Temperature-rise-resistant current terminal and overcurrent alarm method thereof

Abstract

This invention discloses a temperature-rise current-resistant terminal block and an alarm method, relating to the field of electrical energy metering instrument calibration and testing technology. The temperature-rise current-resistant terminal block includes a base, a contact temperature sensor, and a micro-displacement detection component. The contact temperature sensor is disposed at the top of the base and is used to contact the fixing screw. The contact temperature sensor has a thermally induced curvature change structure; when the temperature rises at the contact point, the curvature changes, causing the contact area to increase with the curvature change. The micro-displacement detection component detects the deformation of the contact temperature sensor. The alarm method collects the slider displacement, stores continuous slider displacements, and generates an alarm judgment result based on the slider displacement, a preset displacement threshold, and displacement change characteristic quantities. This solution can reduce the risk of temperature rise at the rapid wiring contact under high current conditions and improve the reliability of overcurrent alarm judgment.

Description

Technical Field

[0001] This invention relates to the field of electrical energy metering instrument calibration and testing technology, and in particular to a temperature rise current-resistant terminal block and an overcurrent alarm method for electrical energy metering instrument calibration and testing. Background Technology

[0002] With the development of verification and testing technology for electricity metering instruments, the verification and testing methods for these instruments are gradually shifting from manual, one-by-one wiring verification to automated or semi-automated verification and testing. In automated or semi-automated verification and testing processes, electricity metering instruments typically need to be transferred between different verification and testing units. The wiring mechanism on the verification and testing device quickly connects to the current and voltage terminals of the electricity metering instrument to complete tests such as withstand voltage, appearance, and error verification. Currently, the current terminals of electricity metering instruments are usually equipped with terminal holes and fixing screws. The current terminals on the verification and testing device typically contact the fixing screws through end-pressing to achieve rapid wiring.

[0003] Under the aforementioned quick-connection method, the contact state between the current terminal and the fixing screw is easily affected by the contact area, contact pressure, and contact position. During high-current calibration and testing, excessive temperature rise at the contact point may damage the tail section of the energy meter, and in severe cases, there is a risk of burnout. Furthermore, the existing method of using temperature detection elements for alarms is affected by the installation location and heat conduction path, making it difficult to directly reflect the actual working state of the contact point. The timeliness and reliability of alarm judgment still need improvement. Summary of the Invention

[0004] The purpose of this invention is to provide a temperature rise resistant current terminal and an overcurrent alarm method to solve the problems in the prior art, such as the high risk of temperature rise at the contact point when the current terminal and the fixing screw make rapid contact and the difficulty in reliably detecting abnormal contact conditions.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a temperature-rising current-resistant terminal block for the calibration and testing of electrical energy metering instruments, comprising a base, a contact temperature sensor, and a micro-displacement detection component; the base is mounted on the connector mechanism of the calibration and testing device for electrical energy metering instruments; the contact temperature sensor is disposed at the top of the base and has a contact surface for contacting a fixing screw; the contact temperature sensor has a thermally induced curvature change structure, causing the curvature of the contact temperature sensor to change when the temperature rises at the contact point, and increasing the contact area between the contact surface and the fixing screw with the change in curvature; the micro-displacement detection component is disposed on the base and is connected to the contact temperature sensor or a transmission component connected to the contact temperature sensor, for detecting the deformation of the contact temperature sensor.

[0006] The above solution solves the problem of insufficient contact area leading to high temperature rise risk in quick-connection scenarios by setting a contact temperature sensor with a thermal curvature change structure at the top of the base column. This allows the contact temperature sensor to change its curvature and expand the contact area with the fixing screw when the temperature rises at the contact point. As a result, it reduces the risk of abnormal temperature rise at the contact point and provides a structural basis for deformation-based abnormal temperature rise detection.

[0007] Furthermore, the contact temperature sensor includes a bimetallic strip, which comprises a first metal layer and a second metal layer that are bonded together, and the first metal layer and the second metal layer have different coefficients of thermal expansion.

[0008] The above-mentioned further solution solves the problem of the lack of a stable structure to realize the thermal curvature change of the contact temperature sensor by using a first metal layer and a second metal layer with different coefficients of thermal expansion to form a bimetallic sheet, thereby enabling the contact temperature sensor to produce a predictable curvature change based on the difference in thermal expansion between the layers.

[0009] Furthermore, the first metal layer is located on the side of the contact temperature sensor away from the base column, and the second metal layer is located on the side of the contact temperature sensor facing the base column. The coefficient of thermal expansion of the first metal layer is smaller than that of the second metal layer.

[0010] The above-mentioned further solution solves the problem of uncertain direction of deformation of the contact temperature sensing element when heated by limiting the relative position of the first metal layer and the relationship of the coefficient of thermal expansion, thereby making the direction of curvature change of the contact temperature sensing element match the direction of the contact surface fixing screw.

[0011] Furthermore, the contact temperature sensing element is a curved contact body with a preset curvature, and the contact surface is a hyperboloid or arc surface; when the anti-temperature rise current terminal contacts the fixing screw, the long side direction of the contact temperature sensing element is parallel to the axial direction of the fixing screw.

[0012] The above-mentioned further solution solves the problem of unstable contact direction between the curved contact body and the screw surface by setting a hyperboloid or arc surface contact surface and limiting the long side direction of the contact temperature sensing body to be parallel to the axis direction of the fixing screw, thereby improving the contact stability and repeatability consistency during the contact area expansion process.

[0013] Furthermore, the base column is a slotted columnar conductor, and a spring is formed at the lower end of the base column. The contact temperature sensor is fixed to the top of the base column by a fastener. An insulating wire is connected to the back side of the contact temperature sensor, and the insulating wire extends to the lower end of the base column and is connected to the spring.

[0014] The above-mentioned further solution solves the problem that the deformation of the contact temperature sensor is difficult to transmit to the detection position by forming a conductive support structure on the base column and establishing a mechanical transmission relationship between the contact temperature sensor and the lower end of the base column through an insulating wire and a spring, thereby providing a stable transmission path for the displacement detection of the contact temperature sensor deformation.

[0015] Furthermore, the micro-displacement detection component is sleeved on the lower end of the base column. The micro-displacement detection component includes a slider and an input / output port. The slider is connected to the upper end of the spring, and the input / output port is used to connect to the alarm module of the power metering instrument calibration and testing device.

[0016] The above-mentioned further solution solves the problem of the difficulty in converting the deformation data of the contact temperature sensor into alarm input by connecting the slider to the upper end of the spring and connecting the input / output port to the alarm module. This realizes the transmission of deformation detection results to the alarm module and improves the directness and closed-loop nature of abnormal contact state detection.

[0017] In a second aspect, the present invention provides an overcurrent alarm method based on the above-mentioned temperature rise current-resistant terminal block, comprising: The electrical energy metering instrument calibration and testing device enables the micro-displacement detection component through the input / output port; Micro-displacement detection component in the first t The slider displacement is measured at several time points, and the slider displacement is used to characterize the deformation of the contact temperature sensing element. The slider displacement is stored in the shift register, and the shift register stores the slider displacement at consecutive time points; Based on the slider displacement, the preset displacement threshold, and the displacement change characteristics obtained from the slider displacement at continuous time points, the alarm judgment result is obtained. Based on the alarm judgment result, an alarm signal is output through the input / output port, or the slider displacement is returned to continue measuring the next time point when the enable signal is present.

[0018] The above scheme solves the problem that a single instantaneous detection value cannot reliably reflect the deformation process of the contact thermocouple by continuously collecting slider displacement, buffering slider displacement at continuous time points, and combining displacement change characteristics for alarm judgment. This enables a joint judgment of the degree and trend of deformation of the contact thermocouple.

[0019] Furthermore, the preset displacement threshold includes a first displacement threshold, which is determined by: when the anti-temperature rise current terminal passes the maximum allowable current, adjusting the length of the spring or insulating wire so that the contact temperature sensing element reaches the deformation limit when the temperature rise reaches the maximum, measuring the slider displacement corresponding to the contact temperature sensing element reaching the deformation limit, and determining the slider displacement as the first displacement threshold.

[0020] The above-mentioned further solution addresses the mismatch between the alarm benchmark and the actual deformation limit of the contact temperature sensor by corresponding the first displacement threshold to the slider displacement when the contact temperature sensor reaches its deformation limit, thereby improving the structural correspondence and traceability of the alarm judgment benchmark.

[0021] Furthermore, the preset displacement threshold also includes a second displacement threshold, which is determined based on the first displacement threshold and a hyperparameter that takes into account the tolerance of the fixing screw.

[0022] The above-mentioned further solution addresses the problem of different fixing screw sizes or assembly differences affecting alarm judgment by introducing a hyperparameter α that takes into account the tolerance of the fixing screws based on the first displacement threshold, thereby improving the adaptability of the overcurrent alarm method to different current terminal structures.

[0023] Furthermore, the displacement change characteristic quantity is obtained by obtaining the displacement change threshold based on the slider displacement at continuous time points; when the temperature rise current terminal passes the maximum allowable current, the slider displacement is continuously measured, and the displacement change threshold is determined by the continuous slider displacement before and after the contact temperature sensing body reaches the deformation limit. The relationship between the slider displacement and the first displacement threshold is determined, as well as the relationship between the slider displacement and the second displacement threshold, and the relationship between the second-order difference characteristic quantity of displacement and the displacement change threshold. When the determination results meet the preset alarm conditions, an alarm determination result for the alarm state is generated.

[0024] The above-mentioned further solution combines the second-order differential displacement characteristic with the first displacement threshold and the second displacement threshold, which solves the problem that it is difficult to identify the deformation trend of the contact temperature sensor by means of displacement amplitude alone, thereby improving the reliability of overcurrent alarm judgment in identifying deformation limit state.

[0025] The beneficial effects of this invention are as follows: By installing a thermally induced curvature change structure at the top of the base column, and making the contact surface of the thermally induced curvature change when the temperature rises at the contact point, the contact area increases with the curvature change, thereby increasing the number of conductive contact points in the contact area, suppressing the increase in contact resistance, and reducing the risk of contact point temperature rise during high current calibration and testing. At the same time, by setting a micro-displacement detection component connected to the thermally induced curvature, the deformation of the thermally induced curvature can be detected, providing a structural basis for subsequent overcurrent alarms.

[0026] By setting the contact temperature sensor as a bimetallic sheet structure including a first metal layer and a second metal layer, and making the thermal expansion coefficients of the first metal layer and the second metal layer different, the contact temperature sensor can bend and deform based on the difference in thermal expansion of the two metal layers under the action of temperature rise, thereby providing a stable structural realization method for the thermal curvature change of the contact temperature sensor.

[0027] By placing the first metal layer on the side of the contact temperature sensor away from the base column and the second metal layer on the side of the contact temperature sensor facing the base column, and making the thermal expansion coefficient of the first metal layer smaller than that of the second metal layer, the contact temperature sensor can undergo curvature change in a predetermined direction when the temperature rises, thereby ensuring that the deformation direction of the contact temperature sensor matches the direction of expanding the contact area between it and the current end fixing screw.

[0028] By setting the contact temperature sensor as a curved contact body with a preset curvature and setting the contact surface as a hyperboloid or arc surface, the contact temperature sensor can form a suitable contact with the fixing screw. At the same time, by making the long side of the contact temperature sensor parallel to the axial direction of the current-end fixing screw, the contact temperature sensor forms a more stable fit relationship along the axial direction of the fixing screw during deformation, thereby improving the effectiveness of contact area expansion and the stability of the contact state.

[0029] By setting the base column as a slotted columnar conductor and forming a spring at the lower end of the base column, the base column combines the functions of conduction, support, and elastic displacement transmission. By fixing the contact temperature sensor to the top of the base column with a fastener and connecting the back of the contact temperature sensor with an insulating wire that extends to the lower end of the base column and connects to the spring, the deformation of the contact temperature sensor can be transmitted to the lower end of the base column through the insulating wire and the spring, thus providing a mechanical transmission path for deformation detection.

[0030] By fitting the micro-displacement detection component onto the lower end of the base column and connecting the slider of the micro-displacement detection component to the upper end of the spring, the deformation of the contact temperature sensing element can be converted into slider displacement and detected by the micro-displacement detection component. By setting an input / output port and connecting it to the alarm module of the calibration and testing device, the detected deformation can be used as input data for the alarm module, thereby realizing the structural connection between the anti-temperature rise terminal and the alarm function of the calibration and testing device.

[0031] By enabling the micro-displacement detection component, measuring the slider displacement at time points and storing the slider displacement in a shift register, the deformation process of the contact temperature sensor can be continuously recorded. By obtaining the alarm judgment result based on the slider displacement, the preset displacement threshold, and the displacement change characteristic quantity obtained from the continuous slider displacement, the alarm judgment no longer relies solely on a single instantaneous value, but can be judged by combining the deformation amount and the deformation change trend. By outputting an alarm signal when the alarm judgment result meets the conditions, an overcurrent alarm can be triggered in a timely manner when the contact temperature sensor approaches or reaches an abnormal deformation state.

[0032] By adjusting the length of the spring or insulating wire when the anti-temperature rise current terminal passes the maximum allowable current, the contact temperature sensor reaches its deformation limit when the temperature rise reaches the maximum. The slider displacement corresponding to this deformation limit is determined as the first displacement threshold, so that the first displacement threshold corresponds to the actual deformation limit of the contact temperature sensor, thereby enabling the alarm judgment benchmark to reflect the structural limit state of the contact temperature sensor.

[0033] The second displacement threshold is determined based on the first displacement threshold and the hyperparameter considering the tolerance of the fixing screw. This allows the second displacement threshold to be set in combination with the size or assembly differences of the fixing screw at the current end, thereby improving the adaptability of the overcurrent alarm method to the current end structure of different energy metering instruments and reducing false alarms or alarm lag caused by terminal tolerances.

[0034] By setting the displacement change characteristic quantity as a second-order differential displacement characteristic quantity obtained based on the slider displacement at continuous time points, and determining the displacement change threshold based on the continuous slider displacement before and after the contact temperature sensing body reaches the deformation limit, the alarm judgment can identify the change in the deformation trend of the contact temperature sensing body. By comprehensively judging the relationship between the slider displacement and the first displacement threshold, the second displacement threshold, and the relationship between the second-order differential displacement characteristic quantity and the displacement change threshold, the overcurrent alarm can simultaneously judge based on the degree of deformation and the deformation trend, thereby improving the reliability and timeliness of the alarm judgment. Attached Figure Description

[0035] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A three-dimensional structural diagram of the temperature rise current-resistant terminal block provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the temperature rise current-resistant terminal provided in an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the working state of the anti-temperature rise current terminal and the fixing screw provided in an embodiment of the present invention.

[0036] Explanation of reference numerals in the attached diagram: 1. Base column; 2. Contact temperature sensing element; 21. Bimetallic strip; 22. Insulating wire; 23. Spring; 3. Micro-displacement detection component; 31. Slider; 32. Input / output port; 4. Current terminal of power metering instrument; 41. Fixing screw. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0038] The following detailed description is exemplary and intended to provide further detailed explanation of the invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used in this invention is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention.

[0039] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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 invention.

[0040] Furthermore, 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. It should be noted in the description of this invention that, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] Example 1 A temperature rise resistant current terminal for the verification and testing of electricity metering instruments, such as Figure 1 and Figure 2 As shown, the temperature-rising current-resistant terminal includes a base 1, a contact temperature sensor 2, and a micro-displacement detection component 3. The base 1 is mounted on the connector mechanism of the energy metering instrument calibration and testing device. The contact temperature sensor 2 is located at the top of the base 1 and has a contact surface for contacting the fixing screw 41 on the current terminal 4 of the energy metering instrument. The contact temperature sensor 2 has a thermally induced curvature change structure, causing a curvature change at the contact point when the temperature rises, and increasing the contact area between the contact surface and the fixing screw 41 with the curvature change. The micro-displacement detection component 3 is located on the base 1 and is connected to the contact temperature sensor 2 or a transmission component connected to the contact temperature sensor 2, for detecting the deformation of the contact temperature sensor 2.

[0042] In this design, the base column 1 serves as the mounting and conductive foundation, the contact temperature sensor 2 is the component that directly contacts the fixing screw 41, and the micro-displacement detection component 3 is the component that detects the deformation of the contact temperature sensor 2. Since the contact temperature sensor 2 is located near the contact point, its thermally induced curvature change directly corresponds to the temperature rise at the contact point. During the temperature rise, the contact surface of the contact temperature sensor 2 gradually changes its contact state with the fixing screw 41, causing a change in the actual contact area between the two, thereby reducing the risk of abnormal temperature rise at the contact point under traditional end-partial contact conditions. Simultaneously, by detecting the deformation of the contact temperature sensor 2 through the micro-displacement detection component 3, a detection basis correlated with the contact point state can be provided for subsequent overcurrent alarms.

[0043] Specifically, the current terminal 4 of an electricity meter typically includes a terminal hole and a fixing screw 41, the center lines of which can be perpendicular to each other and fixed by threads. When the electricity meter calibration and testing device is working, the temperature-resistant current terminal can be pressed into contact with the fixing screw 41 by the connection mechanism. After the calibration current is applied, a temperature rise occurs at the contact point, and the contact temperature sensing element 2 changes curvature with the temperature rise, causing its contact surface to gradually form a larger contact area with the fixing screw 41. According to electrical contact theory, contact resistance is related to the number of conductive spots and the average radius of the conductive spots. In the same connection mechanism, when the contact pressure is relatively fixed, increasing the contact area will increase the number of conductive spots, thereby improving the conductivity at the contact point.

[0044] In one embodiment, the contact temperature sensor 2 includes a bimetallic strip 21, which comprises a first metal layer and a second metal layer bonded together, the first and second metal layers having different coefficients of thermal expansion. The bimetallic strip 21 can be manufactured by welding, composite pressing, or other methods capable of forming a stable interlayer bond, as long as it can produce a curvature change based on the difference in thermal expansion between the first and second metal layers upon temperature rise. This structure provides a definite source of thermally induced deformation for the contact temperature sensor 2, making the curvature change of the contact temperature sensor 2 repeatable and structurally stable.

[0045] The principle is that the first metal layer and the second metal layer elongate to different degrees under the same temperature rise conditions. The difference in elongation between the layers causes the bimetallic strip 21 to bend, thereby causing the contact surface of the contact temperature sensor 2 to change its curvature. Compared with the terminal block that only relies on elastic compression, this embodiment forms an active deformation basis through the difference in thermal expansion between the material layers, enabling the contact temperature sensor 2 to change its contact shape as the temperature rises at the contact point.

[0046] This embodiment further solves the problem of how to stably realize the thermal curvature change structure by using a bimetallic sheet 21 as the specific structure of the contact temperature sensor 2, so that the deformation of the contact temperature sensor 2 has a clear material basis and improves the repeatability and manufacturability of the contact state change.

[0047] In one embodiment, a first metal layer is located on the side of the contact temperature sensor 2 away from the base pillar 1, and a second metal layer is located on the side of the contact temperature sensor 2 facing the base pillar 1. The coefficient of thermal expansion of the first metal layer is smaller than that of the second metal layer. With the above layer arrangement, when the temperature rises at the contact point, the first metal layer generates greater thermal expansion relative to the second metal layer, causing the contact temperature sensor 2 to change its curvature in a predetermined direction.

[0048] Specifically, the relative positions of the first metal layer and the second metal layer determine the bending direction of the contact temperature sensor 2 after being heated. Placing the first metal layer, which has a larger coefficient of thermal expansion, on the side away from the base column 1 allows the contact temperature sensor 2 to change in a direction that facilitates contact with the fixing screw 41 when heated. This limitation is not simply a matter of material selection, but rather a way to ensure that the direction of thermal deformation matches the direction of contact area expansion.

[0049] This embodiment further solves the problem of uncertain deformation direction of the contact temperature sensor 2 when heated by limiting the relative position and thermal expansion coefficient relationship of the two metal layers in the bimetallic sheet 21, so that the contact temperature sensor 2 has a more stable contact direction consistency in repeated verification and testing.

[0050] In one embodiment, the contact temperature sensor 2 is a curved contact body with a preset curvature, and the contact surface is a hyperboloid or an arc surface. When the anti-temperature rise current terminal contacts the fixing screw 41, the long side of the contact temperature sensor 2 is parallel to the axial direction of the fixing screw 41.

[0051] Specifically, the contact surface of the contact temperature sensor 2 can be configured as a hyperboloid or an arc surface, depending on the end or outer contour of the fixing screw 41. The hyperboloid or arc surface is not limited to a specific fixed curved surface shape, as long as it can form a contact surface with an initial curvature and change its contact area with the fixing screw 41 as the curvature changes with temperature rise. The long side of the contact temperature sensor 2 is parallel to the axial direction of the fixing screw 41, enabling the contact temperature sensor 2 to form a relatively continuous contact area along the axial direction of the fixing screw 41 during deformation.

[0052] This embodiment further solves the problem of unstable contact path between the contact temperature sensor 2 and the fixing screw 41 by limiting the contact surface shape and installation direction of the curved contact body, and improves the positioning stability and contact consistency during the contact area change process.

[0053] In one embodiment, the base column 1 is a slotted columnar conductor, with a spring 23 formed at the lower end of the base column 1. The contact temperature sensor 2 is fixed to the top of the base column 1 by a fastener. An insulating wire 22 is connected to the back side of the contact temperature sensor 2, extending to the lower end of the base column 1 and connecting to the spring 23. The fastener can be a miniature screw located in the middle of the contact temperature sensor 2, or an equivalent fixing structure that can reliably fix the contact temperature sensor 2 to the top of the base column 1.

[0054] Specifically, the base column 1 can be made of copper or other conductive materials to meet the conductivity requirements during the calibration and testing of electrical energy metering instruments. The slotted columnar structure provides space for the arrangement of the spring 23 and the insulating wire 22. The insulating wire 22 is connected to the back side of the contact temperature sensor 2, and the insulating wire 22 is used to transfer the deformation of the contact temperature sensor 2 to the lower end of the base column 1; the spring 23 is used to cooperate with the insulating wire 22 to form a recoverable displacement transfer structure. The insulating wire 22 should be made of high-temperature resistant and aging-resistant materials, and its coefficient of thermal expansion should be as low as possible to reduce the influence of the thermal expansion of the insulating wire 22 itself on the slider displacement detection results.

[0055] Furthermore, after the test ends or the current decreases, the temperature of the contact temperature sensor 2 drops, its shape gradually returns to normal, and the spring 23 and the insulating wire 22 reset accordingly, so that the temperature rise current-resistant terminal can adapt to the repeated wiring operations in the power metering instrument calibration and testing device.

[0056] This embodiment further solves the problem of difficult deformation signal transmission when the contact temperature sensor 2 is located at the contact end and the detection component is located at the lower end of the base column 1 by combining the base column 1, the insulating wire 22 and the spring 23 to form a deformation transmission path, thereby improving the structural reliability and repeatability of deformation detection.

[0057] In one embodiment, the micro-displacement detection component 3 is sleeved on the lower end of the base column 1. The micro-displacement detection component 3 includes a slider 31 and an input / output port 32. The slider 31 is connected to the upper end of the spring 23, and the input / output port 32 is used to connect to the alarm module of the power metering instrument calibration and testing device.

[0058] Specifically, after the contact temperature sensor 2 deforms, the deformation is transmitted to the spring 23 through the insulating wire 22. The spring 23 drives the slider 31 to displace, and the micro-displacement detection component 3 detects the displacement of the slider 31 and outputs a detection signal through the input / output port 32. The input / output port 32 can also be used to receive an enable signal from the electrical energy metering instrument calibration and testing device, enabling the micro-displacement detection component 3 to start detection during the operation of the calibration and testing device and stop detection after the calibration and testing is completed. The alarm module can receive the alarm signal output from the input / output port 32 and provide audible and visual prompts, shutdown prompts, or cooperate with the protection control logic of the calibration and testing device.

[0059] This embodiment connects the slider 31 to the upper end of the spring 23, converting the deformation of the contact temperature sensor 2 into a detectable slider displacement, and forming a signal connection with the alarm module through the input / output port 32. This further solves the problem of unclear output path of deformation detection results and improves the integrity of overcurrent alarm signal transmission.

[0060] Example 2 An overcurrent alarm method based on the aforementioned temperature rise current-resistant terminal block, such as... Figure 3 As shown, the method includes: Step 1: The electrical energy metering instrument calibration and testing device enables the micro-displacement detection component 3 through the input / output port 32; Step 2, the micro-displacement detection component 3 in the first... t Measure slider displacement at each time point slider displacement Used to characterize the deformation of the contact temperature sensor 2; Step 3, displace the slider The displacement of the slider at consecutive time points is stored in the shift register. Step 4, based on slider displacement The alarm judgment result is obtained by using a preset displacement threshold and displacement change characteristics obtained from the slider displacement at continuous time points. Step 5: Based on the alarm judgment result, output an alarm signal through input / output port 32, or return to step 2 to continue measuring the slider displacement at the next time point when the enable signal is present.

[0061] In this method, the slider displacement The displacement of slider 31 originates from the measurement results of the micro-displacement detection component 3. The displacement of slider 31 is caused by the deformation of the contact temperature sensor 2 transmitted through the insulating wire 22 and the spring 23. Therefore, the slider displacement... The data is not isolated detection data, but rather a physical quantity used to characterize the deformation state of the contact temperature sensor 2. The shift register is used to store the slider displacement at continuous time points, enabling step 4 to simultaneously utilize the current displacement value and continuous displacement change information for alarm judgment.

[0062] Specifically, when the electrical energy metering instrument calibration and testing device begins calibration and testing, it sends an enable signal to the micro-displacement detection component 3 through the input / output port 32. In the enabled state, the micro-displacement detection component 3 collects the slider displacement at set time intervals. and the slider displacement Write to the shift register. The shift register can store at least the number of consecutive slider displacements required to calculate the displacement change characteristic, and automatically overwrites earlier historical slider displacements after a new slider displacement is written. The alarm judgment result can include an alarm state and a non-alarm state. When the alarm judgment result is an alarm state, an alarm signal is output through input / output port 32; when the alarm judgment result is a non-alarm state and the enable signal is still present, the micro-displacement detection component 3 continues to collect the slider displacement at the next time point.

[0063] This embodiment uses slider displacement By performing continuous data acquisition, buffering, and trend judgment, the problem of relying solely on a single instantaneous detection value being easily affected by disturbances is further solved. This enables the overcurrent alarm to simultaneously consider the deformation amplitude and deformation trend of the contact temperature sensor 2, thereby improving the reliability of alarm judgment.

[0064] In one embodiment, the preset displacement threshold includes a first displacement threshold. First displacement threshold The determination method includes: when the anti-temperature rise current terminal passes the maximum allowable current, adjusting the length of spring 23 or insulating wire 22 so that the contact temperature sensor 2 reaches the deformation limit when the temperature rise reaches the maximum, measuring the slider displacement corresponding to the contact temperature sensor 2 reaching the deformation limit, and determining this slider displacement as the first displacement threshold. .

[0065] Specifically, the deformation limit can be understood as the position where the curvature of the contact temperature sensor 2 increases to the point where the contact state with the fixing screw 41 reaches a preset limit, such as the position where the contact temperature sensor 2 and the fixing screw 41 reach a predetermined fit. First displacement threshold. The deformation limit is determined by the slider displacement, so it reflects the structural state of the contact temperature sensor 2, rather than the temperature measurement value far from the contact point.

[0066] This embodiment uses a first displacement threshold. By establishing a correspondence with the deformation limit of the contact temperature sensor 2, the problem of the lack of physical structural reference for the alarm threshold is further solved, and the traceability of the threshold setting and the consistency of alarm judgment are improved.

[0067] In one embodiment, the preset displacement threshold further includes a second displacement threshold. Second displacement threshold Based on the first displacement threshold And considering the hyperparameters of the 41 tolerance of the fixing screw Sure: ; in, The value ranges from 0.4 to 0.75.

[0068] Specifically, the initial contact state between the fixing screw 41 and the contact temperature sensor 2 may differ due to manufacturing tolerances, installation conditions, or specification variations. This can be addressed by introducing hyperparameters. , making the second displacement threshold With the first displacement threshold By using the standard to determine the proportion, it can provide a benchmark for advance judgment or auxiliary judgment under different fixing screw 41 conditions.

[0069] This embodiment sets a second displacement threshold. This further solves the problem of the impact of different fixing screw tolerances on alarm judgment and improves the adaptability of the overcurrent alarm method under different terminal structures.

[0070] In one embodiment, the displacement change feature is a second-order difference feature obtained based on the slider displacement at continuous time points, and the displacement change threshold corresponding to the displacement change feature is... When the temperature rise current-resistant terminal carries the maximum allowable current, the slider displacement is continuously measured. The displacement change threshold is determined by the continuous slider displacement before and after the contact temperature sensor 2 reaches its deformation limit. In step 4, the displacement of the slider is determined. With the first displacement threshold The relationship between the two is used to determine the displacement of the slider. With the second displacement threshold The relationship between the second-order difference characteristic quantity of displacement and the displacement change threshold The relationship is such that when the judgment result meets the preset alarm conditions, an alarm judgment result of the alarm state is generated.

[0071] Specifically, the second-order difference characteristic of displacement is used to characterize the change trend of continuous slider displacement. As an example, the second-order difference characteristic of displacement can be calculated as follows:

[0072] in, , , , These represent the slider displacements at consecutive time points in the shift register. Each slider displacement in this formula originates from the continuous measurement results of slider 31 by the micro-displacement detection component 3.

[0073] Furthermore, the slider displacement is continuously measured when the temperature rise current-resistant terminal passes the maximum allowable current. And assuming that the contact temperature sensor 2 is at time point to If the deformation limit is reached, then the displacement change threshold is... It can be determined in the following way:

[0074] in, Hyperparameters are introduced to account for margin. The value can range from 1.1 to 2. , , , All of these are slider displacements continuously measured when the temperature rise current-resistant terminal passes the maximum allowable current.

[0075] For example, alarm determination may include: determining the slider displacement. Is it less than the first displacement threshold? If the slider displacement Not less than the first displacement threshold If the slider displacement is..., then an alarm judgment result is generated for the alarm status; if... Less than the first displacement threshold Then continue to determine the slider displacement. Is it less than the second displacement threshold? Alternatively, determine whether the second-order difference characteristic of the displacement is less than the displacement change threshold. When the slider is displaced Less than the second displacement threshold Or the second-order difference characteristic of the displacement is less than the displacement change threshold. When the slider displacement is reached, an alarm judgment result is generated for the non-alarm state; when the slider displacement is reached... Not less than the second displacement threshold Furthermore, the second-order difference characteristic of the displacement is not less than the displacement change threshold. At that time, an alarm judgment result is generated for the alarm status.

[0076] This embodiment further solves the problem that a single displacement threshold is insufficient to identify changes in the deformation trend of the contact temperature sensor 2 by simultaneously setting displacement amplitude judgment and displacement change trend judgment. When the contact temperature sensor 2 gradually approaches the deformation limit, the change characteristics of the continuous slider displacement can reflect the change in deformation trend. Therefore, combining the second-order differential displacement characteristic can improve the reliability and timeliness of overcurrent alarm judgment in identifying critical states.

[0077] In practical use, the anti-temperature rise current terminal can be first installed on the connector mechanism of the power metering instrument calibration and testing device, ensuring that the long side of the contact temperature sensor 2 is parallel to the axial direction of the fixing screw 41 to be contacted. After the connector mechanism pushes the anti-temperature rise current terminal into contact with the fixing screw 41, the calibration and testing device applies a calibration current and enables the micro-displacement detection component 3 through the input / output port 32. The micro-displacement detection component 3 continuously detects the slider displacement. Displace the slider Write to the shift register, and the alarm judgment logic determines the slider displacement. First displacement threshold Second displacement threshold The second-order differential characteristic of the displacement is used to generate an alarm judgment result. When an alarm judgment result is generated, input / output port 32 outputs an alarm signal to the alarm module; when no alarm state is generated and the enable signal still exists, the slider displacement acquisition continues at the next time point.

[0078] The first displacement threshold in the above embodiments Second displacement threshold Displacement change threshold The hyperparameters α and β can be obtained through calibration under the maximum permissible current condition before the anti-temperature rise current terminal is put into use. The calibration process should be matched with the structure of the specific fixing screw 41, the contact pressure of the connection mechanism, and the material and size of the contact temperature sensor 2. The above calibration method can make the alarm judgment parameters correspond to the actual deformation process of the contact temperature sensor 2, and avoid the alarm judgment from deviating from the specific terminal structure.

[0079] It should be noted that the terms "hyperbolic surface or arc surface," "spring," "insulating wire," and "miniature screw" used in the above embodiments are used to illustrate specific implementations of the present invention and do not imply that only one form can be used. Any equivalent structure that can achieve the fixing of the contact temperature sensor 2, deformation transmission, slider displacement detection, and alarm signal output without departing from the concept of the present invention can be used to implement the present invention.

[0080] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0081] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or equivalent to the scope of this invention are included in this invention.

Claims

1. A temperature-rise current-resistant terminal block for the calibration and testing of electrical energy metering instruments, characterized in that, The device includes a base column (1), a contact temperature sensor (2), and a micro-displacement detection component (3). The base column (1) is used to install on the connector mechanism of the power metering instrument calibration and testing device. The contact temperature sensor (2) is located at the top of the base column (1) and has a contact surface for contacting a fixing screw (41). The contact temperature sensor (2) has a thermal curvature change structure, which causes the curvature of the contact temperature sensor (2) to change when the temperature rises at the contact point, and causes the contact area between the contact surface and the fixing screw (41) to increase with the curvature change. The micro-displacement detection component (3) is located on the base column (1) and is connected to the contact temperature sensor (2) or a transmission component connected to the contact temperature sensor (2) for detecting the deformation of the contact temperature sensor (2).

2. The temperature rise current resistant terminal block as described in claim 1, characterized in that, The contact temperature sensor (2) includes a bimetallic strip (21), which includes a first metal layer and a second metal layer that are bonded together, and the first metal layer and the second metal layer have different coefficients of thermal expansion.

3. The temperature rise current resistant terminal block as described in claim 2, characterized in that, The first metal layer is located on the side of the contact temperature sensor (2) away from the base column (1), and the second metal layer is located on the side of the contact temperature sensor (2) facing the base column (1). The coefficient of thermal expansion of the first metal layer is smaller than that of the second metal layer.

4. The temperature rise current resistant terminal block as described in claim 1, characterized in that, The contact temperature sensing body (2) is a curved contact body with a preset curvature. The contact surface of the curved contact body is a hyperboloid or an arc surface. When the anti-temperature rise current terminal is in contact with the fixing screw (41), the long side direction of the contact temperature sensing body (2) is parallel to the axial direction of the fixing screw (41).

5. The temperature rise current resistant terminal block as described in claim 1, characterized in that, The base column (1) is a slotted columnar conductor. A spring (23) is formed at the lower end of the base column (1). The contact temperature sensor (2) is fixed to the top of the base column (1) by a fastener. An insulating wire (22) is connected to the back side of the contact temperature sensor (2). The insulating wire (22) extends to the lower end of the base column (1) and is connected to the spring (23).

6. The temperature rise current resistant terminal block as described in claim 5, characterized in that, The micro-displacement detection component (3) is sleeved on the lower end of the base column (1). The micro-displacement detection component (3) includes a slider (31) and an input / output port (32). The slider (31) is connected to the upper end of the spring (23). The input / output port (32) is used to connect to the alarm module of the power metering instrument calibration and testing device.

7. An overcurrent alarm method for a temperature rise resistant current terminal block, applied to a temperature rise resistant current terminal block, the temperature rise resistant current terminal block comprising a base body (1), a contact temperature sensor (2), and a micro-displacement detection component (3), the contact temperature sensor (2) being disposed at the top end of the base body (1) and used to contact a fixing screw (41), the micro-displacement detection component (3) being connected to the contact temperature sensor (2) or a transmission component connected to the contact temperature sensor (2), characterized in that, include: The calibration and testing device enables the micro-displacement detection component (3) through the input / output port (32); The micro-displacement detection component (3) measures the displacement of the slider (31) at the t-th time point; The displacement of the slider (31) is stored in a shift register, which is used to store the displacement of the slider (31) at consecutive time points; Based on the displacement of the slider (31), the preset displacement threshold, and the displacement change characteristic quantity obtained from the displacement of the slider (31) at the continuous time points, the alarm judgment result is obtained; Based on the alarm judgment result, an alarm signal is output through the input / output port (32), or the displacement of the slider (31) at the next time point is measured when the enable signal is present.

8. The overcurrent alarm method for the temperature rise current-resistant terminal block as described in claim 7, characterized in that, The preset displacement threshold includes a first displacement threshold, and the method for determining the first displacement threshold includes: When the anti-temperature rise current terminal passes the maximum allowable current, adjust the length of the spring (23) or the insulating wire (22) so that the contact temperature sensor (2) reaches the deformation limit when the temperature rise reaches the maximum. Measure the displacement of the slider (31) corresponding to the contact temperature sensor (2) reaching the deformation limit, and determine the displacement of the slider (31) as the first displacement threshold.

9. The overcurrent alarm method for the temperature rise current-resistant terminal block as described in claim 8, characterized in that, The preset displacement threshold also includes a second displacement threshold, which is determined based on the first displacement threshold and a hyperparameter that takes into account the tolerance of the fixing screw (41).

10. The overcurrent alarm method for the temperature rise current-resistant terminal block as described in claim 9, characterized in that, Based on the displacement of the slider (31), the preset displacement threshold, and the displacement change characteristic quantity obtained from the displacement of the slider (31) at the continuous time points, the alarm judgment result is obtained, including: Based on the displacement of the slider (31) at continuous time points, the displacement change characteristic quantity is obtained, and the displacement change threshold corresponding to the displacement change characteristic quantity is obtained; when the anti-temperature rise current terminal passes through the maximum allowable current, the displacement of the slider (31) is continuously measured, and the displacement change threshold is determined by the continuous slider (31) displacement before and after the contact temperature sensing body (2) reaches the deformation limit. The relationship between the displacement of the slider (31) and the first displacement threshold is determined, and the relationship between the displacement of the slider (31) and the second displacement threshold, as well as the relationship between the second-order difference feature of the displacement and the displacement change threshold, is determined. When the determination result meets the preset alarm conditions, an alarm determination result of the alarm state is generated.

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