Combined transposed conductor resistance online detection method

Abstract

The invention provides a combined transposed conductor resistance on-line detection method, which belongs to the technical field of transformer manufacturing, and comprises the following steps: cleaning the surface of a contact area of a combined transposed conductor to be detected, starting a detection device, and completing self-detection and short circuit zero clearing operation; driving the clamp head to clamp the wire from at least two directions to form a stable conductive loop; multiple times of on-off measurement are carried out through a stabilizing circuit, a resistance average value is obtained by adopting a Fourier derivative calculation method, and winding phase sequence information is recorded in real time; calculating a resistance unbalance rate according to the connection mode of the transformer, and starting an alarm mechanism and generating a matching suggestion after comparison and analysis; and marking unqualified lead sections, enabling qualified leads to enter the next process, and resetting the device to prepare for the next detection. According to the combined transposed conductor resistance online detection method provided by the invention, online detection of the combined transposed conductor resistance can be realized, the resistance matching problem can be found in time, the production cost is reduced, and the production efficiency and the product quality are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of transformer manufacturing, and more particularly relates to a combined transposed conductor resistance online detection method. BACKGROUND

[0002] As the core equipment of power system energy conversion and transmission, the operation stability of a transformer is directly related to the safe and reliable power supply of the power system. The matching accuracy of the DC resistance of the three-phase winding is one of the key indicators for measuring the quality of the transformer product, and is also the core requirement of the qualified product specified in the national standard. If the three-phase winding resistance imbalance rate exceeds the standard, it will cause circulating current loss during the operation of the transformer, aggravate the heating of the equipment, reduce the insulation performance, shorten the service life, and even cause equipment failure, resulting in serious economic loss and power interruption.

[0003] In the production process of the transformer, although the conductor will be subjected to preliminary resistance testing during the manufacturing stage, the resistance matching may still exceed the standard due to the influence of various factors during the subsequent winding winding and shaping and pressing processes. In the prior art, for simple single conductors such as round conductors and flat copper wires, online resistance measurement during winding can be realized, but for non-single conductors such as combined transposed conductors (composed of multiple conductors in parallel, with complex structure), measurement and matching can only be performed after the winding winding, shaping, and semi-finished product packaging are completed. If it is found that the resistance matching is unqualified at that time, the quality cost of product repair will be generated, and the product progress and delivery time will inevitably be affected.

[0004] Late discovery of quality problems will cause huge production cost pressure to the manufacturer, and the process of repairing and finding problems is no less than re-manufacturing a same transformer product, resulting in huge loss. SUMMARY

[0005] The purpose of the present application is to provide a combined transposed conductor resistance online detection method, which can realize online detection of the resistance of the combined transposed conductor, timely find resistance matching problems, reduce production cost, and improve production efficiency and product quality.

[0006] To achieve the above purpose, the technical solution adopted by the present application is to provide a combined transposed conductor resistance online detection method, comprising the following steps: S1, cleaning the surface of the contact area of the combined transposed conductor to be detected, starting the detection device and completing self-checking and short-circuit zero-setting operation; S2, clamping the conductor from at least two directions by using a pneumatic or electrically driven clamping jaw head to form a stable conductive loop; S3, measuring the on-off multiple times through a stable circuit, obtaining the average value of the resistance by using the Fourier derivative calculation method, and recording the winding phase sequence information in real time; S4, calculate the resistance imbalance rate according to the transformer connection mode, start the alarm mechanism and generate matching suggestions after comparison and analysis; S5, mark the unqualified wire segment, and the qualified wire enters the next process, and the device is reset for the next detection.

[0007] In a possible implementation, in step S2, the wire spatial position information is collected by the displacement sensor, and the clamping direction and clamping force of the clamping jaw are automatically adjusted.

[0008] In a possible implementation, in step S3, the number of measurements is dynamically adjusted according to the deviation rate of the first measurement value from the preset standard value. The greater the deviation rate, the more the number of measurements, and the data is processed by using the weighted average method.

[0009] In a possible implementation, the temperature parameter and the humidity parameter of the environment are collected by the temperature sensor and the humidity sensor respectively, and in step S4, the resistance value calculated is temperature compensated and humidity corrected according to the temperature parameter and the humidity parameter.

[0010] In a possible implementation, the adaptive transformer connection mode includes Y connection and D connection, and the resistance matching analysis is completed by the corresponding calculation model.

[0011] In a possible implementation, in step S2, the clamping direction of the clamping jaw can be extended to three-dimensional direction, and a step-by-step clamping mode is adopted, that is, the reference direction is positioned first, and then the clamping force in each direction is gradually adjusted, and the contact pressure is detected in real time by the pressure sensor.

[0012] In a possible implementation, when the deviation rate is ≤5%, the number of measurements is 3-4 times, when the deviation rate is >5% and ≤10%, the number of measurements is 5 times, and when the deviation rate is >10%, the number of measurements is 6-8 times.

[0013] In a possible implementation, the temperature compensation is calculated by using the resistance temperature coefficient formula, the humidity correction is realized by using the preset humidity influence correction coefficient model, and the correction coefficient is dynamically adjusted according to the wire material.

[0014] In a possible implementation, a preset transformer winding connection mode database is provided, the connection mode of the transformer winding can be determined by manual input of the user or automatic identification of the detection device, and the database supports addition of a connection mode and update of a corresponding calculation model.

[0015] In a possible implementation, the detection device eliminates the line resistance of itself by short-circuit zero operation in the preprocessing step, and the on-off state of the conductive loop is detected in real time during the resistance measurement process.

[0016] The combination transposed conductor resistance online detection method has the advantages that compared with the prior art, the combination transposed conductor resistance online detection method can realize online detection in the combination transposed conductor winding process, can timely find resistance matching problems, can avoid production cost waste caused by large-scale repair in the later period, and can improve detection efficiency and detection result accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0018] Figure 1 The combination transposed conductor resistance online detection method provided by the present application is shown in the flowchart. DETAILED DESCRIPTION

[0019] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects more clearly, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0020] Please refer to Figure 1 The combination transposed conductor resistance online detection method provided by the present application will be described. The combination transposed conductor resistance online detection method comprises the following steps: S1, pretreatment before detection: the surface of the contact area of the combination transposed conductor to be detected is cleaned to remove impurities such as oxidation layer and oil stain, so that the conductor surface can be well contacted; at the same time, the detection device is started to complete the equipment self-checking, the interference of the device itself line resistance on the measurement result is eliminated through the short-circuit zero operation, and an accurate measurement reference is established; S2, self-adaptive clamping of the conductive clamp head: according to the specifications (number, cross-sectional size, arrangement mode) of the combination transposed conductor to be detected, the pneumatic or electric drive mode is selected, the clamp head is clamped to the conductor from at least two directions of axial and lateral directions, the clamping force is adjusted to make the multiple parallel conductors tightly contact, and a stable conductive loop is formed; the clamp head is wrapped with insulating material to avoid the risk of electric shock; In this step, according to the real-time state of the combined transposed conductor to be detected (such as conductor arrangement offset, surface flatness, and single conductor tightness), the spatial position information of the conductor is collected by a displacement sensor, and the clamping direction (extensible to three dimensions) and clamping force of the clamping jaw are automatically adjusted. Specifically, when it is detected that the conductor arrangement is irregular (such as lateral offset and longitudinal inclination), the jaw adopts a step-by-step clamping mode: first, an initial clamping force is applied from the reference direction (usually the length direction of the conductor, i.e. the axial direction) to realize overall positioning of the conductor; second, the clamping force in other directions (lateral and vertical) is gradually adjusted according to the deviation information fed back by the displacement sensor to ensure that each parallel conductor can achieve uniform and effective contact, avoiding measurement errors caused by local poor contact; third, the contact pressure of each conductor is detected in real time by a pressure sensor to ensure that the pressure fluctuation range is controlled within a reasonable range, further improving the stability of the conductive loop.

[0021] S3, resistance measurement: resistance measurement is performed using a bridge stabilization circuit (or equivalent filter stabilization circuit). First, a first estimated value is read, the data is recorded, and the deviation range from the preset standard value is determined. Then, multiple on-off tests are automatically performed (the basic measurement number is not less than 5 times). The multiple measurement data are processed by Fourier derivative calculation method to obtain the average resistance value. The transformer winding phase sequence information is recorded in real time during the measurement process to ensure the accuracy of data tracing.

[0022] In this step, the number of measurements is dynamically adjusted according to the deviation rate of the first measurement value from the preset standard value. The larger the deviation rate, the more the number of measurements. Specifically, after the first measurement is completed, the deviation rate of the first measurement value from the preset standard value is calculated. According to different intervals of the deviation rate, the number of measurements is automatically adjusted. If the deviation rate is ≤5%, the measurement data stability is good, the number of measurements is automatically reduced (which can be reduced to 3-4 times), and the detection efficiency is significantly improved under the premise of ensuring the measurement accuracy. If the deviation rate is >5% and ≤10%, the basic measurement number (5 times) is maintained, and the accuracy and efficiency are considered. If the deviation rate is >10%, the measurement data fluctuation is large, the number of measurements is automatically increased (which can be increased to 6-8 times), and the secondary estimated value calibration is started. The multiple measurement data are processed by weighted average method, the measurement value with larger deviation is given lower weight, and the measurement value with smaller deviation is given higher weight, to further improve the measurement accuracy.

[0023] S4, data processing: according to the preset connection mode of the transformer (such as Y connection and D connection), the corresponding resistance imbalance rate calculation formula is substituted, and the resistance measurement values of the three-phase winding are compared and analyzed. If the resistance deviation exceeds the preset threshold, the alarm mechanism is immediately started, and the specific matching suggestion is generated. At the same time, historical measurement data can be called for comparison and analysis, supporting data printing and whole-process tracing, which is convenient for production quality control.

[0024] In this step, the preset transformer winding connection mode database is used, the resistance imbalance rate calculation model, the wiring coefficient, the number of turns ratio and other parameters corresponding to the Y connection and the D connection are stored in the database, the user can manually input the transformer connection mode, or the detection device can automatically identify the connection mode by identifying the winding connection mark, reading the production work order information and other ways; after determining the connection mode, the detection device automatically calls the corresponding resistance imbalance rate calculation model from the database, adjusts the key parameters (such as the number of turns ratio k, the wiring coefficient and the like) in the calculation formula, completes the resistance matching analysis under different connection modes, and generates the corresponding alarm threshold and matching suggestion.

[0025] Before step S4, the temperature parameter T and the humidity parameter H of the environment are collected in real time by the temperature sensor and the humidity sensor, and in step S4, the temperature compensation and the humidity correction are performed on the calculated resistance value according to the temperature parameter and the humidity parameter, wherein the temperature compensation includes , wherein, is the resistance value at the standard temperature (typically 20℃), is the temperature coefficient of the wire material, such as the temperature coefficient of copper =0.00393 / ℃), the temperature compensation is performed on the measured resistance value, and the influence of temperature change on the resistance measurement is eliminated; the humidity correction includes introducing a humidity influence correction coefficient , a correction model is preset according to the wire material and the surface state, different value ranges of different material wires are used to compensate and correct the change of the wire surface contact resistance caused by humidity, and the measurement error caused by environmental interference is further reduced.

[0026] S5, subsequent processing: according to the resistance matching result, the unqualified wire segment is marked, the operator is notified to adjust or replace; the qualified wire segment directly enters the next production process; after the detection device completes the single detection, the clamping jaw is automatically loosened, the contact surface of the jaw is cleaned, and the detection of the next group of wires is prepared.

[0027] Compared with the prior art, the combination transposed conductor resistance online detection method provided by the application eliminates interference through pre-detection cleaning and short-circuit zeroing, guarantees the stability of the conductive loop through multi-directional self-adaptive clamping, improves the measurement precision through dynamic adjustment of the measurement times combined with Fourier derivative calculation and temperature and humidity compensation, adapts to the transformer connection modes such as Y connection and D connection and generates matching suggestions, realizes online detection in the combination transposed conductor winding process, can timely find the resistance matching problem, avoids the waste of production cost caused by large-scale repair in the later period, and improves the detection efficiency and the accuracy of the detection result.

[0028] Embodiment The commonly used "10 parallel flat copper wire combination transposed conductor" in the production of 110 kV transformer winding is taken as the detection object, the conductor specification is 20 mm x 5 mm in cross-sectional size, and the transformer winding connection mode adopts Y connection. The detailed implementation process is as follows: S1, pretreatment before detection S11, conductor surface cleaning: the surface of the two end contact areas (about 50 mm in length) of the combined transposed conductor to be detected is cleaned. A dust-free cloth dipped in anhydrous ethanol is used to wipe the contact area in one direction along the length of the conductor, removing surface oxidation, oil stains, dust and other impurities; after wiping, it is naturally dried to ensure that the contact area is free of residual impurities and the influence of contact resistance on the measurement results is minimized. If the surface oxidation layer is thick, first polish it gently with fine sandpaper (the polishing force should not damage the conductor body), and then wipe it with anhydrous ethanol to ensure the cleaning effect.

[0029] S12, detection device startup and self-checking: start the special detection device (integrated pneumatic / electric clamping module, bridge measurement module, data processing module, alarm module, environmental parameter acquisition module, data storage module). The device automatically enters the self-checking process: Circuit continuity self-checking: test the conductivity of the clamping jaw head, the stability of the bridge circuit and the connection reliability of the terminal through the internal preset circuit. If there is a circuit failure or poor contact, the device will immediately issue a fault alarm and display the fault location; Drive mechanism self-checking: test the running state of the pneumatic / electric drive system, including the opening and closing flexibility of the clamping jaw head and the stability of the drive pressure / push force to ensure that the clamping process can proceed normally; Sensor self-checking: check the working state of the displacement sensor, pressure sensor, temperature sensor and humidity sensor to ensure that the data collected by each sensor is accurate and effective.

[0030] S13, short-circuit zero operation: after passing the self-checking, the device automatically performs the short-circuit zero operation. The two electrodes of the clamping jaw head are short-circuited, and the device's own line resistance (including the inherent resistance of the internal conductor, terminal and jaw electrode) is detected and recorded by the bridge measurement module. The resistance value is usually between 0.0005-0.001Ω; then the resistance value is taken as the reference error for zero processing to ensure that the subsequent measurement results only reflect the self-resistance of the combined transposed conductor, avoid the device's own resistance from being included in the measurement data, and ensure the accuracy of the measurement reference.

[0031] S2, self-adaptive clamping of conductive jaw head S21, wire specification identification: the detection device identifies the specification parameters of the wire to be detected through manual input or automatic scanning, including the number of wires (10), the cross-sectional size (20 mm x 5 mm), and the arrangement mode (parallel arrangement). According to the wire specification, the device automatically selects the pneumatic driving mode (for large cross-section and multiple parallel wires, the clamping force of pneumatic driving is more stable and uniform, and it is easy to adjust).

[0032] S22, wire positioning and position collection: place the cleaned combined transposed wire on the wire support table of the detection device and manually assist in positioning. Start the displacement sensor to collect the spatial position of the wire comprehensively. The collected data includes the straightness of the wire in the axial direction, the lateral offset, and the vertical flatness. It is found through collection that there is a slight lateral offset (0.5 mm) and a vertical flatness deviation of 0.3 mm, and there is no obvious unevenness in the single wire.

[0033] S23, multi-directional clamping of the jaw First step: reference direction positioning. Apply an initial clamping force (initial pressure set to 0.5 MPa) from the axial direction (wire length direction), fix the wire as a whole through the axial clamping plate of the jaw, limit the axial movement of the wire, and complete the reference positioning; Second step: lateral offset correction. According to the lateral offset (0.5 mm) collected by the displacement sensor, gradually apply clamping force to the lateral clamping jaw (from 0.3 MPa to 0.6 MPa), while the displacement sensor feedbacks the position change of the wire in real time until the lateral offset of the wire is ≤0.05 mm, and the lateral correction is completed; Third step: vertical flatness adjustment. For the vertical flatness deviation (0.3 mm), the vertical clamping jaw applies uniform clamping force (0.4 MPa) to ensure that the upper surface of each wire is in full contact with the electrode of the jaw without suspension; Fourth step: contact pressure confirmation. Real-time detection of the contact pressure of each wire through the pressure sensor ensures that the contact pressure of the 10 wires is between 0.4-0.6 MPa, and the pressure fluctuation range is ≤0.05 MPa, forming a stable and uniform conductive loop.

[0034] S3, resistance measurement S31, measurement circuit start: start the bridge measurement module, use a double-arm bridge circuit, which has good anti-interference ability and stability, can effectively filter electromagnetic interference signals in the measurement process, and ensure the reliability of the measurement data.

[0035] S32, first estimate measurement: the bridge circuit makes a first resistance measurement on the combined transposed conductor, and reads the resistance estimate value as 0.025Ω. According to the design requirements of the transformer winding, the preset resistance standard value range is 0.020-0.028Ω, the standard value is 0.024Ω, and the deviation rate of the first measurement value from the standard value is calculated: deviation rate = (0.025-0.024) / 0.024*100% ≈ 4.17%.

[0036] S33, adaptive optimization of measurement times: according to the deviation rate calculation result (4.17%≤5%), the device automatically adjusts the measurement times to 4 times (compared with the basic times of 5 times, the detection efficiency is improved). Start multiple on-off test, the device automatically controls the on-off of the conductive loop through the internal switch, complete 4 times of resistance measurement, and record the measurement data as 0.0248Ω, 0.0252Ω, 0.0249Ω, 0.0251Ω.

[0037] S34, Fourier derivative calculation method processes data: the Fourier derivative calculation method is used to process the 4 times of measurement data, and the random error in the measurement process is eliminated. The core formula of Fourier derivative calculation is:

[0038] Among them: Ri is the resistance value obtained by single measurement; n is the measurement times (1-4); N is the total number of measurements (4); m is the harmonic number (in this implementation case, m=1, i.e. only considering the direct current component, ignoring alternating current noise interference), =1, i.e. only considering the direct current component, ignoring alternating current noise interference, R is the direct current resistance average value (i.e. the final measurement result); , is the alternating current component or noise component in the measurement data (in this implementation case, it has been greatly reduced through circuit filtering, so the value is 0).

[0039] Substitute the 4 times of measurement data into the formula to calculate: =(0.0248+0.0252+0.0249+0.0251) / 4=0.025Ω, i.e. after Fourier derivative calculation, the initial resistance average value of the conductor segment is 0.025Ω.

[0040] S35, environmental interference compensation: environmental parameter collection: through the temperature sensor and humidity sensor integrated in the device, the environmental parameters of the detection site are collected in real time: environmental temperature T=25℃, standard temperature T0=20℃; environmental humidity H=60%, the conductor material is copper, and the preset humidity correction coefficient = 0.998.

[0041] Temperature compensation calculation: according to the resistance temperature coefficient formula of copper material , wherein = 0.00393 / ℃, is the initial resistance average value 0.025Ω, substitute calculation: = 0.025×[1+0.00393×(25 20)]=0.025×1.01965≈0.0255Ω Humidity correction calculation: using the preset humidity correction coefficient The resistance value after temperature compensation is corrected, and the correction formula is , substitute data calculation: =0.0255×0.998=0.02545Ω The final accurate resistance value of the combined transposed conductor segment is 0.0255Ω (retaining four decimal places to ensure measurement accuracy).

[0042] S36, phase sequence information recording: during the measurement process, the operator inputs the transformer winding phase sequence (A phase) corresponding to the conductor through the device touch screen, and the device automatically stores the resistance measurement value and the phase sequence information to ensure the accuracy of subsequent data processing and matching.

[0043] S4, data processing S41, three-phase conductor resistance measurement: according to the above pretreatment, adaptive clamping, and resistance measurement steps, the resistance of the B phase and C phase combined transposed conductors of the transformer winding is detected respectively, and the accurate resistance values are obtained: B phase = 0.0253Ω, C phase = 0.0254Ω.

[0044] S42, resistance matching analysis under Y connection mode: Connection mode determination: the transformer winding adopts Y connection mode, and the operator manually inputs "Y connection" through the device touch screen, or the device automatically identifies the connection mode by reading the production work order; Calculation model calling: the multi-connection mode adaptive matching sub-method calls the resistance imbalance rate calculation model corresponding to the Y connection mode from the preset database, and the calculation formula is:

[0045] Among them: is the resistance imbalance rate, is the maximum value of three-phase resistance, is the minimum value of three-phase resistance, , , A, B, C are three-phase resistance values.

[0046] Unbalance rate calculation: Substitute three-phase resistance values (A, B, C) into the formula. = 0.0255 Ω, = 0.0253 Ω, = 0.0254 Ω), = 0.0255 Ω, = 0.0253 Ω, ≈ 0.79% Matching judgment and alarm: The resistance imbalance rate alarm threshold under Y connection mode is 1% (which can be adjusted according to different transformer specifications). Since the calculated imbalance rate is 0.79% < 1%, it is determined that the three-phase conductor resistance is matched and qualified, and the device does not issue an alarm, displays a "qualified" prompt, and records the matching results.

[0047] S43, data storage and traceability: Regardless of whether the matching is qualified or not, the device automatically stores complete data such as three-phase resistance values, imbalance rate calculation results, matching judgment conclusions, alarm records (if any), operating personnel, detection time, environmental parameters, etc.; supports querying historical data through detection date, transformer model, conductor batch, etc. key words, and can also print detection reports by connecting a printer, which is convenient for production quality traceability and control.

[0048] S5, subsequent processing S51, qualified conductor processing: For A, B, C three-phase conductor segments matched under Y connection mode, the device prints "qualified" marks on the surface of the conductor through the mechanical marking module (marking content includes conductor batch, detection time, phase sequence, resistance value), and then the conductor automatically enters the winding winding process through the conveying device.

[0049] S52, unqualified conductor processing: For A-phase conductor segments that do not match under Y connection mode, the device prints "unqualified" marks and displays the unqualified reasons and adjustment suggestions. The operator replaces a spare combined transposed conductor segment according to the suggestions and re-detects according to the complete detection process described above; if the resistance value meets the requirements after replacement, mark "qualified" and enter the next process; if it is still unqualified, further investigate the conductor material, processing technology, etc. until the detection is qualified.

[0050] S53, device reset: After single detection is completed, the device automatically performs reset operation: the clamping jaw head is loosened; the built-in cleaning brush automatically cleans the residual impurities on the surface of the electrode of the jaw head; the data processing module updates the detection statistical data (such as the detection qualified rate of this batch, the average detection time, etc.); The device enters standby state, waiting for the detection instruction of the next group of conductors.

[0051] The above merely describes preferred embodiments of the present application, and is not used to limit the present application, any modification, equivalent replacement and improvement within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for on-line detection of resistance of a bundled transposed conductor, characterized in that, The method comprises the following steps: S1, cleaning the contact area surface of the combined transposed conductor to be detected, starting the detection device and completing self-checking and short-circuit zero operation; S2, driving the clamp head to clamp the conductor from at least two directions to form a stable conductive loop; S3, performing multiple on-off measurements through the stable circuit, obtaining the average resistance value by using the Fourier derivative calculation method, and recording the winding phase sequence information in real time; S4, calculating the resistance imbalance rate according to the transformer connection mode, starting the alarm mechanism and generating matching suggestions after comparison and analysis; S5, marking the unqualified conductor section, and the qualified conductor enters the next process, and the device is reset for the next detection.

2. The method of claim 1, wherein the method comprises: In step S2, the displacement sensor collects the spatial position information of the conductor, and automatically adjusts the clamping direction and clamping force of the clamping clamp.

3. The method of claim 1, wherein the method comprises: In step S3, the measurement times are dynamically adjusted according to the deviation rate of the first measurement value and the preset standard value. The larger the deviation rate, the more the measurement times, and the data is processed by using the weighted average method.

4. The method of claim 1, wherein the method comprises: The temperature sensor and the humidity sensor collect the temperature parameter and the humidity parameter of the environment respectively. In step S4, the resistance value calculated is temperature compensated and humidity corrected according to the temperature parameter and the humidity parameter.

5. The method of claim 1, wherein the method comprises: The adaptive transformer connection mode includes Y connection and D connection, and the resistance matching analysis is completed through the corresponding calculation model.

6. The method of claim 2, wherein the method further comprises: In step S2, the clamping direction of the clamping clamp can be extended to three dimensions, and a step-by-step clamping method is used, that is, first positioning through the reference direction, and then gradually adjusting the clamping force in each direction, and the contact pressure is detected in real time through the pressure sensor.

7. The method of claim 3, wherein the method comprises: When the deviation rate is ≤5%, the measurement times are 3-4 times, when the deviation rate is >5% and ≤10%, the measurement times are 5 times, and when the deviation rate is >10%, the measurement times are 6-8 times.

8. The method of claim 4, wherein the method further comprises: determining the resistance of the first and second transposed conductors by measuring the voltage across the first and second transposed conductors and the current through the first and second transposed conductors. The temperature compensation is calculated by using the resistance temperature coefficient formula, and the humidity correction is realized by using the preset humidity influence correction coefficient model, and the correction coefficient is dynamically adjusted according to the conductor material.

9. The method of claim 5, wherein the method further comprises: determining the resistance of the first and second conductors; and determining the resistance of the third and fourth conductors. A preset transformer winding connection mode database is provided, and the connection mode of the transformer winding can be determined by manual input of the user or automatic recognition of the detection device.

10. The method for online detection of resistance of a combined transposed wire as described in claim 1, characterized in that, The detection device eliminates the line resistance of itself by short-circuit zero operation in the pretreatment step, and detects the on-off state of the conductive loop in real time during the resistance measurement process.

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