A circuit breaker wobbler contact pressure detection device and method

Abstract

The application discloses a circuit breaker wrench contact pressure detection device and method, and relates to the technical field of electrical equipment detection, which comprises a box body and a detector in the box body, a host computer is arranged outside the detector, a probe is connected to the detector, the probe is a multilayer composite structure, and the multilayer composite structure comprises a calibration excitation core, a rigid constraint layer, a piezoresistive sensing array layer and a wear-resistant protective layer which are sequentially arranged from inside to outside; a heating wire and a first temperature sensor are integrated in the calibration excitation core; the rigid constraint layer is coated on the outside of the calibration excitation core; the piezoresistive sensing array layer is attached to the outer surface of the rigid constraint layer, and the piezoresistive sensing array layer is composed of a plurality of independent piezoresistive sensing units arranged in an array; and the wear-resistant protective layer is coated on the outside of the piezoresistive sensing array layer. The application realizes in-situ self-calibration of the detection device, completely gets rid of the dependence on external calibration equipment, effectively overcomes sensor drift, and significantly improves the accuracy, reliability and convenience of field measurement.

Description

Technical Field

[0001] This application relates to the field of electrical equipment testing technology, and in particular to a circuit breaker sprite contact pressure testing device and method. Background Technology

[0002] In high-voltage switchgear, such as high-voltage circuit breakers, the sprite contact is a key component for carrying and interrupting large currents. The sprite contact is composed of multiple independent elastic contact fingers that hug each other, and the contact pressure between the sprite contact and the central conductive rod is the core indicator for ensuring low contact resistance and good current-carrying capacity.

[0003] During long-term operation of equipment, if the contact pressure of the spline contacts decreases or becomes uneven due to material fatigue, mechanical deformation, or other reasons, the contact resistance will increase. When a large current passes through, the increased contact resistance will cause severe localized overheating at the contact point. This can lead to minor issues such as contact surface ablation and welding, or even severe issues such as insulation breakdown and explosions. Therefore, during routine maintenance of circuit breakers, it is essential to regularly and accurately inspect the contact pressure distribution of the spline contacts.

[0004] Currently, a mainstream detection method uses a thin-film probe integrating a flexible piezoresistive sensor array, inserted between a swivel contact and a conductive rod. Pressure distribution is inferred by measuring the compression on the probe surface. However, the piezoresistive sensor unit itself, the core of the measurement, has inherent technical limitations. The resistive-pressure response characteristics of piezoresistive materials are highly sensitive to ambient temperature, exhibiting temperature drift. Furthermore, with increased usage and time, the material's response characteristics change due to mechanical fatigue and natural aging, resulting in time drift. These drift phenomena cause the sensor's pressure signal response model (i.e., calibration curve) to become inaccurate. To address this issue, existing detection devices must rely on offline calibration: periodically sending the entire system back to the manufacturer or a specialized metrology laboratory for recalibration using a large, expensive external standard pressure source. This offline calibration method is not only cumbersome and costly but also leads to long equipment downtime periods, severely impacting maintenance efficiency. More importantly, this calibration, performed under standard laboratory conditions, cannot resolve the immediate errors caused by temperature drift during actual measurements at the maintenance site, nor can it eliminate the accumulated errors due to fatigue aging between two calibration cycles. Therefore, the accuracy and reliability of its on-site measurements remain difficult to guarantee. To address this, this invention proposes a circuit breaker sprite contact pressure detection device and method. Summary of the Invention

[0005] This application provides a circuit breaker plum blossom contact pressure detection device and method, which solves the problem that existing pressure detection probes are prone to inaccurate measurement data due to the sensor being susceptible to temperature and aging drift, and that they must rely on external equipment for cumbersome offline calibration.

[0006] The first aspect of this application provides a circuit breaker sprite contact pressure detection device, comprising: a housing;

[0007] A detector is installed inside the enclosure;

[0008] The detector is equipped with a host unit on its exterior.

[0009] The detector is electrically connected to the host computer;

[0010] The detector is connected to a probe for inserting into and contacting the plum blossom contact.

[0011] The probe has a multi-layer composite structure;

[0012] The multi-layer composite structure includes, from the inside out, a calibration excitation core, a rigid constraint layer, a piezoresistive sensing array layer, and a wear-resistant protective layer.

[0013] The calibration excitation core integrates a heating wire and a first temperature sensor.

[0014] The rigid constraint layer covers the outside of the calibration excitation core;

[0015] The calibration excitation core has a thermal expansion coefficient of not less than 20×10⁻⁶. -6 Made of materials at / ℃;

[0016] The rigid constraint layer has a thermal expansion coefficient of no more than 2×10⁻⁶. -6 Made of materials at / ℃;

[0017] The piezoresistive sensing array layer is attached to the outer surface of the rigid constraint layer;

[0018] The piezoresistive sensing array layer consists of multiple independent piezoresistive sensing units arranged in an array.

[0019] The wear-resistant protective layer covers the outside of the piezoresistive sensing array layer;

[0020] The host is configured to: control the heating wire to heat the calibration excitation core to generate a standard pressure on the piezoresistive sensing array layer, and establish a pressure signal response model for each piezoresistive sensing unit based on the standard pressure and the electrical signals output by each piezoresistive sensing unit.

[0021] And after the probe is inserted into the plum blossom contact, the original electrical signal output by each of the piezoresistive sensing units after being squeezed by the plum blossom contact is collected, and the corresponding pressure signal response model is called to convert the original electrical signal into the final pressure value.

[0022] Optionally, the host is further configured to: reconstruct the two-dimensional pressure field distribution on the probe surface using a spatial interpolation algorithm based on the final pressure value of each of the piezoresistive sensing units and their known spatial coordinates on the piezoresistive sensing array layer.

[0023] Optionally, the host is further configured to: perform connected domain analysis on the two-dimensional pressure field distribution, identify at least one independent contact region, and calculate at least one of the pressure peak, average pressure, and effective contact area for each contact region.

[0024] Optionally, the calibration excitation core is made of aluminum alloy;

[0025] The rigid constraint layer is made of Invar or carbon fiber composite material.

[0026] Optionally, a printer is also provided on the outside of the detector;

[0027] The printer is electrically connected to the host computer.

[0028] The printer is equipped with a USB interface for exporting data.

[0029] Optionally, the detector is provided with a sensor interface;

[0030] The probe is connected to the sensor interface.

[0031] Optionally, the detector is provided with a grounding terminal.

[0032] The second aspect of this application provides a detection method based on the above-mentioned circuit breaker sprite contact pressure detection device, which specifically includes the following steps:

[0033] S1. In-situ calibration: Before measurement, the heating wire in the probe is controlled to heat the calibration excitation core. The difference in thermal expansion coefficient between the calibration excitation core and the rigid constraint layer is used to generate a known standard pressure on the piezoresistive sensing array layer. Based on the standard pressure and the electrical signal output by each piezoresistive sensing unit in the piezoresistive sensing array layer, a pressure signal response model is established for each piezoresistive sensing unit.

[0034] S2. Online measurement: Insert the probe into the plum blossom contact to be tested, collect the original electrical signal output by each of the piezoresistive sensing units after being squeezed, and call the corresponding pressure signal response model to calculate the final pressure value of each of the piezoresistive sensing units.

[0035] Optionally, in S2, the method further includes: reconstructing the two-dimensional pressure field distribution on the probe surface based on the final pressure value and spatial coordinates of each piezoresistive sensing unit.

[0036] Optionally, it also includes: S3, diagnostic analysis: analyzing the two-dimensional pressure field distribution to obtain the diagnostic results of the pressure distribution status of each finger of the plum blossom contact.

[0037] As can be seen from the above technical solutions, the embodiments of this application have the following advantages: This circuit breaker plum blossom contact pressure detection device, through the design of a multi-layer composite probe structure including a calibration excitation core made of a material with a specific coefficient of thermal expansion and a rigid constraint layer, and the integration of a control system with self-calibration function into the host, enables the device to actively generate a precise and known standard pressure inside the probe by controlling the heating wire at the measurement site, thereby quickly establishing an instantaneous and accurate pressure signal response model for each unit in the piezoresistive sensor array; this innovative design fundamentally overcomes the inherent temperature drift and time drift problems of existing piezoresistive sensors, realizes in-situ, online self-calibration of the detection device, completely eliminates the dependence on offline calibration processes and expensive external calibration equipment, not only greatly simplifies operation, reduces long-term maintenance costs and shortens equipment downtime, but more importantly, ensures that the data of each on-site measurement is based on the latest calibration benchmark of the current environment, thereby significantly improving the long-term accuracy, reliability and overall maintenance efficiency of pressure distribution detection. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the circuit breaker sprite contact pressure detection device in the embodiments of this application;

[0039] Figure 2 This is a cross-sectional view of the probe in an embodiment of this application;

[0040] Figure 3 This is a schematic diagram of the host control system and its interaction relationships in an embodiment of this application.

[0041] The attached figures are labeled as follows:

[0042] 1-Box, 2-Detector, 3-Main unit, 4-Probe, 5-Calibration excitation core, 6-Rigid constraint layer, 7-Piezoresistive sensor array layer, 8-Wear-resistant protective layer, 9-Sensor interface, 10-Grounding terminal, 11-Printer, 12-USB interface. Detailed Implementation

[0043] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0044] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0045] Unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0046] This application provides an embodiment of a circuit breaker sprite contact pressure detection device, please refer to [link to specific details]. Figures 1 to 3 .

[0047] The circuit breaker sprite contact pressure detection device in this embodiment includes: a housing 1, a detector 2 installed inside the housing 1, a host 3 installed outside the detector 2, the detector 2 being electrically connected to the host 3, and a probe 4 connected to the detector 2 for insertion into and contacting the sprite contact. The probe 4 has a multi-layer composite structure, which includes, from the inside out, a calibration excitation core 5, a rigid constraint layer 6, a piezoresistive sensing array layer 7, and a wear-resistant protective layer 8. The calibration excitation core 5 integrates a heating wire and a first temperature sensor. The rigid constraint layer 6 covers the outside of the calibration excitation core 5. The calibration excitation core 5 is made of a material with a thermal expansion coefficient of not less than 20 × 10⁻⁶. -6 Made of a material with a thermal expansion coefficient not exceeding 2×10⁻⁶℃; the rigid constraint layer 6 is made of a material with a thermal expansion coefficient not exceeding 2×10⁻⁶℃. -6Made of a material of / ℃; the piezoresistive sensing array layer 7 is attached to the outer surface of the rigid constraint layer 6, and the piezoresistive sensing array layer 7 is composed of multiple independent piezoresistive sensing units arranged in an array; the wear-resistant protective layer 8 covers the outside of the piezoresistive sensing array layer 7; the host 3 is configured to: control the heating wire to heat the calibration excitation core 5 to generate a standard pressure on the piezoresistive sensing array layer 7, and establish a pressure signal response model for each piezoresistive sensing unit based on the standard pressure and the electrical signals output by each piezoresistive sensing unit; and after the probe 4 is inserted into the plum blossom contact, collect the original electrical signals output by each piezoresistive sensing unit after being squeezed by the plum blossom contact, and call the corresponding pressure signal response model to convert the original electrical signals into the final pressure value.

[0048] It should be noted that this circuit breaker plum blossom contact pressure detection device employs a multi-layer composite probe 4 structure, comprising a calibration excitation core 5 made of a material with a specific coefficient of thermal expansion and a rigid constraint layer 6. Furthermore, a self-calibrating control system is integrated into the host unit 3. This allows the device to generate precise and known standard pressure within the probe 4 at the measurement site, controlled by the host unit 3. This enables the rapid establishment of an instantaneous and accurate pressure signal response model for each unit in the piezoresistive sensor array. This innovative design fundamentally overcomes the inherent temperature and time drift problems of existing piezoresistive sensors, achieving in-situ, online self-calibration of the detection device. It completely eliminates the reliance on offline calibration processes and expensive external calibration equipment. This not only greatly simplifies operation, reduces long-term maintenance costs, and shortens equipment downtime, but more importantly, ensures that the data from each on-site measurement is based on the latest calibration benchmark for the current environment. This significantly improves the long-term accuracy, reliability, and overall maintenance efficiency of pressure distribution detection.

[0049] The above is Embodiment 1 of a circuit breaker sprite contact pressure detection device provided in this application. The following is Embodiment 2 of a circuit breaker sprite contact pressure detection device provided in this application. Please refer to the following for details. Figures 1 to 3 .

[0050] The circuit breaker sprite contact pressure detection device in this embodiment includes: a housing 1, a detector 2 installed inside the housing 1, a main unit 3 installed outside the detector 2, the detector 2 being electrically connected to the main unit 3, and a probe 4 connected to the detector 2 for insertion into and contacting the sprite contact. The probe 4 has a multi-layer composite structure, which includes, from the inside out, a calibration excitation core 5, a rigid constraint layer 6, a piezoresistive sensing array layer 7, and a wear-resistant protective layer 8. The calibration excitation core 5 integrates a heating wire and a first temperature sensor; the rigid constraint layer 6 tightly covers the outside of the calibration excitation core 5; the calibration excitation core 5 is made of material with a thermal expansion coefficient of not less than 20 × 10⁻⁶. -6 Made of a material with a thermal expansion coefficient not exceeding 2×10⁻⁶℃; the rigid constraint layer 6 is made of a material with a thermal expansion coefficient not exceeding 2×10⁻⁶℃. -6Made of a material of / ℃; the piezoresistive sensing array layer 7 is tightly attached to the outer surface of the rigid constraint layer 6, and the piezoresistive sensing array layer 7 is composed of multiple independent piezoresistive sensing units arranged in an array; the wear-resistant protective layer 8 covers the outside of the piezoresistive sensing array layer 7; the host 3 is configured to: control the heating wire to heat the calibration excitation core 5 to generate a standard pressure on the piezoresistive sensing array layer 7, and establish a pressure signal response model for each piezoresistive sensing unit based on the standard pressure and the electrical signals output by each piezoresistive sensing unit; and after the probe 4 is inserted into the plum blossom contact, collect the original electrical signals output by each piezoresistive sensing unit after being squeezed by the plum blossom contact, and call the corresponding pressure signal response model to convert the original electrical signals into the final pressure value.

[0051] The host 3 is further configured to reconstruct the two-dimensional pressure field distribution on the surface of the probe 4 using a spatial interpolation algorithm based on the final pressure value of each piezoresistive sensing unit and its known spatial coordinates on the piezoresistive sensing array layer 7.

[0052] The host 3 is also configured to perform connected domain analysis on the two-dimensional pressure field distribution, identify at least one independent contact region, and calculate at least one of the peak pressure, average pressure, and effective contact area for each contact region.

[0053] The host 3 is preferably an industrial tablet PC or portable industrial computer with an integrated touch screen, which is connected to the detector 2 via a cable. The host 3 has a built-in control system, which includes an in-situ calibration module and an online measurement module. The in-situ calibration module is used to control the heating wire to generate a temperature rise before measurement, so that the calibration excitation core 5 generates a standard pressure due to the constraint of the rigid constraint layer 6, and establishes a pressure signal response model for each piezoresistive sensing unit based on the standard pressure and the electrical signal output by the piezoresistive sensing unit. The online measurement module is used to collect the original electrical signal output by the piezoresistive sensing unit after being squeezed by the piezoresistive contact during measurement, and call the pressure signal response model to convert the original electrical signal into the final pressure value.

[0054] It should be noted that the in-situ calibration module is specifically used for: controlling the heating wire to sequentially heat and stabilize the calibration excitation core 5 at multiple preset target temperature points; at each target temperature point, the interaction between the calibration excitation core 5 and the rigid constraint layer 6 generates a corresponding standard pressure; under each standard pressure, recording the electrical signal output by each piezoresistive sensing unit; based on the recorded series of standard pressure and electrical signal data, fitting a pressure signal response curve for each piezoresistive sensing unit as a pressure signal response model. Before establishing the pressure signal response model, the in-situ calibration module first obtains the current ambient temperature through the first temperature sensor and uses the current ambient temperature as the effective calibration temperature of the pressure signal response model. The online measurement module is specifically used for: acquiring the original electrical signal output by each piezoresistive sensing unit in the piezoresistive sensing array layer 7 when squeezed by the swivel contact; for each piezoresistive sensing unit, substituting the original output electrical signal into the pressure signal response model corresponding to the piezoresistive sensing unit to calculate the final pressure value corresponding to the piezoresistive sensing unit. The online measurement module is also used to reconstruct the two-dimensional pressure field distribution based on the known spatial coordinates of each piezoresistive sensing unit in the piezoresistive sensing array layer 7 and the calculated final pressure value, using a spatial interpolation algorithm.

[0055] The control system also includes a diagnostic analysis and visualization module, which is used to process the two-dimensional pressure field distribution. It calculates the peak pressure, average pressure, and effective contact area of ​​each plum blossom contact finger area (i.e., contact area) through a connected component analysis algorithm; and presents the two-dimensional pressure field distribution on the display screen of the host 3 in the form of a pseudo-color cloud map.

[0056] The in-situ calibration module specifically adopts a proportional-integral-derivative control algorithm. Through real-time feedback from the first temperature sensor, it precisely controls the heating power of the heating wire and stabilizes the temperature rise of the calibration excitation core 5.

[0057] The diagnostic analysis and visualization module is also used to compare the calculated peak pressure, average pressure, or effective contact area with the standard threshold preset in the host 3, and automatically output the status diagnosis conclusion of the plum blossom contact.

[0058] Preferably, the coefficient of thermal expansion of the material selected for the calibration excitation core 5 is in the range of 22.0 × 10⁻⁶. -6 / ℃ to 24.0×10 -6 / ℃; the thermal expansion coefficient of the material selected for the rigid constraint layer 6 is in the range of 0.5×10. -6 / ℃ to 1.5×10 -6 / ℃. Specifically, the calibration excitation core 5 is made of aluminum alloy (such as 7075 aluminum alloy or 6061 aluminum alloy); the rigid constraint layer 6 is made of Invar or carbon fiber composite material. The heating wire is preferably armored resistance wire.

[0059] A printer 11 is also installed externally on the detector 2. The printer 11 is electrically connected to the host 3 and has a USB interface 12 for exporting data. Specifically, the USB interface 12 is used to connect an external storage device to export data reports or for system firmware upgrades. The printer 11 is a thermal micro printer 11 used for printing diagnostic conclusions on-site.

[0060] The detector 2 is equipped with a sensor interface 9, to which the probe 4 is connected. Specifically, the sensor interface 9 is located on the panel of the detector 2 and is a high-density data interface (specifically a multi-pin aviation connector). It is used to transmit the analog signals from each piezoresistive sensing unit in the piezoresistive sensing array layer 7 within the probe 4, as well as the signal from the first temperature sensor, to the detector 2 for A / D conversion and processing. The probe 4 is detachably connected to the sensor interface 9 via a flexible shielded cable assembly. More specifically, one end of the flexible shielded cable assembly is fixedly connected to the tail of the probe 4 (or integrally molded using injection molding), and the other end is equipped with a multi-pin aviation connector that matches the sensor interface 9. The aviation connector and the aviation connector are mechanically locked using a threaded locking ring or a push-pull self-locking mechanism to ensure a secure connection. The flexible shielded cable assembly contains multiple independent wires, which are used for: transmitting power signals to the heating wire; transmitting temperature feedback signals from the first temperature sensor; and transmitting pressure measurement signals from each piezoresistive sensing unit in the piezoresistive sensing array layer 7.

[0061] The detector 2 is equipped with a grounding terminal 10, which is used to ensure that the equipment is reliably grounded in strong electromagnetic environments such as substations, so as to ensure measurement safety and signal stability.

[0062] Specifically, the complete workflow of the circuit breaker sprite contact pressure detection device includes three core steps: in-situ calibration, online measurement, and diagnostic analysis.

[0063] In-situ calibration steps:

[0064] Triggered by the user before actual measurement (e.g., in the field, when probe 4 is not inserted), the purpose is to establish an accurate pressure signal response model for each piezoresistive sensing unit in the piezoresistive sensing array layer 7 under the current environment.

[0065] Obtaining Ambient Temperature: Upon startup of the in-situ calibration module, the current ambient temperature is first obtained through the first temperature sensor inside the calibration excitation core 5. .this It was recorded as the effective calibration temperature of the calibration model in this calibration.

[0066] Point-by-point heating and pressure generation: The in-situ calibration module reads a set (e.g., N) of preset target temperature points from the memory of host 3. .

[0067] For the Target points The in-situ calibration module employs a PID control algorithm, using the real-time readings of the first temperature sensor as feedback to precisely control the power of the heating wire, thereby stabilizing the temperature of the calibration excitation core 5. .

[0068] Under steady-state conditions, calibrate excitation core 5 (thermal expansion coefficient). (relative to rigid constraint layer 6) The temperature rise produced is .

[0069] because The thermal expansion of the calibration excitation core 5 is constrained by the rigid constraint layer 6, generating a precise standard pressure at the interface between the two. The relationship between pressure and temperature rise has been calibrated at the factory and stored in the main unit 3. This relationship can be expressed as:

[0070] ;

[0071] in, Indicates the first At each target temperature point, the standard pressure generated by the interaction of the calibration excitation core 5 and the rigid constraint layer 6, measured in megapascals (MPa), typically ranges from 0.1 MPa to 200 MPa, depending on the pressure level of the application scenario. This represents a thermodynamic conversion coefficient related to the geometry of probe 4, typically ranging from 0.5 to 2.0. This represents the effective Young's modulus of the combined structure of the calibration excitation core 5 and the rigid constraint layer 6, expressed in megapascals (MPa), with a value range of 1.0 × 10⁻⁶. 3 MPa up to 2.1×10 5 MPa This indicates the first calibration excitation core 5 relative to the ambient temperature. Temperature rise, measured in Kelvin (K) or degrees Celsius (°C), with a working range of 0K to 150K. This represents the overall thermal conversion coefficient, expressed in megapascals per Kelvin (MPa / K). Based on the parameters mentioned above, its value typically ranges from 0.1 MPa / K to 5.0 MPa / K. For high expansion materials, the value ranges from (20 to 500) × 10 -6 / K; For low-expansion confinement materials, the value ranges from (1 to 15) × 10 -6 / K, the unit is per Kelvin ( Or 1 / ℃).

[0072] Data acquisition: After probe 4 stabilizes at and generate At that time, the module immediately acquires and records data from each piezoresistive sensing unit in the piezoresistive sensing array layer 7 (assuming a total of...). , index is The output electrical signal .

[0073] Response model fitting: Repeat steps until all All target temperature points have been traversed. At this point, for each piezoresistive sensing unit... ( to Host 3 acquired a set of Correct calibration data points:

[0074] ;

[0075] in, This represents the total number of sampling points during the calibration process. It is a dimensionless integer, and its value range is usually from 5 to 50, to ensure that there are enough data points to fit a high-precision pressure and signal response curve. This represents the total number of piezoresistive sensing units in the piezoresistive sensing array layer 7. It is a dimensionless integer ranging from 1 to 1024, depending on the resolution and array size of the piezoresistive sensing array layer 7. Indicates the first The piezoresistive sensing unit in the first... The output electrical signal response value at each temperature point (i.e., the corresponding pressure point). This physical quantity is usually expressed as a change in voltage or capacitance, and is uniformly defined here as an analog voltage value, with the unit being volts (V), and the value range being 0V to 10V (or defined as 0mV to 5000mV depending on the accuracy of the acquisition circuit). This value reflects the rate of change of impedance or capacitance of the piezoresistive sensing array layer 7 under pressure. Indicates the first The standard pressure value generated by thermal expansion at a specific temperature point. This value serves as the reference for calibration, and its unit is megapascals (MPa), ranging from 0.1 MPa to 200 MPa. This pressure value is related to the aforementioned electrical signal. These data pairs, in a one-to-one correspondence, together form the fundamental data pairs for solving the sensor sensitivity coefficient and nonlinear error.

[0076] The in-situ calibration module then calibrates each piezoresistive sensing unit. This Independent curve fitting (e.g., least squares polynomial fitting) is performed on each set of data to establish its specific pressure signal response model. For example, a second-order polynomial model:

[0077] ;

[0078] in, Indicates the application of the first The pressure value on each piezoresistive sensing unit is expressed in megapascals (MPa), ranging from 0.1 MPa to 200 MPa. This indicates that the least squares method and other algorithms are used to obtain the first... The calibration coefficients of the model fitted by each piezoresistive sensing unit The unit is megapascal per square volt. The value range is from -5.0 to 5.0. The value ranges from 0.5 to 50.0. The unit is megapascal (MPa), and the value range is typically from -5.0 MPa to 5.0 MPa. Indicates the first The electrical signal output by each piezoresistive sensing unit during calibration is in volts (V) and ranges from 0V to 10V.

[0079] The module calculates the coefficients for each group. And store it as in An effective calibration model is required. The pressure signal response model is not limited to a second-order polynomial. Depending on the actual response characteristics of the piezoresistive sensing unit, a linear model, a higher-order polynomial model, or a look-up table model established through piecewise linear interpolation can also be used. Choosing a second-order polynomial model is the preferred implementation method, achieving a good balance between computational efficiency and fitting accuracy.

[0080] Online measurement procedure: Perform immediately after in-situ calibration is completed.

[0081] Signal acquisition: The operator inserts probe 4 into the device to be tested (which has been shut down and cooled to room temperature). The probe 4 is located in the vicinity of the Phillips-shaped contact. The contact fingers of the Phillips-shaped contact exert pressure on the wear-resistant protective layer 8 on the outside of the probe 4. To ensure measurement accuracy, after the probe 4 is fully inserted, the online measurement module will wait for a preset time (e.g., 3-5 seconds), or monitor the rate of change of the reading of the first temperature sensor, until the probe 4 and the Phillips-shaped contact reach a thermal equilibrium state before proceeding with subsequent signal acquisition, in order to eliminate the interference of transient thermal stress caused by temperature difference on the measurement results.

[0082] Pressure calculation: The online measurement module acquires data in real time from each piezoresistive sensing unit in the piezoresistive sensing array layer 7. The original electrical signal output .

[0083] Pressure calculation: The online measurement module acquires data in real time from each piezoresistive sensing unit in the piezoresistive sensing array layer 7. The original electrical signal output .

[0084] For each The module immediately invokes the unit's dedicated pressure signal response model. Calculate the corresponding final pressure value. :

[0085] ;

[0086] in, Indicates the first The final pressure value calculated by each piezoresistive sensing unit in actual measurement is in megapascals (MPa), and its effective measurement range is from 0.1 MPa to 200 MPa. Indicates the first The raw electrical signal collected by each piezoresistive sensing unit in actual measurement is in volts (V) and ranges from 0V to 10V.

[0087] Pressure field reconstruction: Module obtains all ( The final pressure value of each piezoresistive sensing unit And combined with their known spatial coordinates in the piezoresistive sensing array layer 7 Using spatial interpolation algorithms (such as bilinear interpolation or kriging interpolation), the online measurement module determines the values ​​based on these discrete... The data points were used to reconstruct a high-resolution, continuous two-dimensional pressure field distribution. .

[0088] Diagnostic analysis and visualization steps:

[0089] Feature extraction: The diagnostic analysis and visualization module receives the two-dimensional pressure field. First, the module identifies [the components] using a connected component analysis algorithm (usually after passing through a noise threshold). Each of the independent high-voltage zones in the field corresponds to a contact spot of a plum blossom contactor.

[0090] Specifically, the preprocessing step is as follows: the module first sets a pressure noise threshold. Two-dimensional pressure field All pressure values ​​are below The points are set to zero, thus filtering out background noise and invalid weak signals. Subsequently, the connected component analysis algorithm aggregates all spatially adjacent non-zero pressure points into an independent connected component on the processed pressure field, i.e., a valid finger contact area for each identified finger area. The module calculates its key diagnostic indicators:

[0091] Peak pressure Within this area The maximum value.

[0092] Mean pressure Within this area The integral value is divided by the area of ​​the region.

[0093] Effective contact area The pressure value in this area is greater than a preset contact threshold (e.g.) The total area.

[0094] Visualization and Diagnosis: The module visualizes the two-dimensional pressure field. The calculated heatmap is displayed on the monitor of host 3 in the form of a pseudo-heatmap. The indicators are displayed overlaid in the corresponding area. Simultaneously, the module retrieves preset standard thresholds (e.g., from the standard database built into host 3) ), to each finger The measured indicators are compared with them.

[0095] Output Results: Finally, the module automatically outputs the status diagnosis conclusion of the plum blossom contact (e.g., contact finger three: pressure too low, contact finger five: insufficient contact area, overall status: good). A complete graphic report can be output through printer 11.

[0096] In addition, users can also export complete reports containing two-dimensional pressure field pseudo-color cloud maps, various finger diagnostic indicators and diagnostic conclusions, or raw pressure field data to external storage devices via USB interface 12 through the host 3's operation interface, so as to facilitate long-term data archiving, traceability and in-depth analysis.

[0097] This application also provides a detection method based on the above-mentioned circuit breaker sprite contact pressure detection device, which specifically includes the following steps:

[0098] S1. In-situ calibration: Before measurement, the heating wire in the control probe 4 heats the calibration excitation core 5. Using the difference in thermal expansion coefficients between the calibration excitation core 5 and the rigid constraint layer 6, a known standard pressure is generated on the piezoresistive sensing array layer 7. Based on the standard pressure and the electrical signal output by each piezoresistive sensing unit in the piezoresistive sensing array layer 7, a pressure signal response model is established for each piezoresistive sensing unit.

[0099] S2. Online measurement: Insert probe 4 into the plum blossom contact to be tested, collect the original electrical signals output by each piezoresistive sensing unit after being squeezed, and call the corresponding pressure signal response model to calculate the final pressure value of each piezoresistive sensing unit.

[0100] S2 also includes: reconstructing the two-dimensional pressure field distribution on the surface of probe 4 based on the final pressure value and spatial coordinates of each piezoresistive sensing unit.

[0101] It also includes: S3, Diagnostic Analysis: Analyze the two-dimensional pressure field distribution, identify the contact area corresponding to each finger of the plum blossom contact, calculate the contact state parameters of each area, and obtain the diagnostic results of the pressure distribution state of each finger of the plum blossom contact.

[0102] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A circuit breaker sprite contact pressure detection device, characterized in that, include: Box; A detector is installed inside the enclosure; The detector is equipped with a host unit on its exterior. The detector is electrically connected to the host computer; The detector is connected to a probe for inserting into and contacting the plum blossom contact. The probe has a multi-layer composite structure; The multi-layer composite structure includes, from the inside out, a calibration excitation core, a rigid constraint layer, a piezoresistive sensing array layer, and a wear-resistant protective layer. The calibration excitation core integrates a heating wire and a first temperature sensor. The rigid constraint layer covers the outside of the calibration excitation core; The calibration excitation core has a thermal expansion coefficient of not less than 20×10⁻⁶. -6 Made of materials at / ℃; The rigid constraint layer has a thermal expansion coefficient of no more than 2×10⁻⁶. -6 Made of materials at / ℃; The piezoresistive sensing array layer is attached to the outer surface of the rigid constraint layer; The piezoresistive sensing array layer consists of multiple independent piezoresistive sensing units arranged in an array. The wear-resistant protective layer covers the outside of the piezoresistive sensing array layer; The host is configured to: control the heating wire to heat the calibration excitation core to generate a standard pressure on the piezoresistive sensing array layer, and establish a pressure signal response model for each piezoresistive sensing unit based on the standard pressure and the electrical signals output by each piezoresistive sensing unit. And after the probe is inserted into the plum blossom contact, the original electrical signal output by each of the piezoresistive sensing units after being squeezed by the plum blossom contact is collected, and the corresponding pressure signal response model is called to convert the original electrical signal into the final pressure value.

2. The circuit breaker sprite contact pressure detection device according to claim 1, characterized in that, The host is further configured to: reconstruct the two-dimensional pressure field distribution on the probe surface using a spatial interpolation algorithm based on the final pressure value of each piezoresistive sensing unit and its known spatial coordinates on the piezoresistive sensing array layer.

3. The circuit breaker sprite contact pressure detection device according to claim 2, characterized in that, The host is also configured to perform connected domain analysis on the two-dimensional pressure field distribution, identify at least one independent contact region, and calculate at least one of the pressure peak, average pressure, and effective contact area for each contact region.

4. The circuit breaker sprite contact pressure detection device according to claim 1, characterized in that, The calibration excitation core is made of aluminum alloy; The rigid constraint layer is made of Invar or carbon fiber composite material.

5. The circuit breaker sprite contact pressure detection device according to claim 1, characterized in that, A printer is also installed on the outside of the detector; The printer is electrically connected to the host computer. The printer is equipped with a USB interface for exporting data.

6. The circuit breaker sprite contact pressure detection device according to claim 1, characterized in that, The detector is equipped with a sensor interface; The probe is connected to the sensor interface.

7. The circuit breaker sprite contact pressure detection device according to claim 1, characterized in that, The detector is equipped with a grounding terminal.

8. A detection method for the circuit breaker sprite contact pressure detection device according to any one of claims 1-7, characterized in that, Includes the following steps: S1. In-situ calibration: Before measurement, the heating wire in the probe is controlled to heat the calibration excitation core. The difference in thermal expansion coefficient between the calibration excitation core and the rigid constraint layer is used to generate a known standard pressure on the piezoresistive sensing array layer. Based on the standard pressure and the electrical signal output by each piezoresistive sensing unit in the piezoresistive sensing array layer, a pressure signal response model is established for each piezoresistive sensing unit. S2. Online measurement: Insert the probe into the plum blossom contact to be tested, collect the original electrical signal output by each of the piezoresistive sensing units after being squeezed, and call the corresponding pressure signal response model to calculate the final pressure value of each of the piezoresistive sensing units.

9. The detection method of the circuit breaker sprite contact pressure detection device according to claim 8, characterized in that, S2 further includes: reconstructing the two-dimensional pressure field distribution on the probe surface based on the final pressure value and spatial coordinates of each piezoresistive sensing unit.

10. The detection method of the circuit breaker sprite contact pressure detection device according to claim 9, characterized in that, Also includes: S3. Diagnostic Analysis: Analyze the two-dimensional pressure field distribution to obtain the diagnostic results of the pressure distribution status of each finger of the plum blossom contact.

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