technical solution, the specific implementation method steps of the comprehensive diagnosis module for comprehensive diagnosis are as follows:

[0042] In the multi-gas characteristic signal monitoring module, the oil chromatography monitoring device takes three parameters: acetylene, hydrogen, and total hydrocarbons; the single hydrogen monitoring device takes hydrogen monitoring parameters; and the single acetylene monitoring device takes acetylene monitoring parameters; if a certain point has only a monitoring value, the monitoring value is selected; if there are both monitoring values ​​and re-measurement values, the re-measurement value is selected; if there are monitoring values, re-measurement values, and offline detection values, the offline detection value is selected, and the commutation transformer is directly processed according to the offline detection value without referring to other parameter measurement data.

[0043] Taking hydrogen content as the first criterion, if the hydrogen amplitude exceeds the set threshold, the monitored amount is considered to have reached the risk range; taking acetylene content and growth rate as the second criterion, if any of the acetylene growth rate every 2 hours, every 4 hours, daily growth rate, and weekly growth rate exceeds the set threshold, the monitored amount is considered to have reached the risk range; taking total hydrocarbon content as the third criterion, if the total hydrocarbon amplitude exceeds the set threshold, the monitored amount is considered to have reached the risk range.

[0044] When at least one of the five oil chromatograms in the multi-gas characteristic signal monitoring module is "valid", if half or more of the valid monitoring quantities reach the risk range, it is considered that an internal fault has occurred in the equipment and the protection trips.

[0045] When the oil chromatogram monitoring quantities in the multi-gas characteristic signal monitoring module are all "invalid", and at least one of the two single hydrogen is "valid", and at least one of the two single acetylene is "valid", if the single hydrogen monitoring quantity reaches the risk range and the single acetylene monitoring quantity reaches the risk range for two consecutive cycles, it is considered that an internal fault has occurred in the equipment and the protection trips.

[0046] When the oil chromatography monitoring data in the multi-gas characteristic signal monitoring module are all "invalid", and the two single hydrogen monitoring data are all "invalid", and the single acetylene monitoring data reaches the risk range for two consecutive cycles, retesting is immediately started, and whether a fault occurs is re-determined according to the above steps based on the monitoring data after retesting.

[0047] In a specific embodiment, the self-test module performs self-tests on 5 oil chromatograms, 2 single hydrogen, and 2 single acetylene monitoring devices in the multi-gas characteristic signal monitoring module, wherein the “validity” of the oil chromatogram acetylene + hydrogen + total hydrocarbon monitoring data, single hydrogen monitoring data, and single acetylene monitoring data on the upper part of the riser is “valid”, and the “validity” of the oil chromatogram monitoring data, single hydrogen monitoring data, and single acetylene monitoring data on other parts is “invalid”;

[0048] The three monitoring points with “valid” data in the multi-gas characteristic signal monitoring module only have monitoring values, and the online monitoring data is taken;

[0049] In the multi-gas characteristic signal monitoring module, the acetylene amplitude in the oil chromatography monitoring data of the upper part of the elevated seat is 3 μL / L, the growth rate every 2 hours is (1 μL / L) / 2h, the growth rate every 4 hours is (1.5 μL / L) / 4h, the daily growth rate is (2 μL / L) / day, and the weekly growth rate is (2 μL / L) / week, the hydrogen amplitude is 440 μL / L, and the total hydrocarbon amplitude is 454 μL / L; the acetylene amplitude in the single acetylene monitoring data of the upper part of the elevated seat is 3.1 μL / L, the growth rate every 2 hours is (1.2 μL / L) / 2h, the growth rate every 4 hours is (1.6 μL / L) / 4h, the daily growth rate is (2.1 μL / L) / day, and the weekly growth rate is (2.3 μL / L) / week; the hydrogen amplitude in the single hydrogen monitoring data of the upper part of the elevated seat is 460 μL / L;

[0050] In this embodiment, the hydrogen amplitude is set to 450 μL / L as the threshold value; the acetylene amplitude is set to 5 μL / L, the growth rate every 2 hours is (1.5 μL / L) / 2h, the growth rate every 4 hours is (2 μL / L) / 4h, the daily growth rate is (2 μL / L) / day, and the weekly growth rate is (2 μL / L) / week as the threshold value; the total hydrocarbon amplitude is set to 450 μL / L as the threshold value;

[0051] The comprehensive diagnosis module performs a comprehensive diagnosis and obtains that the daily growth rate of the acetylene monitoring amount in the oil chromatogram monitoring data of the upper part of the lifting seat exceeds the set threshold and reaches the risk range, the hydrogen monitoring amount does not reach the risk range, and the total hydrocarbon monitoring amount reaches the risk range; the daily growth rate of the single acetylene monitoring data of the upper part of the lifting seat exceeds the set threshold and reaches the risk range; the single hydrogen monitoring amount of the upper part of the lifting seat reaches the risk range; 4 out of the above 5 monitoring amounts reach the risk range, it is considered that the equipment has an internal fault;

[0052] The tripping protection module is activated to control the circuit breaker operating mechanisms on both sides of the large oil-filled equipment to trip, thereby cutting off the protected large oil-filled equipment.

[0053] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computers containing computer-usable program code, or on available storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.).

[0054] The present invention is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate a function system for implementing one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0055] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction system that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0056] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0057] Compiling the above-mentioned method steps into a program and then storing it on a hard disk or other non-transitory storage medium constitutes an embodiment of the present invention's "a non-transitory readable recording medium"; and electrically connecting the storage medium to a computer processor and performing oil-filled transformer condition monitoring and active protection through data processing constitutes an embodiment of the present invention's "a data processing system".

[0058] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for monitoring and actively protecting an oil-filled transformer, characterized in that The following steps are involved: Perform self-inspection on the oil chromatogram, single hydrogen, and single acetylene monitoring devices, set the monitoring data obtained from abnormal detection items as invalid, and set the remaining monitoring data as valid, and only set valid monitoring data to participate in subsequent fault judgment; The monitoring data include the content of each gas component contained in the transformer oil collected from the upper part, middle part and upper, middle and lower part of the oil-filled transformer body and the oil chromatography monitoring device, the hydrogen content of the transformer oil in the upper part of the oil-filled transformer body and the upper part of the riser measured by the single hydrogen monitoring device, and the acetylene content measured by the single acetylene monitoring device; The total hydrocarbon content is calculated according to the content of each gas component; the growth rate of the acetylene content is calculated according to the acetylene content; the sampling period, risk threshold and fault judgment criteria of various monitoring data are set, and the trip protection is started when the fault is determined to be established.

2. The method for monitoring and actively protecting the oil-filled transformer state according to claim 1, characterized in that: The sampling period is set as follows: the single acetylene monitoring data sampling period is <30min, the single hydrogen monitoring data sampling period is <10min, and the oil chromatography monitoring data sampling period is <30min.

3. The method for monitoring and actively protecting the oil-filled transformer state according to claim 2, characterized in that: In the criterion, hydrogen content is used as the first criterion. If the hydrogen content exceeds the set risk threshold of hydrogen content, it is determined that a fault occurs. If the hydrogen content is within the set threshold, the acetylene content or the growth rate is used as the second criterion. If any one of them exceeds the risk threshold set for acetylene, it is determined that a fault occurs. Otherwise, the total hydrocarbon content is used as the third criterion. Only when the total hydrocarbon content exceeds the set risk threshold of the total hydrocarbon content can the transformer be considered to have reached the risk range.

4. The method for monitoring and actively protecting the oil-filled transformer state according to claim 3 is characterized in that: If the hydrogen content obtained by more than half of the sampling points in any monitoring device is greater than the set risk threshold of hydrogen content, a fault is determined to have occurred.

5. The method for monitoring and actively protecting the oil-filled transformer state according to claim 4, characterized in that: If any of the acetylene growth rate, i.e., the growth rate every 2 hours, the growth rate every 4 hours, the growth rate every day, or the growth rate every week, exceeds the risk threshold set for acetylene, a fault is determined to have occurred.

6. The method for monitoring and actively protecting the oil-filled transformer state according to claim 2, characterized in that: If the monitoring data measured by the oil chromatography monitoring device are all invalid, and at least one piece of monitoring data in the single hydrogen monitoring device and the single acetylene monitoring device is valid, if the obtained hydrogen content exceeds the set risk threshold of the hydrogen content and the acetylene content exceeds the set risk threshold of the acetylene content for two consecutive cycles, it is determined that the fault is established.

7. The method for monitoring and actively protecting the oil-filled transformer state according to claim 2, characterized in that: If the monitoring data measured by the oil chromatography monitoring device and the single hydrogen monitoring device are both invalid and the obtained acetylene content exceeds the set acetylene content risk threshold for two consecutive cycles, retesting is initiated.

8. The method for monitoring and actively protecting the oil-filled transformer state according to claim 7, characterized in that: It also includes the screening process of transformer oil sampling at any location. Off-line sampling is better than repeated sampling, and repeated sampling is better than online sampling. Only the monitoring data obtained by the best sampling is taken within a sampling cycle.

9. A non-transitory readable recording medium for storing one or more programs including a plurality of instructions, characterized in that: The program includes the steps included in the method for state monitoring and active protection of an oil-filled transformer according to any one of claims 1-8.

10. A data processing system, comprising a processing circuit and a memory electrically coupled thereto, characterized in that: The memory configuration stores at least one program, the program includes a plurality of instructions, and the processing circuit runs the program to execute the steps included in the method for oil-filled transformer condition monitoring and active protection as described in any one of claims 1-8.

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