Residual current detection protection device

Abstract

The utility model discloses a residual current detection protection device, which comprises a pair of sleeved detection blocks, each sleeved detection block is provided with a concave detection groove and a pair of semicircular holes, the sleeved detection blocks are fixed through bolts, the inner side of each concave detection groove is provided with a movable detector, and the movable detector is provided with a pair of semicircular holes. The movable detector comprises a pair of concave fixed limiting blocks, the pair of concave fixed limiting blocks are oppositely and parallelly installed on the inner side of the concave detection groove, and a pair of limiting plates are installed on the inner side of the concave detection groove. Accurate positioning and non-abrasion stepping movement of the detection module are achieved, and the problem of precision attenuation of a traditional mechanical transmission mechanism is effectively solved. The double-semicircle current transformer structure is matched with a differential detection algorithm, the high-sensitivity residual current detection capability is achieved, and harmonic interference is effectively restrained through the power frequency wave trap.

Description

Technical Field

[0001] This utility model relates to the field of cable testing technology, specifically to a residual current detection and protection device. Background Technology

[0002] This invention addresses the technical bottlenecks of traditional residual current devices (RCDs), such as detection blind spots, uneven contact, and limited functionality, by combining electromagnetic drive, differential detection, and intelligent protection technologies to propose an innovative solution. Existing RCDs mostly employ a fixed ring-shaped current transformer structure, whose position is not adjustable after installation and is prone to contact pressure fluctuations due to mechanical wear, affecting detection accuracy. Their protection function is limited to basic overcurrent protection, lacking self-diagnosis and status feedback mechanisms. Therefore, this invention was developed through in-depth research to address these issues. Utility Model Content

[0003] To achieve the above objectives, this utility model provides the following technical solution: a residual current detection and protection device, comprising a pair of fitted detection blocks, each fitted detection block having a concave detection groove and a pair of semi-circular holes, the pair of fitted detection blocks being fixed by bolts, a movable detector being installed inside the concave detection groove, the movable detector including a pair of concave fixed limiting blocks, the pair of concave fixed limiting blocks being installed parallel to each other inside the concave detection groove, a pair of limiting plates being installed inside the concave detection groove, and two pairs of horizontal limiting shafts being installed on the limiting plates and the concave fixed limiting blocks. A concave movable limiting block is mounted on the shaft. A compression conveyor is mounted on the inner side of both the concave fixed limiting block and the concave movable limiting block. The compression conveyor includes a telescopic compression block with a convex cross-section. A compression conveying magnet is mounted on the telescopic compression block. A compression conveying electromagnet is mounted on the inner side of both the concave fixed limiting block and the concave movable limiting block. An arc-shaped compression block is mounted on the telescopic compression block. A horizontal moving electromagnet is mounted on both the concave fixed limiting block and the limiting plate. Horizontal moving magnets are mounted on both sides of the concave movable limiting block. A tension detector is mounted on the inner side of the concave detection groove.

[0004] Preferably, the tension detector includes two pairs of clamping electric push rods, which are installed in parallel on the inner side of the concave detection groove. A pair of clamping plates are installed on the pushing end of the two pairs of clamping electric push rods, and a semi-circular current transformer is installed on the clamping plates.

[0005] Preferably, the horizontal moving electromagnet and the pressing and conveying electromagnet are equipped with a resistance regulator and a current regulator.

[0006] Preferably, the concave movable limiting block and the concave detection groove are provided with position detection sensors.

[0007] Preferably, a pressure sensor is provided on the surface of the arc-shaped extrusion block.

[0008] Preferably, the kit detection block is equipped with a wireless signal transmitter.

[0009] Beneficial effects

[0010] This utility model provides a residual current detection and protection device. It offers the following advantages: The device employs a graded electromagnetic drive system to achieve precise positioning and wear-free stepping movement of the detection module, effectively solving the accuracy attenuation problem of traditional mechanical transmission mechanisms; the double semi-circular current transformer structure, combined with a differential detection algorithm, provides high-sensitivity residual current detection capability, and effectively suppresses harmonic interference through a power frequency notch filter; a three-level intelligent protection system is constructed, integrating pressure closed-loop control, transformer open-circuit protection, and fault waveform recording functions, with daily zero-point calibration ensuring long-term operational stability; the electromagnetic compatibility design adopts twisted-pair shielding, dual surge suppression, and low-impedance grounding measures, complying with international electromagnetic compatibility standards; the modular structure supports online maintenance, and the horizontal moving magnetic drive mechanism works in conjunction with the servo electric cylinder, maintaining reliable detection performance even in complex electromagnetic environments, forming a complete technological advantage from mechanical positioning to intelligent protection. Attached Figure Description

[0011] Figure 1 This is a front sectional view of the residual current detection and protection device of this utility model.

[0012] Figure 2 This is a three-dimensional cross-sectional view of the residual current detection and protection device of this utility model.

[0013] Figure 3 This is a side cross-sectional view of the residual current detection and protection device of this utility model.

[0014] In the diagram: 1. Set of detection blocks; 2. Concave detection groove; 3. Semicircular hole; 4. Concave fixed limit block; 5. Limiting plate; 6. Horizontal limit shaft; 7. Concave moving limit block; 8. Telescopic extrusion block; 9. Extrusion transport magnet; 10. Extrusion transport electromagnet; 11. Arc extrusion block; 12. Horizontal moving electromagnet; 13. Horizontal moving magnet; 14. Clamping electric push rod; 15. Clamping plate; 16. Semicircular current transformer. Detailed Implementation

[0015] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0016] Those skilled in the art should connect all electrical components and their compatible power supplies in this case via wires. Appropriate controllers and encoders should be selected according to the actual situation to meet control requirements. The specific connection and control sequence should refer to the working principle described below, where the electrical components are connected in sequence. The detailed connection methods are well-known in the art. The following mainly introduces the working principle and process, and will not describe the electrical control further.

[0017] Example

[0018] Please see Figure 1-3 In existing technologies, residual current devices (RCDs) mostly adopt a fixed installation structure, using a current transformer looped with a cable to achieve current detection. These devices suffer from three major technical bottlenecks: first, their position is not adjustable after installation, easily creating detection blind spots in long-distance cable laying scenarios; second, the mechanical fixing method easily leads to uneven contact pressure, affecting detection accuracy; and third, their protection function is limited, lacking self-diagnosis and status feedback mechanisms. In the field of industrial automation, the principle of electromagnetic repulsion has been applied to material handling systems. This invention creatively introduces graded electromagnetic drive technology into the detection device: through PLC timing control, the fixed-side electromagnet is first activated to complete the initial positioning, and then the moving-side electromagnetic system achieves step-by-step adjustment. This design solves the wear problem of traditional mechanical transmission mechanisms while improving the accuracy of position adjustment.

[0019] Therefore, this application protects a residual current detection and protection device. A pair of semi-circular holes 3 on a pair of fitted detection blocks 1 are fitted onto a detection cable. The pair of fitted detection blocks 1 are fixed with bolts. A compression-transfer electromagnet 10, located inside a replaceable limiting block arranged within a concave detection groove 2, is energized. The compression-transfer electromagnet 10 magnetically repels the compression-transfer magnet 9, which in turn drives the telescopic compression block 8. The telescopic compression block 8 then drives the arc-shaped compression block 11, thereby compressing the cable. A horizontally moving electromagnet 12 on a concave fixed limiting block 4 magnetically repels a horizontally moving magnet 13, causing the horizontally moving magnet 13 to drive the concave moving limiting block 7 to perform stable horizontal telescopic movement. The two pairs of horizontal limiting shafts 6 perform stable horizontal extension and retraction. Similarly, the squeezing and transporting electromagnet 10 inside the concave moving limiting block 7 is energized, so that the concave fixed limiting block 4 is first squeezed and fixed by the arc squeezing block 11 inside the concave fixed limiting block 4, and then squeezed by the arc squeezing block 11 inside the concave moving limiting block 7. After that, the arc squeezing block 11 inside the concave fixed limiting block 4 is released, and the squeezing and transporting electromagnet 10 and the squeezing and transporting magnet 9 perform magnetic repulsion, thereby changing the position of a pair of set detection blocks 1 on the cable, so that the set detection blocks 1 move horizontally and stably on the cable. At the same time, the clamping electric push rod 14 is operated, driving the clamping plate 15 on it. Through the relative extension and retraction of the clamping plate 15, the semi-circular current transformer 16 on it is driven to perform set detection on the cable.

[0020] In summary, the system employs a graded electromagnetic repulsion system. A PLC controller supplies power to the compression conveying electromagnet 10 and the horizontal moving electromagnet 12 according to a preset sequence. First, the electromagnet inside the concave fixed limiting block 4 is activated, pushing the telescopic compression block 8 to make the arc-shaped compression block 11 contact the cable. After it is fixed in place, a delay mechanism activates the electromagnetic system inside the concave moving limiting block 7, enabling the step-by-step horizontal movement of the detection device. The clamping electric push rod 14 uses a servo electric cylinder with position feedback. A PID algorithm controls the push rod stroke to ensure the contact pressure of the semi-circular current transformer 16. A pressure sensor monitors the clamping force in real time and automatically compensates for deviations. In terms of detection principle, a double semi-circular current transformer 16 structure is used. During normal operation, the magnetic flux generated by the cable current cancels each other out. During a leakage fault, the vector sum of the inflow and outflow currents is not zero, generating an induced voltage on the secondary side of the transformer. The signal is filtered and enters a differential amplifier, compared with a set threshold to trigger protection action, and a power frequency notch filter is used to eliminate interference. In terms of safety protection, it has self-diagnostic functions, automatically performs zero-point calibration of the current transformer daily, immediately cuts off the power and alarms when an open circuit is detected on the secondary side of the current transformer, and simultaneously sets up electromagnet overcurrent protection; when the residual current exceeds the threshold, it immediately activates an audible and visual alarm, delays cutting off the contactor coil power supply, and simultaneously records fault waveform data. The electromagnetic compatibility design uses twisted-pair shielded cables to connect the sensor and control unit. The control circuit is equipped with dual surge protection using TVS diodes and varistors, and the grounding resistance of the metal casing meets standard requirements. This device, through the integrated design of mechanical positioning, current monitoring, and fault protection, constructs a complete residual current protection system.

[0021] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A residual current detection protection device, characterized in that, Includes a pair of assembled detection blocks (1), each of which has a concave detection groove (2) and a pair of semi-circular holes (3). The pair of assembled detection blocks (1) are fixed by bolts. A movable detector is installed on the inner side of the concave detection groove (2). The movable detector includes a pair of concave fixed limiting blocks (4). The pair of concave fixed limiting blocks (4) are installed parallel to each other on the inner side of the concave detection groove (2). A pair of limiting plates (5) are installed on the inner side of the concave detection groove (2). Two pairs of horizontal limiting shafts (6) are installed on the limiting plates (5) and the concave fixed limiting blocks (4). Concave movable limiting blocks (7) are installed on the two pairs of horizontal limiting shafts (6). 4) A compression transporter is installed on the inner side of the concave moving limit block (7). The compression transporter includes a telescopic compression block (8). The cross-section of the telescopic compression block (8) is convex. A compression transport magnet (9) is installed on the telescopic compression block (8). A compression transport electromagnet (10) is installed on the inner side of the concave fixed limit block (4) and the concave moving limit block (7). An arc compression block (11) is installed on the telescopic compression block (8). A horizontal moving electromagnet (12) is installed on the concave fixed limit block (4) and the limit plate (5). Horizontal moving magnets (13) are installed on both sides of the concave moving limit block (7). A tension detector is installed on the inner side of the concave detection groove (2).

2. A residual current detection protection device according to claim 1, characterized in that, The tension detector includes two pairs of clamping electric push rods (14), which are installed in parallel on the inner side of the concave detection groove (2). A pair of clamping plates (15) are installed on the pushing end of the two pairs of clamping electric push rods (14), and a semi-circular current transformer (16) is installed on the clamping plate (15).

3. A residual current detection protection device according to claim 2, characterised in that, The horizontal moving electromagnet (12) and the squeezing and conveying electromagnet (10) are equipped with a resistance regulator and a current regulator.

4. A residual current detection protection device according to claim 3, characterised in that, Position detection sensors are provided on the concave movable limiting block (7) and the concave detection groove (2).

5. A residual current detection protection device according to claim 4, characterised in that, A pressure sensor is provided on the surface of the arc extrusion block (11).

6. A residual current detection protection device according to claim 5, characterised in that, The kit detection block (1) is equipped with a wireless signal transmitter.

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