A power electrical transformer with lightning protection function

Abstract

The present invention relates to the technical field of transformers, and provides a power electrical transformer with a lightning protection function, including: a protective cover, a lightning protection device, a data processing module, and an overvoltage protection module. The data processing module includes obtaining a surge index according to a current analysis sequence; obtaining a main fluctuation abnormality degree according to the main current value of the current analysis sequence; obtaining a comparison abnormality degree according to the current value in a current reference sequence; obtaining a lightning strike confidence level according to the main fluctuation abnormality degree and the comparison abnormality degree; and obtaining an external lightning strike index according to the lightning strike confidence level and the surge index. The present invention determines whether the power electrical transformer is affected by lightning strikes through the external lightning strike index, and then adjusts the current path, increasing the accuracy of the decision-making of the lightning protection system of the power electrical transformer and improving the protection of the power electrical transformer.

Description

Technical Field

[0001] The present invention relates to the technical field of transformers, and particularly to a power electrical transformer with a lightning protection function. Background Art

[0002] Power electrical transformers are key equipment in the power system, responsible for voltage conversion to meet transmission and distribution requirements. The strong current and voltage fluctuations generated by lightning may be transmitted to the transformer through the air, transmission lines or grounding systems, causing serious damages such as short circuits, insulation breakdowns or fires. Therefore, the lightning protection function of transformers is crucial to ensure the safety of equipment and the stable operation of the system.

[0003] The lightning protection function design of transformers is usually achieved through overvoltage protection and regulation. When the system detects abnormal voltage, it will automatically adjust the voltage or cut off the power supply to prevent overvoltage from damaging the transformer. However, this design may increase the sensitivity of the system. During the operation of the transformer, instantaneous voltage fluctuations such as switch operations in the power system or subsequent impact currents of lightning strikes may interfere with the lightning protection system of the power electrical transformer, leading to misjudgment and thus triggering incorrect response strategies, resulting in equipment damage. Summary of the Invention

[0004] The present invention provides a power electrical transformer with a lightning protection function to solve the problem of misjudgment of the lightning protection system of the power electrical transformer caused by existing instantaneous voltage fluctuations or subsequent impact currents of lightning strikes. The specific technical solutions adopted are as follows:

[0005] The present invention proposes a power electrical transformer with a lightning protection function, which includes:

[0006] A protective cover for providing support and insulation protection to the power electrical transformer and reducing the electromagnetic interference generated by the transformer;

[0007] A lightning protection device for connecting to an overcurrent protection module and achieving targeted current diversion according to the overcurrent protection module;

[0008] A data processing module for obtaining a current analysis sequence; the current analysis sequence contains several current values; according to the fluctuation and periodic change of the current values in the current analysis sequence, the surge index of the power electrical transformer is obtained;

[0009] Obtaining the main current value of the current analysis sequence; according to the main current value of the current analysis sequence, the main fluctuation abnormal degree of the power electrical transformer is obtained;

[0010] Obtaining a current reference sequence according to the current time series sequence; according to the current values in the current reference sequence, the comparison abnormal degree of the power electrical transformer is obtained;

[0011] Obtain the lightning strike confidence level of the power electrical transformer according to the main fluctuation anomaly degree and the comparison anomaly degree of the power electrical transformer;

[0012] Obtain the external lightning strike index of the power electrical transformer according to the lightning strike confidence level and the surge index of the power electrical transformer;

[0013] The overcurrent protection module is used to adjust the path of the current according to the external lightning strike index of the power electrical transformer.

[0014] Further, the specific method for obtaining the surge index of the power electrical transformer according to the fluctuation situation and the periodic change situation of the current values in the current analysis sequence includes:

[0015] Obtain the period of the current analysis sequence, and record the ratio of the variance of all current values in the current analysis sequence to the period of the current analysis sequence as the surge index of the power electrical transformer.

[0016] Further, the specific method for obtaining the main fluctuation anomaly degree of the power electrical transformer according to the main current value of the current analysis sequence includes:

[0017] Perform curve fitting on all current values in the current analysis sequence to obtain a real-time fitting curve, record the fitting value corresponding to any current value in the current analysis sequence on the real-time fitting curve as the real-time fitting value of the current value, and obtain the slope of the real-time fitting value of each current value on the real-time fitting curve;

[0018] Obtain the main conventional index of the power electrical transformer according to the real-time fitting value of the main current value and the real-time fitting curve;

[0019] Record the mean value of the slopes of the real-time fitting values of all main current values in the current analysis sequence on the real-time fitting curve as the main fluctuation index of the power electrical transformer;

[0020] Record the inverse proportional normalization result of the product of the main conventional index and the main fluctuation index of the power electrical transformer as the main fluctuation anomaly degree of the power electrical transformer.

[0021] Further, the specific method for obtaining the main conventional index of the power electrical transformer according to the real-time fitting value of the main current value and the real-time fitting curve includes:

[0022] Record the product of the number of occurrences of the real-time fitting values of all main current values in the current analysis sequence on the real-time fitting curve as the main conventional index of the power electrical transformer.

[0023] Further, the specific method for obtaining the current reference sequence according to the current time sequence includes:

[0024] Intercept the last days of current values from the current time series sequence, and the resulting sequence is denoted as the current reference sequence; where is the preset reference interception length.

[0025] Furthermore, obtaining the comparison anomaly degree of the power electrical transformer according to the current values in the current reference sequence includes the following specific method:

[0026] Perform curve fitting on all current values in the current reference sequence to obtain a reference fitting curve. Denote the sequence composed of the fitting values corresponding to all current values in the current reference sequence on the real-time fitting curve as the reference fitting sequence; obtain all the maximum values of the reference fitting sequence; construct a window with a length of ending with any maximum value in the reference fitting sequence, and denote the standard deviation of all elements within this window as the regional fluctuation index of this maximum value; where is the preset regional length;

[0027] Obtain the mean value of the regional fluctuation indices of all maximum values in the reference fitting sequence, and denote the ratio of the standard deviation of the real-time fitting values of all main current values in the current analysis sequence to the mean value of the regional fluctuation indices of all maximum values in the reference fitting sequence as the comparison anomaly degree of the power electrical transformer.

[0028] Furthermore, obtaining the lightning strike confidence level of the power electrical transformer according to the main fluctuation anomaly degree and the comparison anomaly degree of the power electrical transformer includes the following specific method:

[0029] Denote the inverse proportional normalization result of the product of the main fluctuation anomaly degree and the comparison anomaly degree of the power electrical transformer as the lightning strike confidence level of the power electrical transformer.

[0030] Furthermore, obtaining the external lightning strike index of the power electrical transformer according to the lightning strike confidence level and the surge index of the power electrical transformer includes the following specific method:

[0031] Denote the product of the lightning strike confidence level and the surge index of the power electrical transformer as the external lightning strike index of the power electrical transformer.

[0032] Furthermore, adjusting the current path according to the external lightning strike index of the power electrical transformer includes the following specific method:

[0033] If the external lightning strike index of the power electrical transformer is greater than or equal to the preset lightning strike threshold, open the relay of the grounding circuit through the adjustment control circuit to direct the lightning strike current to the ground system; if the external lightning strike index of the power electrical transformer is less than the preset lightning strike threshold, keep the relay of the transformer circuit open and close the relay of the grounding circuit through the adjustment control circuit.

[0034] Further, the specific method for obtaining the main current value of the current analysis sequence is as follows:

[0035] Denote the last current values in the current analysis sequence as the main current value of the current analysis sequence; where is the preset number of main currents.

[0036] The beneficial effects of the present invention are as follows: Since voltage surges will occur when a power electrical transformer is struck by lightning or during an instantaneous switching overvoltage operation, it is first necessary to judge the possibility of being affected by the current voltage surge phenomenon. The present invention obtains the surge index of the power electrical transformer through the fluctuation and periodic change of the current values in the current analysis sequence, and judges the possibility of being affected by the current voltage surge phenomenon; both external lightning strikes and instantaneous switching overvoltage operations will cause short-term fluctuations in the current, and these fluctuations will exceed the normal operating current level within a short time. The present invention obtains the main fluctuation abnormality degree of the power electrical transformer according to the main current value of the current analysis sequence, and judges the current fluctuation abnormality; since the behavior pattern of lightning current has strong randomness and the frequency of occurrence in historical data is much less than the frequency of current fluctuations caused by instantaneous switching overvoltage operations, and because the current fluctuations caused by instantaneous switching overvoltage operations have a certain similarity, the present invention distinguishes the causes of current fluctuations by obtaining the comparative abnormality degree of the power electrical transformer. Thus, the present invention obtains the lightning strike confidence level through the main fluctuation abnormality degree and the comparative abnormality degree of the power electrical transformer, combines the surge index of the power electrical transformer to obtain the external lightning strike index of the power electrical transformer, and then adjusts the current path, which increases the accuracy of the lightning protection system decision-making of the power electrical transformer and improves the protection of the power electrical transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained without creative efforts based on these drawings.

[0038] Figure 1 It is a structural diagram of a power electrical transformer with lightning protection function provided by an embodiment of the present invention;

[0039] Figure 2 It is a schematic diagram of a protective cover, Figure 21. Protective housing (steel); 2. Insulating base; 3. Main body space; 4. Grounding circuit; 5. Insulating film; 6. Heat dissipation holes (on the surface of the protective housing); 7. Overvoltage protection module; 8. Positioning shaft; 9. Insulating platform; 10. Current transmission line;

[0040] Figure 3 It is a schematic diagram of a lightning protection device. Figure 3 Among them, 9. Insulating platform; 11. Polymer housing; 12. Lightning arrester main body; 13. Conductor connection port. Specific implementation manners

[0041] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0042] Please refer to Figure 1 , which shows a flowchart of a power electrical transformer with lightning protection function provided by an embodiment of the present invention. The power electrical transformer includes:

[0043] Protective cover: Provides support and insulation protection for the power electrical transformer, and reduces the electromagnetic interference generated by the transformer.

[0044] It should be noted that when a transformer is struck by lightning or a transient high voltage is caused by a power grid fault in a harsh environment, it is called a voltage surge. Voltage surges can damage equipment. Generally, by installing lightning arresters, strengthening the grounding system, or using overvoltage protection devices, etc., the overvoltage is guided to the ground or other safe paths to avoid direct damage to the equipment caused by voltage surges.

[0045] Specifically, this embodiment provides a protective cover. The schematic diagram of the protective cover is as shown in Figure 2 . In the schematic diagram of the protective cover, the structure of the protective cover includes a protective housing (steel), an insulating base, a main body space, a grounding circuit, an insulating film, heat dissipation holes (on the surface of the protective housing), an overvoltage protection module, a positioning shaft, an insulating platform, and a current transmission line;

[0046] Among them, the protective housing is used for physically protecting the power electrical transformer;

[0047] Among them, the insulating base provides support and insulation for the power electrical transformer;

[0048] Among them, the main body space is used for arranging the power electrical transformer;

[0049] Among them, the grounding circuit guides the lightning strike current to the ground through a safe conduction path, preventing electric shock or damage to equipment and personnel;

[0050] Among them, the insulating film is used to isolate the electrical components inside the transformer from the external environment, preventing external voltage surges or lightning currents from directly contacting the internal circuit of the transformer, thereby improving the overall insulation performance of the device and reducing the risk of electrical faults such as short circuits and breakdowns;

[0051] Among them, the heat dissipation holes are used to prevent the equipment from overheating;

[0052] Among them, the overvoltage protection module is used to detect and cut off overvoltage situations, preventing the transformer from being damaged or having a safety accident due to excessive voltage;

[0053] Among them, the positioning shaft connects the insulating platform and the protective cover. This split design effectively reduces the electromagnetic interference generated by the lightning protection device on the transformer during operation in the traditional design. At the same time, maintenance personnel can independently check the electrical parts of the lightning arrester and the transformer, avoiding overall disassembly, thereby improving the maintenance efficiency and safety;

[0054] Among them, the insulating platform is used to install the lightning protection device, enabling the transformer to concentrate on absorbing lightning current or instantaneous overvoltage when struck by lightning, facilitating the subsequent weakening protection of the lightning current instantaneous voltage by the overvoltage protection module, and ensuring the safe operation of the transformer body;

[0055] Among them, the function of the current transmission line is to safely transmit the current generated by the transformer to the load or power distribution system, ensuring stable and reliable output of electrical energy.

[0056] Lightning protection device: After being connected to the overvoltage protection module, it realizes targeted current diversion according to the overvoltage protection module.

[0057] It should be noted that since power electrical transformers are vulnerable to lightning strikes, when lightning occurs, the transformer may be damaged due to excessive voltage and current, and even cause fires or equipment failures. The lightning protection device reduces the direct impact of lightning on the transformer by guiding the lightning strike current to the ground, effectively protecting the transformer and its surrounding facilities from lightning damage, and ensuring the stable operation of the power system and personnel safety.

[0058] Specifically, this embodiment provides a lightning protection device, which is fixed on the insulating platform of the protective cover through a nut structure to collect lightning current in a timely manner and ensure the safe operation of the transformer; the schematic diagram of the lightning protection device is as Figure 3 shown. In the schematic diagram of the lightning protection device, the structure of the lightning protection device includes an insulating platform, a polymer shell, a lightning arrester body, and a wire connection port;

[0059] Among them, the insulating platform is a structure in the protective cover and is used to install a lightning protection device, enabling the transformer to concentrate and absorb lightning current or transient overvoltage when struck by lightning, facilitating subsequent weakening and protection of the lightning current instantaneous voltage by the overvoltage protection module, and ensuring the safe operation of the transformer body;

[0060] Among them, the polymer shell provides strong weather resistance and insulation protection, preventing damage to the lightning protection device by the external environment, and ensuring its safe and effective conduction during lightning strikes;

[0061] Among them, the lightning arrester body quickly conducts when a lightning strike occurs, guiding the overvoltage to the ground and protecting the transformer from damage by lightning overvoltage;

[0062] Among them, the wire connection port is used to connect the overvoltage protection module inside the transformer.

[0063] It should be noted that in traditional transformers, the lightning protection device is directly connected to the grounding system wire to directly conduct the lightning current into the ground. However, frequent lightning currents can cause the grounding resistance to increase, thereby reducing the grounding effect. The lightning protection device provided in this embodiment connects the lightning protection device to the overvoltage protection module through a wire and then accesses the grounding system. The lightning protection device is not directly connected to the grounding system but realizes targeted current diversion through the overvoltage protection module. When the lightning current voltage exceeds the set threshold, the overvoltage protection module will enable the current diversion function, effectively reducing the continuous impact of the lightning current on the equipment and the grounding system.

[0064] Data processing module: Obtain the current analysis sequence; According to the fluctuation situation and periodic change situation of the current values in the current analysis sequence, obtain the surge index of the power electrical transformer; Obtain the main current value of the current analysis sequence; According to the main current value of the current analysis sequence, obtain the main fluctuation abnormality degree of the power electrical transformer; Obtain the current reference sequence according to the current time series sequence; According to the current values in the current reference sequence, obtain the comparison abnormality degree of the power electrical transformer; According to the main fluctuation abnormality degree and comparison abnormality degree of the power electrical transformer, obtain the lightning strike confidence level of the power electrical transformer; According to the lightning strike confidence level and surge index of the power electrical transformer, obtain the external lightning strike index of the power electrical transformer.

[0065] It should be noted that the data processing module is used to analyze the current fluctuation pattern according to the current time series sequence, identify whether the transformer voltage surge phenomenon is caused by external lightning strikes, and then conduct different current path orientation control through the adjustment control circuit.

[0066] Specifically, intercept the sequence composed of the current values in the last minutes stored in the data storage module and record it as the current analysis sequence; among them, is the preset current interception length, and in this embodiment, will be described by way of example.

[0067] It should be noted that when a power electrical transformer is struck by lightning or subjected to an instantaneous switching overvoltage operation, a voltage surge phenomenon will occur inside the power electrical transformer, that is, the current of the power electrical transformer will fluctuate disorderly, breaking the frequency of the current fluctuation in the stable operation state. Therefore, the surge index of the power electrical transformer is obtained accordingly.

[0068] Specifically, the period of the current analysis sequence is obtained by using the autocorrelation function method, and the ratio of the variance of all current values in the current analysis sequence to the period of the current analysis sequence is denoted as the surge index of the power electrical transformer; among them, the autocorrelation function method is a well-known technology, and the specific method will not be introduced here.

[0069] It should be noted that the larger the surge index of the power electrical transformer, the more disorderly and non-periodic the current value fluctuations in the current analysis sequence are, and the more significant the impact of the voltage surge is. For the current fluctuations with a more significant impact of the voltage surge.

[0070] It should be noted that when the cause of the voltage surge is due to external lightning strikes, it is more likely to cause greater damage to power equipment; while the voltage surge caused by instantaneous switching overvoltage operation belongs to normal equipment operation and has little impact on power equipment. Therefore, it is necessary to distinguish whether the voltage surge is caused by external lightning strikes or instantaneous switching overvoltage operation, and then obtain the current guiding control strategy accordingly.

[0071] It should be noted that both external lightning strikes and instantaneous switching overvoltage operations will cause short-term current fluctuations. These fluctuations will exceed the normal operating current level within a short period of time. This kind of fluctuation is called transient overcurrent fluctuation. The current of the external lightning strike will rise rapidly in the initial stage and quickly break through the voltage threshold; while the instantaneous switching overvoltage operation is manifested as a relatively gentle current fluctuation, the starting current amplitude is small, and usually accompanied by abnormal current fluctuations and a long duration.

[0072] Specifically, the last current value in the current analysis sequence is denoted as the main current value of the current analysis sequence; among them, is the preset number of main currents. In this embodiment, will be described.

[0073] The least squares method is used to perform curve fitting on all current values in the current analysis sequence to obtain a real-time fitting curve. The fitting value corresponding to any current value in the current analysis sequence on the real-time fitting curve is denoted as the real-time fitting value of the current value, and the slope of the real-time fitting value of each current value on the real-time fitting curve is obtained; among them, the least squares method is a well-known technology, and the specific method will not be introduced here;

[0074] The product of the number of occurrences of the real-time fitting values of all the main current values in the current analysis sequence in the real-time fitting curve is denoted as the main conventional index of the power electrical transformer;

[0075] The mean value of the slopes of the real-time fitting values of all the main current values in the current analysis sequence on the real-time fitting curve is denoted as the main fluctuation index of the power electrical transformer;

[0076] The inverse proportional normalization result of the product of the main conventional index and the main fluctuation index of the power electrical transformer is denoted as the main fluctuation abnormality degree of the power electrical transformer.

[0077] It should be noted that the smaller the main conventional index of the power electrical transformer, the fewer the number of occurrences of the real-time fitting values of the main current values in the real-time fitting curve, and the more abnormal the main current values. At the same time, if the main fluctuation index of the power electrical transformer is smaller, it indicates that the current state of the current power electrical transformer is more stable, that is, the persistence of the current state is stronger; the greater the main fluctuation abnormality degree of the electrical transformer, the more abnormal the main current values and the persistence of this abnormal state.

[0078] It should be noted that due to the strong randomness of the behavior pattern of lightning current and the frequency of its occurrence in historical data being much smaller than the frequency of current fluctuations caused by instantaneous switching overvoltage operations, and since the current fluctuations caused by instantaneous switching overvoltage operations have a certain similarity, the causes of current fluctuations are further distinguished accordingly.

[0079] Specifically, the sequence composed of the current values of the last days intercepted from the current time series stored in the data storage module is denoted as the current reference sequence; where is the preset reference interception length, and this embodiment is described by taking as an example.

[0080] Furthermore, the least squares method is used to perform curve fitting on all the current values in the current reference sequence to obtain a reference fitting curve. The sequence composed of the fitting values corresponding to all the current values in the current reference sequence on the real-time fitting curve is denoted as the reference fitting sequence; all the maximum values of the reference fitting sequence are obtained; a window with a length of is constructed with any one of the maximum values as the end in the reference fitting sequence, and the standard deviation of all the elements in this window is denoted as the regional fluctuation index of this maximum value; where the least squares method is a well-known technology and the specific method is not introduced here; where is the preset regional length, and this embodiment is described by taking as an example; it should be noted that if the number of elements in the window constructed with the maximum value as the end is less than When there are elements, only calculate the regional fluctuation index for the existing elements;

[0081] Obtain the mean value of the regional fluctuation indices of all the maximum values in the reference fitting sequence, and denote the ratio of the standard deviation of the real-time fitting values of all the main current values in the current analysis sequence to the mean value of the regional fluctuation indices of all the maximum values in the reference fitting sequence as the comparison anomaly degree of the power electrical transformer.

[0082] It should be noted that the mean value of the regional fluctuation indices of all the maximum values in the reference fitting sequence represents the current fluctuation state caused by instantaneous switching overvoltage operation, and the standard deviation of the real-time fitting values of all the main current values in the current analysis sequence represents the current fluctuation state at present. When the comparison anomaly degree of the power electrical transformer is larger, it indicates that the current fluctuation state at present differs more from the current fluctuation state caused by instantaneous switching overvoltage operation, and the current fluctuation state at present is more likely to be caused by lightning current.

[0083] Furthermore, denote the inverse proportional normalization result of the product of the main fluctuation anomaly degree and the comparison anomaly degree of the power electrical transformer as the lightning strike confidence level of the power electrical transformer.

[0084] It should be noted that after obtaining the lightning strike confidence level of the power electrical transformer, it is necessary to obtain the external lightning strike index of the power electrical transformer according to the surge index and the lightning strike confidence level of the power electrical transformer. The larger the external lightning strike index of the power electrical transformer, the more it represents that the power electrical transformer is suffering from the invasion of external lightning strike current, and it is necessary to adjust the current direction in time to ensure the safe operation of the equipment.

[0085] Specifically, denote the product of the lightning strike confidence level of the power electrical transformer and the surge index as the external lightning strike index of the power electrical transformer.

[0086] Overvoltage protection module: Adjust the current path according to the external lightning strike index of the power electrical transformer.

[0087] It should be noted that the purpose of this embodiment is to adjust the lightning protection process of the power electrical transformer with lightning protection function, and solve the problem that the lightning protection system of the power electrical transformer is misjudged due to the existing instantaneous voltage fluctuation or the subsequent influence of lightning strike on the current.

[0088] Specifically, this embodiment proposes a power electrical transformer with lightning protection function, and this power electrical transformer includes a sampling circuit, an integrated sensor, an overvoltage protection module, a power supply circuit, a load circuit, a data storage module, a verification module, a communication interface, a line regulation module, a grounding circuit, and a transformer load circuit;

[0089] Among them, the sampling circuit uses a built-in current sensor to collect the current values on the high-voltage side of the transformer at a frequency of 1 kHz, and records the time series sequence composed of all current values as the initial current sequence;

[0090] Among them, the integrated sensor is used to perform a preprocessing operation of mean filtering denoising on the initial current sequence to obtain the current time series sequence; among them, mean filtering denoising is a well-known technology, and the specific method will not be introduced here;

[0091] Among them, the overcurrent protection module is mainly used to obtain the current time series sequence and obtain the current guiding control strategy to adjust the current path;

[0092] Among them, the power supply circuit provides a stable power supply for each module inside the power electrical transformer to ensure the normal operation of the system;

[0093] Among them, the load circuit is used to connect to the load of the transformer to ensure that the transformer can output stable power according to the load demand;

[0094] Among them, the data storage module is used to store the data of the current time series sequence;

[0095] Among them, the verification module verifies the collected current time series sequence to ensure the accuracy of the data and the stability of the system;

[0096] Among them, the communication interface is used for data exchange and communication with external devices;

[0097] Among them, the line regulation module is responsible for adjusting the line settings of the transformer to ensure that the transformer can automatically cut off or adjust the power flow in case of abnormal situations such as lightning strikes to reduce damage;

[0098] Among them, the grounding circuit is used to ensure that when the transformer is struck by lightning or the current is abnormal, the current can be safely guided to the ground through the grounding circuit to avoid damage to the transformer or faults of other equipment due to excessive voltage;

[0099] Among them, the transformer load circuit is directly connected to the load of the transformer to ensure the stable output of the load current and voltage. At the same time, during the lightning protection process, it can also quickly isolate the electrical connection between the transformer and the load to avoid load damage caused by lightning.

[0100] It should be noted that the overcurrent protection module is the core device of the transformer with lightning protection function, which is used to prevent the transformer and other electrical equipment from being damaged due to voltage surges caused by lightning, circuit faults, etc.

[0101] Specifically, this embodiment provides an overcurrent protection module, and the structure of the overcurrent protection module includes an input circuit, a communication circuit, a data processing module, a regulation control circuit, and an output circuit;

[0102] Among them, the input circuit is used to receive the current signal at the input end of the transformer;

[0103] Among them, the communication circuit is used to transmit the current time sequence to the data processing module;

[0104] Among them, the data processing module is used to obtain the current guiding control strategy according to the current time sequence;

[0105] Among them, the adjustment control circuit is used to adjust the current path through a conventional switch according to the current guiding control strategy, so as to guide the abnormal current to a safe path;

[0106] Among them, the output circuit is connected to the grounding circuit and the transformer load circuit, and guides the current affecting the operation of the equipment inside the transformer to different equipment systems to ensure the safe operation of the transformer equipment.

[0107] It should be noted that the larger the external lightning strike index of the power electrical transformer, the more it represents that the power electrical transformer is suffering from the invasion of external lightning strike current, and it is necessary to adjust the current direction in time to ensure the safe operation of the equipment.

[0108] Furthermore, if the external lightning strike index of the power electrical transformer is greater than or equal to the preset lightning strike threshold, the relay of the grounding circuit is opened through the adjustment control circuit to guide the lightning strike current to the ground system; if the external lightning strike index of the power electrical transformer is less than the preset lightning strike threshold, the relay of the transformer circuit is kept open and the relay of the grounding circuit is closed through the adjustment control circuit; among them, the preset lightning strike threshold is 1.5, and this embodiment is described by taking this as an example.

[0109] This embodiment adopts a model to present the inverse proportional relationship and normalization processing, which is an exponential function with the natural constant as the base, and is the input of the model. The implementer can set the inverse proportional function and the normalization function according to the actual situation.

[0110] The above are only the preferred embodiments of the present invention, and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A power transformer with lightning protection function, characterized in that: The power electrical transformer comprises: Protective cover, used to provide support and insulation protection for power electrical transformers, reducing electromagnetic interference generated by transformers; Lightning protection device, used to realize targeted current diversion according to the overcurrent protection module after being connected to the overcurrent protection module; A data processing module is used to obtain a current analysis sequence; the current analysis sequence includes a number of current values; according to the fluctuation and periodic variation of the current values ​​in the current analysis sequence, the surge index of the power transformer is obtained; the current analysis sequence is a sequence consisting of the current values ​​of the last preset number of minutes intercepted from the current time sequence; Obtaining the main current value of the current analysis sequence; obtaining the main fluctuation abnormality degree of the power transformer according to the main current value of the current analysis sequence; the main current value is the last preset number of current values ​​in the current analysis sequence; Obtaining a current reference sequence according to the current time series sequence; obtaining a comparative abnormality degree of the power transformer according to the current value in the current reference sequence; the current reference sequence is a sequence consisting of the current values ​​of the last preset number of days intercepted from the current time series sequence; According to the main fluctuation abnormality degree and comparative abnormality degree of the power electrical transformer, the lightning strike confidence of the power electrical transformer is obtained; According to the lightning confidence and surge index of the power electrical transformer, the external lightning index of the power electrical transformer is obtained; The overcurrent protection module is used to adjust the current path according to the external lightning strike index of the power electrical transformer.

2. The power transformer with lightning protection function according to claim 1, characterized in that: The specific method of obtaining the surge index of the power transformer according to the fluctuation and periodic variation of the current value in the current analysis sequence includes: The period of the current analysis sequence is obtained, and the ratio of the variance of all current values ​​in the current analysis sequence to the period of the current analysis sequence is recorded as the surge index of the power electrical transformer.

3. The power transformer with lightning protection function according to claim 1, characterized in that: The method of obtaining the main fluctuation abnormality degree of the power transformer according to the main current value of the current analysis sequence includes the following specific methods: Performing curve fitting on all current values ​​in the current analysis sequence to obtain a real-time fitting curve, recording the fitting value corresponding to any current value in the current analysis sequence on the real-time fitting curve as the real-time fitting value of the current value, and obtaining the slope of the real-time fitting value of each current value on the real-time fitting curve; According to the real-time fitting value of the main current value and the real-time fitting curve, the main conventional indexes of the power transformer are obtained; The average of the slopes of the real-time fitting values ​​of all the main current values ​​of the current analysis sequence on the real-time fitting curve is recorded as the main fluctuation index of the power transformer; The inversely proportional normalized result of the product of the main conventional index and the main fluctuation index of the power electrical transformer is recorded as the main fluctuation abnormality degree of the power electrical transformer.

4. The power transformer with lightning protection function according to claim 3, characterized in that: The method of obtaining the main conventional indexes of the power transformer according to the real-time fitting value of the main current value and the real-time fitting curve includes the following specific methods: The product of the number of times the real-time fitting values ​​of all main current values ​​of the current analysis sequence appear in the real-time fitting curve is recorded as the main conventional index of the power electrical transformer.

5. The power transformer with lightning protection function according to claim 3, characterized in that: The specific method of obtaining the comparative abnormality degree of the power transformer according to the current value in the current reference sequence includes: Performing curve fitting on all current values ​​in the current reference sequence to obtain a reference fitting curve, recording a sequence consisting of fitting values ​​corresponding to all current values ​​in the current reference sequence on the real-time fitting curve as a reference fitting sequence; obtaining all maximum values ​​of the reference fitting sequence; constructing a window of a preset region length ending with any maximum value in the reference fitting sequence, recording the standard deviation of all elements in the window as the region fluctuation index of the maximum value; The mean of the regional fluctuation index of all the maximum values ​​in the reference fitting sequence is obtained, and the ratio of the standard deviation of the real-time fitting values ​​of all the main current values ​​of the current analysis sequence to the mean of the regional fluctuation index of all the maximum values ​​in the reference fitting sequence is recorded as the comparative abnormality degree of the power electrical transformer.

6. The power transformer with lightning protection function according to claim 1, characterized in that: The lightning strike confidence of the power electrical transformer is obtained according to the main fluctuation abnormality degree and the comparative abnormality degree of the power electrical transformer, including the specific method of: The inversely proportional normalized result of the product of the main fluctuation abnormality degree and the comparative abnormality degree of the power electrical transformer is recorded as the lightning stroke confidence of the power electrical transformer.

7. The power transformer with lightning protection function according to claim 1, characterized in that: The specific method of obtaining the external lightning strike index of the power electrical transformer according to the lightning strike confidence and surge index of the power electrical transformer is as follows: The product of the lightning strike confidence of the power electrical transformer and the surge index is recorded as the external lightning strike index of the power electrical transformer.

8. The power transformer with lightning protection function according to claim 1, characterized in that: The specific method of adjusting the current path according to the external lightning strike index of the power transformer includes: If the external lightning strike index of the power electrical transformer is greater than or equal to the preset lightning strike threshold, the relay of the grounding circuit is opened by adjusting the control circuit to guide the lightning current to the ground system; if the external lightning strike index of the power electrical transformer is less than the preset lightning strike threshold, the transformer circuit relay is kept open by adjusting the control circuit and the grounding circuit relay is closed.

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