Self-shielding anti-interference current transformer and dynamic magnetic field compensation method thereof

Abstract

According to the self-shielding type anti-interference current transformer and the dynamic magnetic field compensation method thereof, external interference magnetic field data are detected in real time through the magnetic field sensing layer, a basis is provided for interference shielding of a magnetic field, reverse magnetic field data are set based on the external interference magnetic field data, a main shielding winding generates a reverse magnetic field, the reverse magnetic field and an interference magnetic field are superposed and offset, and the self-shielding type anti-interference current transformer is obtained. Auxiliary magnetic field data are set for further magnetic field shielding through the residual suppression layer based on the offset condition of reverse magnetic field data on external interference magnetic field data, the auxiliary shielding winding further eliminates high-frequency residual interference, finally 0-20 kHz broadband interference suppression is achieved, performance stability can be kept within the temperature range of-40 DEG C to 120 DEG C, three dynamic shielding layers are adopted, and the performance stability is improved. The problem of dynamic interference in a complex electromagnetic environment is solved, and the measurement precision is improved to 0.1%.

Description

Technical Field

[0001] The present invention relates to the technical field of power system measurement, and particularly relates to a self-shielding anti-interference current transformer and a dynamic magnetic field compensation method thereof. Background Art

[0002] Electromagnetic current transformers can convert high currents into low currents, facilitating accurate measurement by measuring instruments. Its primary winding is connected in series in the circuit to be measured, and the secondary winding is connected in series in the measuring instrument. The current transformation is achieved through the principle of electromagnetic induction. In the power system, electromagnetic current transformers are also used in relay protection devices to ensure that the circuit can be quickly cut off in case of a fault, protecting the safety of equipment and personnel. Since its secondary load impedance is small, the magnitude of the secondary current mainly depends on the primary current, thus realizing the current transformation function. Electromagnetic current transformers are also applied in automatic control systems to achieve automatic control and monitoring of the system by providing standard current signals.

[0003] Traditional electromagnetic current transformers have the following defects in the above applications: 1) Traditional electromagnetic current transformers are vulnerable to external stray magnetic field interference, resulting in a decrease in measurement accuracy with an error > 0.5%; 2) Existing shielding technologies mostly use static metal shielding layers and cannot adapt to dynamically changing interference magnetic fields; 3) The multi-layer shielding structure increases the volume and cost, and there is a problem of coupling interference between shielding layers. Summary of the Invention

[0004] The present invention provides a self-shielding anti-interference current transformer and a dynamic magnetic field compensation method thereof to solve the problems raised in the background art.

[0005] A self-shielding anti-interference current transformer includes: A magnetic field sensing layer for real-time detection of external interference magnetic field data; A dynamic cancellation layer for setting reverse magnetic field data based on the external interference magnetic field data; A residual suppression layer for setting auxiliary magnetic field data for further magnetic field shielding based on the cancellation of the external interference magnetic field data by the reverse magnetic field data.

[0006] Preferably, the material of the dynamic cancellation layer is high-permeability permalloy, and the material of the residual suppression layer is nanocrystalline alloy.

[0007] Preferably, the magnetic field sensing layer includes: A range determination unit for determining the scanning range based on the position of the interference source; A parameter determination unit, configured to determine the probe scanning direction based on the scanning range and determine the scanning frequency range based on the operating frequency of the interference source; A magnetic field detection unit, configured to detect an external interference magnetic field based on the probe scanning direction and the scanning frequency range to obtain external interference magnetic field data.

[0008] Preferably, the dynamic cancellation layer includes: A data processing unit, configured to process the interference magnetic field data based on Fourier transform to obtain the frequency components of the interference magnetic field, and divide the frequency components into power frequency interference components and broadband interference components; A power frequency analysis unit, configured to determine the phase and amplitude of the first compensation coil based on the power frequency interference component to obtain first reverse magnetic field data; A broadband analysis unit, configured to adjust the waveform of the compensation current in real time based on the broadband interference component to obtain second reverse magnetic field data.

[0009] Preferably, the residual suppression layer includes: A data determination unit, configured to determine external residual interference magnetic field data after the influence of the reverse magnetic field data on the external interference magnetic field data is cancelled based on the magnetic field sensing layer; An auxiliary compensation unit, configured to determine the compensation current for the auxiliary shielding coil based on the external residual interference magnetic field data in combination with a residual suppression control model.

[0010] Preferably, it further includes: Determine the temperature compensation coefficient for the high-permeability permalloy based on the magnetic permeability change trend of the high-permeability permalloy with temperature; Determine the temperature compensation coefficient for the nanocrystalline alloy based on the magnetic permeability change trend of the nanocrystalline alloy with temperature.

[0011] Preferably, the broadband analysis unit includes: An error determination unit, configured to input the broadband interference component into a current transformer model to obtain output magnetic field data, and obtain the data error between the output magnetic field data and the broadband interference component; A strategy determination unit, configured to determine the initial correspondence between the waveform and the error based on the historical data of the current waveform, and establish an initial dynamic compensation strategy based on the initial correspondence; An optimization determination unit, configured to obtain the operating parameters of the current transformer and the magnetic field distribution of the external magnetic field, determine a first compensation optimization coefficient based on the difference between the operating parameters and the standard operating parameters, obtain the unique characteristics of the magnetic field distribution, refine the unique characteristics to obtain a plurality of characteristic combinations, and integrate the compensation coefficients determined for all characteristics to obtain a second compensation optimization coefficient; A strategy optimization unit, configured to perform real-time dynamic optimization on an initial dynamic compensation strategy based on the first compensation optimization coefficient and the second compensation optimization coefficient, so as to obtain a target dynamic compensation strategy; A compensation determination unit, configured to determine compensation current parameters based on the target dynamic compensation strategy and in combination with the data error between the output magnetic field data and the broadband interference component, and adjust the waveform of the compensation current in real time based on the compensation current parameters to obtain initial reverse magnetic field data; A cyclic compensation unit, configured to perform feedback on the target dynamic compensation strategy based on the latest data error between the initial reverse magnetic field data and the broadband interference component to obtain the latest compensation current parameters, so as to achieve cyclic compensation for the broadband interference component.

[0012] Preferably, the broadband analysis unit further includes: A relationship optimization unit, configured to update the historical data of the current waveform at each preset time to obtain new historical data, and adjust the initial corresponding relationship based on the new historical data to obtain the latest corresponding relationship; A strategy update unit, configured to update the initial dynamic compensation strategy based on the latest corresponding relationship to obtain the latest initial dynamic compensation strategy.

[0013] Preferably, it further includes a collaborative working module, configured to perform collaborative work on the dynamic cancellation layer and the residual suppression layer; The collaborative working module includes: A priority setting unit, configured to establish a circular buffer for bidirectional data transmission between the dynamic cancellation layer and the residual suppression layer, and establish different transmission priorities for the magnetic field data based on the data type in the magnetic field data before data transmission; A synchronization unit, configured to establish a time synchronization mechanism for the dynamic cancellation layer and the residual suppression layer; A template retrieval unit, configured to trigger the residual suppression layer to retrieve the magnetic field response template in advance when the dynamic cancellation layer responds to the external interference magnetic field data; A compression determination unit, configured to establish an adaptive strategy for the transmission compression rate according to the rule of setting a high compression rate for low interference and a low compression rate for high interference based on the degree of the external interference magnetic field data; An operation determination unit, configured to establish an operation rule between the circular buffer, the transmission priority, the time synchronization mechanism, the trigger for retrieving the magnetic field response template, and the adaptive strategy for the transmission compression rate based on the association between functional features; A collaborative determination unit, configured to establish a collaborative working mechanism based on the circular buffer, the transmission priority, the time synchronization mechanism, the trigger for retrieving the magnetic field response template, and the adaptive strategy for the transmission compression rate in combination with the operation rule.

[0014] A dynamic magnetic field compensation method for a self-shielding anti-interference current transformer, comprising: S1: Real-time detection of external interference magnetic field data based on a magnetic field sensing layer; S2: Based on a dynamic cancellation layer, combined with the external interference magnetic field data, set the reverse magnetic field data; S3: Based on a residual suppression layer, combined with the cancellation of the external interference magnetic field data by the reverse magnetic field data, set the auxiliary magnetic field data for further magnetic field shielding.

[0015] Compared with the prior art, the present invention has the following beneficial effects: By real-time detecting the external interference magnetic field data through the magnetic field sensing layer, it provides a basis for the interference shielding of the magnetic field. Based on the external interference magnetic field data, the reverse magnetic field data is set to realize that the main shielding winding generates a reverse magnetic field, which is superimposed and cancelled with the interference magnetic field. Through the residual suppression layer, based on the cancellation of the external interference magnetic field data by the reverse magnetic field data, the auxiliary magnetic field data is set for further magnetic field shielding, and the auxiliary shielding winding further eliminates high-frequency residual interference, and finally realizes 0-20kHz broadband interference suppression, can maintain stable performance in the temperature range of -40°C to 120°C, adopts a three-layer dynamic shielding layer, solves the dynamic interference problem in a complex electromagnetic environment, and improves the measurement accuracy to 0.1%.

[0016] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures specifically pointed out in this application document.

[0017] The technical solution of the present invention will be further described in detail below through the drawings and embodiments. Description of the Drawings

[0018] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention. In the drawings: Figure 1 It is a structural diagram of a self-shielding anti-interference current transformer in an embodiment of the present invention; Figure 2 It is a structural diagram of the magnetic field sensing layer in an embodiment of the present invention; Figure 3 It is a flowchart of a dynamic magnetic field compensation method for a self-shielding anti-interference current transformer in an embodiment of the present invention. Detailed Embodiments

[0019] The following describes the preferred embodiments of the present invention with reference to the drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0020] Example 1 An embodiment of the present invention provides a self-shielding anti-interference current transformer, as Figure 1 shown, including: A magnetic field sensing layer for real-time detection of external interference magnetic field data; A dynamic cancellation layer for setting reverse magnetic field data based on the external interference magnetic field data; A residual suppression layer for setting auxiliary magnetic field data for further magnetic field shielding based on the cancellation of the external interference magnetic field data by the reverse magnetic field data.

[0021] In this embodiment, the external interference magnetic field data includes magnetic field direction, magnetic field intensity, magnetic field signal, etc.

[0022] In this embodiment, the reverse magnetic field data is used to cancel the external interference magnetic field data.

[0023] In this embodiment, based on the cancellation of the external interference magnetic field data by the reverse magnetic field data, setting the auxiliary magnetic field data for further magnetic field shielding is, for example, for the residual magnetic field caused by the existence of non-linear factors, sensor noise, etc.

[0024] The beneficial effects of the above design scheme are as follows: By the magnetic field sensing layer, the external interference magnetic field data is detected in real time, providing a basis for the interference shielding of the magnetic field. Based on the external interference magnetic field data, the reverse magnetic field data is set to realize that the main shielding winding generates a reverse magnetic field, which is superimposed and cancelled with the interference magnetic field. Through the residual suppression layer, based on the cancellation of the external interference magnetic field data by the reverse magnetic field data, the auxiliary magnetic field data is set for further magnetic field shielding, and the auxiliary shielding winding further eliminates high-frequency residual interference. Finally, 0-20 kHz broadband interference suppression is achieved, and the performance can be maintained stable in the temperature range of -40°C to 120°C. By adopting a three-layer dynamic shielding layer, the dynamic interference problem in a complex electromagnetic environment is solved, and the measurement accuracy is improved to 0.1% level.

[0025] Example 2 Based on Example 1, an embodiment of the present invention provides a self-shielding anti-interference current transformer, wherein the material of the dynamic cancellation layer is high-permeability permalloy, and the material of the residual suppression layer is nanocrystalline alloy.

[0026] The beneficial effects of the above design scheme are as follows: By designing the material of the dynamic cancellation layer as high-permeability permalloy and the material of the residual suppression layer as nanocrystalline alloy, the shielding layer thickness is reduced by 40% and the weight is reduced by 35%, realizing the volume optimization of the anti-interference current transformer.

[0027] Example 3 Based on Example 1, an embodiment of the present invention provides a self-shielding anti-interference current transformer, asFigure 2 As shown, the magnetic field sensing layer includes: A range determination unit for determining a scanning range based on the position of the interference source; A parameter determination unit for determining the probe scanning direction based on the scanning range and determining the scanning frequency range based on the operating frequency of the interference source; A magnetic field detection unit for detecting an external interference magnetic field based on the probe scanning direction and the scanning frequency range to obtain external interference magnetic field data.

[0028] The beneficial effects of the above design solution are as follows: By determining the scanning range based on the position of the interference source, determining the probe scanning direction based on the scanning range, determining the scanning frequency range based on the operating frequency of the interference source, and detecting the external interference magnetic field based on the probe scanning direction and the scanning frequency range to obtain external interference magnetic field data, accurate acquisition of external interference magnetic field data is achieved, providing an accurate data basis for setting the reverse magnetic field data of the dynamic cancellation layer and ensuring the shielding anti-interference effect.

[0029] Embodiment 4 Based on Embodiment 1, an embodiment of the present invention provides a self-shielding anti-interference current transformer. The dynamic cancellation layer includes: A data processing unit for processing the interference magnetic field data based on Fourier transform to obtain the frequency components of the interference magnetic field and dividing the frequency components into power frequency interference components and broadband interference components; A power frequency analysis unit for determining the phase and amplitude of the first compensation coil based on the power frequency interference component to obtain the first reverse magnetic field data; A broadband analysis unit for adjusting the waveform of the compensation current in real time based on the broadband interference component to obtain the second reverse magnetic field data.

[0030] In this embodiment, the first reverse magnetic field data and the second reverse magnetic field data form the final reverse magnetic field data.

[0031] In this embodiment, the first reverse magnetic field data is fixed, and the second reverse magnetic field data is dynamically adjusted according to the actual situation.

[0032] The beneficial effects of the above design are as follows: By processing the interference magnetic field data based on Fourier transform, the frequency components of the interference magnetic field are obtained, and the frequency components are divided into power frequency interference components and broadband interference components, providing a basis for setting the reverse magnetic field data. Based on the power frequency interference components, the phase and amplitude of the first compensation coil are determined to obtain the first reverse magnetic field data, realizing the cancellation of the power frequency interference components. Based on the broadband interference components, the waveform of the compensation current is adjusted in real time to obtain the second reverse magnetic field data, realizing the cancellation of the broadband interference components. Finally, broadband interference suppression in the range of 0 - 20 kHz is achieved, and the performance can be maintained stable in the temperature range of -40°C to 120°C, solving the dynamic interference problem in a complex electromagnetic environment and improving the measurement accuracy to 0.1% level.

[0033] Embodiment 5 Based on Embodiment 1, an embodiment of the present invention provides a self - shielding anti - interference current transformer. The residual suppression layer includes: A data determination unit for determining the external residual interference magnetic field data after the reverse magnetic field data determined based on the magnetic field sensing layer cancels the influence of the external interference magnetic field data; An auxiliary compensation unit for determining the compensation current for the auxiliary shielding coil based on the external residual interference magnetic field data and in combination with the residual suppression control model.

[0034] In this embodiment, the residual suppression control model is trained based on deep learning in combination with historical residual interference magnetic field data.

[0035] The beneficial effects of the above design are as follows: By determining the external residual interference magnetic field data after the reverse magnetic field data determined based on the magnetic field sensing layer cancels the influence of the external interference magnetic field data, and determining the compensation current for the auxiliary shielding coil based on the external residual interference magnetic field data and in combination with the residual suppression control model, the auxiliary shielding winding further eliminates high - frequency residual interference. Finally, broadband interference suppression in the range of 0 - 20 kHz is achieved, and the performance can be maintained stable in the temperature range of -40°C to 120°C. With a three - layer dynamic shielding layer, the dynamic interference problem in a complex electromagnetic environment is solved, and the measurement accuracy is improved to 0.1% level.

[0036] Embodiment 6 Based on Embodiment 2, an embodiment of the present invention provides a self - shielding anti - interference current transformer, further including: Determining the temperature compensation coefficient for the high - permeability permalloy based on the magnetic permeability change trend of the high - permeability permalloy with temperature; Determining the temperature compensation coefficient for the nanocrystalline alloy based on the magnetic permeability change trend of the nanocrystalline alloy with temperature.

[0037] The beneficial effects of the above design solution are as follows: By setting the temperature compensation coefficients for high-permeability permalloy and nanocrystalline alloy, the influence of material temperature changes on magnetic field detection is eliminated, ensuring the accuracy of magnetic field detection and magnetic field cancellation.

[0038] Embodiment 7 Based on Embodiment 4, an embodiment of the present invention provides a self-shielded anti-interference current transformer. The broadband analysis unit includes: An error determination unit for inputting the broadband interference component into the transformer model to obtain output magnetic field data and obtaining the data error between the output magnetic field data and the broadband interference component; A strategy determination unit for determining the initial correspondence between the waveform and the error based on the historical current waveform data, and establishing an initial dynamic compensation strategy based on the initial correspondence; An optimization determination unit for obtaining the operating parameters of the current transformer and the magnetic field distribution of the external magnetic field, determining the first compensation optimization coefficient based on the difference between the operating parameters and the standard operating parameters, obtaining the unique characteristics of the magnetic field distribution, refining the unique characteristics to obtain multiple characteristic combinations, and integrating the compensation coefficients determined for all characteristics to obtain the second compensation optimization coefficient; A strategy optimization unit for performing real-time dynamic optimization on the initial dynamic compensation strategy based on the first compensation optimization coefficient and the second compensation optimization coefficient to obtain a target dynamic compensation strategy; A compensation determination unit for determining the compensation current parameters based on the target dynamic compensation strategy in combination with the data error between the output magnetic field data and the broadband interference component, and adjusting the waveform of the compensation current in real time based on the compensation current parameters to obtain the initial reverse magnetic field data; A cyclic compensation unit for feeding back the target dynamic compensation strategy based on the latest data error between the initial reverse magnetic field data and the broadband interference component to obtain the latest compensation current parameters, and realizing cyclic compensation for the broadband interference component.

[0039] In this embodiment, the second reverse magnetic field data is the sum of the output magnetic field data and the initial reverse magnetic field data.

[0040] In this embodiment, the transformer model is preset according to the parameters of the current transformer.

[0041] In this embodiment, the operating parameters of the current transformer are, for example, operating parameters such as temperature and power. When the difference between the operating parameters and the standard operating parameters is outside the range of the standard operating parameters, the first compensation optimization coefficient is determined based on the influence of the operating parameters on the generation of the electromagnetic field.

[0042] In this embodiment, the unique feature of the magnetic field distribution is different from that of the historical magnetic field. It is necessary to refine the analysis to obtain the second compensation optimization coefficient to compensate for the error in determining the reverse magnetic field caused by the change in the magnetic field distribution.

[0043] The beneficial effects of the above design are as follows: By adjusting the waveform of the compensation current in real time based on the broadband interference component, using historical data, the characteristics of the inductor itself, and the distribution of the electromagnetic field to analyze the influence on the determination of the reverse magnetic field one by one during the adjustment process, and adopting the strategy of seeking control adjustment to ensure the real-time and accuracy of dynamic adjustment, realizing the cancellation of the broadband interference component, and finally achieving the suppression of broadband interference from 0 to 20 kHz. It can maintain stable performance in the temperature range of -40°C to 120°C, solve the problem of dynamic interference in complex electromagnetic environments, and improve the measurement accuracy to 0.1% level.

[0044] Embodiment 8 Based on Embodiment 7, the embodiment of the present invention provides a self-shielding anti-interference current transformer. The broadband analysis unit further includes: A relationship optimization unit for updating the historical data of the current waveform based on each preset time to obtain new historical data, and adjusting the initial corresponding relationship based on the new historical data to obtain the latest corresponding relationship; A strategy update unit for updating the initial dynamic compensation strategy based on the latest corresponding relationship to obtain the latest initial dynamic compensation strategy.

[0045] The beneficial effects of the above design are as follows: By updating the historical data of the current waveform based on each preset time to obtain new historical data, adjusting the initial corresponding relationship based on the new historical data to obtain the latest corresponding relationship, and updating the initial dynamic compensation strategy based on the latest corresponding relationship to obtain the latest initial dynamic compensation strategy, realizing the real-time update of the strategy, making the strategy more able to meet the current accuracy requirements, and providing a basis for the shielding of the magnetic field.

[0046] Embodiment 9 Based on Embodiment 1, the embodiment of the present invention provides a self-shielding anti-interference current transformer, further including a cooperative working module for the cooperative working of the dynamic cancellation layer and the residual suppression layer; The cooperative working module includes: A priority setting unit for establishing a circular buffer for bidirectional data transmission between the dynamic cancellation layer and the residual suppression layer, and establishing different transmission priorities for the magnetic field data based on the data type in the magnetic field data before data transmission; A synchronization unit for establishing a time synchronization mechanism for the dynamic cancellation layer and the residual suppression layer; A template retrieval unit, configured to trigger the residual suppression layer to retrieve a magnetic field response template in advance when the dynamic cancellation layer responds to external interference magnetic field data; A compression determination unit, configured to establish an adaptive transmission compression rate strategy based on the degree of external interference magnetic field data, according to the rule of setting a high compression rate for low interference and a low compression rate for high interference; An operation determination unit, configured to establish an operation rule among a circular buffer, a transmission priority, a time synchronization mechanism, triggering the retrieval of a magnetic field response template, and the adaptive transmission compression rate strategy based on the association between functional characteristics; A cooperation determination unit, configured to establish a cooperative working mechanism based on the circular buffer, the transmission priority, the time synchronization mechanism, triggering the retrieval of a magnetic field response template, and the adaptive transmission compression rate strategy, in combination with the operation rule;

[0047] In this embodiment, before data transmission, different transmission priorities are established for magnetic field data based on the data type in the magnetic field data. For example, high priorities are set for intensity and frequency, and low priorities are set for auxiliary information.

[0048] In this embodiment, triggering the residual suppression layer to retrieve a magnetic field response template in advance provides a basis for the rapid response determination of the parameters of the residual suppression layer.

[0049] In this embodiment, the adaptive transmission compression rate strategy ensures the transmission speed and transmission quality according to different situations.

[0050] In this embodiment, the operation rule is, for example, to first determine the transmission priority and then determine the compression rate according to the adaptive transmission compression rate strategy. Another example is that after obtaining the magnetic field data, the retrieval of the magnetic field response template is triggered based on the circular buffer.

[0051] The beneficial effects of the above design solution are as follows: By establishing an operation rule among a circular buffer, a transmission priority, a time synchronization mechanism, triggering the retrieval of a magnetic field response template, and the adaptive transmission compression rate strategy based on the association between functional characteristics, and establishing a cooperative working mechanism based on the circular buffer, the transmission priority, the time synchronization mechanism, triggering the retrieval of a magnetic field response template, and the adaptive transmission compression rate strategy, in combination with the operation rule, the rapid response transmission of information between the dynamic cancellation layer and the residual suppression layer is realized, the timeliness of information data is ensured, efficient cooperative work is achieved, and for the rapid response and mutual cooperation of the dynamic cancellation layer and the residual suppression layer to the interference magnetic field, the shielding effect of the self-shielding anti-interference current transformer is ensured from the aspect of data transmission and interaction.

[0052] Embodiment 10: An embodiment of the present invention provides a dynamic magnetic field compensation method for a self-shielding anti-interference current transformer, as Figure 3 shown, including: S1: Detect the external interference magnetic field data in real time based on the magnetic field sensing layer; S2: Based on the dynamic cancellation layer, combine the external interference magnetic field data to set the reverse magnetic field data; S3: Based on the residual suppression layer, combine the cancellation situation of the external interference magnetic field data by the reverse magnetic field data to set the auxiliary magnetic field data for further magnetic field shielding.

[0053] In this embodiment, the external interference magnetic field data includes magnetic field direction, magnetic field intensity, magnetic field signal, etc.

[0054] In this embodiment, the reverse magnetic field data is used to cancel the external interference magnetic field data.

[0055] In this embodiment, based on the cancellation situation of the external interference magnetic field data by the reverse magnetic field data, setting the auxiliary magnetic field data for further magnetic field shielding is, for example, for the residual magnetic field caused by the existence of non-linear factors, sensor noise, etc.

[0056] The beneficial effects of the above design scheme are as follows: By detecting the external interference magnetic field data in real time through the magnetic field sensing layer, it provides a basis for the interference shielding of the magnetic field. Based on the external interference magnetic field data, the reverse magnetic field data is set to realize that the main shielding winding generates a reverse magnetic field, which is superimposed and cancelled with the interference magnetic field. Through the residual suppression layer, based on the cancellation situation of the external interference magnetic field data by the reverse magnetic field data, the auxiliary magnetic field data is set for further magnetic field shielding, and the auxiliary shielding winding further eliminates the high-frequency residual interference. Finally, the 0-20 kHz broadband interference suppression is realized, and the performance can be kept stable in the temperature range of -40°C to 120°C. Using a three-layer dynamic shielding layer, it solves the dynamic interference problem in a complex electromagnetic environment and improves the measurement accuracy to the 0.1% level.

[0057] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of this application document and its equivalent technologies, the present invention also intends to include these changes and modifications.

Claims

1. A self-shielded anti-interference current transformer, characterized in that: include: The magnetic field sensing layer is used to detect external interference magnetic field data in real time; A dynamic offset layer is used to set reverse magnetic field data based on external interference magnetic field data; The residual suppression layer is used to set auxiliary magnetic field data for further magnetic field shielding based on the offset of external interfering magnetic field data by reverse magnetic field data.

2. A self-shielded anti-interference current transformer according to claim 1, characterized in that: The material of the dynamic compensation layer is high magnetic permeability Permalloy, and the material of the residual suppression layer is nanocrystalline alloy.

3. A self-shielded anti-interference current transformer according to claim 1, characterized in that: The magnetic field sensing layer comprises: a range determination unit, configured to determine a scanning range based on a location of an interference source; A parameter determination unit, used to determine a probe scanning direction based on the scanning range, and to determine a scanning frequency range based on an operating frequency of an interference source; The magnetic field detection unit is used to detect the external interference magnetic field based on the probe scanning direction and scanning frequency range to obtain the external interference magnetic field data.

4. A self-shielded anti-interference current transformer according to claim 1, characterized in that: The dynamic offset layer comprises: A data processing unit, used for processing the interference magnetic field data based on Fourier transform to obtain the frequency components of the interference magnetic field, and dividing the frequency components into power frequency interference components and broadband interference components; A power frequency analysis unit, used to determine the phase and amplitude of the first compensation coil based on the power frequency interference component to obtain first reverse magnetic field data; The broadband analysis unit is used to adjust the waveform of the compensation current in real time based on the broadband interference component to obtain the second reverse magnetic field data.

5. The self-shielded anti-interference current transformer according to claim 1, characterized in that: The residual inhibition layer comprises: A data determination unit, configured to determine, based on the magnetic field sensing layer, external residual interference magnetic field data after the influence of the reverse magnetic field data on the external interference magnetic field data is offset; The auxiliary compensation unit is used to determine the compensation current for the auxiliary shielding coil based on the external residual interference magnetic field data in combination with the residual suppression control model.

6. A self-shielded anti-interference current transformer according to claim 2, characterized in that: Also includes: Based on the variation trend of the magnetic permeability of the high magnetic permeability Permalloy with temperature, the temperature compensation coefficient of the high magnetic permeability Permalloy is determined; Based on the variation trend of the magnetic permeability of the nanocrystalline alloy with temperature, the temperature compensation coefficient of the nanocrystalline alloy is determined.

7. A self-shielded anti-interference current transformer according to claim 4, characterized in that: The broadband analysis unit comprises: An error determination unit, used for inputting the broadband interference component into a mutual inductor model to obtain output magnetic field data, and obtaining a data error between the output magnetic field data and the broadband interference component; A strategy determination unit, configured to determine an initial correspondence between the waveform and the error based on the current waveform history data, and to establish an initial dynamic compensation strategy based on the initial correspondence; an optimization determination unit, configured to obtain working parameters of the current transformer and magnetic field distribution of the external magnetic field, determine a first compensation optimization coefficient based on a difference between the working parameters and standard working parameters, obtain unique features of the magnetic field distribution, refine the unique features to obtain a plurality of feature combinations, and integrate the compensation coefficients determined based on all the features to obtain a second compensation optimization coefficient; A strategy optimization unit, configured to perform real-time dynamic optimization on an initial dynamic compensation strategy based on the first compensation optimization coefficient and the second compensation optimization coefficient to obtain a target dynamic compensation strategy; A compensation determination unit, configured to determine compensation current parameters based on the target dynamic compensation strategy and in combination with a data error between the output magnetic field data and the broadband interference component, and adjust the waveform of the compensation current in real time based on the compensation current parameters to obtain initial reverse magnetic field data; The cyclic compensation unit is used to provide feedback to the target dynamic compensation strategy based on the latest data error between the initial reverse magnetic field data and the broadband interference component, obtain the latest compensation current parameter, and realize cyclic compensation for the broadband interference component.

8. A self-shielded anti-interference current transformer according to claim 7, characterized in that: The broadband analysis unit further includes: A relationship optimization unit, used for updating the current waveform historical data based on each preset time to obtain new historical data, and adjusting the initial corresponding relationship based on the new historical data to obtain the latest corresponding relationship; The strategy updating unit is used to update the initial dynamic compensation strategy based on the latest corresponding relationship to obtain the latest initial dynamic compensation strategy.

9. The self-shielded anti-interference current transformer according to claim 1, characterized in that: Also included is a collaborative working module, used for collaborative working of the dynamic cancellation layer and the residual suppression layer; The collaborative working module includes: A priority setting unit, used to establish a ring buffer between the dynamic cancellation layer and the residual suppression layer for bidirectional data transmission, and to establish different transmission priorities for the magnetic field data based on the data type in the magnetic field data before data transmission; A synchronization unit, used for establishing a time synchronization mechanism for the dynamic cancellation layer and the residual suppression layer; A template retrieving unit, used to trigger the residual suppression layer to retrieve the magnetic field response template in advance when the dynamic cancellation layer responds to the external interference magnetic field data; A compression determination unit, used to establish a transmission compression rate adaptive strategy based on the degree of external interference magnetic field data according to the rule of setting a high compression rate for low interference and setting a low compression rate for high interference; An operation determination unit, used for establishing operation rules among a ring buffer, a transmission priority, a time synchronization mechanism, a trigger magnetic field response template, and a transmission compression rate adaptive strategy based on associations among functional features; The collaborative determination unit is used to establish a collaborative working mechanism based on the ring buffer, transmission priority, time synchronization mechanism, trigger magnetic field response template retrieval and transmission compression rate adaptive strategy, combined with operation rules.

10. A dynamic magnetic field compensation method for a self-shielded anti-interference current transformer, specifically used in a self-shielded anti-interference current transformer as claimed in claim 1, characterized in that: include: S1: Real-time detection of external interference magnetic field data based on the magnetic field sensing layer; S2: Based on the dynamic offset layer and combined with the external interference magnetic field data, the reverse magnetic field data is set; S3: Based on the residual suppression layer and in combination with the offset of the external interference magnetic field data by the reverse magnetic field data, auxiliary magnetic field data is set to perform further magnetic field shielding.

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