Transformer respiratory system blocking judgment method and equipment and computer program product

Abstract

The invention provides a transformer respiratory system blocking judgment method and device and a computer program product thereof, and relates to the technical field of transformer respiratory system monitoring, and the transformer respiratory system blocking judgment method comprises the steps: obtaining a pressure measured value at a pressure relief valve of a transformer; under the condition that the numerical relationship between the pressure measured value and the preset pressure threshold value meets the preset blocking judgment condition, it is determined that the transformer breathing system is in the blocking state; the preset pressure threshold value is obtained according to the product parameters of the transformer. According to the method, the preset pressure threshold value is set, then the preset pressure threshold value is compared with the pressure actual measurement value at the pressure relief valve, and the transformer respiratory system blockage identification can be realized according to the met preset blockage judgment condition, and the pressure actual measurement value at the pressure relief valve directly comes from the pressure sensor of the pressure relief valve; therefore, other sensors do not need to be additionally arranged.

Description

Technical Field

[0001] This application relates to the field of transformer breathing system monitoring technology, and in particular to methods, equipment and computer programs for judging blockage in transformer breathing systems. Background Technology

[0002] The transformer breathing system is a crucial component of oil-immersed transformers. A smooth breathing system is essential for the safe and stable operation of the transformer. A malfunction in the breathing system can lead to abnormal operating conditions such as overheating and a sudden increase in oil pressure, jeopardizing the transformer's safe and stable operation. The most common breathing system malfunction is blockage. Currently, the method for determining breathing system blockage primarily relies on the condition of the transformer oil, requiring monitoring of oil pressure, oil flow velocity, and oil temperature at various measuring points on the transformer at fixed time intervals. However, this method necessitates the placement of numerous sensors inside the transformer. When sensors malfunction, timely replacement is impossible, and the loss or failure of any sensor can affect the transformer's operating status.

[0003] Therefore, how to determine respiratory obstruction without using a large number of sensors is a technical problem that urgently needs to be solved. Summary of the Invention

[0004] The main purpose of this application is to provide a method, device and computer program product for judging the blockage of the transformer breathing system, which aims to solve the technical problem of how to judge the blockage of the breathing system without using a large number of sensors.

[0005] To achieve the above objectives, this application proposes a method for determining blockage in a transformer breathing system, which includes: Obtain the measured pressure value at the transformer's pressure relief valve; If the numerical relationship between the measured pressure value and the preset pressure threshold satisfies the preset blockage judgment condition, the transformer breathing system is determined to be in a blocked state; the preset pressure threshold is obtained based on the product parameters of the transformer.

[0006] In one embodiment, the preset pressure threshold includes a positive pressure blocking threshold and a negative pressure blocking threshold; The aforementioned preset blocking judgment conditions include: The measured pressure value is greater than the positive pressure blocking threshold, or The measured pressure value is less than the negative pressure blockage threshold.

[0007] In one embodiment, before the above-mentioned preset blockage judgment condition is met, the above-mentioned transformer breathing system blockage judgment method further includes: Obtain the measured value of the transformer's breather pressure; If the measured pressure of the above-mentioned breather is greater than the preset pressure threshold of the breather, and the measured pressure is greater than the positive pressure blockage threshold, it is determined that the breathing pipeline of the above-mentioned transformer breathing system is in a positive pressure blockage state and the above-mentioned breather itself is in a blockage state.

[0008] In one embodiment, the above-mentioned transformer breathing system blockage determination method further includes: If the measured pressure value is less than the negative pressure blockage threshold, it is determined that the breathing pipeline of the transformer breathing system is in a negative pressure blockage state.

[0009] In one embodiment, determining that the transformer breathing system is in a blocked state when the numerical relationship between the measured pressure value and the preset pressure threshold satisfies a preset blockage judgment condition includes: If the numerical relationship between the measured pressure value and the preset pressure threshold satisfies the preset blockage judgment condition and the duration exceeds the time delay threshold, the transformer breathing system is determined to be in a blocked state.

[0010] In one embodiment, before obtaining the measured pressure value at the transformer's pressure relief valve, the transformer breathing system blockage determination method further includes: Based on the product parameters of the above transformer, determine the reference pressure of the pressure relief valve, the oil pressure change of the oil conservator when the above transformer breathing system is blocked, and the air pressure change of the bladder. The product of the blockage coefficient and the aforementioned air pressure change, plus the sum of the aforementioned oil pressure change, is used as the reference pressure deviation. The positive value of the above-mentioned reference pressure deviation and the sum of the above-mentioned reference pressure of the pressure relief valve are used as the positive pressure blocking threshold, and the negative value of the above-mentioned reference pressure deviation and the sum of the above-mentioned reference pressure of the pressure relief valve are used as the negative pressure blocking threshold.

[0011] In one embodiment, determining the reference pressure of the pressure relief valve, the change in oil pressure of the oil conservator when the transformer breathing system is blocked, and the change in air pressure of the bladder includes: Determine the change in oil volume under the above-mentioned breathing line blockage condition; Using the relationship between the oil volume in the oil reservoir and the oil level height, the oil level height under the condition of blocked breathing tubing can be obtained based on the change in oil volume. Based on the above liquid level and reference oil level, the pressure at the pressure relief valve and the above reference pressure of the pressure relief valve are obtained; The difference between the pressure at the pressure relief valve and the reference pressure of the pressure relief valve is taken as the oil pressure change.

[0012] In one embodiment, determining the pressure change of the capsule includes: The difference between the oil volume in the oil conservator at the above-mentioned reference oil level and the change in the oil volume is taken as the gas volume in the oil conservator when the above-mentioned transformer breathing system is blocked. Using the standard equation of state for gases, based on the gas pressure of the capsule when the transformer breathing system is unobstructed, the gas volume of the oil conservator, and the oil volume of the oil conservator at the reference oil level, the gas pressure of the capsule when the transformer breathing system is blocked is obtained. The difference between the air pressure of the capsule when the transformer's breathing system is unobstructed and the air pressure of the capsule when the transformer's breathing system is blocked is taken as the change in air pressure of the capsule.

[0013] In addition, to achieve the above objectives, this application also proposes a transformer breathing system blockage detection device, which is connected to a pressure sensor at the pressure relief valve of the transformer. The transformer breathing system blockage detection device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. The computer program is configured to implement the steps of the transformer breathing system blockage detection method described above.

[0014] In addition, to achieve the above objectives, this application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the transformer breathing system blockage judgment method described above.

[0015] One or more technical solutions proposed in this application have at least the following technical effects: This application provides a method for determining blockage in a transformer breathing system. The method includes: obtaining the measured pressure value at the transformer's pressure relief valve; and determining that the transformer breathing system is blocked if the numerical relationship between the measured pressure value and a preset pressure threshold satisfies a preset blockage judgment condition. The preset pressure threshold is obtained based on the transformer's product parameters. This application achieves transformer breathing system blockage identification by self-setting a preset pressure threshold and comparing it with the measured pressure value at the pressure relief valve, based on the satisfied preset blockage judgment condition. The measured pressure value at the pressure relief valve directly comes from the pressure sensor built into the pressure relief valve, thus eliminating the need for additional sensors. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0017] To more clearly illustrate the technical solutions in this embodiment or the prior art, the accompanying drawings used in the description of the embodiment or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the transformer breathing system blockage judgment method provided in this embodiment; Figure 2 This is a schematic diagram of the transformer structure provided in this embodiment; Figure 3 This is a structural diagram of the transformer oil conservator in this embodiment; Figure 4 This is a simplified flowchart illustrating the transformer breathing system blockage determination method provided in this embodiment; Figure 5 This is a schematic diagram of the transformer breathing system blockage detection device in this embodiment. Detailed Implementation

[0019] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] It should be noted that if this embodiment involves directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0021] Furthermore, if this embodiment involves descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0022] In related technologies, the state of transformer oil is used as the main criterion in the method of judging the blockage of the transformer breathing system. Therefore, it is necessary to monitor the oil pressure, oil flow velocity and oil temperature data at each measuring point of the transformer at fixed time intervals. This requires the deployment of a large number of sensors to monitor the oil pressure, oil flow velocity and oil temperature data at each measuring point. Since the sensors are all located inside the transformer, they cannot be replaced in time when they fail, and the sensors may also fall off. Both of these situations will affect the operating status of the transformer.

[0023] This application provides a method for judging the blockage of a transformer breathing system. Because the method has a self-set preset pressure threshold, it can identify the blockage status of the transformer breathing system by using only pressure as the main criterion. Therefore, this application does not require monitoring the oil pressure, oil flow velocity and oil temperature data at each measuring point of the transformer, thus eliminating the need to deploy a large number of sensors and avoiding the impact on the transformer's operating status.

[0024] Figure 1 This is a schematic diagram of the transformer breathing system blockage judgment method provided in this embodiment, refer to... Figure 1 The method for determining blockage in the transformer breathing system includes steps S10~S20: Step S10: Obtain the measured pressure value at the pressure relief valve of the transformer; It should be noted that the actual pressure value at the pressure relief valve is monitored by the sensor built into the pressure relief valve.

[0025] Additionally, it should be noted that the executing entity in this embodiment can be a transformer breathing system blockage detection device, which is connected to the pressure sensor at the transformer's pressure relief valve. The transformer can be an oil-immersed transformer; the following description will use an oil-immersed transformer as an example.

[0026] Step S20: If the numerical relationship between the measured pressure value and the preset pressure threshold satisfies the preset blockage judgment condition, it is determined that the transformer breathing system is in a blocked state; the preset pressure threshold is obtained based on the product parameters of the transformer.

[0027] In this embodiment, the preset pressure threshold is the pressure value at the pressure relief valve under the condition of transformer breathing system blockage, which is obtained by mathematical modeling. In a feasible implementation, the preset pressure threshold includes a positive pressure blockage threshold and a negative pressure blockage threshold; the preset blockage judgment condition includes: the measured pressure value is greater than the positive pressure blockage threshold, or the measured pressure value is less than the negative pressure blockage threshold.

[0028] Understandably, when the transformer breathing system is unobstructed, the air pressure in the bladder of the transformer oil conservator cancels out the external atmospheric pressure, resulting in the measured pressure at the transformer's pressure relief valve being equal to the oil pressure in the transformer oil conservator. However, when the transformer breathing system becomes blocked, it causes a change in the transformer oil temperature, leading to changes in the oil pressure in the transformer oil conservator and the air pressure in the bladder. Therefore, in this embodiment, based on the positive value of this change, a positive pressure blocking threshold is obtained through mathematical modeling, and based on the negative value of this change, a negative pressure blocking threshold is obtained through mathematical modeling. In a feasible implementation, before obtaining the measured pressure at the transformer's pressure relief valve, the transformer breathing system blocking judgment method further includes: determining the pressure relief valve reference pressure, the change in oil pressure in the oil conservator when the transformer breathing system is blocked, and the change in air pressure in the bladder according to the transformer's product parameters; using the sum of the product of the blocking coefficient and the change in air pressure and the change in oil pressure as the reference pressure deviation; using the sum of the positive value of the reference pressure deviation and the reference pressure of the pressure relief valve as the positive pressure blocking threshold, and using the sum of the negative value of the reference pressure deviation and the reference pressure of the pressure relief valve as the negative pressure blocking threshold.

[0029] like Figure 2 As shown, Figure 2 The transformer structure provided in this embodiment is shown in the schematic diagram. The transformer 10 includes an oil tank 101, and the oil tank 101 contains a capsule 1011. The capsule 1011 is connected to a respirator 103 through a breathing tube 102 / 102-1.

[0030] In this embodiment, the product parameters may include transformer oil density, oil weight, transformer oil expansion coefficient, oil conservator length, oil conservator radius, and oil level height. After obtaining the product parameters of transformer 10, a relationship can be established between the oil pressure change of oil conservator 101 and the air pressure change of bladder 1011 when the transformer breathing system is blocked, and the deviation from the reference pressure. This relationship is ΔP. T =△P0+α△P 阻塞 , where △P T The reference pressure deviation refers to the deviation from the reference pressure of the pressure relief valve, which is obtained from the reference oil level. △P0 is the theoretical value, representing the change in oil pressure at the reference oil level of the oil conservator under varying oil temperature conditions when the transformer breathing system is completely blocked. This oil temperature change, △T, refers to the change in transformer oil temperature when the transformer breathing system is blocked. 阻塞The theoretical value represents the pressure change in the bladder of the transformer when the oil level is completely blocked, assuming the transformer's breathing system is completely obstructed, based on the change in oil temperature. This oil temperature change, ΔT, refers to the change in transformer oil temperature when the breathing system is blocked. α is the blockage coefficient, where 0 < α < 1. This coefficient is a set empirical value and can be selected based on actual conditions. A value of 1 indicates complete blockage of the transformer's breathing system. A smaller value indicates a smaller deviation, resulting in more accurate and sensitive calculations. In one example, α is chosen as 0.25. It should be noted that when the transformer's breathing system is partially blocked, the pressure change should be less than ΔP. 阻塞 The change in oil pressure should be less than ΔP0.

[0031] Considering that transformer breathing system blockage can be positive or negative, this embodiment determines transformer breathing system blockage based on the following criteria. Then, based on these criteria, the positive value of the reference pressure deviation and the sum of the reference pressure of the pressure relief valve are used as the positive pressure blockage threshold, and the negative value of the reference pressure deviation and the sum of the reference pressure of the pressure relief valve are used as the negative pressure blockage threshold.

[0032] The criterion is: ; Among them, P R P represents the measured value of the pressure relief valve. S This is the reference pressure for the pressure relief valve.

[0033] To obtain the oil pressure change ΔP0 and the gas pressure change ΔP of the bladder under the condition of complete blockage of the transformer breathing system. 阻塞 In one feasible implementation, determining these two theoretical values—the reference pressure of the pressure relief valve, the oil pressure change in the oil conservator when the transformer breathing system is blocked, and the gas pressure change in the bladder—includes: determining the oil volume change when the breathing line is blocked; using the correlation between the oil volume in the oil conservator and the oil level height, obtaining the liquid level height when the breathing line is blocked based on the oil volume change; obtaining the pressure at the pressure relief valve and the reference pressure of the pressure relief valve based on the liquid level height and the reference oil level; and using the difference between the pressure at the pressure relief valve and the reference pressure of the pressure relief valve as the oil pressure change.

[0034] In this embodiment, the formula used to determine the change in oil volume under conditions of ventilator blockage is:

[0035] Among them, △ v H represents the change in oil volume when the breathing line is blocked. T Oil weight, provided by the transformer manufacturer; ρ Oil R is the density of transformer oil. OilThe coefficient of thermal expansion of transformer oil is taken as 0.78*10. -3 / ℃, where △T is the change in transformer oil temperature.

[0036] The relationship between the oil volume in the transformer oil conservator and the oil level height in the conservator is as follows:

[0037] Transformer oil conservator can be a barrel-shaped oil conservator, such as... Figure 3 As shown, Figure 3 This is a structural diagram of the transformer oil conservator in this embodiment, which establishes the relationship between the oil volume and the oil level in the barrel-shaped oil conservator. l The length of the oil cushion, h This refers to the liquid level height. r Let the radius of the oil cushion be... h 0 represents the baseline oil level, and x represents the required oil level. v This represents the volume of oil in the oil reservoir.

[0038] In actual calculations, the relationship between the oil volume in the transformer oil tank and the oil level can be simplified as follows:

[0039] Using r as the reference oil level, and substituting the obtained liquid level height h into the oil level height in the pressure formula, we obtain the pressure at the pressure relief valve and the reference pressure of the pressure relief valve. The difference between the pressure at the pressure relief valve and the reference pressure of the pressure relief valve is used as the oil pressure change for subsequent determination of the preset pressure threshold. The pressure formula is as follows:

[0040] in, P 0 represents the pressure at the pressure relief valve. ρ Oil The density of the transformer oil is taken as 0.88 kg / dm³. 3 , g The acceleration due to gravity is taken as 9.8 N / kg. h Oil level. H C The oil level in the oil conservator is provided by the transformer manufacturer.

[0041] In one feasible implementation, determining the pressure change of the capsule includes: taking the difference between the oil volume in the oil tank at the reference oil level and the change in oil volume as the oil tank gas volume when the transformer breathing system is blocked; using the standard equation of state for gases, based on the pressure of the capsule when the transformer breathing system is unobstructed, the oil tank gas volume, and the oil tank oil volume at the reference oil level, to obtain the pressure of the capsule when the transformer breathing system is blocked; and taking the difference between the pressure of the capsule when the transformer breathing system is unobstructed and the pressure of the capsule when the transformer breathing system is blocked as the pressure change of the capsule.

[0042] In this embodiment, the oil volume V of the oil conservator at the reference oil level is... 正常 The change in oil volume Δ obtained above v The difference is used as the volume of gas in the oil conservator, V, when the transformer's breathing system is blocked. 阻塞 The relationship between the three satisfies △ v =V 正常 -V 阻塞 .

[0043] When the transformer breathing system is blocked, the oil level in the oil conservator changes due to the oil temperature change ΔT, compressing the gas in the bladder. The gas pressure in the bladder is no longer equal to atmospheric pressure, therefore it needs to be recalculated using the standard equation of state for gases. This standard equation of state is P. 正常 V 正常 =P 阻塞 V 阻塞 , where P 正常 P represents the air pressure in the capsule when the transformer's breathing system is unobstructed. 阻塞 This refers to the air pressure in the capsule when the transformer's breathing system is blocked.

[0044] Next, when the transformer's breathing system is unobstructed, the pressure P in the capsule... 正常 When the transformer's breathing system is blocked, the pressure P in the capsule 阻塞 The difference is taken as the pressure change ΔP of the capsule. 阻塞 This is used to obtain the preset pressure threshold in the future.

[0045] After obtaining the positive and negative pressure blocking thresholds through mathematical modeling, the blocking status of the transformer breathing system can be judged based on the positive and negative pressure blocking thresholds. In one feasible implementation, before the preset blocking judgment conditions are met, the transformer breathing system blocking judgment method further includes: obtaining the measured value of the transformer's breather pressure; judging whether the measured value of the breather pressure is greater than the preset pressure threshold of the breather; and determining that the breathing pipeline of the transformer breathing system is in a positive pressure blocking state and the breather itself is in a blocking state when the measured value of the breather pressure is greater than the preset pressure threshold of the breather and the measured value of the pressure is greater than the positive pressure blocking threshold.

[0046] It is understandable that the state of transformer oil can be used as the main criterion in the method of judging the blockage of the transformer breathing system. This requires monitoring the oil pressure, oil flow velocity and oil temperature data at each measuring point of the transformer at fixed time intervals. Therefore, a large number of sensors need to be deployed to monitor the oil pressure, oil flow velocity and oil temperature data at each measuring point. Since the sensors are all located inside the transformer, they cannot be replaced in time when they fail, and the sensors may also fall off. Both of these situations will affect the operating status of the transformer.

[0047] The transformer breathing system blockage judgment method provided in this embodiment uses only pressure as the main criterion. Therefore, this embodiment does not require monitoring the oil pressure, oil flow velocity and oil temperature data at each measuring point of the transformer, thus eliminating the need to deploy a large number of sensors and avoiding the impact on the transformer's operating status. Specifically, this embodiment involves two measuring points, one at the pressure relief valve and the other at the breather. The measured pressure values ​​at the measuring points all come from the transformer's matching components, thus eliminating the need to install other sensors. Here, other sensors can refer to pressure sensors, speed sensors and temperature sensors.

[0048] The transformer breathing system includes a breathing tubing 102 and a respirator 103. The breathing tubing 102 includes an inhalation channel 102-2 and an exhalation channel 102-1.

[0049] In this embodiment, the blockage status of the breathing tubing 102 and the respirator 103 is determined by using a preset pressure threshold and a positive pressure blockage threshold for the respirator, thereby identifying the blockage status of the entire transformer breathing system. When the measured pressure value of the respirator is greater than the preset pressure threshold and the measured pressure value is greater than the positive pressure blockage threshold, it is determined that the breathing tubing 102 of the transformer breathing system is in a positive pressure blockage state and the respirator 103 itself is in a blockage state; that is, the blockage status of the entire transformer breathing system is positive pressure blockage. It should also be noted that the positive pressure blockage state of the breathing tubing 102 refers to only the expiratory channel 102-1 being blocked.

[0050] The preset pressure threshold of the respirator is a self-set value. In one example, the preset pressure threshold of the respirator is 5 kPa.

[0051] This embodiment uses a dual-threshold criterion method to determine the positive pressure blockage state of the entire transformer breathing system. The dual thresholds refer to the preset pressure threshold of the pressure relief valve and the preset pressure threshold of the breather.

[0052] Since the actual situation of transformers is quite complex, the dual threshold criterion method is likely to miss the blockage state that meets a single threshold. Since the missed reports cannot be detected manually, in a feasible implementation, when the measured pressure value is greater than the positive pressure blockage threshold, the blockage state of the breathing pipe of the transformer breathing system is determined to be positive pressure blockage.

[0053] In this embodiment, the obstruction state of the breathing circuit is determined to be positive pressure obstruction by the positive pressure obstruction threshold. Specifically, the obstruction state of the breathing circuit as positive pressure obstruction refers to the obstruction of the expiratory channel 102-1.

[0054] The transformer breathing system blockage judgment method provided in this embodiment uses only pressure as the primary criterion. Therefore, this embodiment does not require monitoring the oil pressure, oil flow velocity, and oil temperature data at various measuring points on the transformer, thus eliminating the need for a large number of sensors and avoiding any impact on the transformer's operating status. Specifically, this embodiment involves only one measuring point, namely at the pressure relief valve. The measured pressure value at this measuring point comes from the transformer's supporting components, thus eliminating the need for additional sensors. These additional sensors can refer to pressure sensors, velocity sensors, and temperature sensors.

[0055] In one feasible implementation, after determining whether the measured pressure value of the respirator is greater than the preset pressure threshold of the respirator, the method for determining blockage of the transformer breathing system further includes: If the measured pressure of the breather is greater than the preset pressure threshold of the breather, and the relationship between the measured pressure at the pressure relief valve and the preset pressure threshold does not meet the preset blockage judgment conditions, the blockage state of the transformer breathing system is determined to be that the breather itself is blocked.

[0056] In this embodiment, the blockage state of the transformer breathing system is determined to be that only the breather itself is blocked. Specifically, the blockage can be caused by the deliquescence and caking of silicone inside the breather 103 or blockage by foreign objects.

[0057] In one feasible implementation, when the measured pressure of the respirator is not greater than the preset pressure threshold of the respirator, and the numerical relationship between the measured pressure at the pressure relief valve and the preset pressure threshold does not meet the preset blockage judgment condition, the entire breathing system of the transformer is determined to be in a smooth state.

[0058] The pressure sensor at the respirator can only detect the pressure during exhalation (positive pressure) and cannot detect the pressure during inhalation (negative pressure). Therefore, in order to realize the identification of negative pressure blockage in the transformer breathing system, in one feasible implementation, the transformer breathing system blockage judgment method further includes: if the numerical relationship between the measured pressure value and the preset pressure threshold satisfies that the measured pressure value is less than the negative pressure blockage threshold, then the breathing pipeline of the transformer breathing system is determined to be in a negative pressure blockage state.

[0059] In this embodiment, the negative pressure blockage state of the breathing tubing 102 refers to the blockage of only the inhalation channel 102-2. It should also be noted that negative pressure blockage is a blockage state caused solely by pressure at the pressure relief valve. In the negative pressure blockage state, the pressure sensor on the respirator displays no value, i.e., it shows 0. Therefore, determining that the breathing tubing 102 of the transformer breathing system is in a negative pressure blockage state indicates that the blockage state of the transformer breathing system is indeed a negative pressure blockage.

[0060] Due to numerical abrupt changes caused by electromagnetic interference in complex on-site operating conditions and increased acquisition errors caused by sensor aging, in a feasible implementation, if the numerical relationship between the measured pressure value and the preset pressure threshold satisfies the preset blockage judgment condition, the transformer breathing system is determined to be in a blocked state, including step S30: Step S30: If the numerical relationship between the measured pressure value and the preset pressure threshold satisfies the preset blockage judgment condition and the duration exceeds the time delay threshold, the transformer breathing system is determined to be in a blocked state.

[0061] This embodiment, by introducing a time delay criterion, can effectively avoid false alarms caused by sudden data changes and provide a certain alarm margin. This time delay threshold is determined by the transformer temperature change cycle. In one feasible implementation, an initial time delay threshold is set, and the longest continuous rise / fall in oil temperature on the previous day is continuously recorded. The time delay threshold is updated to this longest continuous rise / fall at midnight each day. In one example, the initial value of the time delay threshold is set to 5 hours.

[0062] In one feasible implementation, after the numerical relationship between the measured pressure value and the preset pressure threshold satisfies the preset blockage judgment condition and the duration exceeds the time delay threshold, the transformer breathing system blockage judgment method further includes: If the measured pressure of the respirator is greater than the preset pressure threshold of the respirator and the duration exceeds the time delay threshold, the transformer breathing system is determined to be in a blocked state.

[0063] The time delay threshold is equal to the time delay threshold of the pressure at the pressure relief valve. This embodiment employs a dual-threshold plus time delay criterion method to more reliably identify positive and negative pressure obstruction in the respiratory system.

[0064] This application provides a method for determining the blockage of a transformer breathing system. The method includes: obtaining the measured pressure value at the transformer's pressure relief valve; and determining that the transformer breathing system is blocked if the numerical relationship between the measured pressure value and a preset pressure threshold satisfies a preset blockage judgment condition. The preset pressure threshold is obtained based on the transformer's product parameters. This application achieves transformer breathing system blockage identification by self-setting a preset pressure threshold and comparing it with the measured pressure value at the pressure relief valve, based on the satisfied preset blockage judgment condition. The measured pressure value at the pressure relief valve directly comes from the pressure sensor built into the pressure relief valve, thus eliminating the need for additional sensors.

[0065] For example, to help understand the implementation flow of the transformer breathing system blockage judgment method obtained by combining this embodiment with the above embodiments, specifically: △T is set to 15K, H TGiven 140t, determine Δ based on the formula used to determine the change in oil volume under conditions of ventilator blockage. v The value is 1861.36L; the reference oil level and volume are 5529.2L and Δ. v The oil volume in the oil reservoir is obtained by adding 1861.36L. v The volume is 7390.56L; the oil volume is... v It is 7270.69L. r It is 0.8m. l Substituting 5.5m into the simplified relationship between the oil volume and the oil level in the transformer oil conservator, we obtain the oil level height. h The value is 1m. The liquid level height is then included. h and reference oil level r The pressure at the pressure relief valve is 25.9 kPa, and the reference pressure of the pressure relief valve is 24.1 kPa. Therefore, the oil pressure change is 1.8 kPa. It should also be noted that this reference pressure of the pressure relief valve refers to the reference pressure at the half-oil level of the pressure relief valve.

[0066] V 正常 V represents the volume of oil in the oil tank at the reference oil level. 正常 The concentration is 5529.2L, P 正常 One atmosphere, or P 正常 The value is 103 kPa.

[0067] Based on V 正常 The value is 5529.2L and the Δ obtained above. v The value is 1861.36L, and V is obtained. 阻塞 It is 3667.84L; then according to P 正常 V 正常 =P 阻塞 V 阻塞 P was obtained 阻塞 The Pa is 155.27 kPa; according to ΔP 阻塞 =P 正常 -P 阻塞 , thus obtaining △P 阻塞 The value is 52.27 kPa.

[0068] Based on the above-obtained △P 阻塞 Given a pressure of 52.27 kPa and an oil pressure change ΔP0 of 1.8 kPa, and α being 0.25, based on ΔP... T =△P0+α△P 阻塞 , thus obtaining △P T The pressure is 14.8 kPa. Based on the criteria The sum of 14.8 kPa and the reference pressure of the pressure relief valve, which is 24.1 kPa, is taken as the positive pressure blocking threshold, i.e., the positive pressure blocking threshold is 38.9 kPa; the sum of -14.8 kPa and the reference pressure of the pressure relief valve, which is 24.1 kPa, is taken as the negative pressure blocking threshold, i.e., the negative pressure blocking threshold is 9.3 kPa.

[0069] Please refer to Figure 4 , Figure 4 A simplified flowchart of a method for determining blockage in a transformer breathing system is provided. The method involves obtaining the measured pressure value from the pressure sensor integrated into the pressure relief valve, and obtaining the measured pressure value from the pressure sensor integrated into the breather. The pressure sensor at the breather is installed at the venting connection pipe of the pressure relief valve.

[0070] If the measured pressure of the respirator is found to be greater than the preset pressure threshold of the respirator by 5 kPa and the measured pressure is greater than the positive pressure blockage threshold of 38.9 kPa, the specific situation of the transformer breathing system blockage is determined to be that the exhalation channel 102-1 is blocked and the respirator itself is blocked. That is, the blockage state of the entire transformer breathing system is determined to be positive pressure blockage.

[0071] If the measured pressure value is less than the negative pressure blockage threshold of 9.3 kPa, the specific situation of the transformer breathing system blockage is determined to be that the intake channel 102-2 is blocked, that is, the blockage state of the transformer breathing system is determined to be negative pressure blockage.

[0072] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the transformer breathing system blockage judgment method of this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0073] In addition, to achieve the above objectives, this application also proposes a transformer breathing system blockage detection device, which is connected to a pressure sensor at the pressure relief valve of the transformer. The transformer breathing system blockage detection device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. The computer program is configured to implement the steps of the transformer breathing system blockage detection method described above.

[0074] The following is for reference. Figure 5The diagram illustrates a structural schematic suitable for implementing the transformer breathing system obstruction detection device of this embodiment. The transformer breathing system obstruction detection device in this embodiment may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital radio receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Description), PMPs (Portable Media Players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 5 The transformer breathing system blockage detection device shown is merely an example and should not impose any limitations on the functionality and scope of use of this embodiment.

[0075] like Figure 5 As shown, the transformer breathing system blockage detection device may include a processing unit 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 1002 or a program loaded from a storage device 1003 into a random access memory (RAM) 1004. The RAM 1004 also stores various programs and data required for the operation of the transformer breathing system blockage detection device. The processing unit 1001, ROM 1002, and RAM 1004 are interconnected via a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to the I / O interface 1006: input devices 1007 including, for example, a touch screen, touchpad, keyboard, mouse, image sensor, microphone, accelerometer, gyroscope, etc.; output devices 1008 including, for example, a liquid crystal display (LCD), speaker, vibrator, etc.; storage devices 1003 including, for example, magnetic tape, hard disk, etc.; and communication devices 1009. The communication device 1009 allows the control module to communicate wirelessly or wiredly with other devices to exchange data. Although the figure shows a control module with various systems, it should be understood that it is not required to implement or have all of the systems shown. More or fewer systems may be implemented alternatively.

[0076] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 1003, or installed from ROM 1002. When the computer program is executed by processing device 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0077] In one feasible implementation, the transformer breathing system blockage detection device is also connected to the pressure sensor at the breather 103 of the transformer breathing system.

[0078] In this embodiment, the transformer breathing system includes a breather 103 and a breathing pipeline 102. The breathing pipeline 102 includes an inhalation channel 102-2 and an exhalation channel 102-1. The inhalation channel 102-2 is the air inlet pipe at the lower part of the breather 103, and the exhalation channel 102-1 is the pipe at the upper part of the breather 103 that connects to the oil tank 101.

[0079] In one feasible implementation, the transformer breathing system blockage detection device also includes a background system connected to the transformer breathing system blockage detection device. The background system is used to provide early warning of the blockage status of the transformer breathing system. The blockage status includes negative pressure blockage status, negative pressure blockage status with a duration exceeding a time delay threshold, positive pressure blockage status, or positive pressure blockage status with a duration exceeding a time delay threshold. The alarm can be in the form of an alarm indicator light or text prompt, without specific limitations.

[0080] The transformer breathing system obstruction detection device provided in this application, employing the transformer breathing system obstruction detection method in the above embodiments, can solve the technical problem of how to perform breathing system obstruction detection without using a large number of sensors. Compared with the prior art, the beneficial effects of the transformer breathing system obstruction detection device provided in this application are the same as those of the transformer breathing system obstruction detection method provided in the above embodiments, and other technical features in this transformer breathing system obstruction detection device are the same as those disclosed in the previous embodiment method, and will not be repeated here.

[0081] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0082] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0083] In addition, to achieve the above objectives, this application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the transformer breathing system blockage judgment method described above.

[0084] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems or devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0085] The computer program product provided in this application solves the technical problem of how to determine respiratory obstruction without using a large number of sensors. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the transformer respiratory obstruction determination method provided in the above embodiments, and will not be repeated here.

[0086] The above description is only a part of the embodiments of this application and does not limit the scope of protection of this application. All equivalent structural transformations made under the technical concept of this application and using the content of this application specification and drawings, or direct / indirect applications in other related technical fields, are included in the scope of protection of this application.

Claims

1. A method for determining blockage in a transformer breathing system, characterized in that, The method for determining blockage in the transformer breathing system includes: Obtain the measured pressure value at the transformer's pressure relief valve; If the numerical relationship between the measured pressure value and the preset pressure threshold satisfies the preset blockage judgment condition, the transformer breathing system is determined to be in a blocked state; the preset pressure threshold is obtained based on the product parameters of the transformer.

2. The method for determining blockage in a transformer breathing system as described in claim 1, characterized in that, The preset pressure thresholds include a positive pressure blocking threshold and a negative pressure blocking threshold; The preset blocking judgment conditions include: The measured pressure value is greater than the positive pressure blockage threshold, or The measured pressure value is less than the negative pressure blocking threshold.

3. The method for determining blockage in a transformer breathing system as described in claim 2, characterized in that, Before the preset blockage judgment condition is met, the transformer breathing system blockage judgment method further includes: Obtain the measured value of the transformer's breather pressure; If the measured pressure of the respirator is greater than the preset pressure threshold of the respirator, and the measured pressure is greater than the positive pressure blockage threshold, it is determined that the breathing pipeline of the transformer breathing system is in a positive pressure blockage state and the respirator itself is in a blockage state.

4. The method for determining blockage in a transformer breathing system as described in claim 2, characterized in that, The method for determining blockage in the transformer breathing system also includes: If the measured pressure value is less than the negative pressure blockage threshold, it is determined that the breathing pipeline of the transformer breathing system is in a negative pressure blockage state.

5. The method for determining blockage in a transformer breathing system as described in claim 1, characterized in that, The step of determining that the transformer breathing system is in a blocked state when the numerical relationship between the measured pressure value and the preset pressure threshold meets the preset blockage judgment condition includes: If the numerical relationship between the measured pressure value and the preset pressure threshold satisfies the preset blockage judgment condition and the duration exceeds the time delay threshold, the transformer breathing system is determined to be in a blocked state.

6. The method for determining blockage in a transformer breathing system as described in claim 1, characterized in that, Before obtaining the measured pressure value at the transformer's pressure relief valve, the method for determining transformer breathing system blockage further includes: Based on the product parameters of the transformer, determine the reference pressure of the pressure relief valve, the change in oil pressure of the oil conservator when the transformer breathing system is blocked, and the change in air pressure of the bladder. The sum of the product of the blockage coefficient and the gas pressure change and the oil pressure change is used as the reference pressure deviation; The positive value of the reference pressure deviation and the sum of the reference pressure of the pressure relief valve are used as the positive pressure blocking threshold, and the negative value of the reference pressure deviation and the sum of the reference pressure of the pressure relief valve are used as the negative pressure blocking threshold.

7. The method for determining blockage in a transformer breathing system as described in claim 6, characterized in that, The determination of the reference pressure of the pressure relief valve, the change in oil pressure of the oil conservator when the transformer breathing system is blocked, and the change in air pressure of the bladder include: Determine the change in oil volume under the condition of obstruction of the breathing line; By utilizing the correlation between the oil volume in the oil reservoir and the oil reservoir level, the oil level under the condition of blocked breathing tubing can be obtained based on the change in oil volume. Based on the liquid level height and the reference oil level, the pressure at the pressure relief valve and the reference pressure of the pressure relief valve are obtained; The difference between the pressure at the pressure relief valve and the reference pressure of the pressure relief valve is taken as the oil pressure change.

8. The method for determining blockage in a transformer breathing system as described in claim 7, characterized in that, Determining the pressure change of the capsule includes: The difference between the oil volume in the oil conservator at the reference oil level and the change in oil volume is taken as the gas volume in the oil conservator when the transformer breathing system is blocked. Using the standard equation of state for gases, based on the gas pressure of the capsule when the transformer breathing system is unobstructed, the gas volume of the oil conservator, and the oil volume of the oil conservator at the reference oil level, the gas pressure of the capsule when the transformer breathing system is blocked is obtained. The difference between the air pressure in the capsule when the transformer's breathing system is unobstructed and the air pressure in the capsule when the transformer's breathing system is blocked is taken as the change in air pressure in the capsule.

9. A device for determining blockage in a transformer breathing system, characterized in that, The transformer breathing system blockage detection device is connected to a pressure sensor at the pressure relief valve of the transformer. The transformer breathing system blockage detection device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. The computer program is configured to implement the steps of the transformer breathing system blockage detection method as described in any one of claims 1 to 8.

10. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the steps of the transformer breathing system blockage determination method as described in any one of claims 1 to 8.

Images