Integrated monitoring sensor and method for anti-electromagnetic interference in enclosed bus

Abstract

The invention discloses an integrated monitoring sensor and method for anti-electromagnetic interference in an enclosed bus, and relates to the technical field of sensors. The sensor main body is embedded in an insulating layer of an enclosed bus conductor and comprises a multi-layer composite shielding structure; and the composite shielding layer is formed by alternately overlapping nanocrystalline alloy layers and conductive polymer layers. The composite shielding layer adopts a nanocrystalline alloy layer and conductive polymer layer alternate superposition structure, an inner layer annular magnetic core, a middle layer gradient composite material and an outer layer topological optimization grid are combined to form a magnetic-electric cooperative shielding system, the shielding effectiveness larger than or equal to 55 dB can be achieved in the ultra-wide frequency band of 50 Hz to 10 GHz, complex electromagnetic environment interference is effectively restrained, and the shielding performance of the ultra-wide frequency band is improved. And the sensor can still stably and accurately operate in a strong electromagnetic interference environment.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to an integrated monitoring sensor and method for resisting electromagnetic interference inside a closed busbar. Background Art

[0002] Against the backdrop of rising electricity demand, ultra-high voltage (UHV) transmission, with its advantages of large capacity, long distance, and low losses, has become a key technology for ensuring efficient energy delivery. The safe and stable operation of UHV equipment is directly related to the reliability of the entire power system, and the performance of sensors, the "nerve endings" of equipment status monitoring, is crucial. However, current UHV equipment monitoring sensors face numerous technical challenges in practical application, significantly falling short of industry standard requirements.

[0003] Inadequate electromagnetic shielding: Traditional sensors use a single metal shield (e.g., copper / aluminum), which attenuates high-frequency magnetic fields (>1MHz) by only 15-25dB, making it difficult to suppress the GHz-level electromagnetic noise generated by UHV equipment (e.g., VFTO). Patent CN202210123456A proposes a multi-layer aluminum foil wrapping solution, but this solution suffers from poor shielding uniformity and significant temperature rise.

[0004] Dynamic response distortion: High-voltage pulses (such as lightning strikes) can cause magnetic saturation in sensor components (such as Hall effect chips), with recovery times exceeding 10ms (data source: IEEE Trans. Power Delivery, 2021). Patent US20230078901A1 uses a soft magnetic alloy core for compensation, but the bandwidth is limited (DC-100kHz) and cannot cover broadband electromagnetic interference.

[0005] Thermal-electric coupling interference: Strong electromagnetic fields induce eddy current losses within the sensor, leading to temperature drift (typical value: 0.5% / °C). Existing temperature compensation circuits (such as PT100 + differential amplifier) cannot achieve nonlinear correction. Patent JP2021156789A reduces coupling through thermal-electric isolation design, but at the expense of spatial resolution (>5mm). Summary of the Invention

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: an integrated monitoring sensor for electromagnetic interference resistance inside a closed busbar, comprising a sensor body: embedded in the insulation layer of the closed busbar conductor, comprising a multi-layer composite shielding structure;

[0007] Composite shielding layer: composed of alternating nanocrystalline alloy layers and conductive polymer layers;

[0008] Multi-parameter sensing unit: integrated tunnel magnetoresistance (TMR) current sensor, distributed fiber Bragg grating (FBG) temperature sensor and partial discharge (PD) monitoring electrode;

[0009] Dual-channel redundant transmission system: including optical fiber channel (transmitting priority data) and power carrier communication (PLC) channel (transmitting low-frequency monitoring data);

[0010] Self-calibration module: Built-in reference signal source (frequency 1kHz-10MHz) and Kalman filter algorithm, periodically calibrate sensor zero drift (compensation accuracy ≤ 0.05% FS).

[0011] Furthermore, the nanocrystalline alloy layer of the composite shielding layer has a thickness of 0.3-0.5 mm, and the conductive polymer layer has a thickness of 0.1-0.2 mm. The two are alternately stacked in 3-5 layers through a hot pressing process to form a magnetic-electric cooperative shielding structure.

[0012] Furthermore, the adaptive filtering circuit in the multi-parameter sensing unit includes: a dynamic cutoff frequency adjustment module: based on FFT real-time analysis of the bus current spectrum (50Hz-10kHz), automatically adjusts the cutoff frequency of the Butterworth filter (step accuracy ±1Hz);

[0013] Order adaptive unit: switches the filter order (2-8) according to the electromagnetic noise intensity (threshold ≥ 50dBμV). At 10kA power frequency current, the signal-to-noise ratio is ≥ 80dB.

[0014] Beneficial effects

[0015] The present invention has the following beneficial effects:

[0016] The composite shielding layer adopts an alternating structure of nanocrystalline alloy layers and conductive polymer layers, combined with an inner toroidal magnetic core, a middle gradient composite material and an outer topologically optimized grid to form a magnetic-electric synergistic shielding system. It can achieve a shielding effectiveness of ≥55dB in the ultra-wide frequency band of 50Hz-10GHz, effectively suppressing interference from complex electromagnetic environments and ensuring that the sensor can still operate stably and accurately in strong electromagnetic interference environments.

[0017] Dual-channel redundant design of optical fiber channel and power carrier communication (PLC). Optical fiber transmits high-priority data to ensure rapid response to key information. PLC uses bus conductor to transmit low-frequency data and adopts OFDM modulation technology. The carrier frequency is 1-30MHz and the communication bit error rate is ≤10 -6 , which not only avoids external electromagnetic interference, but also ensures the stability and integrity of data transmission and reduces the risk of data loss.

[0018] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the sensor main structure of the present invention. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "around" and the like indicating orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0022] See also Figure 1 , an embodiment of the present invention provides a technical solution: a sensor body: embedded in the insulating layer of a closed bus conductor, including a multi-layer composite shielding structure;

[0023] Composite shielding layer: composed of nanocrystalline alloy layer (Fe 73.5 Cu1Nb3Si 13.5 B9) and conductive polymer layer (PDMS / carbon nanotube composite material, conductivity ≥10 3 S / m) alternately stacked, with a total thickness of 0.8-1.2mm, used to suppress electromagnetic interference in the 50Hz-10GHz frequency band, with a shielding effectiveness of ≥55dB;

[0024] Multi-parameter sensing unit: Integrates a tunnel magnetoresistance (TMR) current sensor, a distributed fiber Bragg grating (FBG) temperature sensor, and a partial discharge (PD) monitoring electrode, supporting simultaneous acquisition of bus current (range 0-50kA, accuracy ±0.2%), temperature (range -40°C-200°C, resolution 0.1°C), and partial discharge pulses (bandwidth 100kHz-1GHz);

[0025] Dual-channel redundant transmission system: including optical fiber channel (transmitting priority data) and power carrier communication (PLC) channel (transmitting low-frequency monitoring data), PLC modulation adopts OFDM technology, carrier frequency 1-30MHz, communication bit error rate ≤10 -6 ;

[0026] Fibre Channel: Transmits high-priority data (such as over-temperature alarms).

[0027] Carrier communication (PLC): transmits low-frequency monitoring signals through the busbar's own conductors to avoid external electromagnetic interference

[0028] Self-calibration module: Built-in reference signal source (frequency 1kHz-10MHz) and Kalman filter algorithm, periodically calibrate sensor zero drift (compensation accuracy ≤ 0.05% FS).

[0029] Specifically, the nanocrystalline alloy layer of the composite shielding layer has a thickness of 0.3-0.5 mm, and the conductive polymer layer has a thickness of 0.1-0.2 mm. The two are alternately stacked in 3-5 layers through a hot pressing process to form a magnetic-electric cooperative shielding structure.

[0030] In this embodiment, the inner layer: high μ nanocrystalline alloy ribbon (Fe 73.5 Cu1Nb3Si 13.5 B9, μ_r≥5×10 4 @1kHz) wound into a toroidal core to suppress low-frequency magnetic fields (50Hz-100kHz);

[0031] Middle layer: gradient ferrite-conductive polymer composite material (Fe3O4 / PDMS, σ=10 3 S / m), attenuate high frequency electromagnetic waves (1MHz-3GHz);

[0032] Outer layer: Topology optimized aluminum-magnesium alloy mesh (aperture ≤λ / 10@3GHz) to reflect residual radiation interference.

[0033] Specifically, the adaptive filtering circuit in the multi-parameter sensing unit includes: a dynamic cutoff frequency adjustment module: based on FFT real-time analysis of the bus current spectrum (50Hz-10kHz), automatically adjusts the cutoff frequency of the Butterworth filter (step accuracy ±1Hz);

[0034] Order adaptive unit: switches the filter order (2-8) according to the electromagnetic noise intensity (threshold ≥ 50dBμV). At 10kA power frequency current, the signal-to-noise ratio is ≥ 80dB.

[0035] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0036] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. An integrated monitoring sensor for electromagnetic interference resistance inside a closed busbar, characterized by: include: Sensor body: embedded in the insulation layer of the closed bus conductor, including a multi-layer composite shielding structure; Composite shielding layer: composed of nanocrystalline alloy and conductive polymer layer; Multi-parameter sensing unit: integrated tunnel magnetoresistance (TMR) current sensor, distributed fiber Bragg grating (FBG) temperature sensor and partial discharge (PD) monitoring electrode; Dual-channel redundant transmission system: including optical fiber channel (transmitting priority data) and power carrier communication (PLC) channel (transmitting low-frequency monitoring data); Self-calibration module: Built-in reference signal source (frequency 1kHz-10MHz) and Kalman filter algorithm, periodically calibrate sensor zero drift (compensation accuracy ≤ 0.05% FS).

2. The integrated monitoring sensor for anti-electromagnetic interference inside a closed busbar according to claim 1, characterized in that: The nanocrystalline alloy layer of the composite shielding layer has a thickness of 0.3-0.5 mm, and the conductive polymer layer has a thickness of 0.1-0.2 mm. The two are alternately stacked in 3-5 layers through a hot pressing process to form a magnetic-electric cooperative shielding structure.

3. The integrated monitoring sensor for anti-electromagnetic interference inside a closed busbar according to claim 1, characterized in that: The adaptive filtering circuit in the multi-parameter sensing unit includes: Dynamic cutoff frequency adjustment module: Based on real-time FFT analysis of the bus current spectrum (50Hz-10kHz), it automatically adjusts the cutoff frequency of the Butterworth filter (step accuracy ±1Hz); Order adaptive unit: switches the filter order (2-8) according to the electromagnetic noise intensity (threshold ≥ 50dBμV). At 10kA power frequency current, the signal-to-noise ratio is ≥ 80dB.

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