Grounding leakage current monitoring device for high-voltage cable in ring main unit

Abstract

The application relates to the technical field of power equipment monitoring, and discloses a ring net cabinet high-voltage cable grounding leakage current monitoring device, which comprises a fixing mechanism fixed to the lateral wall outside a device to be monitored, a rotating ring body in rotation connection with a ring base body to form a fixing ring, and a monitoring sensor, and the fixing ring mechanism utilizes the monitoring sensor to monitor the device to be monitored. The ring net cabinet high-voltage cable grounding leakage current monitoring device utilizes the surplus space of the equipment body wiring end, respectively sets vibration sensors, temperature sensors and zero sequence current transformers at positions close to the cable body, multi-dimensionally monitors the working condition of the cable body, integrates information through a mainboard, triggers remote alarm when the cable body is faulty, so that the fast early warning of the cable fault in the narrow space in the ring net cabinet can be realized, the repair time of the staff is ensured, and the damage of the equipment and the risk of power failure accidents are reduced.

Description

Technical Field

[0001] This invention relates to the field of power equipment monitoring technology, specifically a high-voltage cable grounding leakage current monitoring device in a ring main unit. Background Technology

[0002] Ring main units are key infrastructure equipment of the State Grid Corporation of China, and their operating status directly affects the security of power supply. Monitoring the grounding of their high-voltage cables can provide early warning of potential faults and prevent equipment damage and power outages. Monitoring is typically performed by connecting a zero-sequence current transformer to a relay protection device.

[0003] However, existing zero-sequence current transformers cannot monitor the leakage current of the high-voltage cable grounding wire inside the ring main unit in real time. If an anomaly occurs, it cannot promptly trigger an alarm to alert relevant personnel for timely repairs, posing a safety hazard to the electrical equipment. Furthermore, to prevent serious disasters such as high-voltage cable disconnection or fire, multi-dimensional monitoring using sensors such as smoke sensors, temperature sensors, and vibration sensors is necessary. However, since ring main units are generally installed outdoors or even near roads in dusty environments, dust enters the ring main unit through its ventilation openings, and the internal components also generate dust due to the operation of electrical equipment. This leads to excessive dust content inside the ring main unit, which, when adhering to the detection end of the smoke sensor, significantly reduces the accuracy of the smoke sensor. Since maintenance is typically performed periodically, dust can quickly accumulate on the smoke sensor's detection end in windy conditions, which staff may not be aware of. This results in the smoke sensor being unable to accurately detect smoke before maintenance, posing a certain safety hazard. Furthermore, since smoke sensors are typically placed at the top of the cabinet, and because there are few gaps inside the ring main unit, smoke usually accumulates in a certain area and then slowly diffuses to the top inside the ring main unit, resulting in a certain lag in the detection of smoke sensors. Summary of the Invention

[0004] (a) Technical problems to be solved: To address the shortcomings of existing technologies, this invention provides a high-voltage cable grounding leakage current monitoring device in a ring main unit, which solves the problems mentioned in the background technology, such as the difficulty of real-time monitoring of leakage current by sequence transformers and the inability to provide timely alarms, and the inaccuracy of smoke sensors due to dust accumulation and the lag in smoke monitoring.

[0005] (II) Technical Solution: To achieve the above objectives, the present invention provides the following technical solution: a high-voltage cable grounding leakage current monitoring device within a ring main unit, comprising a ring main unit, an equipment body disposed within the ring main unit, a terminal block on the equipment body, and a cable body connected to the equipment body at the terminal block, comprising: A fixing mechanism, fixed to the outer sidewall of the device to be monitored, includes an annular base, a rotating ring body rotatably connected to the annular base to form a fixing ring, and a monitoring sensor. The fixing ring mechanism uses the monitoring sensor to monitor the device to be monitored and provides an inclined mounting base opened on the rotating ring body. The smoke detection mechanism, detachably connected to the mounting base, includes an inclined smoke sensor, a housing, a filter screen rotatably connected to the housing, and a rangefinder. The rangefinder is used to determine the rotation angle when the filter screen has different contact areas with the outside environment and thus different amounts of dust, to determine the amount of dust adhering to the filter screen, and to actively send information to the staff after the filter screen rotates to a certain angle.

[0006] Preferably, the fixing mechanism further includes: The main housing is located on the side of the annular base away from the rotating ring, and cooperates with the annular base to form a closed cavity; The motherboard is fixed inside the enclosed cavity and integrates a signal isolation circuit, an amplification circuit, a data acquisition chip, a microcontroller, a remote alarm module, and a power supply module. The monitoring sensors include a vibration sensor and a temperature sensor. Both the vibration sensor and the temperature sensor are installed inside the rotating ring and connected to the main board via wiring. The output terminals of both the vibration sensor and the temperature sensor penetrate the side wall of the rotating ring and contact the device to be monitored.

[0007] Preferably, the fixing mechanism further includes: A ratchet rack is fixedly connected to one end of the rotating ring body near the annular base. A limiting tooth is rotatably connected to the inside of the annular base near the ratchet rack, and is used to restrict the ratchet rack so that the ratchet rack can only move in one direction; The lever is located on one side of the limiting tooth; A limiting elastic element is disposed inside the annular base, with one end fixedly connected to the inner wall of the annular base and the other end fixedly connected to the side of the limiting tooth away from the ratchet, for limiting the position of the limiting tooth; The button has one end located outside the annular base and the other end inserted into the annular base, located on the side of the lever away from the ratchet rack; A reset spring element is disposed between the button and the annular base, with one end fixedly connected to the outer sidewall of the annular base and the other end fixedly connected to the button, for providing a reset spring force to the button.

[0008] Preferably, the fixing mechanism further includes: Several first retaining teeth are disposed on the side of the annular base near the rotating ring body to improve the fixing effect of the fixing ring; Several second locking teeth are disposed on the side of the rotating ring body near the annular base, for cooperating with several first locking teeth to further improve the fixing effect of the fixing ring.

[0009] Preferably, the smoke detection mechanism further includes: A connecting base plate is fixed to the mounting base, and the side of the connecting base plate away from the rotating ring is fixedly connected to the smoke sensor. The housing extends from the side of the smoke sensor away from the connecting substrate to form a smoke inlet channel, and the end of the housing away from the smoke sensor is flush with the end of the housing. The rangefinder is fixed to the side wall of the connecting base plate away from the rotating ring, with the detection end facing downwards.

[0010] Preferably, the filter screen is elliptical and initially set horizontally.

[0011] Preferably, the smoke detection device further includes: The sensing end is fixedly connected to the end of the filter screen near the rangefinder and is located at the bottom of the detection end of the rangefinder.

[0012] Preferably, it further includes: A zero-sequence current transformer is installed on the outside of the device to be monitored, and the device to be monitored passes through the zero-sequence current transformer. The zero-sequence current transformer is used to collect the ground leakage current signal of the device to be monitored.

[0013] (III) Beneficial Effects: The high-voltage cable grounding leakage current monitoring device in a ring main unit provided by this invention has the following beneficial effects: 1. The high-voltage cable grounding leakage current monitoring device in this ring main unit utilizes the spare space at the wiring terminals of the equipment body to install vibration sensors, temperature sensors, and zero-sequence current transformers near the cable body. This allows for multi-dimensional monitoring of the cable body's operating status. The information is integrated through the main board, and a remote alarm is triggered when the cable body fails. This enables rapid early warning of cable faults within the confined space of the ring main unit, giving staff more time for emergency repairs and reducing the risk of equipment damage and power outages.

[0014] 2. The high-voltage cable grounding leakage current monitoring device in the ring main unit fixes a fixed ring consisting of a ring-shaped base and a rotating ring at the interface between the cable body and the equipment body. The vibration sensor, temperature sensor and main board inside work together, and the monitoring sensor is in direct contact with the cable body, so that the monitoring sensor can monitor the data of the cable body faster and more accurately.

[0015] 3. The high-voltage cable grounding leakage current monitoring device in this ring main unit utilizes the tilted mounting base of the rotating ring to tilt the smoke detection mechanism mounted on the mounting base, allowing smoke to enter the detection range more smoothly and significantly shortening the smoke capture response time. At the same time, through the cooperation of the filter, sensing end, and rangefinder, the filter rotates due to the difference in the amount of dust attached to both ends. The rangefinder judges the amount of dust accumulation by monitoring the position change of the sensing end. When the value is reached, the main board will trigger an alarm, avoiding the problem of a significant decrease in the accuracy of the smoke sensor due to the rapid attachment of dust to the filter during the interval between maintenance by the staff.

[0016] 4. The high-voltage cable grounding leakage current monitoring device in this ring main unit utilizes the smoke detection mechanism mounted on a fixed ring. The fixed ring takes advantage of the spare space at the wiring terminals of the device body, allowing the smoke detection mechanism to be placed close to all lines. This enables the smoke sensor to react quickly when a line fault generates smoke, avoiding any lag in smoke sensor monitoring, ensuring real-time monitoring, and improving the speed at which staff can respond to faults. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the connection structure of the device body, terminal block, cable body, annular base and rotating ring of the present invention; Figure 2 This is a schematic diagram of the connection structure of the cable body, the ring-shaped base, the rotating ring, and the smoke sensor of the present invention; Figure 3 This is a schematic diagram of the connection structure of the annular substrate, the first locking tooth, the rotating ring, the connecting substrate, and the smoke sensor of the present invention. Figure 4 This is a schematic diagram of the annular base, main housing, motherboard, rotating ring, and connecting structure of the present invention; Figure 5 This is a cross-sectional schematic diagram of the fixing mechanism of the present invention; Figure 6 For the present invention Figure 7 Enlarged structural diagram at point A in the middle; Figure 7 This is a schematic diagram of the overall structure of the smoke detection mechanism of the present invention; Figure 8 This is a cross-sectional schematic diagram of the smoke detection mechanism of the present invention; Figure 9 This is a schematic diagram of the connection structure between the filter and the sensing end of the present invention; Figure 10 This is a second schematic diagram of the internal structure of the ring network cabinet of the present invention; Figure 11 For the present invention Figure 10 Enlarged structural diagram at point B.

[0018] In the diagram: 30. Ring-shaped base; 31. Main unit housing; 32. Main board; 33. Vibration sensor; 34. Temperature sensor; 35. Limiting tooth; 351. Lever; 36. Limiting spring element; 37. Button; 38. Reset spring element; 39. First locking tooth; 40. Rotating ring; 41. Ratchet; 42. Second locking tooth; 50. Connecting base plate; 51. Smoke sensor; 52. Housing; 53. Filter; 54. Sensing end; 55. Rangefinder; 60. Zero-sequence current transformer. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1 refer to Figures 1 to 6 , Figure 10 and Figure 11 The high-voltage cable grounding leakage current monitoring device in a ring main unit according to a preferred embodiment of the present invention will be described in detail below, including: A fixing mechanism, fixed to the outer sidewall of the device to be monitored, includes an annular base 30, a rotating ring body 40 rotatably connected to the annular base 30 to form a fixed ring, and a monitoring sensor. The fixed ring mechanism uses the monitoring sensor to monitor the device to be monitored, thereby using a vibration sensor 33 and a temperature sensor 34 to monitor the vibration and operating temperature status of the device in real time, providing data for fault early warning. An inclined mounting base is provided on the rotating ring body 40. The device to be monitored is a cable, which is inserted into a functional unit. Several functional units are integrated within the ring main unit. Since each functional unit needs to connect several pipelines, including cables, terminals are typically provided to allow space for these pipelines to be inserted. This monitoring device can utilize the space at the terminals by installing it at the end of the cable closest to the functional unit. This eliminates the need to occupy the limited space inside the ring main unit, making it suitable for scenarios with dense electrical equipment within the ring main unit. Furthermore, it can monitor the end most prone to failure, taking advantage of the fact that the connection between the cable and the functional unit is prone to faults due to excessive contact resistance, insulation damage, or concentrated current load.

[0021] The annular base 30 and the rotating ring 40 can be hollow to avoid excessive weight of the annular base 30 and the rotating ring 40, which would result in excessive mass of the interface of the device under monitoring and poor connection with the socket of the functional unit.

[0022] The smoke detection mechanism is detachably connected to the mounting base for easy installation and removal. Maintenance is also possible without it if this function is not needed, reducing weight and cost. It includes an inclined smoke sensor 51, which allows smoke to enter its detection range more smoothly, significantly shortening the response time for smoke capture and thus more efficiently collecting smoke signals and triggering alarms. The housing 52, the filter 53 rotatably connected to the housing 52, and the rangefinder 55 are used to determine the amount of dust adhering to the filter 53 due to differences in the contact area between its two ends and the outside environment. The rangefinder 55 determines the amount of dust adhering to the filter 53 and actively sends information to the staff after the filter 53 rotates to a certain angle, ensuring that the staff can promptly know the pollution status of the filter 53. This prevents the smoke sensor 51 from failing to accurately monitor due to rapid dust accumulation during regular maintenance intervals, thus allowing for earlier maintenance and ensuring stable and accurate operation of the filter 53.

[0023] The fixed mechanism also includes: The main unit housing 31 is located on the side of the annular base 30 away from the rotating ring 40. It works with the annular base 30 to form a closed cavity, providing protection for the motherboard 32. It also prevents dust in the ring network cabinet from contacting the motherboard 32 and causing corrosion and damage to the motherboard 32, thereby ensuring the stable operation of the motherboard 32. At the same time, this closed cavity can also shield external electromagnetic interference.

[0024] The motherboard 32 is fixed in a closed cavity and integrates a signal isolation circuit, an amplification circuit, a data acquisition chip, a microcontroller, a remote alarm module, and a power supply module. Thus, signal processing, data calculation, alarm transmission, and power supply protection can be achieved through the motherboard 32.

[0025] The monitoring sensors include a vibration sensor 33 and a temperature sensor 34, both of which are housed within the rotating ring 40 and connected to the main board 32 via wiring. The outputs of both sensors penetrate the sidewall of the rotating ring 40 and contact the device under monitoring, thereby shortening the distance between them and improving their response speed and data accuracy. Real-time data can also be transmitted to the main board 32 via wiring for monitoring and control.

[0026] The fixed mechanism also includes: The ratchet 41 is fixedly connected to one end of the rotating ring 40 near the annular base 30. It is used to move synchronously with the rotating ring 40. When it is necessary to fix the fixed ring to the outside of the device to be monitored, the rotating ring 40 can be rotated to insert the ratchet 41 into the annular base 30 for fixation.

[0027] The limiting tooth 35 is rotatably connected to the inside of the annular base 30 near the ratchet 41. It is used to limit the ratchet 41 so that the ratchet 41 can only move in one direction. The limiting tooth 35's one-way limiting function allows the rotating ring 40 to move in the direction of the annular base 30 when it is assembled with the annular base 30. This facilitates the quick closing and locking of the entire fixing ring and also prevents the ring from loosening in the opposite direction after it is closed and locked. This ensures that the fixing ring can be fixed to the outside of the device to be monitored for a long time without shifting. It also prevents the vibration sensor 33 and temperature sensor 34 from being unable to be fixed in the designated position due to insecure fixing, which would lead to the problem of distorted monitoring data.

[0028] The lever 351 is located on one side of the limiting tooth 35; A limiting elastic element 36 is disposed inside the annular base 30. One end is fixedly connected to the inner wall of the annular base 30, and the other end is fixedly connected to the side of the limiting tooth 35 away from the ratchet rack 41, used to limit the position of the limiting tooth 35. Specifically, through its own elastic force, it constantly applies pressure to the limiting tooth 35 in the direction of the ratchet rack 41, thereby ensuring that the limiting tooth 35 can always maintain a meshing state with the ratchet on the smoke sensor 51, ensuring that the one-way limiting function of the limiting tooth 35 can be stably realized, and preventing the fixing ring from loosening due to the deviation of the limiting tooth 35.

[0029] Button 37 has one end located outside the annular base 30 and the other end inserted into the annular base 30, located on the side of lever 351 away from ratchet 41.

[0030] A reset spring element 38 is disposed between the button 37 and the annular base 30, with one end fixedly connected to the outer sidewall of the annular base 30 and the other end fixedly connected to the button 37. It provides a reset spring force to the button 37. Specifically, when the button 37 is pressed, it pushes the lever 351, causing the limiting tooth 35 to rotate at a certain angle, thereby releasing the one-way fixing effect of the limiting tooth 35 on the ratchet rack 41, allowing the fixing ring to open. The reset spring element 38 then generates an elastic restoring force through its own deformation, returning the reset spring element 38 to its initial position. This ensures that the button 37 can be pressed repeatedly and prevents the button 37 from failing to reset after being pressed, which would cause the limiting tooth 35 to remain in the unlocked state, thus preventing the fixing ring from being secured.

[0031] The fixed mechanism also includes: Several first locking teeth 39 are all set on the side of the annular base 30 near the rotating ring 40 to improve the fixing effect of the fixing ring.

[0032] Several second locking teeth 42 are all located on the side of the rotating ring body 40 near the annular base 30, and are used to cooperate with several first locking teeth 39 to further improve the fixing effect of the fixing ring.

[0033] Several first locking teeth 39 and several second locking teeth 42 work together to increase the contact area and friction when the fixing ring is fixed on the outside of the device to be monitored, thereby effectively preventing the fixing ring from sliding relative to the outside after installation and further improving the fixing effect of the fixing ring.

[0034] The zero-sequence current transformer 60 is located inside the ring main unit and installed at the outgoing end of the equipment to be monitored. The equipment to be monitored passes through the zero-sequence current transformer 60. The zero-sequence current transformer 60 is used to collect the grounding leakage current signal of the equipment to be monitored. Specifically, it adopts an open-type zero-sequence current transformer 60. Its open-type design makes it easy to assemble without cutting the cable. By passing the equipment to be monitored through the zero-sequence current transformer 60, the accuracy of current signal acquisition is ensured. The acquired signal can provide data reference for subsequent judgment of whether there is a grounding leakage fault in the cable.

[0035] Alternatively, vibration sensor 33 and temperature sensor 34 can be fixed to the side wall of the ring main unit to monitor the overall temperature and vibration at the wiring terminals of the entire ring main unit in real time. Smoke sensor 51 is fixed to the top of the ring main unit to monitor the smoke inside the entire ring main unit. Temperature sensor 34, limit tooth 35, smoke sensor 51 and zero-sequence current transformer 60 are all connected to the main board 32 through lines to realize data transmission and coordinated alarm.

[0036] The following is the complete working process and working principle of the above embodiments: First, open the fixing ring so that the device to be monitored is in the middle of the fixing ring. Rotate the rotating ring body 40 to insert the ratchet 41 into the annular base 30. The limiting teeth 35 engage with the ratchet 41 under the elastic force of the limiting elastic member 36 to achieve unidirectional limiting. The first locking teeth 39 and the second locking teeth 42 increase the friction force, and the fixing ring is firmly fixed on the outside of the end where the device to be monitored is connected to the functional unit. Pressing the button 37 can push the lever 351 to release the limiting for disassembly. The closed cavity formed by the main housing 31 and the annular base 30 protects the internal main board 32. The vibration sensor 33 and temperature sensor 34 inside the rotating ring body 40 penetrate the side wall and contact the device to be monitored, collecting vibration and temperature data in real time and transmitting them to the main board 32. At the same time, the zero-sequence current transformer 60 synchronously collects the ground leakage current signal and feeds it back to the main board 32. This device utilizes the space of the functional unit's wiring terminals and does not require additional space inside the ring main unit.

[0037] Example 2 refer to Figures 7 to 9 Smoke detection agencies also include: The connecting base plate 50 is fixed to the mounting base, typically by bolts and nuts. The side of the connecting base plate 50 away from the rotating ring 40 is fixedly connected to the smoke sensor 51. Because the connecting base plate 50 is mounted on the mounting base at an angle, the connecting base plate 50 and the smoke sensor 51 connected to it can be tilted, thereby guiding the smoke more smoothly into the detection range of the smoke sensor 51.

[0038] The housing 52 extends from the side of the smoke sensor 51 away from the connecting substrate 50 to form a smoke inlet channel, providing a directional movement path for the smoke, thereby accurately guiding the smoke flow to the detection end of the smoke sensor 51 and improving the smoke capture efficiency. The end of the housing 52 away from the smoke sensor 51 is flush, so that it can form a vertical shielding of the horizontally set filter 53. When dust enters the housing 52, it is blocked by the housing 52, which causes most of the dust entering the housing 52 to contact the end of the filter 53 near the rangefinder 55. This causes the two ends of the filter 53 to rotate due to the uneven weight distribution. The rangefinder 55 captures the rotation angle, thereby indirectly determining the amount of dust attached to the filter 53, and selecting whether to trigger a remote alarm based on the amount of dust.

[0039] The rangefinder 55 is fixed to the side wall of the connecting base plate 50 away from the rotating ring 40, with the detection end facing downwards, so as to detect the rotation angle of the filter 53 through the sensing end 54. The rangefinder 55 can be set to trigger a remote alarm only when the rotation angle of the filter 53 remains stable at a preset angle for a set time, thereby avoiding the situation where the filter 53 is passively rotated too much due to external collisions or other factors, thus avoiding the occurrence of false alarms.

[0040] The filter 53 is elliptical and initially set horizontally, providing a reference position for the filter 53 and ensuring that the rangefinder 55 can accurately monitor changes in the rotation angle of the filter 53. While adapting to the inclined channel of the smoke sensor 51, the size of the filter 53 is further increased to prevent the gap between the filter 53 and the inner wall of the smoke sensor 51 from increasing further during rotation, which would reduce the filtration efficiency of the filter 53. At the same time, due to the larger area of ​​the filter 53, more dust can adhere to it.

[0041] Smoke detection agencies also include: The sensing end 54 is fixedly connected to the end of the filter 53 near the rangefinder 55 and is located at the bottom of the detection end of the rangefinder 55. The sensing end 54 can rotate synchronously with the filter 53, thereby cooperating with the rangefinder 55 to accurately determine the distance between the sensing end 54 and itself, and thus determine the rotation angle of the filter 53.

[0042] The following is the complete working process and working principle of the above embodiments: The smoke detection mechanism is detachably mounted on the inclined mounting base of the rotating ring 40 via the connecting base plate 50, ensuring the entire smoke detection mechanism is in an inclined state. The smoke sensor 51, together with the housing 52, forms a smoke inlet channel, facilitating the rapid entry of smoke into the detection range. The filter 53 rotates due to the different amounts of dust adhering to its two ends. The rangefinder 55 monitors the positional change of the sensing end 54, which rotates synchronously with the filter 53, to determine the amount of dust accumulation. When the rotation angle reaches a threshold, the main board 32 sends a message to the staff via the remote alarm module. This prevents the smoke sensor 51 from becoming less accurate or even malfunctioning due to dust accumulation during regular maintenance intervals, which could lead to delayed response in emergencies and untimely rescue.

[0043] Although embodiments of the 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 invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-voltage cable grounding leakage current monitoring device in a ring main unit, characterized in that, include: The fixing mechanism is fixed to the outer sidewall of the device to be monitored, including an annular base (30), a rotating ring body (40) rotatably connected to the annular base (30) to form a fixing ring, and a monitoring sensor. The fixing ring mechanism uses the monitoring sensor to monitor the device to be monitored and provides an inclined mounting base opened on the rotating ring body (40). The smoke detection mechanism is detachably connected to the mounting base and includes an inclined smoke sensor (51), a housing (52), a filter (53) rotatably connected to the housing (52), and a rangefinder (55). The rangefinder (55) is used to determine the rotation angle when the filter (53) has different contact areas with the outside world and thus different amounts of dust, to determine the amount of dust attached to the filter (53), and to actively send information to the staff after the filter (53) has rotated to a certain angle.

2. The high-voltage cable grounding leakage current monitoring device in a ring main unit according to claim 1, characterized in that: The fixing mechanism also includes: The main housing (31) is located on the side of the annular base (30) away from the rotating ring (40), and cooperates with the annular base (30) to form a closed cavity; The motherboard (32) is fixed in the enclosed cavity and integrates a signal isolation circuit, an amplification circuit, a data acquisition chip, a microcontroller, a remote alarm module and a power supply module; The monitoring sensors include a vibration sensor (33) and a temperature sensor (34). Both the vibration sensor (33) and the temperature sensor (34) are located inside the rotating ring (40) and connected to the main board (32) via a circuit. The output ends of the vibration sensor (33) and the temperature sensor (34) penetrate the side wall of the rotating ring (40) and come into contact with the device to be monitored.

3. The high-voltage cable grounding leakage current monitoring device in a ring main unit according to claim 1, characterized in that: The fixing mechanism also includes: A ratchet rack (41) is fixedly connected to one end of the rotating ring (40) near the annular base (30); The limiting tooth (35) is rotatably connected to the inside of the end of the annular base (30) near the ratchet (41) to restrict the ratchet (41) so that the ratchet (41) can only move in one direction; A lever (351) is provided on one side of the limiting tooth (35); A limiting elastic element (36) is disposed inside the annular base (30), with one end fixedly connected to the inner wall of the annular base (30) and the other end fixedly connected to the side of the limiting tooth (35) away from the ratchet (41), for limiting the position of the limiting tooth (35); Button (37), one end of which is located outside the annular base (30), and the other end is inserted into the annular base (30) and located on the side of the lever (351) away from the ratchet (41); A reset spring element (38) is disposed between the button (37) and the annular base (30), with one end fixedly connected to the outer sidewall of the annular base (30) and the other end fixedly connected to the button (37), for providing reset spring force to the button (37).

4. The high-voltage cable grounding leakage current monitoring device in a ring main unit according to claim 1, characterized in that: The fixing mechanism also includes: Several first locking teeth (39) are all disposed on the side of the annular base (30) near the rotating ring (40) to improve the fixing effect of the fixing ring; Several second locking teeth (42) are disposed on the side of the rotating ring body (40) near the annular base (30) to cooperate with several first locking teeth (39) to further improve the fixing effect of the fixing ring.

5. The high-voltage cable grounding leakage current monitoring device in a ring main unit according to claim 1, characterized in that: The smoke detection device also includes: A connecting base plate (50) is fixed on the mounting base, and the side of the connecting base plate (50) away from the rotating ring (40) is fixedly connected to the smoke sensor (51). The housing (52) extends from the side of the smoke sensor (51) away from the connecting substrate (50) to form a smoke inlet channel, and the end of the housing (52) away from the smoke sensor (51) is flush. The rangefinder (55) is fixed to the side wall of the connecting base plate (50) away from the rotating ring (40), with the detection end facing downward.

6. The high-voltage cable grounding leakage current monitoring device in a ring main unit according to claim 1, characterized in that: The filter (53) is elliptical and is initially set horizontally.

7. The high-voltage cable grounding leakage current monitoring device in a ring main unit according to claim 1, characterized in that: smoke Testing institutions also include: The sensing end (54) is fixedly connected to one end of the filter (53) near the rangefinder (55) and is located at the bottom of the detection end of the rangefinder (55).

8. The high-voltage cable grounding leakage current monitoring device in a ring main unit according to claim 1, characterized in that: Also includes: A zero-sequence current transformer (60) is installed on the outside of the device to be monitored. The device to be monitored passes through the zero-sequence current transformer (60). The zero-sequence current transformer (60) is used to collect the ground leakage current signal of the device to be monitored.

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