Current transformer calibrating device and detection method

Abstract

The invention relates to the technical field of current transformer calibration equipment, and discloses a current transformer calibration device and a detection method. An integrated controller, a signal generation module, a data processing unit, a man-machine interaction unit, a signal processing unit, a communication relay unit and an error calculation module are arranged in the device, and a master-slave clock distributor is arranged in the communication relay unit. And the detection probe is internally provided with a plurality of current sensors, and each current sensor has a broadband response characteristic. The design is reasonable, the multi-station mutual inductor fixing clamp is in linkage with the bevel gear set through the driving motor, the driving shaft and the spiral groove connecting cylinder are driven to achieve synchronous rotating propelling, and the rotating frame and the arc-shaped connecting rod are matched to drive the clamping plate to retract in a self-adaptive mode. According to an original constant force control mechanism, after the clamping plate makes contact with the mutual inductor, the balance weight mechanism is triggered through axial displacement of the connecting cylinder to dynamically balance pressure, and it is ensured that constant clamping force is applied to all stations.

Description

Technical Field

[0001] This invention relates to the field of current transformer calibration equipment technology, and in particular to a current transformer calibration device and testing method. Background Technology

[0002] As a core metering device in the power system, the accuracy of current transformers directly affects the reliability of electricity trade settlement and relay protection. Traditional calibration devices mostly use single-station manual clamps, relying on operators to adjust the position and clamping force of each transformer individually. This is prone to core damage or loosening due to uneven force application. Existing fixed clamps lack multi-specification adaptive capabilities, making it difficult to guarantee the parallelism of the primary conductors during batch testing, and they cannot monitor the clamping status in real time, posing a risk of overvoltage damage. Conventional testing probe positioning requires repeated calibration, and insufficient background electromagnetic interference suppression leads to distortion of broadband measurement results.

[0003] Current characteristic current injection units generally suffer from temperature drift compensation lag. When multiple circuits are connected in parallel, sampling timing deviations occur due to clock asynchrony, affecting the accuracy of high-frequency phase angle difference calculation. Mainstream equipment still adopts a serial detection mode, switching the test frequency point for each current transformer individually, which is inefficient and difficult to simulate parallel loads under actual working conditions. Mechanical adjustment mechanisms mostly rely on simple lifting platforms, which lack a rigid locking mechanism after positioning, and the detection probe is prone to deviating from the predetermined position due to vibration. Therefore, we propose a current transformer calibration device and detection method to solve this problem. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings mentioned in the background section by providing a current transformer calibration device and testing method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A current transformer calibration device, comprising:

[0007] The test host integrates an integrated controller, a signal generation module, a data processing unit, a human-machine interface unit, a communication relay unit, and an error calculation module. The communication relay unit has a built-in master-slave clock distributor. The signal generation module generates characteristic current parameters according to the instructions of the integrated controller and transmits them to the communication relay unit. After receiving the parameters, the communication relay unit drives the characteristic current injection unit group. Simultaneously, the master-slave clock distributor built into the communication relay unit sends synchronous clock signals to the detection probe, the characteristic current injection unit group, and the precision measurement module group via a communication link. The raw current data collected by the detection probe is transmitted back to the communication relay unit via a flexible cable. The communication relay unit forwards the data to the signal processing unit. The signal processing unit extracts the characteristic components and transmits them to the data processing unit and the error calculation module. The temperature data of the characteristic current injection unit group and the reference current value of the precision measurement module group are both transmitted to the error calculation module through the communication relay unit. The error calculation module calculates the error result based on all input data and feeds it back to the integrated controller. The final result is output by the human-machine interface unit, realizing multi-channel synchronous detection.

[0008] The detection probe contains multiple current sensors, each with wideband response characteristics. The detection probe is connected to the communication relay unit via a flexible cable.

[0009] A multi-position current transformer fixing fixture is used to fix multiple current transformers and ensure that the primary conductors are in parallel detection positions. The multi-position current transformer fixing fixture includes: a mounting box, a drive motor, and multiple clamping components. The top of the mounting box is provided with multiple signal feedback mechanisms. The clamping components include: a mounting plate, a drive shaft, a driven shaft, a mounting frame, a connecting cylinder, and multiple clamping parts. A counterweight mechanism is provided on one side of the mounting frame.

[0010] The characteristic current injection unit group includes multiple injection units. Each injection unit contains an independent standard resistor circuit, a reference low-resistance circuit, a fast on / off switch, and a temperature monitoring chip. The injection units support parallel connection of multiple circuits and real-time temperature compensation of the injected current.

[0011] The precision measurement module group provides an independent current reference measurement channel;

[0012] An automatic moving adjustment mechanism is used for the installation and movement control of the detection probe. The automatic moving adjustment mechanism includes a fixed frame, a moving frame, an electric push rod, and a moving base. A lifting mechanism is provided at the bottom of the automatic moving adjustment mechanism.

[0013] Preferably, the clamping component includes: a clamping plate, an L-plate, and an adjusting screw. A connecting frame is fixedly installed on the outer side of the clamping plate. The adjusting screw is rotatably installed within the clamping plate and the connecting frame. The connecting frame is slidably installed within the L-plate. A knob is fixedly installed at one end of the adjusting screw. A sliding plate is fixedly installed on one side of the L-plate. An arc-shaped connecting rod is rotatably installed on the other side of the sliding plate. A rotating frame is fixedly sleeved on the outer side of the driven shaft. The other end of the arc-shaped connecting rod is hinged to the outer side of the rotating frame. Multiple slide rails are fixedly installed on one side of the mounting plate. The L-plate is slidably sleeved on the outer side of the slide rails. Multiple sliding holes are opened on one side of the mounting plate. Limiting rods are fixedly installed in the sliding holes. The sliding plate is slidably sleeved on the outer side of the limiting rods.

[0014] Preferably, both the drive shaft and the driven shaft are rotatably mounted in the mounting bracket, which is fixedly mounted in the mounting box. A stop button and a signal button are fixedly mounted inside the mounting bracket. A vertical plate is slidably mounted inside the mounting bracket. The connecting cylinder is rotatably mounted inside the vertical plate. Limiting plates are fixedly mounted on both sides of the bottom of the connecting cylinder, and the two limiting plates movably abut against the two sides of the vertical plate. The connecting cylinder has multiple strip grooves and multiple spiral grooves inside. Multiple spiral strips are integrally formed at one end of the driven shaft and are slidably mounted in the spiral grooves. Multiple limiting strips are integrally formed on the outer side of the drive shaft and are slidably mounted in the strip grooves.

[0015] Preferably, a driven bevel gear is fixedly sleeved on the outer side of the drive shaft, the drive motor is fixedly mounted on the front side of the mounting box, a drive shaft is fixedly mounted on the output shaft of the drive motor, a plurality of drive bevel gears are fixedly mounted on the drive shaft, the drive bevel gears mesh with the corresponding driven bevel gears, a support frame is fixedly mounted on the bottom of the mounting box, and the signal feedback mechanism includes: a base and a working signal light and a fault signal light mounted on the top of the base;

[0016] The counterweight mechanism includes a base plate, a top plate, and a counterweight plate. Multiple support plates are fixedly installed between the base plate and the top plate. The counterweight plate is slidably sleeved on the outside of the support plates. A pull rope is fixedly installed on the top of the counterweight plate. The other end of the pull rope is fixedly connected to a vertical plate. A fixed pulley is rotatably installed inside the top plate. The pull rope is wound around the outside of the fixed pulley. Both the top plate and the base plate are fixedly installed inside a mounting box.

[0017] Preferably, the movable frame is slidably installed inside the fixed frame, the electric push rod is fixedly installed inside the movable frame, the movable seat is fixedly installed on the output end of the electric push rod, the detection probe is fixedly installed on one side of the movable seat, a crossbar is fixedly installed on the other side of the movable seat, the crossbar is slidably installed inside the movable frame, guide rails are fixedly installed on the top and bottom inner walls of the fixed frame, the movable frame is slidably sleeved on the outside of the guide rails, a servo motor is fixedly installed on the front side of the fixed frame, a drive screw is fixedly installed on the output shaft of the servo motor, and the movable frame is threadedly sleeved on the outside of the drive screw.

[0018] Preferably, the lifting mechanism includes: a base frame, a lifting plate, a lifting screw, and a horizontal shaft. The base frame and the support frame are fixedly mounted on the same support base. The lifting plate is slidably mounted inside the base frame. Side plates are fixedly mounted on both inner walls of the base frame. The lifting plate is slidably sleeved on the outer side of the side plates. The bottom end of the lifting screw is rotatably mounted inside the base frame. The bottom end of the lifting screw is threadedly mounted inside the lifting plate. The top of the lifting plate is fixedly connected to the fixed frame. A large bevel gear is fixedly mounted on the outer side of the lifting screw. The horizontal shaft is rotatably mounted on the side wall of the base frame. A small bevel gear is fixedly mounted on one end of the horizontal shaft. The small bevel gear meshes with the large bevel gear. A locking mechanism is provided at the other end of the horizontal shaft.

[0019] Guide plates are fixedly connected to the front and rear sides of the bottom of the fixed frame, and guide seats are fixedly installed on the front and rear sides of the bottom frame. The guide plates are slidably connected in the corresponding guide seats.

[0020] The locking mechanism includes a turntable, a pin, and a fixing plate. The turntable has multiple slots on its outer side, and the pin is movably inserted into the corresponding slot. A compression spring and a pull rod are fixedly installed on the top of the pin. The pull rod is slidably installed in the fixing plate, and a handle is fixedly installed on the top of the pull rod. The top of the compression spring is fixedly connected to the fixing plate. The fixing plate is fixedly installed on one side of the base frame, and the turntable is fixedly installed on the other end of the horizontal axis. A handle is fixedly installed on the other side of the turntable.

[0021] The present invention also provides a current transformer testing method, applied to the aforementioned current transformer calibration device, comprising the following steps:

[0022] Step 1: Current Transformer Fixing: Install the multiple current transformers to be inspected into the clamping assembly inside the multi-position transformer fixing fixture. Start the drive motor to drive the drive shaft to rotate. The drive shaft, through the cooperation of the driving bevel gear, driven bevel gear, drive shaft, connector, driven shaft, rotating frame, arc connecting rod, slide plate, L-plate and clamping plate, drives the clamping plate to move closer to the current transformer to achieve clamping. Rotate the knob and adjust the screw to ensure the fit between the clamping plate and the current transformer.

[0023] Step 2, Equipment Initialization: Connect the characteristic current injection unit group's connection clips in parallel to the primary circuit of each current transformer, start the test host, and automatically move the adjustment mechanism to perform self-calibration, so that the monitoring head is reset to the standby position;

[0024] Step 3: Automatic Probe Positioning and Background Noise Scanning: Select the target current transformer number on the human-machine interface console. The automatic movement adjustment mechanism drives the probe to move to the primary conductor surface of the corresponding current transformer. The test host controls the current probe to scan the background noise spectrum and stores the noise characteristics of the transformer. Repeat this step until the noise scanning of all current transformers under test is completed.

[0025] Step 4: Parallel injection of multi-location characteristic signals: The signal processing unit and error calculation module independently generate optimal characteristic signal parameters for each transformer, including frequency and amplitude. The test host synchronously triggers all precision characteristic current injection unit groups through the communication relay unit, and simultaneously injects characteristic current into each circuit; the reference low-resistance circuit and measurement module group synchronously measure the reference current value of each injection unit.

[0026] Step 5: Data Acquisition and Processing: The detection probe acquires the total current of the primary conductor. The signal processing unit and error calculation module execute independently on the data of each channel, extract the characteristic signal component of the current transformer, compare the component with the corresponding reference current value, and calculate the ratio error and phase angle difference of the individual transformer.

[0027] Step Six: Cyclic Detection and Result Integration: Steps Four and Five are automatically cycled, the characteristic signal frequency is changed and re-acquired, the human-machine interaction unit generates a summary report, and outputs the error curves and pass / fail judgments for each frequency point according to the current transformer number.

[0028] Compared with the prior art, the present invention provides a current transformer calibration device and testing method, which has the following advantages:

[0029] (1) The multi-station current transformer fixing fixture drives the drive motor to drive the bevel gear set to drive the drive shaft and the spiral groove connecting cylinder to achieve synchronous rotation and propulsion. With the help of the rotating frame and the arc connecting rod, the clamping plate adaptively retracts. Its unique constant force control mechanism triggers the counterweight mechanism to dynamically balance the pressure after the clamping plate contacts the current transformer through the axial displacement of the connecting cylinder, ensuring that a constant clamping force is applied to all stations. The dual-level signal button design provides real-time feedback on the clamping status. When all the work signal lights are on, the feed is automatically stopped. The fault signal light accurately locates the abnormal station. This not only avoids damage to the current transformer due to overvoltage, but also realizes the parallel and stable clamping of multiple specifications of current transformers, greatly shortening the manual adjustment time and eliminating safety hazards.

[0030] (2) The characteristic current injection unit group integrates an independent standard resistor circuit and a reference low-resistance circuit, supports multiple circuits in parallel, and each unit has a built-in fast on / off switch and temperature monitoring chip to compensate for current temperature drift error in real time. The master-slave clock distributor of the communication relay unit realizes strict synchronization of the sampling time of the detection probe and the injection unit, and controls the timing deviation at the nanosecond level. This design breaks through the limitations of traditional single-frequency point verification. Combined with a wideband response current sensor, it provides a full-band error analysis basis for complex working conditions such as high-frequency harmonics and transient currents, and significantly improves the metering reliability of wideband current transformers.

[0031] (3) The detection probe is equipped with a wideband current sensor array. It achieves three-dimensional precise positioning through an automatic movement adjustment mechanism. A servo motor drives a screw to control the forward and backward displacement, an electric push rod adjusts the horizontal docking distance, and a lifting mechanism with bevel gear transmission achieves height locking. The unique noise scanning process automatically collects the background noise spectrum of each transformer before each test. The signal processing unit dynamically optimizes the characteristic signal parameters based on this, effectively separating environmental electromagnetic interference from the target signal. This technology solves the problem of cross-interference when testing multiple transformers in parallel, ensuring the authenticity of measurement data in complex electromagnetic environments.

[0032] (4) The integrated controller embedded in the test host coordinates the signal generation module, data processing unit and error calculation module to realize multi-channel independent control. The characteristic current injection unit group synchronously triggers multi-loop signal output, the detection probe array collects primary conductor current in parallel, and the data processing unit independently performs characteristic signal extraction and error calculation for each channel. This architecture breaks through the traditional serial detection mode. With the batch clamping capability of multi-station fixtures, the system can complete the full-band test of all the current transformers under test in a single run. The efficiency improvement is linearly related to the number of current transformers.

[0033] (5) The lifting mechanism adopts a large / small bevel gear transmission in conjunction with a spiral lifting screw. The guide plate and guide seat have double limit to ensure vertical movement accuracy. The turntable pin-type locking mechanism automatically resets and fixes the height through the compression spring, eliminating the displacement drift of the detection probe. The rigid connection design between the moving frame guide rail and the drive screw eliminates horizontal movement deviation. The crossbar helps to reinforce the detection probe mounting position. The deep collaboration between this mechanical system and the electronic unit realizes full-process automation from clamping and positioning, noise scanning, signal injection to data acquisition, reducing manual intervention links and ensuring the stability of long-term continuous operation. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the overall three-dimensional structure of a current transformer calibration device proposed in this invention;

[0035] Figure 2 This is a schematic cross-sectional view of the current transformer calibration device proposed in this invention.

[0036] Figure 3 This is a three-dimensional structural diagram of the multi-station current transformer fixing fixture proposed in this invention;

[0037] Figure 4 This is a partial three-dimensional structural diagram of the multi-station current transformer fixing fixture proposed in this invention;

[0038] Figure 5 This is a cross-sectional view of the multi-station current transformer fixing fixture proposed in this invention.

[0039] Figure 6 This is a three-dimensional structural diagram of the clamping assembly and counterweight mechanism proposed in this invention;

[0040] Figure 7 This is a cross-sectional view of the clamping assembly and counterweight mechanism proposed in this invention.

[0041] Figure 8 for Figure 7 A magnified view of part A in the middle;

[0042] Figure 9 This is a three-dimensional structural diagram of the clamping component proposed in this invention from another perspective;

[0043] Figure 10 This is a partial three-dimensional structural diagram of the clamping component proposed in this invention;

[0044] Figure 11 This is a three-dimensional structural diagram of the clamping member proposed in this invention;

[0045] Figure 12 This is a three-dimensional structural diagram of the automatic moving adjustment mechanism and lifting mechanism proposed in this invention;

[0046] Figure 13 This is a cross-sectional structural schematic diagram of the automatic moving adjustment mechanism and lifting mechanism proposed in this invention;

[0047] Figure 14 for Figure 13 A magnified view of part B in the middle section;

[0048] Figure 15 This is a three-dimensional structural diagram of the locking mechanism proposed in this invention.

[0049] In the diagram: 1. Test host; 2. Detection probe; 201. Current sensor; 3. Multi-station current transformer fixing fixture; 301. Mounting box; 302. Drive motor; 303. Drive shaft; 304. Driving bevel gear; 305. Driven bevel gear; 306. Base; 307. Working indicator light; 308. Fault indicator light; 4. Clamping assembly; 401. Clamping component; 40101. L-plate; 40102. Connecting frame; 40 103. Clamping plate; 40104. Adjusting screw; 40105. Knob; 40106. Slide rail; 40107. Slide plate; 40108. Limiting rod; 40109. Arc-shaped connecting rod; 402. Mounting plate; 403. Driven shaft; 404. Rotating frame; 405. Spiral strip; 406. Mounting frame; 407. Signal button; 408. Stop button; 409. Vertical plate; 410. Connecting cylinder; 411. Limiting plate; 4 12. Drive shaft; 5. Characteristic current injection unit group; 6. Measurement module group; 7. Automatic movement adjustment mechanism; 701. Fixed frame; 702. Guide rail; 703. Moving frame; 704. Drive screw; 705. Servo motor; 706. Moving seat; 707. Electric push rod; 708. Crossbar; 8. Lifting mechanism; 801. Base frame; 802. Guide seat; 803. Guide plate; 804. Lifting plate; 805. Side plate; 8 06. Lifting screw; 807. Large bevel gear; 808. Small bevel gear; 809. Horizontal shaft; 810. Turntable; 811. Handle; 812. Fixing plate; 813. Handle; 814. Pull rod; 815. Compression spring; 816. Pin; 817. Slot; 9. Counterweight mechanism; 901. Base plate; 902. Counterweight plate; 903. Pull rope; 904. Support plate; 905. Fixed pulley; 906. Top plate; 10. Support base. Detailed Implementation

[0050] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0051] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "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.

[0052] Reference Figure 1-15 A current transformer calibration device, comprising:

[0053] Test host 1 integrates an integrated controller, a signal generation module, a data processing unit, a human-machine interface unit, a communication relay unit, and an error calculation module. The signal generation module generates characteristic current parameters according to the instructions of the integrated controller and transmits them to the communication relay unit. After receiving the parameters, the communication relay unit drives the characteristic current injection unit group. At the same time, the master-slave clock distributor built into the communication relay unit sends synchronous clock signals to the detection probe, the characteristic current injection unit group, and the precision measurement module group through the communication link. The raw current data collected by the detection probe is transmitted back to the communication relay unit through a flexible cable. The communication relay unit forwards the data to the signal processing unit. The signal processing unit extracts the characteristic components and transmits them to the data processing unit and the error calculation module. The temperature data of the characteristic current injection unit group and the reference current value of the precision measurement module group are both transmitted to the error calculation module through the communication relay unit. The error calculation module integrates all input data to calculate the error result and feeds it back to the integrated controller. The final result is output by the human-machine interface unit, realizing multi-channel synchronous detection function.

[0054] The detection probe 2 is equipped with multiple current sensors 201, each of which has wideband response characteristics. The detection probe 2 is connected to the communication relay unit via a flexible cable.

[0055] The multi-position current transformer fixing fixture 3 is used to fix multiple current transformers and ensure that the primary conductors are in parallel detection positions. The multi-position current transformer fixing fixture 3 includes: a mounting box 301, a drive motor 302 and multiple clamping components 4. The top of the mounting box 301 is provided with multiple signal feedback mechanisms. The clamping components 4 include: a mounting plate 402, a drive shaft 412, a driven shaft 403, a mounting frame 406, a connecting cylinder 410 and multiple clamping parts 401. A counterweight mechanism 9 is provided on one side of the mounting frame 406.

[0056] The characteristic current injection unit group 5 includes multiple injection units. Each injection unit contains an independent standard resistor circuit, a reference low-resistance circuit, a fast on / off switch, and a temperature monitoring chip. The injection units support parallel access of multiple circuits and real-time temperature compensation of the injected current. The communication relay unit has a built-in master-slave clock distributor to ensure that the sampling time deviation between the detection probe 2 and the characteristic current injection unit group 5 is <1 nanosecond.

[0057] Precision measurement module group 6 provides an independent current reference measurement channel;

[0058] The automatic moving adjustment mechanism 7 is used for the installation and movement control of the detection probe 2. The automatic moving adjustment mechanism 7 includes: a fixed frame 701, a moving frame 703, an electric push rod 707 and a moving base 706. A lifting mechanism 8 is provided at the bottom of the automatic moving adjustment mechanism 7.

[0059] In this embodiment, the clamping member 401 includes: a clamping plate 40103, an L-plate 40101, and an adjusting screw 40104. The adjusting screw 40104 is threadedly connected to the L-plate 40101. A connecting frame 40102 is fixedly installed on the outer side of the clamping plate 40103. The adjusting screw 40104 is rotatably installed within the clamping plate 40103 and the connecting frame 40102. The connecting frame 40102 is slidably installed within the L-plate 40101. A knob 40105 is fixedly installed at one end of the adjusting screw 40104. A knob 40105 is fixedly installed on one side of the L-plate 40101. The slide plate 40107 has an arc-shaped connecting rod 40109 rotatably mounted on the other side. A rotating frame 404 is fixedly sleeved on the outside of the driven shaft 403. The other end of the arc-shaped connecting rod 40109 is hinged to the outside of the rotating frame 404. Multiple slide rails 40106 are fixedly mounted on one side of the mounting plate 402. The L-plate 40101 is slidably sleeved on the outside of the slide rails 40106. Multiple sliding holes are opened on one side of the mounting plate 402. Limiting rods 40108 are fixedly installed in the sliding holes. The slide plate 40107 is slidably sleeved on the outside of the limiting rods 40108.

[0060] In this embodiment, both the drive shaft 412 and the driven shaft 403 are rotatably mounted in the mounting bracket 406, which is fixedly mounted in the mounting box 301. A stop button 408 and a signal button 407 are fixedly mounted inside the mounting bracket 406. A vertical plate 409 is slidably mounted inside the mounting bracket 406. A connecting cylinder 410 is rotatably mounted inside the vertical plate 409. Limiting plates 411 are fixedly mounted on both sides of the bottom of the connecting cylinder 410. The two limiting plates 411 are movably abutting against the two sides of the vertical plate 409, respectively. The connecting cylinder 410 has multiple strip grooves and multiple spiral grooves inside. Multiple spiral strips 405 are integrally formed on one end of the driven shaft 403 and are slidably mounted in the spiral grooves. Multiple limiting strips are integrally formed on the outer side of the drive shaft 412 and are slidably mounted in the strip grooves.

[0061] In this embodiment, a driven bevel gear 305 is fixedly sleeved on the outer side of the drive shaft 412, the drive motor 302 is fixedly installed on the front side of the mounting box 301, a drive shaft 303 is fixedly installed on the output shaft of the drive motor 302, a plurality of drive bevel gears 304 are fixedly installed on the drive shaft 303, the drive bevel gears 304 mesh with the corresponding driven bevel gears 305, a support frame is fixedly installed at the bottom of the mounting box 301, and the signal feedback mechanism includes: a base 306 and a working signal light 307 and a fault signal light 308 installed on the top of the base 306;

[0062] The counterweight mechanism 9 includes a base plate 901, a top plate 906, and a counterweight plate 902. Multiple support plates 904 are fixedly installed between the base plate 901 and the top plate 906. The counterweight plate 902 is slidably sleeved on the outside of the support plates 904. A pull rope 903 is fixedly installed on the top of the counterweight plate 902. The other end of the pull rope 903 is fixedly connected to the vertical plate 409. A fixed pulley 905 is rotatably installed inside the top plate 906. The pull rope 903 is wound around the outside of the fixed pulley 905. The top plate 906 and the base plate 901 are both fixedly installed inside the mounting box 301.

[0063] Specifically, during implementation, rotating the knob 40105 drives the adjusting screw 40104 to rotate. The adjusting screw 40104, through its threaded transmission with the L-plate 40101, drives the clamping plate 40103 to move, thereby adjusting the initial position of each clamping plate 40103 according to the shape of the current transformer. Starting the drive motor 302 drives the drive shaft 303 to rotate, which in turn drives multiple active bevel gears 304 to rotate. The active bevel gears 304, through meshing with their corresponding driven bevel gears 305, drive the main... The rotating shaft 412 drives the connecting cylinder 410 to rotate synchronously through the cooperation of the limiting strip and the strip groove. The connecting cylinder 410 drives the driven shaft 403 and the rotating frame 404 to rotate through the cooperation of the spiral groove and the spiral strip 405. The rotating frame 404 drives multiple L-plates 40101 to move closer to each other through the linkage rod, so that the clamping plate 40103 abuts against the outside of the current transformer to achieve clamping. After the clamping plate 40103 contacts the current transformer, the corresponding rotating frame 404 and driven shaft 403 stop rotating. Shaft 412 drives connecting cylinder 410 to continue rotating, causing connecting cylinder 410 to rotate and move to the right simultaneously through the cooperation of spiral groove and spiral strip 405, driving vertical plate 409 to move synchronously, and pulling counterweight plate 902 upward through pull rope 903. During this process, the pressure generated by clamping plate 40103 on current transformer is constant. Signal button 407 is slightly longer than stop button 408. Vertical plate 409 first contacts signal button 407 and controls work indicator light 307 to light up through integrated controller. When all work indicator lights 307 are lit, integrated controller controls drive motor 302 to stop feeding, completing normal clamping. When vertical plate 409 contacts stop button 408, integrated controller controls corresponding fault indicator light 308 to light up and controls drive motor 302 to stop running, which facilitates the staff to troubleshoot problems of clamping component 4 and current transformer at designated positions, thereby ensuring the clamping stability of multiple current transformers and ensuring constant clamping force on current transformers to avoid damage to current transformers.

[0064] In this embodiment, the movable frame 703 is slidably installed inside the fixed frame 701, the electric push rod 707 is fixedly installed inside the movable frame 703, the movable seat 706 is fixedly installed on the output end of the electric push rod 707, the detection probe 2 is fixedly installed on one side of the movable seat 706, and a crossbar 708 is fixedly installed on the other side of the movable seat 706. The crossbar 708 is slidably installed inside the movable frame 703. Guide rails 702 are fixedly installed on the top inner wall and the bottom inner wall of the fixed frame 701. The movable frame 703 is slidably sleeved on the outside of the guide rails 702. A servo motor 705 is fixedly installed on the front side of the fixed frame 701. A drive screw 704 is fixedly installed on the output shaft of the servo motor 705. The movable frame 703 is threadedly sleeved on the outside of the drive screw 704.

[0065] In this embodiment, the servo motor 705 is controlled to start and drive the drive screw 704 to rotate. The drive screw 704 drives the moving frame 703 to move back and forth through the thread engagement with the moving frame 703, so that the detection probe 2 is precisely aligned with the corresponding current transformer. The electric push rod 707 drives the moving seat 706 and the detection probe 2 to move horizontally, thereby realizing the docking of the detection probe 2 with the current transformer.

[0066] In this embodiment, the lifting mechanism 8 includes: a base frame 801, a lifting plate 804, a lifting screw 806, and a horizontal shaft 809. The base frame 801 and the support frame are fixedly installed with the same support base 10. The lifting plate 804 is slidably installed inside the base frame 801. Side plates 805 are fixedly installed on both inner walls of the base frame 801. The lifting plate 804 is slidably sleeved on the outside of the side plates 805. The bottom end of the lifting screw 806 is rotatably installed inside the base frame 801. The bottom end of the lifting screw 806 is threaded inside the lifting plate 804. The top of the lifting plate 804 is fixedly connected to the fixed frame 701. A large bevel gear 807 is fixedly installed on the outside of the lifting screw 806. The horizontal shaft 809 is rotatably installed on the side wall of the base frame 801. A small bevel gear 808 is fixedly installed at one end of the horizontal shaft 809. The small bevel gear 808 meshes with the large bevel gear 807. A locking mechanism is provided at the other end of the horizontal shaft 809.

[0067] Guide plates 803 are fixedly connected to the front and rear sides of the bottom of the fixed frame 701, and guide seats 802 are fixedly installed on the front and rear sides of the bottom frame 801. The guide plates 803 are slidably connected in the corresponding guide seats 802.

[0068] The locking mechanism includes a turntable 810, a pin 816, and a fixing plate 812. The turntable 810 has multiple slots 817 on its outer side. The pin 816 is movably inserted into the corresponding slot 817. A compression spring 815 and a pull rod 814 are fixedly installed on the top of the pin 816. The pull rod 814 is slidably installed in the fixing plate 812. A handle 813 is fixedly installed on the top of the pull rod 814. The top of the compression spring 815 is fixedly connected to the fixing plate 812. The fixing plate 812 is fixedly installed on one side of the base frame 801. The turntable 810 is fixedly installed on the other end of the horizontal shaft 809. A handle 811 is fixedly installed on the other side of the turntable 810.

[0069] In this embodiment, by manually pulling the handle 813, the pull rod 814 and the pin 816 move upward, causing the pin 816 to disengage from the slot 817 and release the fixation on the turntable 810. Then, the grip 811 is controlled to rotate the turntable 810, the horizontal shaft 809 and the small bevel gear 808, and through meshing with the large bevel gear 807, it drives the lifting screw 806 to rotate. The lifting screw 806 drives the fixed frame 701 to move up and down through the threaded engagement with the lifting plate 804, thereby realizing the height adjustment of the detection probe 2. After adjusting to the required height, the handle 813 and the grip 811 are released, so that the pin 816 is locked into the slot 817 under the action of the compression spring 815, thereby locking the height of the fixed frame 701.

[0070] The present invention also provides a current transformer testing method, applied to the aforementioned current transformer calibration device, comprising the following steps:

[0071] Step 1: Current Transformer Fixing: Install the multiple current transformers to be inspected into the clamping assembly 4 inside the multi-position transformer fixing fixture 3. Start the drive motor 302 to drive the drive shaft 303 to rotate. The drive shaft 303, through the cooperation of the driving bevel gear 304, driven bevel gear 305, drive shaft 412, connector, driven shaft 403, rotating frame 404, arc-shaped connecting rod 40109, sliding plate 40107, L-plate 40101 and clamping plate 40103, drives the clamping plate 40103 to move closer to the current transformer to achieve clamping. Rotate the knob 40105 in conjunction with the adjusting screw 40104 to ensure the fit between the clamping plate 40103 and the current transformer.

[0072] Step 2, Equipment Initialization: Connect the characteristic current injection unit group 5 to the primary circuit of each current transformer in parallel, start the test host 1, and the automatic moving adjustment mechanism 7 performs self-calibration, so that the monitoring head is reset to the standby position.

[0073] Step 3: Automatic positioning and background noise scanning of probe 2: Select the target current transformer number on the human-machine interface console, and the automatic movement adjustment mechanism 7 drives probe 2 to move to the primary conductor surface of the corresponding current transformer. The test host 1 controls the current probe 2 to scan the background noise spectrum and stores the noise characteristics of the current transformer. Repeat this step until the noise scanning of all current transformers under test is completed.

[0074] Step 4: Parallel injection of multi-location characteristic signals: The signal processing unit and error calculation module independently generate optimal characteristic signal parameters for each transformer, including frequency and amplitude. The test host 1 synchronously triggers all precision characteristic current injection unit groups 5 through the communication relay unit, and simultaneously injects characteristic current into each circuit; the reference low-resistance circuit and measurement module group 6 synchronously measure the reference current value of each injection unit.

[0075] Step 5: Data Acquisition and Processing: Detection probe 2 acquires the total current of the primary conductor. The signal processing unit and error calculation module execute independently on the data of each channel, extract the characteristic signal component of the current transformer, compare the component with the corresponding reference current value, and calculate the ratio error and phase angle difference of a single transformer.

[0076] Step Six: Cyclic Detection and Result Integration: Steps Four and Five are automatically cycled, the characteristic signal frequency is changed and re-acquired, the human-machine interaction unit generates a summary report, and outputs the error curves and pass / fail judgments for each frequency point according to the current transformer number.

[0077] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

Claims

1. A current transformer calibration device, characterized in that, include: The test host (1) has an integrated controller, a signal generation module, a data processing unit, a human-machine interaction unit, a communication relay unit, and an error calculation module. The communication relay unit has a built-in master-slave clock distributor. The signal generation module generates characteristic current parameters according to the instructions of the integrated controller and transmits them to the communication relay unit. After receiving the parameters, the communication relay unit drives the characteristic current injection unit group. At the same time, the master-slave clock distributor built into the communication relay unit sends synchronous clock signals to the detection probe, the characteristic current injection unit group, and the precision measurement module group through the communication link. The raw current data collected by the detection probe is transmitted back to the communication relay unit through a flexible cable. The communication relay unit forwards the data to the signal processing unit. The detection probe (2) is equipped with multiple current sensors (201), each of which has wideband response characteristics. The detection probe (2) is connected to the communication relay unit via a flexible cable. Multi-position current transformer fixing fixture (3) is used to fix multiple current transformers and ensure that the primary conductors are in parallel detection positions; The characteristic current injection unit group (5) includes multiple injection units. Each injection unit contains an independent standard resistor circuit, a reference low-resistance circuit, a fast on / off switch and a temperature monitoring chip. The injection unit supports parallel access of multiple circuits and real-time temperature compensation of the injected current. The precision measurement module group (6) provides an independent current reference measurement channel; An automatic moving adjustment mechanism (7) is used for the installation and movement control of the detection probe (2). The automatic moving adjustment mechanism (7) includes: a fixed frame (701), a moving frame (703), an electric push rod (707), and a moving base (706). A lifting mechanism (8) is provided at the bottom of the automatic moving adjustment mechanism (7).

2. The current transformer calibration device according to claim 1, characterized in that, The multi-station current transformer fixing fixture (3) includes: a mounting box (301), a drive motor (302), and multiple clamping components (4). The top of the mounting box (301) is provided with multiple signal feedback mechanisms. The clamping components (4) include: a mounting plate (402), a drive shaft (412), a driven shaft (403), a mounting frame (406), a connecting cylinder (410), and multiple clamping parts (401). A counterweight mechanism (9) is provided on one side of the mounting frame (406). The clamping parts (401) include: a clamping plate (40103), an L-plate (40101), and an adjusting screw (40104). A connecting frame (40102) is fixedly installed on the outside of the clamping plate (40103). The adjusting screw (40104) is rotatably installed in the clamping plate (40103) and the connecting frame (40102). The connecting frame (40102) is slidably installed. A knob (40105) is fixedly installed at one end of the adjusting screw (40104) inside the L-plate (40101). A sliding plate (40107) is fixedly installed on one side of the L-plate (40101), and an arc-shaped connecting rod (40109) is rotatably installed on the other side of the sliding plate (40107). A rotating frame (404) is fixedly sleeved on the outer side of the driven shaft (403), and the other side of the arc-shaped connecting rod (40109)... One end is hinged to the outside of the rotating frame (404). Multiple slide rails (40106) are fixedly installed on one side of the mounting plate (402). The L plate (40101) is slidably sleeved on the outside of the slide rails (40106). Multiple sliding holes are opened on one side of the mounting plate (402). Limiting rods (40108) are fixedly installed in the sliding holes. The sliding plate (40107) is slidably sleeved on the outside of the limiting rods (40108).

3. The current transformer calibration device according to claim 2, characterized in that, The drive shaft (412) and driven shaft (403) are both rotatably mounted in the mounting bracket (406), which is fixedly mounted in the mounting box (301). A stop button (408) and a signal button (407) are fixedly mounted inside the mounting bracket (406). A vertical plate (409) is slidably mounted inside the mounting bracket (406), and the connecting cylinder (410) is rotatably mounted inside the vertical plate (409). The bottom two... Each side is fixedly installed with a limiting plate (411), and the two limiting plates (411) are respectively movably abutting against the two sides of the vertical plate (409). The interior of the connecting cylinder (410) is provided with multiple strip grooves and multiple spiral grooves. One end of the driven shaft (403) is integrally formed with multiple spiral strips (405), and the spiral strips (405) are slidably installed in the spiral grooves. The outer side of the drive shaft (412) is integrally formed with multiple limiting strips, and the limiting strips are slidably installed in the strip grooves.

4. The current transformer calibration device according to claim 3, characterized in that, A driven bevel gear (305) is fixedly sleeved on the outside of the drive shaft (412). The drive motor (302) is fixedly installed on the front side of the mounting box (301). A drive shaft (303) is fixedly installed on the output shaft of the drive motor (302). Multiple drive bevel gears (304) are fixedly installed on the drive shaft (303). The drive bevel gears (304) mesh with the corresponding driven bevel gears (305). A support frame is fixedly installed at the bottom of the mounting box (301). The signal feedback mechanism includes: a base (306) and a working signal light (307) and a fault signal light (308) installed on the top of the base (306). The counterweight mechanism (9) includes: a base plate (901), a top plate (906), and a counterweight plate (902). Multiple support plates (904) are fixedly installed between the base plate (901) and the top plate (906). The counterweight plate (902) is slidably sleeved on the outside of the support plate (904). A pull rope (903) is fixedly installed on the top of the counterweight plate (902). The other end of the pull rope (903) is fixedly connected to the vertical plate (409). A fixed pulley (905) is rotatably installed inside the top plate (906). The pull rope (903) is wound around the outside of the fixed pulley (905). The top plate (906) and the base plate (901) are both fixedly installed in the mounting box (301).

5. The current transformer calibration device according to claim 4, characterized in that, The movable frame (703) is slidably installed inside the fixed frame (701). The electric push rod (707) is fixedly installed inside the movable frame (703). The movable seat (706) is fixedly installed on the output end of the electric push rod (707). The detection probe (2) is fixedly installed on one side of the movable seat (706). A crossbar (708) is fixedly installed on the other side of the movable seat (706). The crossbar (708) is slidably installed inside the movable frame (703). Guide rails (702) are fixedly installed on the top inner wall and bottom inner wall of the fixed frame (701). The movable frame (703) is slidably sleeved on the outside of the guide rails (702). A servo motor (705) is fixedly installed on the front side of the fixed frame (701). A drive screw (704) is fixedly installed on the output shaft of the servo motor (705). The movable frame (703) is threadedly sleeved on the outside of the drive screw (704).

6. The current transformer calibration device according to claim 5, characterized in that, The lifting mechanism (8) includes: a base frame (801), a lifting plate (804), a lifting screw (806), and a horizontal shaft (809). The base frame (801) and the support frame are fixedly installed with the same support base (10). The lifting plate (804) is slidably installed inside the base frame (801). Side plates (805) are fixedly installed on both inner walls of the base frame (801). The lifting plate (804) is slidably sleeved on the outside of the side plates (805). The bottom end of the lifting screw (806) is rotatably installed inside the base frame (801). The bottom end of the lifting screw (806) is threaded into the lifting plate (804), the top of the lifting plate (804) is fixedly connected to the fixed frame (701), a large bevel gear (807) is fixedly installed on the outside of the lifting screw (806), the horizontal shaft (809) is rotatably installed on the side wall of the bottom frame (801), a small bevel gear (808) is fixedly installed at one end of the horizontal shaft (809), the small bevel gear (808) meshes with the large bevel gear (807), and a locking mechanism is provided at the other end of the horizontal shaft (809). Guide plates (803) are fixedly connected to the front and rear sides of the bottom of the fixed frame (701), and guide seats (802) are fixedly installed on the front and rear sides of the bottom frame (801). The guide plates (803) are slidably connected in the corresponding guide seats (802).

7. The current transformer calibration device according to claim 6, characterized in that, The locking mechanism includes a turntable (810), a pin (816), and a fixing plate (812). The turntable (810) has multiple slots (817) on its outer side. The pin (816) is movably inserted into the corresponding slot (817). A compression spring (815) and a pull rod (814) are fixedly installed on the top of the pin (816). The pull rod (814) is slidably installed in the fixing plate (812). A handle (813) is fixedly installed on the top of the pull rod (814). The top of the compression spring (815) is fixedly connected to the fixing plate (812). The fixing plate (812) is fixedly installed on one side of the bottom frame (801). The turntable (810) is fixedly installed on the other end of the horizontal axis (809). A grip (811) is fixedly installed on the other side of the turntable (810).

8. A method for testing a current transformer, applied to the current transformer calibration device according to any one of claims 1-7, characterized in that, Includes the following steps: Step 1: Current transformer fixing: Install the multiple current transformers to be inspected into the clamping assembly (4) in the multi-station transformer fixing fixture (3). Start the drive motor (302) to drive the drive shaft (303) to rotate. The drive shaft (303) drives the clamping plate (40103) to move closer to the current transformer to achieve clamping through the cooperation of the active bevel gear (304), driven bevel gear (305), active shaft (412), connector, driven shaft (403), rotating frame (404), arc connecting rod (40109), sliding plate (40107), L plate (40101) and clamping plate (40103). Step 2, Equipment initialization: Connect the characteristic current injection unit group (5) to the primary circuit of each current transformer in parallel, start the test host (1), and automatically move the adjustment mechanism (7) to perform self-calibration so that the monitoring head is reset to the standby position; Step 3: Automatic positioning and background noise scanning of the detection probe (2): Select the target current transformer number on the human-machine interaction console, and the automatic moving adjustment mechanism (7) drives the detection probe (2) to move to the primary conductor surface of the corresponding current transformer. The test host (1) controls the current detection probe (2) to scan the background noise spectrum and stores the noise characteristics of the current transformer. Repeat this step until the noise scan of all current transformers under test is completed; Step 4: Parallel injection of multi-location characteristic signals: The signal processing unit and the error calculation module independently generate optimal characteristic signal parameters for each transformer, including frequency and amplitude; Step 5: Data acquisition and processing: The detection probe (2) acquires the total current of the primary conductor. The signal processing unit and the error calculation module execute the data of each channel independently, extract the characteristic signal component of the current transformer, compare the component with the corresponding reference current value, and calculate the ratio error and phase angle difference of a single transformer. Step Six: Cyclic Detection and Result Integration: Steps Four and Five are automatically cycled, the characteristic signal frequency is changed and re-acquired, the human-machine interaction unit generates a summary report, and outputs the error curves and pass / fail judgments for each frequency point according to the current transformer number.

9. The current transformer detection method according to claim 8, characterized in that, In step one, rotating the knob (40105) in conjunction with adjusting the screw (40104) ensures the fit between the clamping plate (40103) and the current transformer.

10. The current transformer detection method according to claim 8, characterized in that, In step four, the test host (1) synchronously triggers all precision characteristic current injection unit groups (5) through the communication relay unit, and injects characteristic current into each circuit at the same time; the reference low resistance circuit and the measurement module group (6) synchronously measure the reference current value of each injection unit.

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