Fault early warning method and early warning system for oil-immersed transformer, and oil-immersed transformer

Abstract

The invention discloses an oil-immersed transformer fault early warning method, an early warning system and an oil-immersed transformer, which can carry out early warning on the fault of the oil-immersed transformer in advance according to the content of characteristic substances in insulating oil. The fault early warning method for the oil-immersed transformer comprises the following steps: acquiring a curve set of the insulating property of insulating oil along with the change of the content of characteristic substances in the insulating oil; according to the curve set and a preset insulating property limit value of the insulating oil, determining an alarm parameter of the characteristic substance content in the insulating oil; measuring parameters of the content of characteristic substances in the insulating oil of the oil-immersed transformer are detected; and comparing the measurement parameter with the alarm parameter to obtain a comparison result, and determining whether to carry out early warning according to the comparison result.

Description

Technical Field

[0001] The present invention belongs to the technical field of transformers, and particularly relates to a fault warning method and warning system for an oil-immersed transformer, and an oil-immersed transformer. Background Art

[0002] Oil-immersed transformers, reactors, etc. are key equipment in the power system, and their operating status is directly related to the safety and stability of the power grid. Insulating oil is mostly used as the electrical insulation and cooling medium inside them. During long-term operation, such equipment may generate trace amounts of metal or powder of other materials due to factors such as the switching of tap changers, the operation of oil pump motors, and the thermal aging of materials, which will cause changes in the insulation performance of the insulating oil, thereby affecting the safe operation of such equipment. Therefore, it is necessary to analyze the content of specific elements in the insulating oil in real time through on-line monitoring, and use a fault diagnosis algorithm to give early warnings of faults, providing decision-making support for the preventive maintenance of electrical equipment.

[0003] At present, the on-line monitoring devices for the insulating oil of electrical equipment such as transformers and reactors on the market mainly carry out monitoring by monitoring the content of fault gases in the insulating oil, and discover the electrical or thermal aging faults that have occurred in the power equipment by monitoring the gases generated due to faults.

[0004] Monitoring the fault gases in the insulating oil is to detect early whether there are latent faults inside the power equipment. The insulation of oil-filled power equipment (such as transformers, reactors, etc.) mainly consists of insulating oil and organic insulating materials immersed in the oil. These insulating materials will decompose fault gases during normal aging. At the same time, if faults such as overheating or discharge occur inside the power equipment, the content of fault gases will increase rapidly. These fault gases mainly include hydrogen, methane, ethane, ethylene, acetylene, carbon monoxide, carbon dioxide, etc. The sum of methane, ethane, ethylene, and acetylene is usually called total hydrocarbons. Most of these gases are dissolved in the insulating oil, and a small part will rise to the surface of the insulating oil or enter the gas relay. Experience shows that the various components and the content of the fault gases are directly related to the nature of the faults. Therefore, by regularly measuring the composition and content of the fault gases dissolved in the oil, it is possible to detect in time whether a fault has occurred inside the oil-filled power equipment, and then take simple repair or replacement measures to effectively prevent the continuous development of the fault and also achieve the qualified operation of the power equipment.

[0005] This method of detecting faulty gas can only detect equipment problems through characteristic data analysis when the equipment has already failed, mainly to avoid the expansion of the fault and maintain the qualified operation requirements of the power equipment. Although the qualified operation of the power equipment can be restored after repair or replacement measures are taken, the performance of the power equipment will deteriorate (such as temperature rise performance deterioration) during the period after the power equipment fails and before the repair or replacement measures are taken. When customers have high requirements for the performance of power equipment, this method of detecting faulty gas and then repairing it cannot meet the customer's requirements.

[0006] Therefore, in order to prevent the performance of power equipment from deteriorating during use, it is necessary to provide early warning before the power equipment fails. However, the current fault judgment method is to detect fault gas, which can only be generated after the power equipment fails. Therefore, according to the existing technology, it is impossible to provide early warning of power equipment failure. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide an oil-immersed transformer fault warning method and warning system, and an oil-immersed transformer in view of the above-mentioned deficiencies in the prior art, which can provide early warning of oil-immersed transformer faults according to the content of characteristic substances in insulating oil.

[0008] In a first aspect, an embodiment of the present invention provides an oil-immersed transformer fault early warning method, the oil-immersed transformer fault early warning method comprising: obtaining a curve set showing that the insulating performance of insulating oil varies with the content of characteristic substances in the insulating oil; determining an alarm parameter of the characteristic substance content in the insulating oil based on the curve set and a preset insulating performance limit value of the insulating oil; detecting a measurement parameter of the characteristic substance content in the insulating oil of the oil-immersed transformer; comparing the measurement parameter with the alarm parameter to obtain a comparison result, and determining whether to issue an early warning based on the comparison result.

[0009] In some embodiments, the step of obtaining a curve set showing how the insulating properties of insulating oil vary with the content of characteristic substances in the insulating oil is specifically as follows: obtaining a curve set showing how the insulating properties of insulating oil vary with the content of characteristic substances in the insulating oil according to a plurality of different flow rates of the insulating oil; the alarm parameter of the content of characteristic substances in the insulating oil includes: an alarm parameter of a plurality of different flow rates of the insulating oil corresponding to the content of characteristic substances in the insulating oil. The method further includes: detecting a measured flow rate of the insulating oil in the oil-immersed transformer. The step of comparing the measured parameter with the alarm parameter to obtain a comparison result, and determining whether to issue an early warning based on the comparison result is specifically as follows: comparing the measured parameter with the alarm parameter of the insulating oil corresponding to the measured flow rate to obtain a comparison result, and if the comparison result is that the measured parameter is greater than the alarm parameter, an early warning is issued.

[0010] In some embodiments, the characteristic substances include copper particles, iron particles, and rubber particles. The curve set includes: multiple curves of the insulation performance of the insulating oil varying with the contents of copper particles, iron particles, and rubber particles in the insulating oil respectively. The alarm parameters include: alarm content values corresponding to copper particles, iron particles, and rubber particles in the insulating oil respectively. The measurement parameters include: measured values of the contents of copper particles, iron particles, and rubber particles corresponding to the insulating oil of the oil-immersed transformer respectively. Comparing the measurement parameters with the alarm parameters corresponding to the measured flow rate of the insulating oil to obtain a comparison result, and determining whether to give an early warning according to the comparison result, specifically: comparing the measured values of the contents of copper particles, iron particles, and rubber particles corresponding to the insulating oil of the oil-immersed transformer with the alarm content values corresponding to copper particles, iron particles, and rubber particles respectively under the measured flow rate of the insulating oil in sequence to obtain a plurality of comparison results. If any one of the comparison results is that the measured value is greater than the corresponding alarm content value, then an early warning is given.

[0011] In some embodiments, after determining whether to give an early warning, the method further includes: giving an operation suggestion for the oil-immersed transformer according to the comparison result.

[0012] In some embodiments, obtaining the curve set of the insulation performance of the insulating oil varying with the content of the characteristic substances in the insulating oil specifically includes: measuring the insulation performance of the corresponding insulating oil according to different contents of the characteristic substances in the insulating oil; drawing each curve according to different contents of the characteristic substances in the insulating oil and the insulation performance of the corresponding insulating oil.

[0013] Through years of practice, the inventors found that it is possible to determine whether the insulation performance of transformer oil deteriorates by measuring the change in the content of characteristic substances in the insulating oil.

[0014] Therefore, the oil-immersed transformer fault warning method provided by the embodiments of the present invention can determine the alarm parameters of the characteristic substance content in the insulating oil by combining the preset insulating performance limit value of the insulating oil through obtaining the curve set of the insulating performance of the insulating oil changing with the content of the characteristic substances in the insulating oil, so as to facilitate the comparison with the measured parameters in the later stage; then, by detecting the measured parameters of the characteristic substance content in the insulating oil of the oil-immersed transformer, comparing the measured parameters with the alarm parameters, obtaining a comparison result, and determining whether to give a warning according to the comparison result, it is possible to give a warning of the change in the content of the characteristic substances, thereby realizing the warning of the insulating performance of the oil-immersed transformer. Since the fault of the oil-immersed transformer is directly related to the change in the insulating performance of the insulating oil, after giving a warning of the insulating performance of the insulating oil, it is equivalent to giving an early warning of the fault of the oil-immersed transformer in advance, so that the staff can timely repair the oil-immersed transformer after receiving the warning and restore the good working state of the oil-immersed transformer, thereby avoiding the final occurrence of a fault due to the continuous deterioration of the insulating performance of the insulating oil. Different from the prior art method that relies on fault gases for warning, the present invention realizes the early warning of the faults of oil-immersed transformers by monitoring the early changes of characteristic substances. The generation of characteristic substances does not start after the occurrence of a fault, but begins from the initial operation of the transformer and shows an accumulative effect as the operation time goes by. This characteristic enables the warning method of the present invention to detect potential risks earlier and give an early warning of the occurrence of a fault.

[0015] In a second aspect, the embodiments of the present invention further provide an oil-immersed transformer fault warning system. The oil-immersed transformer fault warning system includes a curve set acquisition component, an alarm parameter determination component, an insulating oil detection component, and an analysis and warning component. The curve set acquisition component is used to acquire a curve set of the insulating performance of the insulating oil changing with the content of the characteristic substances in the insulating oil. The alarm parameter determination component is connected to the curve set acquisition component and is used to determine the alarm parameters of the characteristic substance content in the insulating oil according to the curve set and the preset insulating performance limit value of the insulating oil, and transmit them to the analysis and warning component. The insulating oil detection component is arranged on the oil tank of the oil-immersed transformer and is used to detect the measured parameters of the characteristic substance content in the insulating oil of the oil-immersed transformer and transmit them to the analysis and warning component. The analysis and warning component is respectively connected to the alarm parameter determination component and the insulating oil detection component and is used to compare the measured parameters with the alarm parameters, obtain a comparison result, and determine whether to give a warning according to the comparison result.

[0016] In some embodiments, the insulating oil detection assembly includes a circulation pipeline, an insulating oil condition monitoring device, and a driving member. The inlet and outlet of the circulation pipeline are both communicated with the interior of the oil tank of the oil-immersed transformer. The insulating oil condition monitoring device is arranged on the circulation pipeline and is used for detecting the measurement parameters of the content of characteristic substances in the insulating oil flowing through the circulation pipeline and transmitting them to the analysis and warning assembly. The driving member is arranged on the circulation pipeline and is used for driving the insulating oil to flow in the circulation pipeline.

[0017] In some embodiments, the inlet of the circulation pipeline includes a first inlet and a second inlet. The first inlet is arranged at the position corresponding to the tap changer on the oil tank, and the second inlet is arranged at the position corresponding to the oil pump of the cooling device on the oil tank.

[0018] In some embodiments, the characteristic substances include copper particles, iron particles, and rubber particles.

[0019] In a third aspect, an embodiment of the present invention further provides an oil-immersed transformer, which includes a transformer body and the oil-immersed transformer fault warning system in the second aspect. The transformer body includes an oil tank, a transformer core, a tap changer, and a cooling device. The oil tank is used for containing insulating oil. The transformer core and the tap changer are immersed in the insulating oil. The tap changer is used for adjusting the output voltage of the transformer body. The cooling device is arranged outside the oil tank and is used for dissipating heat from the insulating oil.

[0020] The oil-immersed transformer fault warning system and the oil-immersed transformer provided by the embodiments of the present invention have the same beneficial effects as the above-mentioned oil-immersed transformer fault warning method, which will not be elaborated here. Description of the Drawings

[0021] Figure 1 : is a flowchart of an oil-immersed transformer fault warning method provided by an embodiment of the present invention;

[0022] Figure 2 : is a front view of an oil-immersed transformer provided by an embodiment of the present invention;

[0023] Figure 3 : is a left view of an oil-immersed transformer provided by an embodiment of the present invention;

[0024] Figure 4 : is a top view of an oil-immersed transformer provided by an embodiment of the present invention.

[0025] Wherein, 1 - transformer body; 2 - tap changer; 3 - cooling device; 4 - oil pump; 5 - insulating oil condition monitoring device; 6 - valve; 7 - second inlet; 8 - circulation pipeline; 9 - first inlet. Detailed Embodiments

[0026] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0027] Embodiment 1:

[0028] As Figure 1 shown, the embodiment of the present invention provides an oil-immersed transformer fault warning method, which is applied to an oil-immersed transformer, for example, in an oil-immersed transformer, and is used to warn the insulation performance of the oil-immersed transformer.

[0029] As Figure 1 shown, the oil-immersed transformer fault warning method includes: steps S100 - S400.

[0030] S100. Obtain a curve set of the insulation performance of the insulating oil varying with the content of characteristic substances in the insulating oil.

[0031] Exemplarily, the characteristic substances in the insulating oil are substances that can reflect the insulation performance of the insulating oil. When the content of the characteristic substances in the insulating oil changes, the insulation performance of the insulating oil changes correspondingly. The types of characteristic substances in the insulating oil can be one or multiple.

[0032] As Figure 2 , Figure 3 and Figure 4 shown, Figure 2 is the front view of the oil-immersed transformer, Figure 3 is the left view, Figure 4 is the top view, Figure 4 In the X direction and Y direction are the length and width directions of the oil-immersed transformer. The oil-immersed transformer body generally includes a tap changer 2 and a cooling device 3. The inventor found that the tap changer 2, as a voltage regulating device of the oil-immersed transformer, has frequent switching actions during the operation of the oil-immersed transformer. Because the mechanical friction during the switching of the tap changer 2 will generate trace amounts of powdery impurities (mainly copper particles). And the cooling device 3 (for example, radiator fins) will have its built-in oil pump 4 running at high speed during operation. Therefore, the oil pump 4 will have high-speed friction with the insulating oil, which will cause trace amounts of metal particles (mainly iron particles) to be generated due to wear on the surface of the oil pump blades. At the same time, due to the high-speed operation of the oil pump, the insulating oil will flow rapidly, impacting the rubber and insulating cardboard used for internal insulation of the oil-immersed transformer, causing particles or fibers of such materials to be incorporated into the insulating oil. All of these will cause the deterioration of the insulation performance of the insulating oil. Moreover, during the continuous operation of the oil-immersed transformer, these powdery impurities, trace amounts of metal particles, and particles of insulating rubber will gradually accumulate, resulting in the continuous deterioration of the insulation performance of the insulating oil, which will lead to the occurrence of faults in the oil-immersed transformer.

[0033] Therefore, the inventor came up with the idea of using the powdery impurities, trace metal particles, and particles of insulating rubber generated during the operation of the tap-changer 2 and the cooling device 3 as characteristic substances, and realizing the early warning of the insulation performance of the oil-immersed transformer by detecting the changes in the characteristic substances.

[0034] Exemplarily, the characteristic substances may be at least one of copper particles, iron particles, and rubber particles.

[0035] Exemplarily, when the characteristic substance is copper particles, as the content of copper particles gradually increases, the insulation performance of the insulating oil gradually decreases.

[0036] For example, in the initial state of the insulating oil, the content of copper particles in the insulating oil is 0, and the insulation performance of the insulating oil is 3.0 kV / 2.5 mm; after the oil-immersed transformer operates for a period of time (for example, half a year), the content of copper particles in the insulating oil increases to 1000 particles / 100 ml. At this time, the insulation performance of the insulating oil decreases to 2.5 kV / 2.5 mm; when the oil-immersed transformer continues to operate, the content of copper particles in the insulating oil will continue to increase, and the insulation performance of the insulating oil will continue to decrease, which may cause the oil-immersed transformer to malfunction.

[0037] Exemplarily, the above curve set includes at least one curve of the insulation performance of the insulating oil changing with the content of the characteristic substances in the insulating oil.

[0038] For example, the abscissa of the curve corresponds to the content of the characteristic substances, and the ordinate corresponds to the insulation performance of the insulating oil.

[0039] S200. Determine the alarm parameter of the content of the characteristic substances in the insulating oil according to the curve set and the preset insulation performance limit value of the insulating oil.

[0040] Exemplarily, the preset insulation performance limit value of the insulating oil is the insulation performance value of the insulating oil before the oil-immersed transformer malfunctions. The preset insulation performance limit value of the insulating oil can be determined by the staff according to long-term work experience, or determined in combination with the above curve set. For example, during daily work, when the oil-immersed transformer malfunctions, the insulation performance of the oil-immersed transformer is all around 2.0 kV / 2.5 mm. At this time, the preset insulation performance limit value can be set to a value slightly less than 2.0 kV / 2.5 mm, for example, set to 1.8 kV / 2.5 mm. Another example is that in the curve set, the image of the insulation performance of the insulating oil changing with the content of the characteristic substances in the insulating oil is an oblique line. When the content of the characteristic substances is greater than point A, the slope of the above oblique line increases. Then, the insulation performance value corresponding to point A can be used as the preset insulation performance limit value of the insulating oil.

[0041] After the preset insulation performance limit value is determined, the content value of the characteristic substance corresponding to the preset insulation performance limit value can be found in the curve set, and this content value is the alarm parameter for the content of the characteristic substance in the insulating oil.

[0042] For example, still taking the characteristic substance as copper particles, when the content value of copper particles corresponding to the preset insulation performance limit value of 1.8 kV / 2.5 mm is 3000 particles / 100 ml, the alarm parameter for the content of the characteristic substance in the insulating oil is: the content value of copper particles is 3000 particles / 100 ml.

[0043] S300. Detect the measurement parameters of the content of the characteristic substance in the insulating oil of the oil-immersed transformer.

[0044] Exemplarily, the content of the characteristic substance can be detected by existing detection devices.

[0045] For example, when detecting the content of copper particles, a spectral analyzer can be used; when detecting the content of rubber particles, a microscopic imaging device can be used.

[0046] S400. Compare the measurement parameters with the alarm parameters to obtain a comparison result, and determine whether to give an early warning according to the comparison result.

[0047] Exemplarily, when the detected measurement parameter of the content of the characteristic substance in the insulating oil is 2000 particles / 100 ml, the result of comparing the measurement parameter with the alarm parameter is: 2000 particles / 100 ml of the measurement parameter is less than 3000 particles / 100 ml of the alarm parameter, and at this time, no early warning is given; when the detected measurement parameter of the content of the characteristic substance in the insulating oil is 3500 particles / 100 ml, the result of comparing the measurement parameter with the alarm parameter is: 3500 particles / 100 ml of the measurement parameter is greater than 3000 particles / 100 ml of the alarm parameter, and at this time, an early warning is given.

[0048] So far, it is possible to give an early warning of the change in the content of the characteristic substance, so as to realize the early warning of the insulation performance of the oil-immersed transformer. And the failure of the oil-immersed transformer is directly related to the change in the insulation performance of the insulating oil. Therefore, after giving an early warning of the insulation performance of the insulating oil, it is equivalent to giving an early warning of the failure of the oil-immersed transformer in advance, so that the staff can timely repair the oil-immersed transformer after receiving the early warning, restore the good working state of the oil-immersed transformer, and thus avoid the final failure due to the continuous deterioration of the insulation performance of the insulating oil.

[0049] Different from the prior art methods that rely on fault gases for early warning, the present invention realizes early warning of faults in oil-immersed transformers by monitoring the early changes of characteristic substances. The generation of characteristic substances does not start after the occurrence of faults, but begins from the initial operation of the transformer and shows an accumulation effect over time. This characteristic enables the early warning method of the present invention to detect potential risks earlier and gain valuable time for equipment maintenance. Since the faults of oil-immersed transformers are often closely related to the deterioration of the insulating oil performance, by real-time monitoring and early warning of the insulating oil performance, it is actually equivalent to an early assessment of the overall health status of the transformer.

[0050] Therefore, for the oil-immersed transformer fault early warning method provided by the embodiments of the present invention, by obtaining a curve set of the insulating performance of the insulating oil varying with the content of characteristic substances in the insulating oil, the alarm parameters of the content of characteristic substances in the insulating oil can be determined in combination with the preset insulating performance limit value of the insulating oil, so as to facilitate the comparison with the measured parameters in the later stage; then, by detecting the measured parameters of the content of characteristic substances in the insulating oil of the oil-immersed transformer, comparing the measured parameters with the alarm parameters to obtain a comparison result, and determining whether to give an early warning according to the comparison result, the change in the content of characteristic substances can be warned, thereby realizing the early warning of the insulating performance of the oil-immersed transformer. Since the faults of the oil-immersed transformer are directly related to the change in the insulating performance of the insulating oil, after giving an early warning of the insulating performance of the insulating oil, it is equivalent to giving an early warning of the faults of the oil-immersed transformer in advance, so that the staff can timely repair the oil-immersed transformer after receiving the early warning and restore the good working state of the oil-immersed transformer, thereby avoiding the ultimate occurrence of faults due to the continuous deterioration of the insulating performance of the insulating oil. Different from the prior art methods that rely on fault gases for early warning, the present invention realizes early warning of faults in oil-immersed transformers by monitoring the early changes of characteristic substances. The generation of characteristic substances does not start after the occurrence of faults, but begins from the initial operation of the transformer and shows an accumulation effect over time. This characteristic enables the early warning method of the present invention to detect potential risks earlier and give an early warning in advance of the occurrence of faults.

[0051] The inventor also found that the flow rate of the insulating oil will also affect the insulating performance of the insulating oil because the flowing insulating oil will affect factors such as the internal pressure of the insulating oil itself and the nearby electric field. Usually, as the flow rate of the insulating oil increases, the insulating performance of the insulating oil will decrease.

[0052] Based on this, in some embodiments, the above step S1 is specifically: according to multiple different flow rates of the insulating oil, obtain a curve set of the insulating performance of the insulating oil varying with the content of characteristic substances in the insulating oil. The alarm parameters of the content of characteristic substances in the insulating oil include: the alarm parameters corresponding to multiple different flow rates of the insulating oil for the content of characteristic substances in the insulating oil.

[0053] Exemplarily, the above different flow rates can be determined according to the actual flow rate of the insulating oil in the oil-immersed transformer. For example, they can be selected as 0.05 m / s, 0.1 m / s, 0.3 m / s, etc.

[0054] At this time, in the curve set, there are multiple curves corresponding to one characteristic substance, and each curve corresponds to the change of the insulating property of the insulating oil with the content of the characteristic substance in the insulating oil under a specific flow rate.

[0055] Correspondingly, in step S200, for the preset insulating property limit value of the same insulating oil at different flow rates, the alarm parameters of the content of the characteristic substance in the insulating oil can be determined. For example, the first alarm parameter corresponding to the flow rate of 0.05 m / s, the second alarm parameter corresponding to the flow rate of 0.1 m / s, etc.

[0056] In this case, the above method further includes: detecting the measured flow rate of the insulating oil in the oil-immersed transformer. Comparing the measured parameter with the alarm parameter to obtain a comparison result, and determining whether to give an early warning according to the comparison result. Specifically: comparing the measured parameter with the alarm parameter corresponding to the measured flow rate of the insulating oil to obtain a comparison result. If the comparison result is that the measured parameter is greater than the alarm parameter, an early warning is given.

[0057] Exemplarily, when the measured flow rate of the insulating oil is 0.1 m / s, the above measured parameter is compared with the alarm parameter corresponding to the flow rate of 0.1 m / s (such as the above second alarm parameter).

[0058] The comparison result obtained through the above steps can reduce the influence of the insulating oil flow rate on the comparison result, and thus can more accurately give an early warning of the insulating property of the insulating oil.

[0059] In some embodiments, the characteristic substances include copper particles, iron particles, and rubber particles.

[0060] The inventor found in daily work that copper particles, iron particles, and rubber particles in the insulating oil mainly affect the insulating property of the insulating oil.

[0061] At this time, the above curve set includes: multiple curves of the insulating property of the insulating oil changing with the content of copper particles, iron particles, and rubber particles in the insulating oil respectively. The alarm parameters include: the alarm content values corresponding to copper particles, iron particles, and rubber particles in the insulating oil respectively. The measured parameters include: the measured values corresponding to copper particles, iron particles, and rubber particles in the insulating oil of the oil-immersed transformer respectively.

[0062] Compare the measured parameters with the alarm parameters of the corresponding measured flow rate of the insulating oil to obtain a comparison result, and determine whether to give an early warning according to the comparison result. Specifically: compare the measured values of the content of copper particles, iron particles, and rubber particles in the insulating oil of the oil-immersed transformer with the alarm content values of copper particles, iron particles, and rubber particles respectively corresponding to the corresponding measured flow rate of the insulating oil, to obtain multiple comparison results. If any one of the comparison results shows that the measured value is greater than the corresponding alarm content value, an early warning is given.

[0063] Specifically, compare the measured value of copper particles with the alarm content value of copper particles at the corresponding measured flow rate of the insulating oil to obtain a first comparison result; compare the measured value of iron particles with the alarm content value of iron particles at the corresponding measured flow rate of the insulating oil to obtain a second comparison result; compare the measured value of rubber particles with the alarm content value of rubber particles at the corresponding measured flow rate of the insulating oil to obtain a third comparison result. If any one of the first comparison result, the second comparison result, and the third comparison result shows that the measured value is greater than the corresponding alarm content value, an early warning is given.

[0064] That is, if the measured value of any one of the characteristic substances (copper particles, iron particles or rubber particles) is greater than the corresponding alarm content value, an early warning is given.

[0065] In this way, each substance in the characteristic substances can be monitored and an early warning can be given simultaneously, improving the sensitivity of monitoring and the timeliness of early warning.

[0066] In some embodiments, in the above step S400, after determining whether to give an early warning, the method further includes: giving an operation suggestion for the oil-immersed transformer according to the comparison result.

[0067] Exemplarily, when one of the comparison results shows that the measured value of copper particles (or iron particles) is greater than the corresponding alarm content value of copper particles (or iron particles), it indicates that the insulation performance of the insulating oil has decreased, and an operation suggestion of reducing the voltage and capacity of the oil-immersed transformer can be given to avoid the occurrence of faults in the oil-immersed transformer due to the decrease in the insulation performance of the insulating oil.

[0068] Or, when one of the comparison results shows that the measured value of rubber particles is greater than the corresponding alarm content value of rubber particles, it indicates that the seal in the oil-immersed transformer has decomposed and broken, and at this time, a suggestion to replace the seal can be given.

[0069] Therefore, in this way, targeted suggestions for the operation of the oil-immersed transformer can be given according to the comparison result.

[0070] It can be understood that after giving an early warning based on the comparison result, it indicates that there are abnormal indicators in the operation of the oil-immersed transformer, but it has not expanded into an operation failure. After giving suggestions for the operation of the oil-immersed transformer according to the comparison result, the staff can perform maintenance on the oil-immersed transformer in a timely manner according to the suggestions to prevent the abnormal indicators of the oil-immersed transformer from expanding into failures.

[0071] In some embodiments, the above-mentioned step S100 is specifically as follows: measure the insulation performance of the corresponding insulating oil according to different contents of characteristic substances in the insulating oil; draw each curve according to the different contents of characteristic substances in the insulating oil and the insulation performance of the corresponding insulating oil.

[0072] Exemplarily, the above operation can be carried out in an experimental environment.

[0073] As described above, in the initial state of the insulating oil, the purity of the insulating oil is relatively high, and the content of characteristic substances in the insulating oil is 0.

[0074] The different contents of characteristic substances in the insulating oil include: starting from the content of characteristic substances in the insulating oil being 0 until the maximum value of the content of characteristic substances in the insulating oil during daily use. In this way, more insulation performances of the corresponding insulating oil can be obtained, and the finally drawn curve can be made more accurate when drawing the curve.

[0075] Furthermore, the actual usage steps of the above early warning method are as follows:

[0076] Step 1: Record data by conducting tests on the electrical insulation performance of the insulating oil under different contents of trace impurities (copper, iron, rubber) in the insulating oil.

[0077] Step 2: Conduct supplementary tests on the data obtained in Step 1 at different oil flow rates respectively.

[0078] Step 3: Statistically analyze the test data, draw the corresponding curve, and find the corresponding point of the key index (i.e., the preset insulation performance limit value of the insulating oil) according to the curve.

[0079] Step 4: Install an on-line monitoring device on the oil-filled power equipment, and extract the operating oil sample of the equipment for data testing.

[0080] Step 5: Compare the real-time measurement data of the oil sample by the on-line monitoring device with the corresponding point of the key index.

[0081] Step 6: If the measured data does not exceed the limit value (the corresponding point of the key index), the product operates normally. If the measured data index exceeds the limit value, an abnormal alarm signal is sent.

[0082] Step 7: Analyze the abnormal indicators of the product oil sample (i.e., the measured data exceeding the limit value) based on the warning signal, and give suggestions for product operation to avoid equipment failure caused by the expansion of the problem.

[0083] Embodiment 2:

[0084] The embodiment of the present invention also provides an oil-immersed transformer fault warning system for an oil-immersed transformer. The oil-immersed transformer fault warning system includes a curve set acquisition component, an alarm parameter determination component, an insulating oil detection component, and an analysis and warning component.

[0085] The curve set acquisition component is used to acquire a curve set of the insulating performance of the insulating oil changing with the content of characteristic substances in the insulating oil.

[0086] Exemplarily, the characteristic substances in the insulating oil are substances that can reflect the insulating performance of the insulating oil. The types of characteristic substances in the insulating oil can be one or multiple.

[0087] In some examples, the characteristic substances include copper particles, iron particles, and rubber particles.

[0088] The inventor found in daily work that copper particles, iron particles, and rubber particles in the insulating oil mainly affect the insulating performance of the insulating oil. Therefore, after selecting the characteristic substances as copper particles, iron particles, and rubber particles, the change in the insulating performance of the insulating oil can be correspondingly obtained according to the change in the content of the characteristic substances, which is convenient for obtaining the curve set of the insulating performance of the insulating oil changing with the content of the characteristic substances in the insulating oil.

[0089] Exemplarily, the curve set acquisition component can be a first computer running a first software (for example, curve generation software), and the above components and functions can be realized by existing technologies.

[0090] Exemplarily, after the staff obtains the values of the insulating performance of multiple groups of insulating oils and the content of the corresponding characteristic substances in the insulating oil through experiments, and then inputs the values of the insulating performance of multiple groups of insulating oils and the content of the corresponding characteristic substances in the insulating oil into the above first computer, the first computer can automatically generate a curve set of the insulating performance of the insulating oil changing with the content of the characteristic substances in the insulating oil.

[0091] The alarm parameter determination component is connected to the curve set acquisition component, and is used to determine the alarm parameters of the content of the characteristic substances in the insulating oil according to the curve set and the preset insulating performance limit value of the insulating oil, and transmit them to the analysis and warning component.

[0092] Exemplarily, the alarm parameter determination component can be a second computer running a second software (for example, data processing software), and the above components and functions can be realized by existing technologies.

[0093] Exemplarily, after the second computer obtains the curve set generated by the first computer and the staff inputs the preset insulation performance limit value of the insulating oil in the second computer, the second computer can determine the alarm parameter of the corresponding characteristic substance content.

[0094] The insulating oil detection component is arranged on the oil tank of the oil-immersed transformer and is used for detecting the measurement parameter of the characteristic substance content in the insulating oil of the oil-immersed transformer and transmitting it to the analysis and warning component.

[0095] Exemplarily, the insulating oil detection component includes a plurality of existing detection sensors to realize the detection of the characteristic substance content.

[0096] For example, the insulating oil detection component can include a spectral analyzer, a microscopic imaging device, etc. The content of copper particles is detected by the spectral analyzer, and the content of rubber particles is detected by the microscopic imaging device.

[0097] The analysis and warning component is respectively connected to the alarm parameter determination component and the insulating oil detection component, and is used for comparing the measurement parameter with the alarm parameter to obtain a comparison result, and determining whether to give an early warning according to the comparison result.

[0098] Exemplarily, the analysis and warning component includes an existing microprocessor and an alarm (such as an audible and visual alarm) with data processing and control functions. The microprocessor can obtain a comparison result after comparing the data, and control the alarm to give an alarm according to the comparison result.

[0099] Through the above settings, after obtaining the curve set, the alarm parameter of the characteristic substance content in the insulating oil can be determined in combination with the preset insulation performance limit value of the insulating oil. After detecting the measurement parameter of the characteristic substance content in the insulating oil of the oil-immersed transformer, the analysis and warning component compares the measurement parameter with the alarm parameter to obtain a comparison result, and gives an early warning according to the comparison result, so as to realize the early warning of the insulation performance of the oil-immersed transformer.

[0100] In some embodiments, as Figure 2 、 Figure 3 and Figure 4 shown, the insulating oil detection component includes a circulation pipeline 8, an insulating oil state monitoring device 5 and a driving member. The inlet and outlet of the circulation pipeline 8 are both communicated with the inside of the oil tank of the oil-immersed transformer. The insulating oil state monitoring device 5 is arranged on the circulation pipeline 8 and is used for detecting the measurement parameter of the characteristic substance content in the insulating oil flowing through the circulation pipeline 8 and transmitting it to the analysis and warning component. The driving member is arranged on the circulation pipeline 8 and is used for driving the insulating oil to flow in the circulation pipeline 8.

[0101] Exemplarily, the circulation pipeline 8 can lead out the insulating oil inside the oil tank of the oil-immersed transformer to facilitate the detection by the insulating oil state monitoring device 5.

[0102] Exemplarily, a valve 6 is provided on the circulation pipeline 8 to control the on-off of the circulation pipeline 8.

[0103] Exemplarily, the insulating oil condition monitoring device 5 includes a spectral analyzer and a microscopic imaging device. The content of copper particles and iron particles can be detected by the spectral analyzer, and the content of rubber particles can be detected by the microscopic imaging device.

[0104] Exemplarily, the driving member can be a circulation pump, and the driving member can be integrated in the insulating oil condition monitoring device 5.

[0105] Through the above settings, the driving member can drive the insulating oil in the oil-immersed transformer to circulate in the circulation pipeline 8, so as to facilitate the insulating oil condition monitoring device 5 to detect the measurement parameters of the content of characteristic substances in the insulating oil flowing through the circulation pipeline 8.

[0106] In some embodiments, the inlet of the circulation pipeline 8 includes a first inlet 9 and a second inlet 7. The first inlet 9 is arranged at the position corresponding to the tap changer 2 on the oil tank, and the second inlet 7 is arranged at the position corresponding to the oil pump 4 of the cooling device 3 on the oil tank.

[0107] The insulating oil in the oil tank enters the circulation pipeline 8 simultaneously through the first inlet 9 and the second inlet 7 and is transported to the insulating oil condition monitoring device 5.

[0108] As a voltage regulating device of the oil-immersed transformer, the tap changer 2 has frequent switching actions during the operation of the oil-immersed transformer. Because the mechanical friction during the switching of the tap changer 2 will generate a small amount of powdery impurities (mainly copper particles), and the oil pump 4 will have high-speed friction with the insulating oil during operation, which will cause a small amount of metal particles (mainly iron particles) to be generated due to wear on the surface of the oil pump blades. Therefore, the content of copper particles in the insulating oil near the tap changer 2 is relatively high, and the content of iron particles in the insulating oil near the oil pump 4 is relatively high.

[0109] Through the above settings, the insulating oil with a relatively high content of characteristic substances in the insulating oil can quickly enter the circulation pipeline 8 through the first inlet 9 and the second inlet 7 and be detected by the insulating oil condition monitoring device 5, which can improve the detection sensitivity of the insulating oil condition monitoring device 5 and also improve the timeliness of the analysis and warning component for early warning.

[0110] Embodiment 3:

[0111] The embodiment of the present invention also provides an oil-immersed transformer, which includes a transformer body 1 and the oil-immersed transformer fault early warning system in Embodiment 2. As Figure 2As shown in the figure, the transformer body 1 includes an oil tank, a transformer core, a tap changer 2, and a cooling device 3. The oil tank is used to contain insulating oil. The transformer core and the tap changer 2 are immersed in the insulating oil. The tap changer 2 is used to adjust the output voltage of the transformer body 1. The cooling device 3 is arranged outside the oil tank and is used to dissipate heat from the insulating oil.

[0112] The insulating oil in the oil tank is used to provide insulation and heat dissipation for the transformer core.

[0113] The oil-immersed transformer fault warning system can issue a warning when the insulation performance of the insulating oil deteriorates, so as to remind the staff to repair the oil-immersed transformer in time, thus being able to detect potential safety hazards in the oil-immersed transformer in advance, avoid the continuous expansion of potential safety hazards into accidents, not only improve the reliability of the operation of the oil-immersed transformer, but also significantly reduce the economic losses caused by equipment failures, providing a strong guarantee for the stable operation of the power system.

[0114] It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principle of the present invention. However, the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims

1. A method for early warning of oil-immersed transformer faults, characterized in that, Including: Obtaining a set of curves showing the change in the insulation performance of insulating oil with the content of characteristic substances in the insulating oil; Determining the alarm parameters for the content of characteristic substances in the insulating oil according to the set of curves and the preset insulation performance limit value of the insulating oil; Detecting the measurement parameters of the content of characteristic substances in the insulating oil of an oil-immersed transformer; Comparing the measurement parameters with the alarm parameters to obtain a comparison result, and determining whether to give an early warning according to the comparison result.

2. The method for early warning of faults in an oil-immersed transformer according to claim 1, wherein: The obtaining of the set of curves showing the change in the insulation performance of insulating oil with the content of characteristic substances in the insulating oil is specifically: obtaining a set of curves showing the change in the insulation performance of insulating oil with the content of characteristic substances in the insulating oil according to multiple different flow rates of the insulating oil; The alarm parameters for the content of characteristic substances in the insulating oil include: the alarm parameters for the content of characteristic substances in the insulating oil corresponding to multiple different flow rates of the insulating oil; The method further includes: detecting the measured flow rate of the insulating oil in the oil-immersed transformer; The comparing the measurement parameters with the alarm parameters to obtain a comparison result, and determining whether to give an early warning according to the comparison result is specifically: comparing the measurement parameters with the alarm parameters corresponding to the measured flow rate of the insulating oil to obtain a comparison result. If the comparison result is that the measurement parameter is greater than the alarm parameter, an early warning is given.

3. The oil-immersed transformer fault warning method according to claim 2, characterized in that The characteristic substances include copper particles, iron particles, and rubber particles; The set of curves includes: multiple curves showing the change in the insulation performance of insulating oil with the content of copper particles, iron particles, and rubber particles in the insulating oil respectively; The alarm parameters include: the alarm content values corresponding to copper particles, iron particles, and rubber particles in the insulating oil respectively; The measurement parameters include: the measured values of the content of copper particles, iron particles, and rubber particles in the insulating oil of the oil-immersed transformer respectively; The comparing the measurement parameters with the alarm parameters corresponding to the measured flow rate of the insulating oil to obtain a comparison result, and determining whether to give an early warning according to the comparison result is specifically: sequentially comparing the measured values of the content of copper particles, iron particles, and rubber particles in the insulating oil of the oil-immersed transformer with the alarm content values corresponding to copper particles, iron particles, and rubber particles respectively under the measured flow rate of the insulating oil to obtain multiple comparison results. If any one of the comparison results is that the measured value is greater than the corresponding alarm content value, an early warning is given.

4. The oil-immersed transformer fault warning method according to claim 3, characterized in that, After determining whether to give an early warning, the method further includes: Giving operation suggestions for the oil-immersed transformer according to the comparison result.

5. The method for early warning of faults in an oil-immersed transformer according to claim 1, wherein: The obtaining of the set of curves showing the change in the insulation performance of insulating oil with the content of characteristic substances in the insulating oil is specifically: Respectively measuring the insulation performance of the corresponding insulating oil according to different contents of characteristic substances in the insulating oil; Drawing each curve according to different contents of characteristic substances in the insulating oil and the insulation performance of the corresponding insulating oil.

6. An oil-immersed transformer fault warning system, characterized in that, Including: A curve set acquisition component for obtaining a set of curves showing the change in the insulation performance of insulating oil with the content of characteristic substances in the insulating oil; An alarm parameter determination component, connected to the curve set acquisition component, is configured to determine alarm parameters for the content of characteristic substances in insulating oil according to the curve set and the preset insulating performance limit value of the insulating oil, and transmit them to the analysis and alarm component; An insulating oil detection component, arranged on the oil tank of the oil-immersed transformer, is configured to detect the measurement parameters of the content of characteristic substances in the insulating oil of the oil-immersed transformer and transmit them to the analysis and alarm component; and, An analysis and alarm component, respectively connected to the alarm parameter determination component and the insulating oil detection component, is configured to compare the measurement parameters with the alarm parameters to obtain a comparison result, and determine whether to give an early warning according to the comparison result.

7. The oil-immersed transformer fault early warning system according to claim 6, wherein, The insulating oil detection component includes: A circulation pipeline (8), the inlet and outlet of the circulation pipeline (8) are both communicated with the inside of the oil tank of the oil-immersed transformer; An insulating oil condition monitoring device, arranged on the circulation pipeline (8), is configured to detect the measurement parameters of the content of characteristic substances in the insulating oil flowing through the circulation pipeline (8) and transmit them to the analysis and alarm component; and, A driving member, arranged on the circulation pipeline (8), is configured to drive the insulating oil to flow in the circulation pipeline (8).

8. The oil-immersed transformer fault warning system according to claim 7, wherein, The inlet of the circulation pipeline (8) includes a first inlet and a second inlet; The first inlet is arranged at the position corresponding to the tap changer on the oil tank, and the second inlet is arranged at the position corresponding to the oil pump (4) of the cooling device (3) on the oil tank.

9. The oil-immersed transformer fault warning system according to any one of claims 6-8, characterized in that, The characteristic substances include copper particles, iron particles and rubber particles.

10. An oil-immersed transformer, characterized in that, It includes: A transformer body (1), including an oil tank, a transformer core, a tap changer (2) and a cooling device (3); the oil tank is used to contain insulating oil, the transformer core and the tap changer (2) are immersed in the insulating oil, the tap changer (2) is used to adjust the output voltage of the transformer body (1), and the cooling device (3) is arranged outside the oil tank and is used to dissipate heat from the insulating oil; and, The oil-immersed transformer fault early warning system according to any one of claims 6-9.

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