Power electrical transformer with lightning protection function

Abstract

The invention relates to the technical field of transformers, and provides a power electrical transformer with a lightning protection function, which comprises a protective cover, a lightning arrester, a data processing module and an over-current protection module, and is characterized in that the data processing module obtains a surge index according to a current analysis sequence; according to a main current value of the current analysis sequence, obtaining a main fluctuation abnormal degree; according to the current value in the current reference sequence, obtaining a comparison abnormal degree; obtaining a lightning stroke confidence coefficient according to the main fluctuation abnormal degree and the comparison abnormal degree; and obtaining an external lightning stroke index according to the lightning stroke confidence coefficient and the surge index. Whether the power electrical transformer is affected by lightning stroke is judged through the external lightning stroke index, then the current path is adjusted, the accuracy of decision making of the lightning protection system of the power electrical transformer is improved, and the protectiveness of the power electrical transformer is improved.

Description

Technical Field

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

[0002] Power electrical transformers are key equipment in power systems, responsible for voltage conversion to meet transmission and distribution needs. Strong currents and voltage fluctuations generated by lightning may be transmitted to transformers through the air, transmission lines or grounding systems, causing serious damage such as short circuits, insulation breakdown or fire. Therefore, the lightning protection function of transformers is crucial to ensure equipment safety and stable system operation.

[0003] The lightning protection function design of the transformer is usually achieved through overvoltage protection and regulation. When the system detects voltage abnormalities, 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 switching operations of the power system or subsequent currents affected by lightning strikes may interfere with the lightning protection system of the power transformer and cause misjudgment, thereby triggering incorrect response strategies and causing equipment damage. Summary of the invention

[0004] The present invention provides a power electrical transformer with lightning protection function to solve the problem of misjudgment of the lightning protection system of the power electrical transformer caused by the existing instantaneous voltage fluctuation or the subsequent impact of lightning on the current. The technical solution adopted is as follows: The present invention provides a power electrical transformer with a lightning protection function, the power electrical transformer comprising: 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; and based on the fluctuation and periodic variation of the current values ​​in the current analysis sequence, the surge index of the power transformer is obtained; Obtaining the main current value of the current analysis sequence; obtaining the main fluctuation abnormality degree of the power electrical transformer according to the main current value of the current analysis sequence; Obtain a current reference sequence according to the current time sequence; obtain a comparative abnormality degree of the power transformer according to the current value in the current reference 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.

[0005] Furthermore, 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.

[0006] Furthermore, the main fluctuation abnormality degree of the power transformer is obtained according to the main current value of the current analysis sequence, including the specific method of: 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.

[0007] Furthermore, the main conventional indexes of the power transformer are obtained according to the real-time fitting value of the main current value and the real-time fitting curve, including the specific method of: 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.

[0008] Furthermore, the specific method of obtaining the current reference sequence according to the current timing sequence includes: Extract the last The sequence of current values ​​of the day is recorded as the current reference sequence; among them, The cut length is preset as a reference.

[0009] Furthermore, the specific method of obtaining the comparative abnormality degree of the power transformer according to the current value in the current reference sequence includes: A reference fitting curve is obtained by curve fitting all current values ​​in the current reference sequence, and a sequence consisting of fitting values ​​corresponding to all current values ​​in the current reference sequence on the real-time fitting curve is recorded as a reference fitting sequence; all maximum values ​​of the reference fitting sequence are obtained; a sequence with a length of 1 is constructed with any maximum value as the end in the reference fitting sequence. The standard deviation of all elements in the window is recorded as the regional fluctuation index of the maximum value; is the preset area length; 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.

[0010] Furthermore, 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.

[0011] Furthermore, the external lightning strike index of the power electrical transformer is obtained according to the lightning strike confidence and surge index of the power electrical transformer, including the specific method of: 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.

[0012] Furthermore, 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.

[0013] Furthermore, the method of obtaining the main current value of the current analysis sequence includes: The last The current values ​​are recorded as the main current values ​​of the current analysis sequence; among them, To preset the main current quantity.

[0014] The beneficial effects of the present invention are as follows: since a voltage surge phenomenon will be generated when a power electrical transformer is struck by lightning or an instantaneous switch overvoltage operation is performed, it is first necessary to judge the possibility of being currently affected by the voltage surge phenomenon. The present invention obtains the surge index of the power electrical transformer through the fluctuation and periodic change of the current value in the current analysis sequence, and judges the possibility of being currently affected by the voltage surge phenomenon; external lightning strikes and instantaneous switch overvoltage operations will cause short-term fluctuations in current, and these fluctuations will exceed the normal operating current level in a short time. The present invention obtains the main fluctuation abnormality degree of the power electrical transformer based on the main current value of the current analysis sequence, and judges the abnormality of the current current fluctuation; since the behavior pattern of lightning current has strong randomness, and the frequency of occurrence in historical data is much smaller than the frequency of current fluctuation caused by instantaneous switch overvoltage operation, and since the current fluctuation caused by instantaneous switch overvoltage operation has certain similarity, the present invention distinguishes the causes of current fluctuation by obtaining the comparative abnormality degree of the power electrical transformer. At this point, the present invention obtains the lightning strike confidence through the main fluctuation abnormality degree and the comparative abnormality degree of the power electrical transformer, and obtains the external lightning strike index of the power electrical transformer in combination with the surge index of the power electrical transformer, and then adjusts the current path, thereby 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 A structural diagram of a power electrical transformer with lightning protection function provided by one embodiment of the present invention; Figure 2 The schematic diagram of the protective cover is shown in Figure 1. Figure 2 1. Protective shell (steel); 2. Insulating base; 3. Main body space; 4. Grounding circuit; 5. Insulating film; 6. Heat dissipation holes (located on the surface of the protective shell); 7. Overcurrent protection module; 8. Positioning shaft; 9. Insulating platform; 10. Current transmission line; Figure 3 This is a schematic diagram of a lightning protection device. Figure 3 9. Insulating platform; 11. Polymer housing; 12. Arrester body; 13. Wire connection port. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] See also Figure 1 , which shows a flow chart of a power electrical transformer with lightning protection function provided by an embodiment of the present invention, the power electrical transformer comprising: Protective cover: Provide support and insulation protection for power electrical transformers, reducing electromagnetic interference generated by the transformer.

[0019] It should be noted that the instantaneous high voltage caused by lightning strikes or power grid failure in harsh environments is called voltage surge. Voltage surge can damage equipment. Generally, the overvoltage is directed to the ground or other safe paths by installing lightning arresters, strengthening the grounding system, or using overvoltage protection devices to avoid direct damage to the equipment caused by voltage surges.

[0020] Specifically, this embodiment provides a protective cover, the protective cover schematic diagram is as shown in Figure 2 As shown in the schematic diagram of the protective cover, the structure of the protective cover includes a protective shell (steel), an insulating base, a main body space, a grounding circuit, an insulating film, a heat dissipation hole (located on the surface of the protective shell), an overcurrent protection module, a positioning shaft, an insulating platform and a current transmission line; Among them, the protective casing is used to physically protect the power electrical transformer; Among them, the insulating base provides support and insulation for the power electrical transformer; Among them, the main space is used to arrange power electrical transformers; Among them, the grounding circuit guides the lightning current to the ground through a safe conductive path to prevent equipment and personnel from being shocked or damaged; 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 circuits 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; Among them, the heat dissipation holes are used to prevent the device from overheating; Among them, the overvoltage protection module is used to detect and cut off the overvoltage situation to prevent the transformer from being damaged or causing safety accidents due to overvoltage; The positioning shaft connects the insulating platform and the protective cover. This separate design effectively reduces the electromagnetic interference generated by the lightning arrester in the traditional design to the transformer during operation. At the same time, maintenance personnel can independently check the electrical parts of the lightning arrester and the transformer to avoid overall disassembly, thereby improving maintenance efficiency and safety. Among them, the insulating platform is used to install the lightning protection device, so that the transformer can concentrate on absorbing the lightning current or instantaneous overvoltage when it encounters lightning strikes, which is convenient for the subsequent overcurrent protection module to weaken the instantaneous voltage of the lightning current and ensure the safe operation of the transformer body; Among them, the function of the current transmission line is to safely transmit the current generated by the transformer to the load or distribution system to ensure stable and reliable output of electrical energy.

[0021] Lightning protection device: After connecting the overcurrent protection module, targeted diversion is achieved according to the overcurrent protection module.

[0022] It should be noted that since power transformers are easily affected by lightning, when lightning occurs, the transformer may be damaged due to excessive voltage and current, and may even cause fire or equipment failure. Lightning arresters guide lightning current to the ground, reduce the direct impact of lightning on transformers, effectively protect transformers and surrounding facilities from lightning damage, and ensure the stable operation of the power system and the safety of personnel.

[0023] Specifically, this embodiment provides a lightning protection device, which is fixed to the insulating platform of the protective cover through a nut structure to collect lightning current in time to ensure the safe operation of the transformer; the schematic diagram of the lightning protection device is shown in Figure 3 As shown, in the schematic diagram of the lightning arrester, the structure of the lightning arrester includes an insulating platform, a polymer shell, a lightning arrester body, and a wire connection port; Among them, the insulating platform is a structure in the protective cover, which is used to install the lightning protection device, so that the transformer can concentrate on absorbing the lightning current or instantaneous overvoltage when it encounters lightning strikes, which is convenient for the subsequent overcurrent protection module to weaken the instantaneous voltage of the lightning current and ensure the safe operation of the transformer body; The polymer shell provides strong weather resistance and insulation protection, preventing the external environment from damaging the lightning arrester and ensuring that it can conduct electricity safely and effectively when struck by lightning. Among them, the main body of the lightning arrester conducts overvoltage to the ground by quickly conducting when lightning strikes, protecting the transformer from damage caused by lightning overvoltage; Among them, the wire connection port is used to connect the overcurrent protection module in the transformer.

[0024] It should be noted that in traditional transformers, the lightning arrester is directly connected to the grounding system wire, and the lightning current is directly directed into the ground. Frequent lightning currents will increase the grounding resistance, thereby reducing the grounding effect. The lightning arrester provided in this embodiment connects the lightning arrester to the overcurrent protection module through a wire, and then connects to the grounding system. The lightning arrester is not directly connected to the grounding system, but is targeted for diversion through the overcurrent protection module. When the lightning current voltage exceeds the set threshold, the overcurrent protection module will enable the diversion function, effectively reducing the continuous impact of lightning current on the equipment and the grounding system.

[0025] Data processing module: obtain the current analysis sequence; obtain the surge index of the power electrical transformer according to the fluctuation and periodic change of the current value in the current analysis sequence; obtain the main current value of the current analysis sequence; obtain the main fluctuation abnormality degree of the power electrical transformer according to the main current value of the current analysis sequence; obtain the current reference sequence according to the current time series sequence; obtain the comparative abnormality degree of the power electrical transformer according to the current value in the current reference sequence; obtain the lightning strike confidence of the power electrical transformer according to the main fluctuation abnormality degree and comparative abnormality degree of the power electrical transformer; obtain the external lightning strike index of the power electrical transformer according to the lightning strike confidence and surge index of the power electrical transformer.

[0026] It should be noted that the data processing module is used to analyze the current fluctuation pattern according to the current timing sequence, identify whether the transformer voltage surge phenomenon is caused by external lightning strike, and then perform different current path guidance and control by adjusting the control circuit.

[0027] Specifically, the last current timing sequence is intercepted from the current timing sequence stored in the data storage module. The sequence of current values ​​of minutes is recorded as the current analysis sequence; among them, To preset the current interception length, this embodiment uses Let's take this as an example.

[0028] It should be noted that when the power transformer is struck by lightning or subjected to instantaneous switch overvoltage operation, a voltage surge will occur inside the power transformer, that is, the current of the power transformer will fluctuate chaotically, breaking the frequency of current fluctuations under stable operating conditions, so the surge index of the power transformer is obtained based on this.

[0029] Specifically, the period of the current analysis sequence is obtained 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 recorded as the surge index of the power transformer; wherein the autocorrelation function method is a well-known technology, and the specific method is not introduced here.

[0030] It should be noted that the larger the surge index of the power transformer, the more chaotic and non-periodic the fluctuation of the current value in the current analysis sequence, the more significant the impact of the voltage surge, and the more significant the current fluctuation that affects the voltage surge.

[0031] It should be noted that when the voltage surge is caused by external lightning strike, it is more likely to cause greater damage to the power equipment; while the voltage surge caused by the instantaneous switch overvoltage operation belongs to the normal operation of the equipment and has little impact on the power equipment. Therefore, it is necessary to distinguish whether the voltage surge is caused by external lightning strike or instantaneous switch overvoltage operation, and then obtain the current-oriented control strategy based on this.

[0032] It should be noted that both external lightning strikes and instantaneous switch overvoltage operations will cause brief fluctuations in current. These fluctuations will exceed the normal operating current level in a short period of time. This fluctuation is called transient overcurrent fluctuation. The external lightning current will rise rapidly in the initial stage and quickly break through the voltage threshold; while the instantaneous switch overvoltage operation will manifest as a relatively gentle current fluctuation, with a smaller initial current amplitude, and is usually accompanied by abnormal current fluctuations and lasts for a longer time.

[0033] Specifically, the last The current values ​​are recorded as the main current values ​​of the current analysis sequence; among them, To preset the main current quantity, this embodiment uses to give a narrative; The least square method is used to perform curve fitting on all current values ​​in the current analysis sequence to obtain a real-time fitting curve, and the fitting value corresponding to any current value in the current analysis sequence on the real-time fitting curve is recorded 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; wherein the least square method is a well-known technology, and the specific method is not introduced here; The product of the number of times the real-time fitting values ​​of all the 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; 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.

[0034] It should be noted that the smaller the main conventional index of the power electrical transformer is, the less times the real-time fitting value of the main current value appears in the real-time fitting curve, and the more abnormal the main current value is. At the same time, if the main fluctuation index of the power electrical transformer is smaller, it means that the current state of the current power electrical transformer is more stable, that is, the continuity of the current state is stronger; the greater the degree of abnormality of the main fluctuation of the power transformer is, the more abnormal the main current value is and the persistence of this abnormal state.

[0035] It should be noted that since the behavior pattern of lightning current is highly random and its frequency of occurrence in historical data is much lower than the frequency of current fluctuations caused by instantaneous switch overvoltage operations, and since the current fluctuations caused by instantaneous switch overvoltage operations have certain similarities, the causes of current fluctuations are further distinguished based on this.

[0036] Specifically, the last current timing sequence is intercepted from the current timing sequence stored in the data storage module. The sequence of current values ​​of the day is recorded as the current reference sequence; among them, To preset the reference intercept length, this embodiment uses Let's take this as an example.

[0037] Furthermore, the least square method is used to perform curve fitting on all current values ​​in the current reference sequence to obtain a reference fitting curve, and the sequence consisting of the fitting values ​​corresponding to all current values ​​in the current reference sequence on the real-time fitting curve is recorded as the reference fitting sequence; all maximum values ​​of the reference fitting sequence are obtained; and a sequence with a length of The standard deviation of all elements in the window is recorded as the regional fluctuation index of the maximum value; the least square method is a well-known technology, and the specific method is not introduced here; is the preset area length. As an example, it should be noted that if the number of elements in the window constructed with the maximum value at the end is insufficient When the number of elements is less than 1, only the existing elements are used to calculate the regional fluctuation index; 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.

[0038] It should be noted that the mean of the regional fluctuation index of all maximum values ​​in the reference fitting sequence represents the current fluctuation state caused by instantaneous switch overvoltage operation, and the standard deviation of the real-time fitting values ​​of all main current values ​​of the current analysis sequence represents the current current fluctuation state. When the contrast abnormality of the power electrical transformer is greater, it means that the current current fluctuation state is more different from the current fluctuation state caused by instantaneous switch overvoltage operation, and the current current fluctuation state is more likely to be caused by lightning current.

[0039] Furthermore, 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.

[0040] It should be noted that after obtaining the lightning strike confidence of the power electrical transformer, it is necessary to obtain the external lightning strike index of the power electrical transformer based on the surge index and lightning strike confidence of the power electrical transformer. The larger the external lightning strike index of the power electrical transformer, the more it means that the power electrical transformer is being invaded by external lightning current, and it is necessary to adjust the current guidance in time to ensure the safe operation of the equipment.

[0041] Specifically, 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.

[0042] Overcurrent protection module: adjusts the current path according to the external lightning strike index of the power transformer.

[0043] 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 to solve the problem of misjudgment of the lightning protection system of the power electrical transformer caused by the existing instantaneous voltage fluctuation or the subsequent impact of lightning strike on the current.

[0044] Specifically, this embodiment proposes a power electrical transformer with a lightning protection function, which includes a sampling circuit, an integrated sensor, an overcurrent protection module, a power circuit, a load circuit, a data storage module, a verification module, a communication interface, a line control module, a grounding circuit, and a transformer load circuit; The sampling circuit uses the built-in current sensor to collect the current value of the high-voltage side of the transformer at a frequency of 1kHz, and records the time sequence composed of all current values ​​as the current initial sequence; The integrated sensor is used to perform a preprocessing operation of mean filtering and denoising on the initial current sequence to obtain a current time series sequence; wherein mean filtering and denoising is a well-known technology, and the specific method is not introduced here; Among them, the overcurrent protection module is mainly used to obtain the current timing sequence and obtain the current steering control strategy to adjust the current path; Among them, the power circuit provides stable power to each module inside the power electrical transformer to ensure the normal operation of the system; 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; Wherein, the data storage module is used to store the data of the current timing sequence; Among them, the verification module verifies the collected current timing sequence to ensure the accuracy of the data and the stability of the system; Wherein, the communication interface is used for data exchange and communication with external devices; Among them, the line control 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 abnormal situations such as lightning strikes to reduce damage; 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 failure of other equipment due to excessive voltage; 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.

[0045] It should be noted that the overcurrent protection module is the core device of a transformer with lightning protection function, which is used to prevent voltage surges caused by lightning, circuit failures, etc. from damaging the transformer and other electrical equipment.

[0046] Specifically, this embodiment provides an over-current protection module, the structure of which includes an input circuit, a communication circuit, a data processing module, a regulation control circuit, and an output circuit; Wherein, the input circuit is used to receive the current signal at the input end of the transformer; Wherein, the communication circuit is used to transmit the current timing sequence to the data processing module; Wherein, the data processing module is used to obtain a current steering control strategy according to the current timing sequence; Wherein, the regulation control circuit is used to regulate the path of the current through a conventional switch according to the current steering control strategy, thereby directing the abnormal current to a safe path; Among them, the output circuit is connected to the grounding circuit and the transformer load circuit, and the current inside the transformer that affects the operation of the equipment is directed to different equipment systems to ensure the safe operation of the transformer equipment.

[0047] It should be noted that the larger the external lightning strike index of the power transformer, the more it means that the power transformer is being invaded by external lightning current, and it is necessary to adjust the current guidance in time to ensure the safe operation of the equipment.

[0048] 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 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; wherein the preset lightning strike threshold is 1.5, and this embodiment is described using this as an example.

[0049] This embodiment adopts Model to present inverse proportional relationship and normalization, is an exponential function with a natural constant as base, As the input of the model, the implementer can set the inverse proportional function and normalization function according to the actual situation.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should 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; and based on the fluctuation and periodic variation of the current values ​​in the current analysis sequence, the surge index of the power transformer is obtained; Obtaining the main current value of the current analysis sequence; obtaining the main fluctuation abnormality degree of the power electrical transformer according to the main current value of the current analysis sequence; Obtain a current reference sequence according to the current time sequence; obtain a comparative abnormality degree of the power transformer according to the current value in the current reference 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 1, characterized in that: The specific method of obtaining the current reference sequence according to the current timing sequence includes: Extract the last The sequence of current values ​​of the day is recorded as the current reference sequence; among them, The cut length is preset as a reference.

6. 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: A reference fitting curve is obtained by curve fitting all current values ​​in the current reference sequence, and a sequence consisting of fitting values ​​corresponding to all current values ​​in the current reference sequence on the real-time fitting curve is recorded as a reference fitting sequence; all maximum values ​​of the reference fitting sequence are obtained; a sequence with a length of 1 is constructed with any maximum value as the end in the reference fitting sequence. The standard deviation of all elements in the window is recorded as the regional fluctuation index of the maximum value; is the preset area length; 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.

7. 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.

8. 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.

9. 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.

10. The power transformer with lightning protection function according to claim 1, characterized in that: The specific method of obtaining the main current value of the current analysis sequence includes: The last The current values ​​are recorded as the main current values ​​of the current analysis sequence; among them, To preset the main current quantity.

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