Discharge protection structure of hall CT sensing cable
By reinforcing the connection of the Hall CT sensing cable with supporting insulating barriers and heat shrink tubing, the problem of local high-voltage discharge caused by insufficient insulation of the Hall CT sensing cable is solved, ensuring the accuracy of current detection and the safety and stability of the equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI ELECTRIC FUJI ELECTRIC ELECTRICAL TECHNOLOGY (WUXI) CO LTD
- Filing Date
- 2025-06-04
- Publication Date
- 2026-06-12
AI Technical Summary
In high-voltage frequency converters, insufficient insulation of the Hall CT sensing cable and inadequate isolation protection of the Hall CT can lead to local high-voltage discharge, affecting the accuracy of current detection and potentially damaging electrical components. Furthermore, the connection point is exposed to a high-voltage environment, increasing the risk of discharge.
The installation position of the Hall CT is fixed by supporting insulating insulators, the cable surface is reinforced by heat shrink tubing, and insulation protection is enhanced by connecting conductors and sealing devices to ensure voltage and creepage distance requirements. It is then fixed with special connecting clamps and sealing rings.
It effectively prevents partial high-voltage discharge, ensures the accuracy of current detection, protects equipment from damage, and improves the safety and stability of high-voltage frequency converters.
Smart Images
Figure CN224355814U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of safety design for high-voltage frequency converters, and in particular to a discharge protection structure for a Hall CT sensing cable. Background Technology
[0002] With the widespread application of high-voltage frequency converters, current detection in electrical equipment has become increasingly important. In high-voltage electrical equipment, especially in frequency converter control systems, Hall effect current transformers (HETC) sensors are used to detect the current flowing through cables.
[0003] Because high-voltage frequency converters typically output high voltage and high current, if the cable insulation and the Hall CT's isolation protection are insufficient when connecting to the cable, partial high-voltage discharge can occur, affecting the accurate detection of current and potentially damaging electrical components. Furthermore, the connection point between the cable and the Hall CT is frequently exposed to a high-voltage environment, increasing the risk of discharge. To avoid the hazards of partial discharge and improve system safety, this invention proposes an improved connection structure for high-voltage electrical equipment, particularly focusing on discharge protection design for Hall CT sensing cables. Utility Model Content
[0004] This invention provides a discharge protection structure for Hall effect CT sensing cables. It can solve the aforementioned problems existing in related technologies. The technical solution is as follows:
[0005] A discharge protection structure for Hall effect CT sensing cables is provided, characterized in that the structure includes:
[0006] The high-voltage frequency converter is electrically connected to the Hall CT via a cable. The high-voltage frequency converter is used to regulate the output current and provide a high-voltage signal.
[0007] The Hall CT is connected to the high-voltage frequency converter via a cable. The Hall CT is used to sense and detect the current passing through it. The Hall CT is installed in a high-voltage environment. The Hall CT is fixed in position by a support insulating insulator. The selection of the support insulating insulator must meet the maximum voltage requirements, creepage distance requirements, and insulation distance requirements between the Hall CT and the support insulating insulator.
[0008] The cable is used to connect the high-voltage frequency converter and the Hall CT. The surface of the cable is reinforced with heat shrink tubing.
[0009] Connecting conductors are located at both ends of the heat shrink sleeve, and supporting insulating barriers are located at the connecting conductors.
[0010] Optionally, the discharge protection structure of the Hall CT sensing cable includes three supporting insulating barriers, two Hall CTs, two heat shrink tubing and three connecting conductors.
[0011] The cable runs between the connecting conductor and the heat shrink tubing, and the arrangement order on the cable is as follows: first connecting conductor MNU, first heat shrink tubing, second connecting conductor MNV, second heat shrink tubing and third connecting conductor MNW.
[0012] The first Hall effect sensor CTCT1 is located at the first heat shrink sleeve, and the second Hall effect sensor CTCT2 is located at the second heat shrink sleeve.
[0013] The first supporting insulating barrier is located at the first connecting conductor MNU, the second supporting insulating barrier is located at the second connecting conductor MNV, and the third supporting insulating barrier is located at the third connecting conductor MNW.
[0014] Optionally, the maximum voltage requirement between the Hall CT and the supporting insulating insulator is 28kV, the creepage distance requirement is 125mm, and the insulation distance requirement is 90mm.
[0015] Optionally, the heat shrink tubing has a withstand voltage rating of ≥15kV, the total length of the reinforced portion of the heat shrink tubing is 200mm, and the reinforced portion of the heat shrink tubing is fixed to the surface of the cable.
[0016] Optionally, the internal electrical components of the discharge protection structure of the Hall CT sensing cable have a flame retardant rating of V1 or higher, and the supporting insulation barrier has a flame retardant rating of V0 or higher.
[0017] Optionally, the first Hall CTCT1 is located in the first heat shrink sleeve at a distance of 0.00 mm relative to the first connecting conductor MNU100 mm and 0.1 mm relative to the second connecting conductor MNV101 mm.
[0018] Optionally, the high-voltage frequency converter is connected to the cable using a metal connector, which is connected to the copper wire of the cable via bolts.
[0019] Optionally, the cable connection may include a grounding device EN.
[0020] Optionally, the heat shrink tubing has a multi-layer structure, with the outer layer made of high-pressure resistant material and the inner layer made of flexible insulating material.
[0021] Optionally, the connection between the cable and the Hall CT is secured using a dedicated connection clamp, which is firmly installed on the terminal of the Hall CT via a cable securing assembly.
[0022] The connection point between the Hall CT and the cable is protected by a sealing device, which is a high-density sealing ring, to prevent the cable surface from directly contacting the external environment.
[0023] This invention provides a discharge protection structure for Hall effect CT sensing cables, aiming to improve the insulation capability at the connection between the cable and the Hall effect CT and avoid the hazards of local high-voltage discharge. The structure includes a high-voltage frequency converter, a Hall effect CT, a cable, a supporting insulating insulator, and a connecting conductor. The high-voltage frequency converter connects to the Hall effect CT via a cable, the surface of which is protected by a heat-shrink tubing. By adding insulation protection at the cable-Hall effect CT connection point and on the cable surface, and by ensuring assembly accuracy through the supporting insulating insulator and connecting conductor, the structure effectively prevents local discharge caused by high voltage, ensures the accuracy of current detection, and protects the equipment from damage. The design of the insulating insulator guarantees the required high-voltage insulation distance and surface distance. This structure is simple in design and can improve the safety and stability of the high-voltage frequency converter equipment.
[0024] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0026] Figure 1 This is a schematic diagram of the discharge protection structure of a Hall CT sensing cable provided in an illustrative embodiment of this application, wherein 01 represents a supporting insulating insulator, 02 represents a Hall CT, 03 represents a cable, 04 represents a heat shrinkable sleeve, and 05 represents a connecting conductor. Detailed Implementation
[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.
[0028] Example 1
[0029] Please refer to Figure 1 This illustration shows a schematic diagram of the discharge protection structure of a Hall CT sensing cable according to an exemplary embodiment of this application. The structure includes:
[0030] A discharge protection structure for Hall effect CT sensing cables is provided, characterized in that the structure includes:
[0031] The high-voltage frequency converter, electrically connected to the Hall current transformer (HCT) via cables, regulates the output current and provides a high-voltage signal. The high-voltage frequency converter utilizes multi-diode full-wave rectification to suppress high-order harmonics, improving the power factor on the power supply side and enhancing customer power efficiency. The design for connecting to the Hall CT employs a combination of high-voltage insulation technology and supporting insulating barriers to ensure stable operation even under extreme high-voltage environments. This design effectively guarantees the long-term operational safety of the equipment by reducing the impact of voltage fluctuations on current detection accuracy.
[0032] The Hall CT is connected to the high-voltage frequency converter via a cable. The Hall CT is used to sense and detect the current passing through it. In order to ensure the high-voltage insulation distance, the Hall CT is installed in a high-voltage environment. The Hall CT is fixed in position by a supporting insulating insulator, and the selection of the supporting insulating insulator must meet the maximum voltage requirements, creepage distance requirements, and insulation distance requirements between the Hall CT and the supporting insulating insulator.
[0033] The cable is a high-voltage cable used to connect the high-voltage frequency converter and the Hall CT. The surface of the cable is reinforced with heat shrink tubing.
[0034] Connecting conductors are located at both ends of the heat shrink sleeve, and supporting insulating barriers are located at the connecting conductors.
[0035] This application discloses a discharge protection structure for a Hall effect CT sensing cable. The structure includes a high-voltage frequency converter, a Hall effect CT, a cable, a supporting insulating insulator, and a connecting conductor. The high-voltage frequency converter is connected to the Hall effect CT via a cable. The surface of the cable is protected by a heat-shrink tubing. By adding insulation protection at the connection point between the cable and the Hall effect CT and on the cable surface, and by ensuring assembly accuracy through the supporting insulating insulator and connecting conductor, the structure effectively prevents partial discharge caused by high voltage, ensures the accuracy of current detection, and protects the equipment from damage. The design of the insulating insulator ensures the requirements for high-voltage insulation distance and surface distance. This structure is simple in design and can improve the safety and stability of the high-voltage frequency converter equipment.
[0036] Example 2
[0037] Optionally, the discharge protection structure of the Hall CT sensing cable includes three supporting insulating barriers, two Hall CTs, two heat shrink tubing and three connecting conductors.
[0038] The cable runs between the connecting conductor and the heat shrink tubing, and the cable is arranged in the following order: first connecting conductor MNU, first heat shrink tubing, second connecting conductor MNV, second heat shrink tubing, and third connecting conductor MNW.
[0039] The first Hall effect sensor CTCT1 is located at the first heat shrink sleeve, and the second Hall effect sensor CTCT2 is located at the second heat shrink sleeve.
[0040] The first supporting insulating barrier is located at the first connecting conductor MNU, the second supporting insulating barrier is located at the second connecting conductor MNV, and the third supporting insulating barrier is located at the third connecting conductor MNW.
[0041] In this embodiment, the supporting insulating insulator is selected according to IEC standards. The requirements include maximum voltage, creepage distance, and insulation distance. The maximum voltage requirement between the Hall effect current transformer (HOT) and the supporting insulating insulator is 28kV, the creepage distance requirement is 125mm, and the insulation distance requirement is 90mm. Creepage distance refers to the shortest distance along an insulating surface between electrical components, while insulation distance refers to the actual distance between components where there is no conductive material. To meet these requirements, a supporting insulating insulator with a creepage distance greater than 290mm and an insulation distance greater than 145mm was selected to ensure safety in high-voltage environments.
[0042] The reason is that, according to IEC and GB standards, the selection of supporting insulating insulators needs to meet a series of electrical requirements, including maximum voltage, creepage distance, and insulation distance. In practical applications, for a maximum voltage of 28kV, the IEC standard specifies a creepage distance of at least 125mm and an insulation distance of 90mm. However, to ensure the safety of equipment in high-voltage environments, longer creepage distances and larger insulation distances are usually chosen. In this design, supporting insulating insulators with a creepage distance greater than 290mm and an insulation distance greater than 145mm were selected. This is because a longer creepage distance effectively prevents current from jumping along the insulation surface, reducing the risk of partial discharge, while a larger insulation distance provides higher electrical isolation, ensuring stable operation of the equipment under high voltage. This selection not only meets the requirements of IEC and GB standards but also provides additional safety assurance for the system, ensuring long-term stability and reliability. This type of supporting insulating insulator was chosen because it effectively provides a longer creepage distance and a higher insulation distance, which is crucial for preventing partial discharge, especially in high-voltage environments, enhancing the reliability and safety of the system.
[0043] Therefore, a support insulating insulator with a creepage distance greater than 290mm and an insulation distance of 145mm is selected, meaning the support insulating insulator is designed with precise high-voltage isolation capabilities. Through reasonable selection of voltage, creepage distance, and insulation distance requirements, the support insulating insulator ensures a safe distance between the Hall CT and other components, meeting the demands of stringent high-voltage environments. The support insulating insulator not only provides installation and fixation but also enhances the overall system's durability and safety.
[0044] Therefore, using insulating barriers to fix the installation position of the Hall CT ensures the required installation insulation distance and surface distance of the entire Hall CT device, reduces the harm of partial discharge, and adds insulating barriers to the cables at both ends of the Hall CT so that it can be directly installed on the manufacturing site, which simply and effectively prevents the possibility of installation errors.
[0045] The primary function of a Hall effect current detector (HPD) is to sense and detect the current flowing through it. In high-voltage environments, the installation stability and insulation capability of the HPD are crucial. This solution employs supporting insulating insulators to position the HPD, ensuring maximum voltage isolation between it and the high-voltage environment. Crucially, the selected supporting insulating insulators not only meet voltage and creepage distance requirements but also enhance the overall system safety, preventing partial discharge interference with current detection and improving data accuracy and equipment reliability.
[0046] In addition, when using Hall CT, since the voltage of the circuit being detected is in a high-voltage environment (ranging from 3kV to 11kV), even the cables are prone to partial discharge during use, which can cause a strong voltage surge to the Hall CT and interfere with the detection results, resulting in a distorted output voltage waveform and an inability to accurately monitor the detected current.
[0047] Considering cost, this embodiment of the application reinforces the insulation of the portion of the cable to be inspected, specifically by using a heat shrink tubing with a withstand voltage rating ≥15kV. The reinforced portion of the heat shrink tubing is fixed to the cable surface to reduce the impact of high-voltage discharge. Considering the creepage distance requirements for high-voltage levels, the total length of the reinforced heat shrink tubing is required to be 200mm. The Hall effect sensor (HPS) is placed slightly off-center. The heat shrink tubing has a withstand voltage rating ≥15kV, and the relative installation positions of the cable and the HPS are fixed at 100mm and 101mm respectively to ensure good electrical performance. Figure 1 In the first heat shrink sleeve, the first Hall CTCT1 is located at a distance of 0.00 mm relative to the first connecting conductor MNU100 mm and 0.1 mm relative to the second connecting conductor MNV101 mm.
[0048] The cable design incorporates a heat-shrink tubing reinforcement scheme to effectively prevent partial discharge under high-voltage operating conditions. By selecting heat-shrink tubing with a withstand voltage rating of 15kV or higher, and employing a multi-layered structure with a high-voltage resistant outer layer and a flexible insulation inner layer, the cable's safety is further enhanced. This design ensures the cable can withstand high voltage and maintain stability under high-voltage conditions, significantly improving the safety of electrical connections.
[0049] Optionally, the internal electrical components of the discharge protection structure of the Hall CT sensing cable have a flame retardant rating of V1 or higher, and the supporting insulation barrier has a flame retardant rating of V0 or higher.
[0050] Optionally, the connection between the high-voltage frequency converter and the cable uses metal connectors, which are connected to the copper wires of the cable via bolts. Specifically, the connecting conductors use metal connectors and are connected via bolts and copper wires to ensure a firm and reliable electrical contact between the high-voltage frequency converter and the Hall current transformer (HCT). Each connecting conductor is used in conjunction with a heat-shrink tubing to ensure the accuracy of current transmission between the cable and the HCT. This ensures that the connecting components maintain good electrical performance during high-voltage current transmission and effectively reduces the risk of partial discharge.
[0051] Figure 1 In a three-phase electrical system, U, V, W, and EN represent the three phases U, V, and W, as well as the grounding EN. In a three-phase electrical system, U, V, and W represent the different phases of the three-phase current, while EN usually represents the grounding wire; the connection part of a cable includes the grounding device EN.
[0052] Optionally, the heat shrink tubing has a multi-layer structure, with the outer layer made of high-pressure resistant material and the inner layer made of flexible insulating material.
[0053] Optionally, the connection between the cable and the Hall CT is secured using a dedicated connection clamp, which is firmly installed on the terminal of the Hall CT via a cable securing assembly.
[0054] The connection point between the Hall CT and the cable is protected by a sealing device, which is a high-density sealing ring, to prevent the cable surface from directly contacting the external environment.
[0055] The combined effect of these design features provides a comprehensive protection solution for high-voltage electrical systems. By optimizing electrical connections, enhancing insulation, and adding protective structures, not only is the operational stability of electrical equipment improved, but the system's service life is also effectively extended.
[0056] The above are merely optional embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A discharge protection structure for a Hall effect CT sensing cable, characterized in that, The structure includes: The high-voltage frequency converter is electrically connected to the Hall CT via a cable. The high-voltage frequency converter is used to regulate the output current and provide a high-voltage signal. The Hall CT is connected to the high-voltage frequency converter via the cable. The Hall CT is used to sense and detect the current passing through it. The Hall CT is installed in a high-voltage environment. The Hall CT is fixed in position by a support insulating insulator. The selection of the support insulating insulator must meet the maximum voltage requirement, creepage distance requirement, and insulation distance requirement between the Hall CT and the support insulating insulator. The cable is used to connect the high-voltage frequency converter and the Hall CT, and the surface of the cable is reinforced with heat shrink tubing. A connecting conductor is provided at both ends of the heat shrink sleeve, and the supporting insulating barrier is located at the connecting conductor.
2. The discharge protection structure according to claim 1, characterized in that, The discharge protection structure of the Hall CT sensing cable includes three supporting insulating barriers, two Hall CTs, two heat shrinkable sleeves, and three connecting conductors. The cable passes through the connecting conductor and the heat shrink sleeve, and the arrangement order on the cable is as follows: first connecting conductor (MNU), first heat shrink sleeve, second connecting conductor (MNV), second heat shrink sleeve and third connecting conductor (MNW). The first Hall CT (CT1) is located at the first heat shrink sleeve, and the second Hall CT (CT2) is located at the second heat shrink sleeve; The first supporting insulating barrier is located at the first connecting conductor (MNU), the second supporting insulating barrier is located at the second connecting conductor (MNV), and the third supporting insulating barrier is located at the third connecting conductor (MNW).
3. The discharge protection structure according to claim 1, characterized in that, The maximum voltage requirement between the Hall CT and the supporting insulating barrier is 28kV, the creepage distance requirement is 125mm, and the insulation distance requirement is 90mm.
4. The discharge protection structure according to claim 1, characterized in that, The heat shrink tubing has a withstand voltage rating of ≥15kV, and the total length of the reinforced portion of the heat shrink tubing is 200mm. The reinforced portion of the heat shrink tubing is fixed to the surface of the cable.
5. The discharge protection structure according to claim 1, characterized in that, The electrical components inside the discharge protection structure of the Hall CT sensing cable have a flame retardant rating of V1 or higher, and the supporting insulation barrier has a flame retardant rating of V0 or higher.
6. The discharge protection structure according to claim 2, characterized in that, The first Hall CT (CT1) is located at a distance of 100 mm relative to the first connecting conductor (MNU) and 101 mm relative to the second connecting conductor (MNV) in the first heat shrink sleeve.
7. The discharge protection structure according to claim 1, characterized in that, The high-voltage frequency converter is connected to the cable using a metal connector, which is connected to the copper wire of the cable via bolts.
8. The discharge protection structure according to claim 1, characterized in that, The connection portion of the cable includes a grounding device (EN).
9. The discharge protection structure according to claim 1, characterized in that, The heat shrink tubing has a multi-layer structure, with the outer layer made of high-pressure resistant material and the inner layer made of flexible insulating material.
10. The discharge protection structure according to claim 1, characterized in that, The connection between the cable and the Hall CT is secured using a special connection clamp, which is firmly installed on the terminal of the Hall CT via a cable fixing assembly. The connection point between the Hall CT and the cable is protected by a sealing device, which is a high-density sealing ring used to prevent the cable surface from directly contacting the external environment.