Transformer body gas protection method and device

Abstract

The invention discloses a transformer body gas protection method and device, and relates to the technical field of transformer protection, and the protection method comprises the steps: continuously obtaining first flow velocity characteristic data and current baffle swing data in a gas relay; the gas relay is mounted in a communicating pipeline for connecting an oil tank and an oil conservator of the transformer body; according to the first flow velocity characteristic data, calculating a flow velocity change rate between every two adjacent moments; and monitoring the operation state of the transformer body based on the flow velocity change rate and the current baffle swing data, so as to send out a first tripping signal when the transformer body is at the target fault level, thereby cutting off the power supply of the transformer body. According to the protection method, the oil flow fluctuation change can be effectively captured, so that the transformer is cut off in advance before the transformer reaches heavy gas tripping, and powerful protection is formed for the transformer.

Description

Technical Field

[0001] The present disclosure generally relates to the technical field of transformer protection, and in particular to a method and device for protecting a transformer body from gas. Background Art

[0002] A gas relay is a protective device used for oil-immersed transformers with oil storage cabinets. When a minor fault occurs inside the transformer, the gas generated by the decomposition of the transformer oil accumulates in the relay in excess of a certain amount, and the signal contacts of the gas relay (also called a gas relay) are connected, sending out an alarm signal.

[0003] However, when a serious fault occurs inside the transformer, a surge of transformer oil will occur, forming oil flow in the pipeline. Therefore, the current transformer body gas tripping mainly refers to the absolute value of the oil flow velocity at the gas installation point. This means that the transformer can only be cut off when a serious fault occurs inside the transformer and the oil flow velocity increases rapidly, resulting in no strong protection for the transformer. For this reason, we propose a transformer body gas protection method to solve the above problem. Summary of the invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a transformer body gas protection method and device.

[0005] In a first aspect, the present application provides a transformer body gas protection method, comprising: Acquiring first flow velocity characteristic data and current baffle swing data in a gas relay installed in a connecting pipe for connecting a transformer body oil tank and an oil pillow; The first flow velocity characteristic data at least includes: a plurality of flow velocity values ​​collected at different times; the first flow velocity characteristic data and the baffle swing data are both used to reflect the fault condition of the transformer body; Calculate the flow velocity change rate between two adjacent moments according to the first flow velocity characteristic data; Based on the flow velocity change rate and the baffle swing data, the operating state of the transformer body is monitored, so that when the transformer body is at a target fault level, a first trip signal is issued to cut off the power supply of the transformer body.

[0006] According to the technical solution provided by the present application, the first flow velocity characteristic data further includes: flow direction data corresponding to each of the flow velocity values; The flow velocity change rate between each two adjacent moments is calculated based on the first flow velocity characteristic data, specifically including: According to the flow direction data corresponding to each flow velocity value, the first flow velocity characteristic data is divided to obtain a target flow velocity data set; the flow direction of each flow velocity value in the target flow velocity data set is from the transformer body to the oil conservator; Based on the multiple flow rate values ​​in the target flow rate data set, the flow rate change rate between every two adjacent moments is calculated.

[0007] According to the technical solution provided by the present application, based on the real-time flow velocity change rate and the baffle swing data, the operating state of the transformer body is monitored to issue a first trip signal when the transformer body is at a target fault level, specifically including: Based on the flow velocity change rate, generating a first real-time monitoring result; Based on the baffle swing data, generating a second real-time monitoring result; When the first monitoring result or the second monitoring result shows that the transformer body is at a target fault level, a first tripping signal is issued.

[0008] According to the technical solution provided by the present application, based on the real-time flow velocity change rate, a first real-time monitoring result is generated, specifically including: Determine whether any of the calculated flow velocity change rates is greater than or equal to a preset change rate threshold, so as to generate the first real-time monitoring result; If yes, it is confirmed that the transformer body is at the target fault level; if no, it is confirmed that the transformer body is not at the target fault level.

[0009] According to the technical solution provided by the present application, based on the real-time flow velocity change rate, a first real-time monitoring result is generated, specifically including: Determine whether any two consecutive calculated flow rate change rates are greater than or equal to a preset change rate threshold value, so as to generate the first real-time monitoring result; If yes, it is confirmed that the transformer body is at the target fault level; if no, it is confirmed that the transformer body is not at the target fault level.

[0010] According to the technical solution provided by the present application, the baffle swing data at least includes: a baffle swing angle value; Based on the baffle swing data, a second real-time monitoring result is generated, specifically including: Determining whether the baffle swing angle value is greater than or equal to a preset swing angle threshold value to generate the second real-time monitoring result; If yes, it is confirmed that the transformer body is at the target fault level; if no, it is confirmed that the transformer body is not at the target fault level.

[0011] In a second aspect, the present application provides a transformer body gas protection device, which is applied with the above-mentioned transformer body gas protection method, and the protection device comprises: a gas relay, which is installed in a connecting pipe for connecting the transformer body oil tank and the oil pillow; The gas relay comprises: a gas relay body, wherein a mounting cavity is provided in the middle of the gas relay body and passes through along the extending direction of the connecting pipe; A flow rate sensor is arranged at the bottom of the installation cavity; the flow rate sensor is used to collect the oil flow rate flowing through the connecting pipe and generate first flow rate characteristic data; the first flow rate characteristic data includes: a plurality of flow rate values ​​collected at different times.

[0012] According to the technical solution provided in the present application, the gas relay further includes: a swingable baffle plate disposed at the top of the installation cavity and a detector for collecting the mechanical swing of the baffle plate; The detector outputs the baffle swing data it has collected by being connected to the secondary terminal.

[0013] To sum up, the present technical scheme specifically discloses a transformer body gas protection method and device, which relates to the field of transformer protection technology, wherein the protection method includes: continuously acquiring first flow velocity characteristic data and current baffle swing data in the gas relay; the gas relay is installed in a connecting pipe used to connect the transformer body oil tank and the oil pillow; according to the first flow velocity characteristic data, the flow velocity change rate between each two adjacent moments is calculated; based on the flow velocity change rate and the baffle swing data, the operating status of the transformer body is monitored, so as to send a first tripping signal when the transformer body is at the target fault level, thereby cutting off the power supply of the transformer body.

[0014] The existing transformer protection method can only cut off the transformer when a serious fault occurs inside the transformer and the oil flow velocity increases rapidly, resulting in no strong protection for the transformer. In the present application, a dual judgment mode of flow velocity change rate and baffle swing angle is used to comprehensively detect the fault risk of the transformer. The transformer can be cut off in advance before the transformer reaches a heavy gas trip. At the same time, the dual judgment mode can also reduce the probability of false operation of the gas relay, thereby improving the operating reliability of the protection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 The present invention is a flow chart of a transformer body gas protection method.

[0016] Figure 2It is a flow chart of step S200 in a transformer body gas protection method.

[0017] Figure 3 It is a flow chart of step S300 in a transformer body gas protection method.

[0018] Figure 4 It is a first flow chart of step S301 in a transformer body gas protection method.

[0019] Figure 5 It is a second flow chart of step S301 in a transformer body gas protection method.

[0020] Figure 6 It is a flow chart of step S302 in a transformer body gas protection method.

[0021] Figure 7 The figure is a structural schematic diagram of a transformer body gas protection device.

[0022] Figure 8 The figure is a schematic diagram of the structure of a processing module in a transformer body gas protection device.

[0023] Numbers in the figure: 1, gas relay body; 11, installation cavity; 2, baffle; 3, flow rate sensor; 4, connecting pipe; 5, secondary terminal; 6 processing module; 61, acquisition unit; 62, calculation unit; 63, processing unit. DETAILED DESCRIPTION

[0024] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] Example 1 In order to make the technical solution of the embodiment of the present application clearer and easier to understand, the application background of the embodiment of the present application is introduced below.

[0027] A gas relay is a protective device used for oil-immersed transformers with oil storage cabinets. When a minor fault occurs inside the transformer, the gas generated by the decomposition of the transformer oil accumulates in the relay in excess of a certain amount, and the signal contacts of the gas relay (also called a gas relay) are connected, sending out an alarm signal.

[0028] However, when a serious fault occurs inside the transformer, a surge of transformer oil will occur, forming oil flow in the pipeline. Therefore, the current gas tripping of the transformer body mainly refers to the absolute value of the oil flow velocity at the gas installation point. This means that the transformer can only be cut off when a serious fault occurs inside the transformer and the oil flow velocity increases rapidly, resulting in no strong protection for the transformer.

[0029] In view of this, the embodiment of the present application is based on the concept of "if the flow rate has not reached the heavy gas tripping, the flow rate change is compared with the preset value, so as to pre-cut off the transformer", so as to strengthen the effective protection of the transformer. In addition, the current gas relay still has the possibility of malfunction, so in the embodiment of the present application, the flow rate change tripping signal and the traditional tripping signal based on the absolute value of the flow rate are logically analyzed before the tripping outlet is tripped, which can reduce the probability of malfunction of the gas relay and thus improve the operational reliability.

[0030] Specifically, please refer to Figure 1 The flowchart of a transformer body gas protection method provided in this embodiment includes the following steps: S100, obtaining first flow velocity characteristic data and current baffle swing data in a gas relay; the gas relay is installed in a connecting pipe for connecting a transformer body oil tank and an oil pillow; The first flow velocity characteristic data at least includes: a plurality of flow velocity values ​​collected at different times; the first flow velocity characteristic data and the baffle swing data are both used to reflect the fault condition of the transformer body; When a serious fault occurs inside the transformer (or on-load switch), a surge of transformer oil will occur, which will then form an oil flow in the connecting pipe. Therefore, by periodically collecting the flow velocity characteristic data of the oil flow through the gas relay and the baffle swing data caused by the impact of the oil flow on the baffle inside the gas relay, a dual real-time monitoring of the transformer operating status can be formed.

[0031] Specifically, the first flow velocity characteristic data and the baffle swing data are both used to reflect the fault condition of the transformer body; further, the first flow velocity characteristic data includes: a plurality of flow velocity values ​​collected at different times, the flow velocity values ​​are collected by a magnetic sensitive flow velocity sensor at the bottom of the gas relay and closer to the oil flow inlet; and the time interval of the plurality of flow velocity values ​​collected is set by the sampling frequency of the flow velocity sensor, which is not specifically limited here; illustratively, the first flow velocity characteristic data A=(s 1 ,s 2 , ...,s n ) ,in, s 1 ,s 2 , ...,s nThe oil flow velocity values ​​collected at different times; the baffle swing data B=(d 1 ,d 2 , ...,d n ) ,in, d 1 ,d 2 , ...,d n They are the baffle swing angle values ​​collected at different times.

[0032] It needs to be explained that the magnetic flow velocity sensor adopts the Hall effect. When the metal teeth pass through the front end of the sensor, it causes the magnetic field to change. The magnetic sensitive element detects the change in the magnetic field and converts it into an alternating electrical signal. The built-in circuit of the sensor amplifies and shapes the signal and outputs a good rectangular pulse signal. The measurement frequency range is wider, the output signal is more accurate and stable, and the installation is simple. It is oil-proof and waterproof, and has been widely used in the electric power field. At the same time, its dual-channel speed measurement sensor integrates two Hall devices inside, which are arranged at a certain angle and equipped with keyways or gears. It can output two square wave signals with stable amplitudes and a phase difference. It has both ordinary speed measurement functions and can distinguish the direction of movement, thereby collecting the direction of oil flow.

[0033] S200, calculating the flow velocity change rate between every two adjacent moments according to the first flow velocity characteristic data; Compared with the previous monitoring of transformer faults by using the absolute value of flow velocity, the present application performs subsequent determination by using the calculated flow velocity change rate after acquiring the first flow velocity characteristic data; This is because the change in flow velocity can usually better reflect the dynamic changes of fluid flow, can capture the instantaneous changes in flow velocity, is more conducive to detecting instantaneous changes in the fluid, and is very effective in predicting abnormal conditions or fault risks, allowing the transformer to be shut down more promptly and quickly.

[0034] However, since transformer monitoring is a long-term monitoring, there will be a situation where the oil in the oil pillow flows to the transformer tank. There are many reasons for this, such as (1) the oil in the oil pillow and the oil in the transformer tank will have different thermal expansion and contraction coefficients due to temperature changes. In a low temperature environment, the oil in the oil pillow cools more and shrinks more, while the oil in the transformer tank cools less and shrinks less. In this way, the oil in the oil pillow will produce an inward pressure relative to the oil in the transformer tank due to the large volume change, causing the oil to flow into the tank; (2) In a low temperature environment, due to the reduction in the volume of the oil in the oil pillow, the oil in the oil flow channel may be drawn back into the tank to balance the oil level between the oil pillow and the tank; (3) If the temperature difference between the oil pillow and the transformer tank is large, the oil in the oil pillow will have a higher density due to the lower temperature, while the oil in the tank will have a lower density due to the higher temperature. This density difference will cause the oil in the oil pillow to flow to the tank to achieve temperature balance.

[0035] For the above situation, see Figure 2 Step S200 includes the following steps: S201, dividing the first flow velocity characteristic data according to the flow direction data corresponding to each flow velocity value to obtain a target flow velocity data set; the flow direction of each flow velocity value in the target flow velocity data set is from the transformer body to the oil conservator; Since the purpose is to monitor transformer faults, it is necessary to distinguish the flow directions corresponding to the obtained flow velocity values ​​to ensure the accuracy of subsequent flow velocity change rate calculations without being disturbed by the reverse oil flow.

[0036] For example, based on the above introduction to the magnetic flow velocity sensor, the first flow velocity characteristic data also includes: flow direction data corresponding to each flow velocity value; therefore, the first flow velocity characteristic data can be finally obtained based on the flow direction data. A=(s 1 , s 2 , ...,s n ) The target flow rate data is obtained by dividing C=(s 1 ,s 7 , ...,s m ) ,in, s 1 ,s 7 , ...,s m They are the flow rate values ​​of the oil flow from the transformer body to the oil pillow collected at different times.

[0037] S202: Based on a plurality of flow rate values ​​in the target flow rate data set, calculate the flow rate change rate between each two adjacent moments.

[0038] After the multiple flow velocity values ​​are classified according to the flow direction, the flow velocity change rate between each two adjacent moments can be calculated based on the multiple flow velocity values ​​in the target flow velocity data set. ΔV , which is convenient for subsequent calculation based on the flow rate change rate ΔV Monitor transformer failure risks.

[0039] For example, it is assumed that the time interval for sampling the flow rate value is Δt ,exist t The flow rate at time 1 is v 1. In t 1 +Δt The flow rate at that moment is v 2; Now according to the following formula (I), we can calculate t 1 and t 1 +Δt The rate of change of flow velocity between two moments ΔV 1.

[0040] Formula (I) Based on this, we can calculate the flow rate change rate between each two adjacent moments. ΔV .

[0041] S300, based on the flow rate change rate and the baffle swing data, monitor the operating state of the transformer body, so as to send a first trip signal when the transformer body is at a target fault level, thereby cutting off the power supply of the transformer body.

[0042] After the flow rate change rate is calculated, subsequent judgments can be made based on the real-time calculated flow rate change rate. At the same time, a double judgment is also made based on the absolute value of the flow rate reflected by the baffle swing data. When it is found that the transformer body is at the target fault level, which can also be understood as reaching a heavy gas (serious fault) situation, a first tripping signal needs to be issued, and the transformer control system will promptly cut off the power supply of the transformer body to protect the transformer.

[0043] The baffle swing data is explained here. First, the baffle swing data at least includes: the baffle swing angle value; the oil flow in the connecting pipe will impact the baffle arranged in the gas relay, causing the baffle to swing, and the swing angle generated by the mechanical action of the baffle can be collected by the position sensor. The sampling interval is also determined by the sampling frequency of the sensor. The sensor is used to convert the mechanical action of the baffle into an electrical signal that can control the cut-off transformer.

[0044] In the present application, the judgment based on the absolute value of the flow velocity is still retained because the absolute value of the flow velocity can reflect the real-time state of the fluid flow, it does not depend on the reference point, and is more stable.

[0045] Specifically, see Figure 3 , step S300 can be expanded to obtain the following steps: S301, generating a first real-time monitoring result based on the flow velocity change rate; S302, generating a second real-time monitoring result based on the baffle swing data; The first real-time monitoring result and the second real-time monitoring result both include two situations: the transformer body is at the target fault level and the transformer body is not at the target fault level; In the actual monitoring and judgment process, the flow velocity change rate and the baffle swing angle value can form two judgment paths; therefore, based on the flow velocity change rate obtained by real-time calculation, the corresponding first real-time monitoring result can be obtained, that is, whether the transformer body is in the target fault level at this time; similarly, based on the real-time baffle swing angle value, the corresponding second real-time monitoring result can also be obtained, the second real-time monitoring result, that is, whether the transformer body is in the target fault level at this time.

[0046] In summary, the two monitoring paths do not conflict with each other and can generate corresponding real-time monitoring results respectively. The two can perform comprehensive fault monitoring on the transformer in parallel.

[0047] S303: When the transformer body is at a target fault level in the first monitoring result or the second monitoring result, a first tripping signal is issued.

[0048] With respect to the first monitoring result and the second monitoring result, if the result obtained by analyzing one of them is that the transformer body is at the target fault level, a first tripping signal will be issued.

[0049] Based on the above description, each monitoring path is described in detail below: Further, see Figure 4 In a preferred embodiment, based on the real-time flow rate change rate, a first real-time monitoring result is generated, specifically including: S301Q, determining whether any of the calculated flow rate change rates is greater than or equal to a preset change rate threshold, to generate a first real-time monitoring result; The first monitoring path is to compare the flow velocity change rate obtained by real-time calculation with the preset change rate threshold, and then generate a corresponding first real-time monitoring result; wherein, the preset change rate threshold is a boundary value for judging whether the transformer body is at the target fault level. The setting of this value needs to be combined with the sensor's own sampling frequency and the foresight experience of the general oil flow rate generated when the transformer is in a heavy gas situation in the past. There is no specific limitation.

[0050] S301Q1. If yes, confirm that the transformer body is at the target fault level; if no, confirm that the transformer body is not at the target fault level.

[0051] Assume that the preset change rate threshold is m The rate of change of flow velocity between any two adjacent moments is ΔV ; Then when ΔV ≥ m When the transformer is at the target fault level, ΔV <m , it is determined that the transformer body is not at the target fault level; thus, a first real-time monitoring result can be generated.

[0052] Further, see Figure 5 In a preferred embodiment, based on the real-time flow rate change rate, a first real-time monitoring result is generated, specifically including: S301P, determining whether any two consecutive calculated flow rate change rates are greater than or equal to a preset change rate threshold value, so as to generate a first real-time monitoring result; In combination with the above description, it can be seen that the judgment of the first real-time monitoring result can also be generated by comparing two consecutive flow rate change rates obtained by real-time calculation with the preset change rate thresholds. This method can improve the fault tolerance of the system judgment and prevent the judgment conditions from being too sensitive, resulting in false alarms.

[0053] S301P1. If yes, confirm that the transformer body is at a target fault level; if no, confirm that the transformer body is not at a target fault level.

[0054] Assume that the preset change rate threshold is m , t 1 and t 1 +Δt The rate of change of flow velocity between two moments ΔV 1, t 1 +Δt and t 1 + 2Δt The rate of change of flow velocity between two moments ΔV 2; Then when ΔV 1 and ΔV 2Average≥ m When the transformer body is at the target fault level, it is determined that the transformer body is at the target fault level; otherwise, it is determined that the transformer body is not at the target fault level; thereby, the first real-time monitoring result can be generated.

[0055] Further, see Figure 6 In a preferred embodiment, based on the swing angle value of the baffle, a second real-time monitoring result is generated, specifically including: S3021, determining whether the baffle swing angle value is greater than or equal to a preset swing angle threshold value to generate a second real-time monitoring result; The first monitoring path is to compare the baffle swing angle value with the preset swing angle threshold, and then generate the corresponding second real-time monitoring result, wherein the preset swing angle threshold is also the boundary value for judging whether the transformer body is at the target fault level. The setting of this value needs to be combined with the foresight experience of the oil flow impacting the baffle when the transformer is in a heavy gas situation in the past, and there is no specific limitation.

[0056] S3022: If yes, confirm that the transformer body is at the target fault level; if no, confirm that the transformer body is not at the target fault level.

[0057] Assume that the preset swing angle threshold is R , when the baffle swing angle value collected in real time d ≥ R When the transformer is at the target fault level, d <R , it is determined that the transformer body is not at the target fault level; thus, a second real-time monitoring result can be generated.

[0058] Based on the above description, it can be known that the present application proposes a transformer body gas protection method, including: real-time acquisition of first flow velocity characteristic data and baffle swing data in the gas relay; the gas relay is installed in a connecting pipe used to connect the transformer body oil tank and the oil pillow; the first flow velocity characteristic data includes: multiple flow velocity values ​​collected at different times and flow direction data corresponding to each flow velocity value; the baffle swing data at least includes: the baffle swing angle value; the first flow velocity characteristic data and the baffle swing data are both used to reflect the fault condition of the transformer body; according to the first flow velocity characteristic data, the flow velocity change rate between each two adjacent moments is calculated; based on the real-time flow velocity change rate and the baffle swing data, the operating status of the transformer body is monitored, so as to send a first tripping signal when the transformer body is at the target fault level, thereby cutting off the power supply of the transformer body.

[0059] On the one hand, this method combines the flow velocity change trip signal with the traditional trip signal based on the absolute value of the flow velocity, and then issues the corresponding first trip signal after rigorous logical analysis, so as to achieve double judgment, reduce the probability of gas relay malfunction, and thus improve operational reliability. On the other hand, the problem of reverse oil flow generated under certain circumstances is taken into consideration in a practical way. In order to improve the overall triggering accuracy of transformer protection, the reverse oil flow is preferentially filtered out when judging the flow velocity change trip signal, and the corresponding calculation is performed to ensure that the obtained flow velocity change rate is accurate and objective; finally, the transformer protection is finely monitored for the two monitoring paths of the absolute value of the flow velocity and the flow velocity change, so that the transformer can be actively cut off when the transformer reaches the eve of a heavy gas trip.

[0060] Example 2 Combination Figure 7 and Figure 8 , Based on a transformer body gas protection method of embodiment 1, the embodiment of the present application proposes a transformer body gas protection device, the protection device comprising: a gas relay, the gas relay is installed in a connecting pipe 4 for connecting the transformer body oil tank and the oil pillow; The gas relay comprises: a gas relay body 1, wherein a mounting cavity 11 is provided in the middle of the gas relay body 1 and passes through the connecting pipe in the extending direction thereof; A flow rate sensor 3 is provided at the bottom of the installation cavity 11; the flow rate sensor 3 is used to collect the oil flow rate flowing through the connecting pipe 4 and generate first flow rate characteristic data; the first flow rate characteristic data includes: a plurality of flow rate values ​​collected at different times.

[0061] In the embodiment of the present application, the gas relay may also be referred to as a gas relay, etc., which is commonly used as a protective device for an oil-immersed transformer with an oil storage cabinet. The gas relay is installed in a connecting pipe 4 for connecting the transformer body oil tank and the oil pillow. When a serious fault occurs inside the transformer and oil flow occurs, it can be detected in time based on the change value and absolute value of the oil flow rate, so that the processing module 6 connected to the gas relay can perform corresponding logical judgment and analysis processing; the processing module 6 here can select a central control console with a higher degree of integration, for example, using DSP (Digital Signal Process, digital signal processing technology) technology, and a DSP chip refers to a chip that can implement digital signal processing technology.

[0062] Specifically, the gas relay comprises: a gas relay body 1, a mounting cavity 11 which penetrates along the extension direction of the connecting pipe in the middle part of the gas relay body 1, and is used to receive the generated oil flow; at the same time, a swingable baffle 2 is arranged on the top of the mounting cavity 11, and a flow rate sensor 3 is arranged on the bottom thereof; regarding the oil flow reversal problem mentioned in the above introduction, this problem has little interference to the baffle, because the baffle 2 has the characteristic of unidirectional swinging when it is designed, that is, the baffle 2 can only swing when it is impacted by the oil flow flowing from the transformer oil tank to the oil pillow; in addition, a flow rate sensor 3 is arranged at the bottom of the mounting cavity 11 and on the side close to the transformer oil tank, so that the flow rate sensor 3 can timely collect the oil flow velocity and generate the corresponding first flow rate characteristic data.

[0063] The flow velocity sensor 3 adopts the Hall effect. When the metal tooth passes through the front end of the sensor, it causes the magnetic field to change. The magnetic sensitive element detects the magnetic field change and converts it into an alternating electrical signal. The built-in circuit of the sensor amplifies and shapes the signal and outputs a good rectangular pulse signal. The measurement frequency range is wider, the output signal is more accurate and stable, and the installation is simple. It is oil-proof and waterproof, and has been widely used in the power field. At the same time, its dual-channel speed sensor integrates two Hall devices inside, which are arranged at a certain angle and equipped with keyways or gears to output two phase-differenced amplitude-stable square wave signals. It has both ordinary speed measurement function and can distinguish the direction of movement, thereby collecting the direction of oil flow. In a preferred embodiment, since the transformer protection also includes monitoring through the absolute value of its flow rate, for this purpose, the gas relay also includes: a swingable baffle 2 arranged at the top of the installation cavity 11 and a detector for collecting the mechanical swing of the baffle 2; The detector outputs the acquired baffle swing data by being connected to the secondary terminal 5; the baffle swing data includes: a plurality of baffle swing angle values ​​acquired at different times.

[0064] Specifically, the detector for monitoring the mechanical swing of the baffle 2 can be a position sensor. The mechanical movement of the baffle 2 can be collected by the position sensor and then transmitted to the outside through the secondary terminal 5, so that the processing device can receive it and make corresponding logical judgments.

[0065] In addition, see Figure 8 The flow rate sensor 3 and the position sensor together form an information acquisition module of the protection device, and the corresponding processing module 6 connected to the signal includes: The acquisition unit 61 is used to acquire the first flow velocity characteristic data and the baffle swing data in the gas relay in real time; the gas relay is installed in the connecting pipe used to connect the transformer body oil tank and the oil pillow; The first flow velocity characteristic data includes: a plurality of flow velocity values ​​collected at different times; the baffle swing data includes at least: a baffle swing angle value; the first flow velocity characteristic data and the baffle swing data are both used to reflect the fault condition of the transformer body; A calculation unit 62, the calculation unit 62 is used to calculate the flow velocity change rate between each two adjacent moments according to the first flow velocity characteristic data; The processing unit 63 is used to monitor the operating status of the transformer body based on the real-time flow rate change rate and the baffle swing data, so as to send a first tripping signal when the transformer body is at a target fault level, thereby cutting off the power supply of the transformer body.

[0066] In some embodiments, the calculation unit 62 is also used to divide the first flow velocity characteristic data according to the flow direction data corresponding to each flow velocity value, obtain a target flow velocity data set, and calculate the flow velocity change rate between each two adjacent moments based on multiple flow velocity values ​​in the target flow velocity data set.

[0067] Among them, the flow direction of each flow rate value in the target flow rate data set is from the transformer body to the oil pillow; In some embodiments, the processing unit 63 is also used to generate a first real-time monitoring result based on the real-time flow rate change rate and a second real-time monitoring result based on the current baffle swing angle value. At the same time, in the first monitoring result and the second monitoring result, when any one of the monitoring results is that the transformer body is at the target fault level, a first tripping signal is issued.

[0068] The first real-time monitoring result and the second real-time monitoring result both include two situations: the transformer body is at the target fault level and the transformer body is not at the target fault level; In some embodiments, the processing unit 63 is specifically used to determine whether any calculated flow rate change rate is greater than or equal to a preset change rate threshold to generate a first real-time monitoring result; if so, it is confirmed that the transformer body is at the target fault level; if not, it is confirmed that the transformer body is not at the target fault level.

[0069] In some embodiments, the processing unit 63 is specifically used to determine in real time whether any two consecutive adjacent flow rate change rates calculated are greater than or equal to a preset change rate threshold to generate a first real-time monitoring result; if so, it is confirmed that the transformer body is at the target fault level; if not, it is confirmed that the transformer body is not at the target fault level.

[0070] In some embodiments, the processing unit 63 is specifically used to determine whether the baffle swing angle value is greater than or equal to a preset swing angle threshold to generate a second real-time monitoring result; if so, it is confirmed that the transformer body is at the target fault level; if not, it is confirmed that the transformer body is not at the target fault level.

[0071] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A transformer body gas protection method, characterized in that: include: Acquiring first flow velocity characteristic data and current baffle swing data in a gas relay installed in a connecting pipe for connecting a transformer body oil tank and an oil pillow; The first flow velocity characteristic data at least includes: a plurality of flow velocity values ​​collected at different times; the first flow velocity characteristic data and the baffle swing data are both used to reflect the fault condition of the transformer body; Calculate the flow velocity change rate between two adjacent moments according to the first flow velocity characteristic data; Based on the flow velocity change rate and the baffle swing data, the operating state of the transformer body is monitored, so that when the transformer body is at a target fault level, a first trip signal is issued to cut off the power supply of the transformer body.

2. A transformer body gas protection method according to claim 1, characterized in that: The first flow velocity characteristic data also includes: flow direction data corresponding to each of the flow velocity values; The flow velocity change rate between each two adjacent moments is calculated based on the first flow velocity characteristic data, specifically including: According to the flow direction data corresponding to each flow velocity value, the first flow velocity characteristic data is divided to obtain a target flow velocity data set; the flow direction of each flow velocity value in the target flow velocity data set is from the transformer body to the oil conservator; Based on the multiple flow rate values ​​in the target flow rate data set, the flow rate change rate between every two adjacent moments is calculated.

3. A transformer body gas protection method according to claim 1, characterized in that: Based on the real-time flow rate change rate and the baffle swing data, the operating state of the transformer body is monitored to issue a first trip signal when the transformer body is at a target fault level, specifically including: Based on the flow velocity change rate, generating a first real-time monitoring result; Based on the baffle swing data, generating a second real-time monitoring result; When the first monitoring result or the second monitoring result shows that the transformer body is at a target fault level, a first tripping signal is issued.

4. A transformer body gas protection method according to claim 3, characterized in that: Based on the real-time flow velocity change rate, a first real-time monitoring result is generated, specifically including: Determine whether any of the calculated flow velocity change rates is greater than or equal to a preset change rate threshold, so as to generate the first real-time monitoring result; If yes, it is confirmed that the transformer body is at the target fault level; if no, it is confirmed that the transformer body is not at the target fault level.

5. A transformer body gas protection method according to claim 3, characterized in that: Based on the real-time flow velocity change rate, a first real-time monitoring result is generated, specifically including: Determine whether any two consecutive calculated flow rate change rates are greater than or equal to a preset change rate threshold value, so as to generate the first real-time monitoring result; If yes, it is confirmed that the transformer body is at the target fault level; if no, it is confirmed that the transformer body is not at the target fault level.

6. A transformer body gas protection method according to claim 3, characterized in that: The baffle plate swing data at least includes: a baffle plate swing angle value; Based on the baffle swing data, a second real-time monitoring result is generated, specifically including: Determining whether the baffle swing angle value is greater than or equal to a preset swing angle threshold value to generate the second real-time monitoring result; If yes, it is confirmed that the transformer body is at the target fault level; if no, it is confirmed that the transformer body is not at the target fault level.

7. A transformer body gas protection device, characterized in that: The transformer body gas protection method according to any one of claims 1 to 6 is applied, wherein the protection device comprises: a gas relay, wherein the gas relay is installed in a connecting pipe (4) for connecting the transformer body oil tank and the oil pillow; The gas relay comprises: a gas relay body (1), wherein a mounting cavity (11) is provided in the middle of the gas relay body (1) and passes through along the extension direction of the connecting pipe; A flow rate sensor (3) is arranged at the bottom of the installation cavity (11); the flow rate sensor (3) is used to collect the flow rate of the oil flow passing through the connecting pipe (4) and generate first flow rate characteristic data; the first flow rate characteristic data comprises: a plurality of flow rate values ​​collected at different times.

8. A transformer body gas protection device according to claim 7, characterized in that: The gas relay further comprises: a swingable baffle (2) arranged at the top of the installation cavity (11) and a detector for collecting mechanical swing of the baffle (2); The detector outputs the baffle swing data it has collected by being connected to the secondary terminal (5).

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