A method and system for common mode interference suppression of a marine isolated transformer

Abstract

The present application relates to the technical field of ship power system electromagnetic compatibility, and particularly relates to a common-mode interference suppression method and system for a ship isolation transformer, which comprises the following steps: using a first magnetic shielding layer to preliminarily suppress common-mode interference, the magnetic shielding performance of the first magnetic shielding layer decays with temperature rise; when the ship isolation transformer is long-term in a high-temperature environment, using a second temperature response layer forming a composite structure with the first magnetic shielding layer to compensate the magnetic performance or control the temperature stability of the first magnetic shielding layer, so as to suppress the magnetic shielding performance decay of the first magnetic shielding layer caused by temperature rise; wherein, the composite structure is used to suppress the radiation coupling effect caused by external high-frequency interference sources, so as to suppress common-mode interference; by introducing the first magnetic shielding layer for preliminary suppression, and combining the second temperature response layer to form a composite structure, the problem of magnetic shielding layer magnetic shielding performance decay in long-term high-temperature environment in the prior art is effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ship power system electromagnetic compatibility, and particularly relates to a common-mode interference suppression method and system of a ship isolation transformer. BACKGROUND

[0002] In a ship power system, an isolation transformer is a key component for ensuring the stable operation of precision electronic equipment on a ship. During the initial design, a magnetic shielding technology is often used to suppress common-mode interference. That is, a shielding layer is constructed by using a high magnetic permeability material to block or attenuate common-mode noise generated by the internal and external electromagnetic environment of the system, so as to avoid the common-mode noise from being transmitted to downstream sensitive equipment through the parasitic capacitance of the winding or space radiation.

[0003] However, the actual service environment of a ship isolation transformer is much more severe than laboratory conditions. Most of the isolation transformers are installed in high-temperature areas such as engine rooms. Due to the operation of the main engine, the generator set, and the long-term heavy load of the isolation transformer itself, the heat generated by the internal winding and the core will cause the magnetic shielding layer to be in a high-temperature environment for a long time. This may cause the magnetic domain structure of the high magnetic permeability material to change or the lattice vibration to intensify, resulting in a significant decrease in the effective magnetic permeability. In turn, this weakens the ability to guide and limit the magnetic field lines and the efficiency of magnetic field energy absorption and reflection, especially the suppression effect of low-frequency common-mode interference. Conventional ship maintenance and monitoring focus on parameters such as the overall temperature rise of the transformer, the stability of the output voltage, the current load, and the insulation state. However, it is difficult to capture the subtle attenuation of the magnetic permeability of the magnetic shielding layer caused by high temperature. This attenuation does not immediately cause temperature abnormalities, voltage, or insulation problems in the transformer. Therefore, the gradual and hidden attenuation of the performance of the magnetic shielding layer cannot be identified in routine inspections, which may cause interference suppression problems.

[0004] In addition, during the layout modification of ship equipment or the maintenance of cables, if the power cables such as frequency converters are accidentally placed close to the isolation transformer due to space limitations, construction habits, or other factors, the electromagnetic coupling problem will be exacerbated. The high-frequency harmonics and switching noise generated by the frequency converter will be enhanced as the distance between the cable and the transformer decreases (the radiation coupling strength is inversely proportional to the square of the distance), and will be coupled to the shielding layer. The performance attenuation of the shielding layer caused by high temperature forms a superposition, further deteriorating the shielding effectiveness.

[0005] Finally, the common mode interference that is not effectively suppressed will be transmitted to downstream precision navigation equipment (such as high-precision GPS receivers, electronic chart systems) and key communication systems (such as satellite communication terminals, very high frequency radios). It causes intermittent data transmission errors, signal distortion or abnormal functions (such as navigation position drift, communication interruption) of the equipment. These abnormalities are not persistent equipment failures, but are periodic under certain working conditions, for example, when a large motor inverter operates at a certain speed (because the switching frequency of the inverter and the harmonic spectrum generated are related to the motor speed). It is difficult to accurately locate the problem source through traditional fault diagnosis processes. Maintenance personnel may first check the affected navigation or communication equipment itself, or the voltage, current and other macro parameters of the power system, but because the problem is caused by the hidden attenuation of the magnetic shielding layer performance and the superposition effect of the accidental proximity of the external interference source, these conventional diagnostic methods often cannot reveal the nature of the problem, which seriously affects the safety of ship navigation and the efficiency of task execution. In this scenario, the existing magnetic shielding method faces serious challenges in terms of the robustness and adaptability of common mode interference suppression when faced with long-term environmental stress, accidental maintenance operations, and superposition effects of complex electromagnetic environments.

[0006] The prior art needs to be improved in view of the above problems. SUMMARY

[0007] The purpose of the present application is to solve the problems existing in the prior art and provide a common mode interference suppression method and system for a marine isolation transformer.

[0008] In a first aspect, the present application provides a common mode interference suppression method for a marine isolation transformer, the method comprising the following steps:

[0009] The first magnetic shielding layer is used to preliminarily suppress the common mode interference, and the magnetic shielding performance of the first magnetic shielding layer decays with increasing temperature;

[0010] When the marine isolation transformer is in a high-temperature environment for a long time, the second temperature-responsive layer forming a composite structure with the first magnetic shielding layer is used to compensate the magnetic performance or control the temperature stability of the first magnetic shielding layer to suppress the decay of the magnetic shielding performance of the first magnetic shielding layer due to the increase in temperature;

[0011] The composite structure is used to suppress the radiation coupling effect generated by an external high-frequency interference source to suppress the common mode interference.

[0012] In a second aspect, a common mode interference suppression system for a marine isolation transformer is provided, the system comprising:

[0013] The first magnetic shielding module is used for preliminarily suppressing common-mode interference by using a first magnetic shielding layer, and the magnetic shielding performance of the first magnetic shielding layer is attenuated with the increase of temperature.

[0014] The second temperature response module is used for, when the marine isolation transformer is long-term in a high-temperature environment, performing magnetic performance compensation or temperature stability control on the first magnetic shielding layer by using a second temperature response layer which forms a composite structure with the first magnetic shielding layer, so as to suppress the attenuation of the magnetic shielding performance of the first magnetic shielding layer caused by the increase of temperature, and the composite structure is used for suppressing the radiation coupling effect caused by an external high-frequency interference source, so as to suppress the common-mode interference.

[0015] Compared with the prior art, the present application has the following beneficial effects:

[0016] By introducing the first magnetic shielding layer for preliminary suppression and combining the second temperature response layer to form a composite structure, the problem of magnetic shielding performance attenuation of the magnetic shielding layer in the prior art under long-term high-temperature environment is effectively solved. Specifically, the first magnetic shielding layer can preliminarily attenuate the common-mode interference, and when the marine isolation transformer is long-term in a high-temperature environment, the second temperature response layer can perform magnetic performance compensation or temperature stability control on the first magnetic shielding layer, so as to suppress the attenuation of the magnetic shielding performance of the first magnetic shielding layer caused by the increase of temperature. In addition, the composite structure can also effectively suppress the radiation coupling effect caused by an external high-frequency interference source. Through the synergistic effect, the method of the present application overcomes the limitation of the prior art magnetic shielding technology that the shielding effectiveness decreases due to the increase of temperature in a complex marine environment, significantly improves the suppression ability of the marine isolation transformer to the common-mode interference, and guarantees the stable operation of the precision electronic equipment on the ship, thereby solving the problem of equipment abnormality and fault difficult to locate caused by the performance attenuation of the magnetic shielding layer and the proximity of external interference sources mentioned in the background art. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The method flowchart of the present application.

[0018] Figure 2 The system structure schematic diagram of the present application.

[0019] In the figure: 201, first magnetic shielding module; 202, second temperature response module. DETAILED DESCRIPTION

[0020] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0021] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] Traditional marine isolation transformers typically employ magnetic shielding to suppress common-mode interference. However, in the harsh environments of ships operating for extended periods, including high temperatures and vibrations, the magnetic shielding performance degrades with increasing temperature, and this subtle degradation is difficult to detect with conventional monitoring. Furthermore, the unexpected approach of external interference sources can further exacerbate common-mode interference, severely impacting the stable operation of shipboard precision equipment. Failure to address these issues will render marine isolation transformers ineffective at suppressing common-mode interference in practical applications, thereby affecting navigation safety and mission efficiency.

[0023] In response, this application proposes a common-mode interference suppression method for marine isolation transformers. This method uses a first magnetic shielding layer to initially suppress common-mode interference, and combines a second temperature response layer to compensate for the magnetic properties of the first magnetic shielding layer or control its temperature stability. This effectively suppresses the attenuation of the magnetic shielding performance of the first magnetic shielding layer due to temperature rise, and also suppresses the radiation coupling effect generated by external high-frequency interference sources, thereby significantly improving the common-mode interference suppression capability of marine isolation transformers in complex environments.

[0024] To better understand the common-mode interference suppression method proposed in this application, the key terms involved are first explained. "Marine isolation transformer" refers to a transformer used in a ship's power system to achieve electrical isolation and transmit electrical energy. Its main function is to prevent common-mode noise from being transmitted to downstream sensitive electronic equipment through parasitic capacitance between the primary and secondary windings of the transformer or through direct spatial radiation. "Common-mode interference" refers to noise signals in multi-conductor transmission lines where all conductors have the same phase and amplitude relative to ground or a reference plane, posing a threat to the stable operation of shipboard precision electronic equipment. "First magnetic shielding layer" refers to a magnetic material layer used for initial suppression of common-mode interference; its magnetic shielding performance is affected by temperature changes. "Second temperature response layer" refers to a material layer that forms a composite structure with the first magnetic shielding layer, used for magnetic performance compensation or temperature stability control of the first magnetic shielding layer in high-temperature environments. "Composite structure" refers to the structure jointly formed by the first magnetic shielding layer and the second temperature response layer, designed to synergistically suppress common-mode interference, especially the radiative coupling effect generated by external high-frequency interference sources.

[0025] like Figure 1 The method for suppressing common-mode interference of a marine isolation transformer, as shown, includes the following steps:

[0026] S101. The first magnetic shielding layer is used to initially suppress common-mode interference. The magnetic shielding performance of the first magnetic shielding layer decreases as the temperature increases.

[0027] It should be noted that the initial suppression of common-mode interference using the first magnetic shielding layer can be achieved in various ways. For example, the first magnetic shielding layer can be made of high-permeability materials such as permalloy, ferrite, or amorphous alloys. These materials can effectively absorb and reflect magnetic field energy, thereby attenuating the common-mode interference magnetic field. The first magnetic shielding layer can be designed as a closed structure surrounding the transformer windings or core; for example, it can be a cylindrical or box-shaped shield, the thickness and material selection of which will be optimized according to the expected common-mode interference frequency range and suppression effect. In practical applications, the first magnetic shielding layer can be directly integrated into the transformer structure, for example, as a sandwich between windings or as an inner lining of the transformer casing.

[0028] S102. When the marine isolation transformer is in a high-temperature environment for a long time, the second temperature response layer, which forms a composite structure with the first magnetic shielding layer, is used to compensate for the magnetic properties of the first magnetic shielding layer or control its temperature stability, so as to suppress the attenuation of the magnetic shielding performance of the first magnetic shielding layer due to the increase in temperature; the composite structure is used to suppress the radiation coupling effect generated by external high-frequency interference sources, so as to suppress common-mode interference.

[0029] It should be noted that the second temperature-responsive layer can employ various materials and structural forms. For example, the second temperature-responsive layer can be a material with a positive temperature coefficient (PTC) or negative temperature coefficient (NTC) permeability, whose permeability changes with temperature in the opposite direction to that of the first magnetic shielding layer. This allows it to compensate for the attenuation of the magnetic properties of the first magnetic shielding layer by changing its own permeability as the temperature rises. Specifically, if the permeability of the first magnetic shielding layer decreases with increasing temperature, the second temperature-responsive layer can be a material whose permeability increases with temperature to achieve compensation. Alternatively, the second temperature-responsive layer can also be a material with good thermal conductivity, such as graphene composites or thermally conductive ceramics. This material rapidly conducts the heat generated by the first magnetic shielding layer away, thereby reducing the operating temperature of the first magnetic shielding layer and indirectly achieving temperature stability control. Furthermore, the second temperature-responsive layer can also be a phase change material that undergoes a phase change at a specific temperature and absorbs or releases heat, thus maintaining the operating temperature of the first magnetic shielding layer within its optimal range.

[0030] The design of the composite structure is crucial for suppressing the radiated coupling effect caused by external high-frequency interference sources. The composite structure can adopt a multi-layer structure, for example, the second temperature-responsive layer is closely attached to the outer surface or inner surface of the first magnetic shielding layer. In one embodiment, the second temperature-responsive layer can be designed as an interlaced grid structure with the first magnetic shielding layer to maximize the heat exchange and magnetic field coupling effect between the two layers. In another embodiment, the composite structure can adopt a sandwich structure, with the second temperature-responsive layer sandwiched between two layers of the first magnetic shielding layer, or the first magnetic shielding layer sandwiched between two layers of the second temperature-responsive layer, to achieve a more optimal shielding effect and temperature control. Through such a composite structure, the radiated electromagnetic field generated by external high-frequency interference sources can be effectively confined inside the composite structure, reducing the chance of penetrating into the transformer, thereby suppressing common-mode interference.

[0031] Specifically, when the marine isolation transformer is in normal operation, the first magnetic shielding layer first performs preliminary suppression of common-mode interference, absorbing and reflecting most of the common-mode noise by its high magnetic permeability characteristics. However, when the ship is in a high-temperature environment for a long time, such as near the engine compartment, the magnetic shielding performance of the first magnetic shielding layer will gradually deteriorate due to the temperature rise. At this time, the second temperature-responsive layer forming a composite structure with the first magnetic shielding layer begins to play a role. If the second temperature-responsive layer has a magnetic performance compensation function, its magnetic permeability will change with the temperature rise to offset or slow down the decrease in magnetic permeability of the first magnetic shielding layer due to the temperature rise, thereby maintaining the magnetic shielding performance of the overall composite structure. If the second temperature-responsive layer is mainly used for temperature stability control, it will maintain the operating temperature of the first magnetic shielding layer within the optimal range through efficient heat conduction or phase change heat absorption, etc., thereby avoiding the deterioration of its magnetic shielding performance due to excessive temperature. Thus, whether the first magnetic shielding layer is directly compensated or maintained stable through temperature control, its suppression ability of common-mode interference is effectively maintained.

[0032] In addition, the composite structure is also specially used to suppress the radiated coupling effect caused by external high-frequency interference sources. During the operation of the ship, for example, when high-frequency interference sources such as large motor frequency converters accidentally approach the isolation transformer, a strong radiated electromagnetic field will be generated. The composite structure, through its multi-layer or interlaced design, can effectively block or attenuate these high-frequency radiation fields, preventing them from coupling into the transformer. For example, the second temperature-responsive layer can act as an additional shielding layer, together with the first magnetic shielding layer, to form a more robust electromagnetic barrier, thereby significantly reducing the impact of external high-frequency interference on the transformer. Through such a synergistic effect, the method of the present application not only solves the performance deterioration problem of the magnetic shielding layer at high temperature, but also enhances the resistance to external high-frequency radiation coupling interference, ensuring the common-mode interference suppression effect of the marine isolation transformer in complex and severe environments.

[0033] The core innovation of the common-mode interference suppression method of the marine isolation transformer proposed in the application is that a second temperature response layer is introduced to form a composite structure with the first magnetic shielding layer to address the problems of magnetic shielding performance attenuation of the marine isolation transformer in a long-term high-temperature environment and the radiation coupling effect of external high-frequency interference sources.

[0034] As an embodiment of the application, the method further comprises:

[0035] When the marine isolation transformer is long-term served in a vibration and periodic high-temperature superimposed environment, the temperature of each local area of the first magnetic shielding layer is perceived.

[0036] It should be noted that the "marine isolation transformer long-term served in a vibration and periodic high-temperature superimposed environment" means that the transformer continuously bears mechanical vibration from the engine, propeller and other equipment during the operation of the ship, and the environmental temperature may fluctuate periodically due to the change of day and night, sailing area or equipment load, resulting in that the first magnetic shielding layer is long-term under the alternating action of complex stress and thermal cycle. Such an environment may accelerate material aging and cause uneven degradation of magnetic shielding performance in local areas. The temperature of each local area of the first magnetic shielding layer can be perceived by pre-setting a distributed temperature sensor array on the surface or inside the first magnetic shielding layer, such as using a thermistor, a thermocouple, an optical fiber temperature sensor, etc. The purpose is to obtain real-time temperature data of different positions of the first magnetic shielding layer to accurately identify potential overheated areas or temperature abnormal areas.

[0037] According to the temperature of the local area, it is judged whether there is a local weak area of magnetic permeability attenuation in the first magnetic shielding layer;

[0038] It should be noted that the above step can be understood as that by analyzing the local temperature data, combining the pre-set material performance attenuation model or empirical threshold, it is evaluated whether the magnetic permeability of the local area has been significantly reduced to the degree of affecting the shielding effect. For example, when the temperature of a local area is continuously higher than a certain threshold or its temperature change rate is abnormal, it can be judged that the local area may have formed a local weak area of magnetic permeability attenuation. The purpose is to accurately locate the specific position of the damaged magnetic shielding performance.

[0039] When there is a local weak area, a local compensation magnetic field is generated at the local weak area, and the local compensation magnetic field is used to offset the external high-frequency common-mode interference magnetic field penetrating the local weak area.

[0040] It should be noted that "generating a local compensation magnetic field at the local weak area" specifically refers to, after identifying the local weak area, activating or adjusting the magnetic field generating device arranged near the area, such as a micro electromagnetic coil array, to generate a magnetic field opposite in direction and matching in strength to the external high-frequency common-mode interference magnetic field penetrating the area. The purpose is to restore or enhance the magnetic shielding effect of the local area by means of active magnetic field cancellation. "The local compensation magnetic field is used to cancel the external high-frequency common-mode interference magnetic field penetrating the local weak area" means that by accurately controlling the strength, direction and phase of the local compensation magnetic field, it forms a superposition with the external high-frequency common-mode interference magnetic field entering the local weak area, so as to realize the mutual cancellation of the magnetic field in space, effectively preventing or greatly weakening the influence of the interference magnetic field on the internal circuit of the transformer.

[0041] The scheme of the present application effectively solves the problem of local magnetic permeability attenuation of the first magnetic shielding layer in complex service environment by introducing a fine perception and dynamic compensation mechanism for the local state of the first magnetic shielding layer. Specifically, when the marine isolation transformer is long-term served in a vibration and periodic high temperature superimposed environment, the thermal distribution information of the first magnetic shielding layer can be obtained in real time by perceiving the temperature of each local area of the first magnetic shielding layer. Based on these local temperature data, it can be judged whether there is a local weak area caused by factors such as temperature rise, material fatigue or stress concentration. Once such a local weak area is identified, a local compensation magnetic field is generated at the area. The local compensation magnetic field is accurately designed to cancel the external high-frequency common-mode interference magnetic field penetrating the local weak area. It is precisely because of this targeted local perception, judgment and active compensation that even in the case of local performance degradation of the first magnetic shielding layer, the overall common-mode interference suppression capability can still be effectively maintained, avoiding the overall shielding failure caused by local defects.

[0042] Through the above technical scheme, the present application can significantly improve the common-mode interference suppression robustness and reliability of the marine isolation transformer in severe service environment. Specifically, by real-time perception of the temperature of the local area of the first magnetic shielding layer and accurate judgment of the magnetic permeability attenuation, potential shielding weak points can be found and located in time, avoiding the blind area that may exist in the traditional overall compensation scheme. Further, by generating a local compensation magnetic field at the local weak area, accurate cancellation of the penetrating interference magnetic field is achieved, effectively making up for the deficiency caused by the local performance degradation of the first magnetic shielding layer. Thus, the present application not only ensures the continuous and stable operation of the marine isolation transformer in a complex environment of vibration and periodic high temperature superposition, but also effectively prolongs the effective life of the magnetic shielding system, reduces the risk of overall interference suppression performance decline caused by local failure, and provides a more solid technical guarantee for the long-term reliable operation of the marine isolation transformer.

[0043] As an embodiment of the present application, the step of generating a local compensation magnetic field at the local weak area includes:

[0044] At the local weak area, the spatial vector distribution information of the external high-frequency common-mode interference magnetic field is obtained;

[0045] It should be noted that the above step can be understood as comprehensively and accurately measuring and characterizing the magnetic field strength, direction, phase and other parameters of the external high-frequency common-mode interference magnetic field at different spatial points in the local weak area. The purpose is to obtain the complete spatial characteristics of the interference magnetic field, and provide a data basis for subsequent accurate compensation. The spatial vector distribution information can include the instantaneous amplitude, direction and phase of the magnetic field, which is crucial for accurately constructing the cancellation magnetic field.

[0046] According to the spatial vector distribution information, the compensation magnetic field vector required by the local weak area is determined;

[0047] It should be noted that the above step refers to obtaining the detailed spatial characteristics of the interference magnetic field, and then calculating and analyzing to obtain the accurate vector representation of the magnetic field required in the local weak area. The compensation magnetic field vector is usually designed to be equal in size and opposite in direction to the interference magnetic field in the local weak area to achieve the best cancellation effect. The determination process can use magnetic field theory and numerical calculation method to ensure the accuracy of the compensation magnetic field.

[0048] A local compensation magnetic field matching the compensation magnetic field vector is generated.

[0049] It should be noted that the above step refers to using a specific magnetic field generating device, such as an electromagnetic coil array, to accurately generate a magnetic field with corresponding strength, direction and phase in the local weak area according to the determined compensation magnetic field vector. The purpose is to form a magnetic field in the local weak area that is equal in size and opposite in direction to the external high-frequency common-mode interference magnetic field, thereby achieving effective cancellation of the interference.

[0050] The scheme of the present application first accurately obtains the spatial vector distribution information of the external high-frequency common-mode interference magnetic field, thereby comprehensively understanding the characteristics of the interference magnetic field. Based on this accurate interference information, the compensation magnetic field vector required by the local weak area can be accurately determined, ensuring that the compensation magnetic field and the interference magnetic field can achieve the best matching in space. Finally, by generating a local compensation magnetic field that accurately matches the compensation magnetic field vector, the precise cancellation of the external high-frequency common-mode interference magnetic field penetrating the local weak area is achieved. This closed-loop control mechanism from perception to calculation to generation ensures the pertinence and effectiveness of the compensation, and solves the problems of blindness and inefficiency that may exist in traditional compensation methods.

[0051] By the technical solution, the spatial vector distribution information of the external high-frequency common-mode interference magnetic field is accurately acquired, and a matched local compensation magnetic field is determined and generated according to the spatial vector distribution information, so that the common-mode interference in the local weak area can be highly accurately and effectively suppressed. Compared with the basic scheme of only sensing the existence of the local weak area and generating a compensation magnetic field, the application can customize the compensation according to the specific spatial characteristics of the interference magnetic field, significantly improving the accuracy and efficiency of the compensation, so as to effectively offset the external high-frequency common-mode interference magnetic field penetrating the local weak area, and further improve the anti-interference ability and operation reliability of the marine isolation transformer in a complex environment.

[0052] As an embodiment of the application, in the local weak area, the step of acquiring the spatial vector distribution information of the external high-frequency common-mode interference magnetic field comprises:

[0053] A reference magnetic field with known characteristics is periodically generated, the reference magnetic field at the local weak area is measured by using a pre-set magnetic field sensor array, and the spatial vector distribution information of the external high-frequency common-mode interference magnetic field is acquired.

[0054] It should be noted that periodically generating a reference magnetic field with known characteristics means that a magnetic field with a predetermined intensity, direction and frequency characteristic is generated at the local weak area by one or more known and controllable magnetic field sources (for example, a small coil or a permanent magnet array) within a specific time interval. The "known characteristics" can include parameters such as the amplitude, phase, frequency and spatial distribution mode of the magnetic field, which are accurately controllable and known when generated. The purpose is to provide a reference or detection signal for subsequent magnetic field measurement. Measuring the reference magnetic field at the local weak area by using a pre-set magnetic field sensor array means that a plurality of magnetic field sensors (for example, Hall sensors, magnetoresistance sensors or coil sensors) are deployed in a predetermined geometric configuration at the local weak area and its vicinity. The magnetic field sensor array can simultaneously or sequentially measure the magnetic field signal generated by the reference magnetic field source. By processing the signals measured by the sensors, the magnetic field response data at different positions in the local weak area can be obtained.

[0055] Therefore, by analyzing the reference magnetic field data measured by the magnetic field sensor array and combining the known characteristics of the reference magnetic field, the spatial vector distribution information of the external high-frequency common-mode interference magnetic field can be inverted or inferred. For example, when there is no external interference, the reference magnetic field measured by the sensor array should be consistent with the known characteristics; when there is an external high-frequency common-mode interference magnetic field, the total magnetic field measured will be the superposition of the reference magnetic field and the interference magnetic field. By separating the reference magnetic field component from the total magnetic field, the spatial vector distribution information of the interference magnetic field can be obtained.

[0056] The scheme of the present application can effectively detect and model the magnetic field environment of the local weak area by periodically generating a reference magnetic field with known characteristics and measuring with a magnetic field sensor array. It is because the characteristics of the reference magnetic field are known that the sensor array can distinguish the response caused by the reference magnetic field from the response caused by the external high-frequency common-mode interference magnetic field during measurement. In this way, the spatial vector distribution information of the external high-frequency common-mode interference magnetic field in the local weak area can be accurately obtained. This method avoids the difficulty of directly measuring the complex and possibly transient interference magnetic field, and instead indirectly and accurately characterizes the interference field through the disturbance of the known reference field.

[0057] As an embodiment of the present application, the step of obtaining the spatial vector distribution information of the external high-frequency common-mode interference magnetic field in the local weak area further comprises:

[0058] Obtaining the actual spatial position or the offset information of the measurement axis of the magnetic field sensor array relative to the preset position or axis;

[0059] It should be noted that the above step can be understood as determining the difference between the actual physical position of each sensor unit in the magnetic field sensor array and its design or initial calibration position, and the angular deviation between its measurement direction axis and the ideal axis, through various measurement techniques or sensor self-calibration mechanisms. For example, inertial measurement units (IMU), optical positioning systems, ultrasonic ranging sensors or self-positioning algorithms based on magnetic field sources can be used to obtain these offset data in real time or periodically. The purpose is to quantify the geometric distortion or attitude change of the sensor array, and provide basic data for subsequent accurate correction.

[0060] According to the offset information, correcting the spatial vector distribution information.

[0061] It should be noted that the above step refers to incorporating the offset amount into the calculation model of the magnetic field spatial vector distribution after obtaining the actual position and axis offset data of the sensor array, and performing geometric transformation or mathematical correction on the original measurement data. For example, through coordinate transformation matrix, interpolation algorithm or inverse solving method based on physical model, the magnetic field data measured by the sensor at the offset position can be mapped or converted to the equivalent data at its ideal position or calibration state. The purpose is to eliminate the measurement error introduced by the position or attitude offset of the sensor array, and ensure that the spatial vector distribution information of the external high-frequency common-mode interference magnetic field obtained has high precision and high reliability.

[0062] The scheme of the present application effectively solves the problem of inaccurate positioning or posture of the sensor array caused by various factors by obtaining the actual spatial position of the magnetic field sensor array or the offset information of the measurement axis relative to the preset position or axis, and correcting the obtained spatial vector distribution information according to the offset information. Specifically, when the sensor array is offset, the magnetic field data measured by the sensor array will no longer accurately reflect the real magnetic field distribution of the local weak area. By accurately measuring and compensating for these offsets, it can be ensured that even in the case of changes in the position or posture of the sensor array, the obtained spatial vector distribution information of the external high-frequency common-mode interference magnetic field can still accurately reflect the actual situation. Thus, a reliable data basis is provided for subsequent determination of accurate compensation magnetic field vectors, thereby ensuring the generation accuracy of the local compensation magnetic field and the effectiveness of common-mode interference suppression.

[0063] Through the above technical scheme, the present application can significantly improve the accuracy of obtaining the spatial vector distribution information of the external high-frequency common-mode interference magnetic field. Even in the case of long-term service of the marine isolation transformer in a vibration and periodic high-temperature superimposed environment, causing the actual spatial position of the magnetic field sensor array or the measurement axis to be offset, real-time or periodic correction can be performed to ensure that the obtained spatial vector distribution information is accurate. This not only improves the accuracy of subsequent local compensation magnetic field generation, but also enhances the robustness and adaptability of the entire common-mode interference suppression system in complex and variable environments, thereby achieving more stable and efficient common-mode interference suppression effect.

[0064] As an embodiment of the present application, the step of generating a local compensation magnetic field matching the compensation magnetic field vector comprises:

[0065] Based on the plurality of independently controllable electromagnetic coils deployed in advance, a local compensation magnetic field is generated in the local weak area.

[0066] It should be noted that the plurality of independently controllable electromagnetic coils refers to a coil array that can independently receive control signals and generate their own magnetic fields. These electromagnetic coils can be deployed around the local weak area of the marine isolation transformer as needed, for example, they can be wrapped around the vicinity of a specific weak point of the first magnetic shielding layer. The current intensity, direction and phase of each electromagnetic coil can be independently adjusted, thereby accurately controlling the magnetic field generated thereby. Through the coordinated control of these independent coils, a local compensation magnetic field with a specific spatial vector distribution can be synthesized to accurately cancel out the external high-frequency common-mode interference magnetic field penetrating the local weak area. The electromagnetic coils can take various forms, such as air-core coils, ferrite-core coils or superconducting coils, and the specific choice can be made according to the required magnetic field strength, frequency response and spatial limitations. The purpose is to provide a flexible and accurate magnetic field generation mechanism to cope with complex common-mode interference situations.

[0067] The scheme of the present application solves the challenge of accurately generating a local compensation magnetic field in a complex electromagnetic environment by introducing multiple independently controllable electromagnetic coils. When a local weak area is identified and the required compensation magnetic field vector is determined, a traditional single magnetic field source may have difficulty accurately implementing this vector field, especially when dynamic adjustments are needed to adapt to changes in interference. However, with multiple electromagnetic coils deployed in advance, each coil is given independent control capability, and its excitation signal can be adjusted according to the requirements of the overall compensation magnetic field vector. These independently generated magnetic fields are superimposed in the local weak area, thereby synthesizing a composite magnetic field that accurately matches the target compensation magnetic field vector. This distributed and controllable magnetic field generation method enables the compensation magnetic field to flexibly adapt to the dynamic changes and complex spatial distribution of external high-frequency common-mode interference magnetic fields, ensuring effective cancellation of interference and improving the precision and adaptability of common-mode interference suppression.

[0068] As an embodiment of the present application, the step of generating a local compensation magnetic field matching the compensation magnetic field vector further comprises:

[0069] During the generation of the local compensation magnetic field by the electromagnetic coils, the operating state parameters of each electromagnetic coil are sensed in real time, and the operating state parameters indicate the performance drift of the electromagnetic coil caused by operation;

[0070] It should be noted that "sensing the operating state parameters of each electromagnetic coil in real time" means continuously or periodically acquiring physical quantities reflecting the current operating state of the electromagnetic coil through sensors integrated in the electromagnetic coil or its vicinity. These operating state parameters can include but are not limited to the resistance value, inductance value, temperature, current, voltage, magnetic field strength, etc. of the coil. Among them, "the operating state parameters indicate the performance drift of the electromagnetic coil caused by operation" can be understood as that through the monitoring of these parameters, it can be judged whether the actual magnetic field generation capability of the electromagnetic coil deviates from its design parameters or initial calibration state. For example, an increase in coil resistance can cause a decrease in current at the same voltage, thereby affecting the magnetic field strength; an increase in coil temperature can change its magnetic permeability, affecting the magnetic field distribution.

[0071] According to the operating state parameters, the adjustment amount of the excitation signal of each electromagnetic coil is calculated;

[0072] It should be noted that the above step means that based on the real-time sensed operating state parameters, in combination with the pre-set electromagnetic coil model or calibration data, the degree of performance drift of the current electromagnetic coil is evaluated, and the correction amount of the excitation signal (such as current, voltage) required for the electromagnetic coil to generate the target compensation magnetic field vector is calculated. This calculation process can be realized by using control algorithms, lookup tables or machine learning models, etc.

[0073] According to the excitation signal adjustment amount, the current intensity, direction and phase of each electromagnetic coil are adjusted to generate a local compensation magnetic field matching the compensation magnetic field vector.

[0074] It should be noted that "according to the excitation signal adjustment amount, the current intensity, direction and phase of each electromagnetic coil are adjusted" means that the calculated excitation signal adjustment amount is applied to the driving circuit of the electromagnetic coil to accurately control the current size, direction and phase relationship of each electromagnetic coil relative to other coils. The purpose is to ensure that even if the performance of the electromagnetic coil itself drifts, it can dynamically adjust its excitation signal to ensure that the local compensation magnetic field it generates can accurately match the expected compensation magnetic field vector.

[0075] The scheme of the present application effectively solves the influence of electromagnetic coil performance drift on the generation accuracy of local compensation magnetic field by introducing real-time sensing of electromagnetic coil operating state parameters and dynamic adjustment mechanism of excitation signal. Specifically, when the electromagnetic coil drifts in performance (such as resistance, inductance, etc.) due to long-term operation or environmental factors, the magnetic field it generates under a given excitation will no longer accurately meet the design requirements. By sensing these operating state parameters in real time, the system can timely obtain the actual working condition of the electromagnetic coil and identify the degree of its performance drift. Based on these sensed parameters, the system can accurately calculate the required excitation signal adjustment amount, such as correcting the current intensity, direction and phase. This dynamic adjustment mechanism enables the electromagnetic coil to overcome the influence of its own performance drift, ensuring that it can generate a local compensation magnetic field highly matching the target compensation magnetic field vector under any working condition. Thus, even in harsh service environments, the local compensation magnetic field can effectively counteract the external high-frequency common-mode interference magnetic field penetrating the local weak area, thereby maintaining the stability and high precision of the common-mode interference suppression of the marine isolation transformer.

[0076] Through the above technical scheme, the present application can significantly improve the robustness and accuracy of the common-mode interference suppression of the marine isolation transformer. The traditional local compensation magnetic field generation scheme may decrease the compensation effect due to the performance drift of the electromagnetic coil, especially when the marine isolation transformer is long-term served in a harsh environment with vibration and periodic high temperature superimposed. The present application effectively offsets the negative effects caused by the performance drift of the electromagnetic coil itself by real-time monitoring of the operating state of the electromagnetic coil and dynamically adjusting its excitation signal, ensuring that the local compensation magnetic field can continuously and accurately counteract the external high-frequency common-mode interference magnetic field. This not only improves the stability of common-mode interference suppression and prolongs the effective service life of the system in complex environments, but also avoids the need for frequent manual calibration or replacement of components due to performance degradation, thereby reducing maintenance costs and improving system reliability.

[0077] As one embodiment of the present invention, the step of calculating the excitation signal adjustment amount of each electromagnetic coil based on the operating state parameters includes:

[0078] Based on the real-time sensed operating status parameters, the drift parameters of the electromagnetic coil are estimated using parameter identification methods.

[0079] It should be noted that operating state parameters can be understood as physical quantities reflecting the current operating state and performance characteristics of an electromagnetic coil, such as the coil's real-time current, voltage, temperature, impedance, and inductance. Real-time sensing of these parameters helps to capture subtle changes in coil performance. Parameter identification methods refer to methods that use mathematical models and algorithms to determine the internal parameters of a system using its input and output data. In practical applications, various parameter identification methods can be used, such as least squares, Kalman filtering, adaptive filtering, and neural networks, with the aim of extracting performance drift information of the electromagnetic coil from the real-time sensed operating state parameters. The drift parameters of an electromagnetic coil refer to the changes in its inherent electrical or magnetic characteristics relative to its initial design or nominal values ​​during long-term operation, such as changes in coil resistance, inductance, and the attenuation of the magnetic permeability of the core material.

[0080] Based on the estimated drift parameters and the target compensation magnetic field vector, the excitation signal adjustment of each electromagnetic coil is calculated.

[0081] It should be noted that these drift parameters directly affect the ability and efficiency of the electromagnetic coil to generate a magnetic field. The target compensation magnetic field vector refers to the precise spatial vector information of the local compensation magnetic field that is expected to be generated in a local weak area to effectively counteract the external high-frequency common-mode interference magnetic field. The excitation signal adjustment amount refers to the amount of correction required to the excitation signal, such as the current intensity, direction, and phase applied to the electromagnetic coil, so that the electromagnetic coil can still accurately generate the target compensation magnetic field vector even when its performance drifts.

[0082] The solution proposed in this application introduces a parameter identification method, enabling dynamic estimation of the electromagnetic coil's drift parameters based on real-time sensed operating state parameters. This means the system no longer relies solely on a preset coil model but can update its understanding of the coil's actual performance in real time. Because the system can accurately estimate the electromagnetic coil's drift parameters, it can combine these parameters with the target compensation magnetic field vector to calculate a more precise excitation signal adjustment. This dynamic and adaptive adjustment mechanism ensures that even if the electromagnetic coil's performance degrades due to long-term operation or environmental changes, the system can still accurately match the target compensation magnetic field vector through precise excitation signal adjustment, thereby effectively counteracting external high-frequency common-mode interference magnetic fields that penetrate local weak areas.

[0083] By the technical solution, the application can overcome the problem of the decline in compensation accuracy of the traditional method when the electromagnetic coil performance drifts. By estimating the drift parameters of the electromagnetic coil in real time, the system can make more fine and adaptive adjustments to the excitation signal, thereby significantly improving the generation accuracy and stability of the local compensation magnetic field. Thus, even in the case of long-term service and performance changes of the electromagnetic coil, the common-mode interference can be effectively suppressed, and the reliability and anti-interference ability of the marine isolation transformer in a complex environment are enhanced.

[0084] As an embodiment of the application, according to the real-time perceived operating state parameters, the step of estimating the drift parameters of the electromagnetic coil by a parameter identification method comprises:

[0085] Based on the dynamic evolution law of the electromagnetic coil state and the drift parameters, the current state and the drift parameters of the electromagnetic coil are predicted.

[0086] It should be noted that the above step refers to using a previously established electromagnetic coil model, which describes the physical state (such as temperature, current, magnetic field strength, etc.) of the electromagnetic coil and the law of change of its drift parameters (such as resistance change, magnetic permeability attenuation, etc.) over time. By taking the estimated state and drift parameters at the last time as input, and combining the dynamic evolution law, the state and drift parameters of the electromagnetic coil at the current time can be predicted. The purpose is to provide a preliminary estimate based on the intrinsic mechanism of the system to deal with the possible delay or incompleteness of the measurement data.

[0087] According to the predicted current state and drift parameters and the real-time perceived operating state parameters, the current state and drift parameters are corrected by fusing the prediction bias and the measurement bias, to obtain the corrected drift parameters.

[0088] It should be noted that the above step can be understood as comparing the state and drift parameters predicted based on the model with the actual operating state parameters perceived in real time by the sensor. The prediction bias refers to the difference between the model prediction value and the actual measurement value, while the measurement bias reflects the uncertainty of the sensor measurement itself. By a fusion algorithm (such as Kalman filter, extended Kalman filter, or unscented Kalman filter, etc.), the two biases are considered comprehensively to correct the prediction value, thereby obtaining more accurate and robust estimates of the current state and drift parameters of the electromagnetic coil. The purpose is to combine the globality of model prediction and the locality of real-time measurement to improve the accuracy and anti-interference ability of parameter estimation.

[0089] The scheme of the present application effectively solves the problem of inaccurate estimation or insufficient robustness of the traditional parameter identification method in a dynamic environment by introducing a prediction mechanism based on dynamic evolution rules and a fusion correction mechanism of prediction deviation and measurement deviation. Specifically, the prediction step utilizes the inherent physical model and drift rules of the electromagnetic coil, so that a reasonable parameter estimation starting point can be provided even when the measurement data has noise or transient fluctuations. Subsequently, the correction step intelligently fuses the prediction results with real-time measurement data, which can dynamically adjust and optimize parameter estimation, thereby offsetting the limitations of single measurement or single model prediction. It is this iterative process of prediction and correction that enables the drift parameters of the electromagnetic coil to be more accurately and stably estimated, providing a reliable basis for subsequent excitation signal adjustment.

[0090] Through the above technical scheme, the estimation accuracy and robustness of the drift parameters of the electromagnetic coil are significantly improved. This dynamic and adaptive parameter identification method can better cope with the performance drift of the electromagnetic coil of the marine isolation transformer due to factors such as vibration and temperature change during long-term service, ensuring that the local compensation magnetic field can accurately offset the external high-frequency common-mode interference magnetic field under various complex working conditions. Thus, the present application can effectively improve the overall performance and long-term stability of the common-mode interference suppression system, reduce the risk of reduced suppression effect due to inaccurate parameter estimation, thereby prolonging the service life of the equipment and improving its reliability.

[0091] As shown in a common-mode interference suppression system of a marine isolation transformer, Figure 2 the system comprises:

[0092] a first magnetic shielding module 201 for preliminarily suppressing common-mode interference by using a first magnetic shielding layer, the magnetic shielding performance of the first magnetic shielding layer decaying with increasing temperature;

[0093] a second temperature response module 202 for, when the marine isolation transformer is long-term in a high-temperature environment, using a second temperature response layer forming a composite structure with the first magnetic shielding layer to perform magnetic performance compensation or temperature stability control on the first magnetic shielding layer, so as to suppress the magnetic shielding performance decay of the first magnetic shielding layer due to increasing temperature, and the composite structure is used to suppress the radiation coupling effect generated by an external high-frequency interference source, so as to suppress common-mode interference.

[0094] The basic principles, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the present application is not limited to the above embodiments, and the above embodiments and descriptions in the specification are only the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A method of suppressing common-mode interference of a marine isolated transformer, characterized by, The method comprises the following steps: The first magnetic shielding layer is used to preliminarily suppress common-mode interference, and the magnetic shielding performance of the first magnetic shielding layer decays with the increase of temperature; When the marine isolation transformer is long-term in a high-temperature environment, a second temperature-responsive layer forming a composite structure with the first magnetic shielding layer is used to compensate the magnetic performance or control the temperature stability of the first magnetic shielding layer to suppress the decay of the magnetic shielding performance of the first magnetic shielding layer caused by the increase of temperature; The composite structure is used to suppress the radiation coupling effect caused by an external high-frequency interference source to suppress common-mode interference; The method further comprises: When the marine isolation transformer is long-term in service in a vibration and periodic high-temperature superimposed environment, the temperature of each local area of the first magnetic shielding layer is sensed; According to the temperature of the local area, it is judged whether there is a local weak area of magnetic permeability decay in the first magnetic shielding layer; When there is a local weak area, a local compensation magnetic field is generated at the local weak area, and the local compensation magnetic field is used to offset the external high-frequency common-mode interference magnetic field penetrating through the local weak area; The step of generating a local compensation magnetic field at the local weak area comprises: At the local weak area, the spatial vector distribution information of the external high-frequency common-mode interference magnetic field is obtained; According to the spatial vector distribution information, the compensation magnetic field vector required by the local weak area is determined; A local compensation magnetic field matching the compensation magnetic field vector is generated.

2. A method of suppressing common-mode interference of a marine isolated transformer according to claim 1, characterized in that, The step of obtaining the spatial vector distribution information of the external high-frequency common-mode interference magnetic field at the local weak area comprises: A reference magnetic field with known characteristics is periodically generated, and the reference magnetic field at the local weak area is measured by using a pre-set magnetic field sensor array to obtain the spatial vector distribution information of the external high-frequency common-mode interference magnetic field.

3. A method of suppressing common-mode interference of a marine isolated transformer according to claim 2, characterized in that, The step of obtaining the spatial vector distribution information of the external high-frequency common-mode interference magnetic field at the local weak area further comprises: The actual spatial position or the offset information of the measurement axis of the magnetic field sensor array relative to the pre-set position or axis is obtained; According to the offset information, the spatial vector distribution information is corrected.

4. The method of claim 1, wherein the common-mode interference of the marine isolated transformer is suppressed by, The step of generating a local compensation magnetic field matching the compensation magnetic field vector comprises: Based on a plurality of independently controllable electromagnetic coils deployed in advance, the local compensation magnetic field is generated at the local weak area.

5. A method of suppressing common-mode interference of a marine isolated transformer according to claim 4, characterized in that, The step of generating a local compensation magnetic field matching the compensation magnetic field vector further comprises: During the generation of the local compensation magnetic field by the electromagnetic coils, the operating state parameters of each electromagnetic coil are sensed in real time, and the operating state parameters indicate the performance drift of the electromagnetic coil caused by operation; According to the operating state parameters, the excitation signal adjustment amount of each electromagnetic coil is calculated; According to the excitation signal adjustment amount, the current intensity, direction and phase of each electromagnetic coil are adjusted to generate a local compensation magnetic field matching the compensation magnetic field vector.

6. A method of suppressing common-mode interference of a marine isolated transformer according to claim 5, characterized in that, The step of calculating the excitation signal adjustment amount of each electromagnetic coil according to the operating state parameters comprises: According to the real-time sensed operating state parameters, the drift parameters of the electromagnetic coil are estimated by a parameter identification method; According to the estimated drift parameter and the target compensation magnetic field vector, an excitation signal adjustment amount of each electromagnetic coil is calculated.

7. A method of suppressing common-mode interference of a marine isolated transformer according to claim 6, characterized in that, The step of estimating the drift parameter of the electromagnetic coil according to the real-time sensed operation state parameter through a parameter identification method comprises: Based on the dynamic evolution law of the electromagnetic coil state and the drift parameter, the current state and the drift parameter of the electromagnetic coil are predicted; According to the predicted current state and drift parameter and the real-time sensed operation state parameter, the current state and the drift parameter are corrected through fusion of prediction deviation and measurement deviation, to obtain the corrected drift parameter.

8. A system for suppressing common-mode interference of a marine isolation transformer for performing a method of suppressing common-mode interference of a marine isolation transformer according to any one of claims 1 to 7, characterized in that The system comprises: The first magnetic shielding module is used for preliminarily suppressing common-mode interference by using a first magnetic shielding layer, and the magnetic shielding performance of the first magnetic shielding layer attenuates with the increase of temperature. The second temperature response module is used for, when the marine isolation transformer is long-term in a high-temperature environment, performing magnetic performance compensation or temperature stability control on the first magnetic shielding layer by using a second temperature response layer forming a composite structure with the first magnetic shielding layer, to suppress the attenuation of the magnetic shielding performance of the first magnetic shielding layer due to the increase of temperature, and the composite structure is used for suppressing the radiation coupling effect generated by an external high-frequency interference source, to suppress common-mode interference.

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