Temporary grounding system and method for auxiliary transformer of giant hydropower station
By designing a temporary grounding system for transformers, and utilizing mechanized operations to achieve automatic connection and locking of grounding wires, the problems of difficult handling and safety hazards of grounding wires during the maintenance of transformers in giant hydropower stations have been solved. This has enabled standardized and safe grounding operations, reduced labor intensity, and provided remote monitoring capabilities.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA YANGTZE POWER
- Filing Date
- 2026-04-30
- Publication Date
- 2026-07-24
AI Technical Summary
During the overhaul of existing giant hydropower station transformers, the grounding wires are difficult to transport, inconvenient to install, pose significant safety hazards, and their status cannot be monitored, which also carries the risk of improper operation.
A temporary grounding system for a giant hydropower station transformer was designed, including a grounding device base, a transmission gear set, a rotary locking device, and a grounding conductor. The system achieves automatic connection and locking of the grounding conductor through mechanized operation and is equipped with a status switch for real-time monitoring.
It achieves standardized and safe grounding operations, reduces labor intensity, improves operational safety, has remote monitoring capabilities to prevent misoperation, is applicable to multiple transformers, and reduces configuration costs.
Smart Images
Figure CN122456201A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of transformer technology, specifically to a temporary grounding system and method for a giant hydropower station's auxiliary transformer. Background Technology To meet the power generation and plant maintenance needs of the large hydropower station, hundreds of dry-type transformers are installed within the station. According to relevant regulations and operational requirements, these transformers must be inspected or repaired annually. During transformer inspections or repairs, to ensure worker safety and prevent risks such as sudden power surges, grounding wires need to be installed on each phase of the transformer. The current method is as follows: when grounding wires are required for transformer maintenance, they are manually moved to the side of the transformer. After the grounding end of the wire is fixed to the grounding point, the threaded grounding clamps are tightened by hand onto the conductors of each phase of the transformer. After the work is completed, the grounding wires are removed, rolled up, and stored in a dedicated grounding cabinet.
[0002] The current method has the following problems: 1. Difficult to transport: The current grounding wires are long and made of copper, making them heavy and requiring considerable effort to move manually. 2. The current grounding clamp has a long operating handle, which is inconvenient for workers in confined spaces after installing grounding wires on smaller dry-type transformers; it also increases the risk of accidental contact causing the grounding wire to detach. 3. The current grounding wire installation on electrical equipment is all done manually; in extreme cases (such as when equipment is energized and voltage is not checked), there are safety hazards. 4. The status of temporary grounding wires cannot be monitored after installation, and the standardization of the operation process cannot be guaranteed, posing safety hazards. Summary of the Invention
[0003] The technical problem to be solved by the present invention is to provide a temporary grounding system and method for the power plant transformer of a giant hydropower station, which can make the operation procedure of temporary grounding during transformer maintenance more standardized and safer, and improve the safety management level of giant hydropower stations.
[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: The temporary grounding system for the power plant transformers of a giant hydropower station includes multiple transformers and a grounding device base on one side of the transformer. The transformer is equipped with a transformer-side grounding contact for grounding operation. The bottom of the grounding device base is slidably connected to a grounding sliding base. The grounding sliding base is equipped with a grounding structure. The grounding device base contains a grounding device, a transmission gear set, and a rotary locking device. The grounding device contains a grounding wire, which extends from the rear end of the grounding device and is electrically connected to the rotary locking device. The grounding device can switch between a horizontal and a vertical state. When the grounding device is in a horizontal state, it can be locked and electrically connected to the grounding contact on the transformer side to make the grounding contact on the transformer side conduct with the grounding conductor. When the grounding device is in a vertical state, it can be stored in the grounding device base. The grounding device is connected to the rotary locking device at the bottom via a transmission gear set. When the grounding device switches between horizontal and vertical states, the rotary locking device can be driven to lock or release the grounding sliding base. When the drive rotation locking device locks with the grounding sliding base, the grounding wire can be connected to the grounding structure on the grounding sliding base, thus grounding the transformer. When the drive rotation locking device and the grounding sliding base are released, the grounding device seat can slide on the grounding sliding base along the arrangement direction of the transformer.
[0005] The aforementioned rotary locking device and the grounded sliding base lock or release mechanism are structured as follows: It includes a rotating surface gear that meshes with a transmission gear set. The rotating surface gear is provided with a telescopic groove that extends outward in an arc shape along the center of the rotating surface gear. A grounding locking contact is provided on the axial direction of the rotating surface gear and is electrically connected to a grounding wire. A sliding lever is provided on the grounding locking contact and extends into the telescopic groove. Guide plates are provided on both sides of the grounding locking contact for telescopic guidance. When the transmission gear set drives the rotating surface gear to rotate, the sliding lever moves in the telescopic groove and drives the grounding locking contact to slide along the guide plates.
[0006] The grounding structure on the aforementioned grounding sliding base is as follows: the part of the grounding sliding base that is locked to the grounding locking contact is connected to the earth.
[0007] The structure in which the grounding sliding base and the grounding locking contact are connected to the ground is as follows: The grounding sliding base is provided with a locking cavity corresponding to each transformer along the arrangement direction of the multiple transformers. The inner surface of the locking cavity is provided with a grounding locking conductor of matching shape, and the grounding locking conductor is electrically connected to the grounding connection line.
[0008] Each of the above-mentioned transformers has a locking cavity set on both sides of the grounding device base to form a pair. There are two telescopic slides evenly distributed on the rotating surface gear. The two grounding locking contacts are arranged symmetrically along the radial direction of the rotating surface gear. The shape of the end of the grounding locking contact matches the inner cavity of the grounding locking conductor.
[0009] The aforementioned grounding locking conductor has a grounding side status switch on one side. The end of the grounding side status switch has a detection contact that extends into the inner cavity of the grounding locking conductor. When the grounding locking contact is locked with the inner cavity of the grounding locking conductor, the detection contact is pushed to change the grounding signal of the grounding side status switch. The grounding side status switch has a power supply, a status indicator light, and a communication module. The communication module can send the status of the grounding side status switch.
[0010] In the preferred embodiment, the transmission ratio between the aforementioned transmission gear set and the rotating surface gear is: such that when the grounding device switches between horizontal and vertical states, i.e., rotates 90 degrees, the rotating surface gear also rotates 90 degrees.
[0011] In a preferred embodiment, the aforementioned transmission gear set includes a first gear fixedly connected to the grounding device, and the grounding device base is provided with a lever locking device for locking the first gear.
[0012] The aforementioned grounding device includes a grounding base body, inside which is a controllable telescopic piston rod. The extended end of the piston rod is provided with a telescopic end, and the telescopic end is provided with a sliding grounding guide seat. The rear end of the grounding guide seat is fixedly connected to the grounding wire, the grounding wire passes through the piston rod, and the rear end of the grounding guide seat is also provided with a buffer spring that abuts against the telescopic end. The front end of the grounding guide seat matches the shape of the grounding contact on the transformer side.
[0013] The aforementioned controllable extension and retraction structure of the piston rod is as follows: The grounding base has a piston chamber inside, and the rear end of the piston rod is located in the piston chamber. The rear end of the piston chamber has a locking groove. The grounding base is equipped with a piston locking device. The end of the piston locking device extends into the piston chamber. The piston chamber is equipped with a telescopic spring that is fixed to the rear end of the piston rod. When the piston rod is at the rear end limit position, the end of the piston locking device is embedded in the locking groove to lock it.
[0014] The aforementioned grounding base is equipped with a damping air pipe to connect the front of the piston chamber with the external atmosphere, so that the gas in the piston chamber becomes a slow-release damping when the piston rod extends.
[0015] The aforementioned telescopic end is equipped with a locking pin that can slide up and down, and the transformer-side grounding contact is equipped with a transformer grounding lock hole. When the piston rod extends to connect the transformer-side grounding contact with the grounding guide seat, the grounding guide seat compresses the buffer spring to its limit, the transformer grounding lock hole aligns with the locking pin, and the locking pin falls into the transformer grounding lock hole to lock the transformer-side grounding contact.
[0016] The aforementioned telescopic end is equipped with a transformer-side status switch. When the locking pin locks the transformer-side grounding contact, the locking pin passes through the transformer grounding lock hole and triggers the transformer-side status switch. The transformer-side status switch is equipped with a power supply, a status indicator light, and a communication module. The communication module can send the status of the transformer-side status switch.
[0017] The aforementioned grounding device base is equipped with a conductor roller for guiding and constraining the grounding conductor when the grounding device is switched between horizontal and vertical states.
[0018] The aforementioned grounding sliding base is equipped with a sliding guide rail, and the slider of the sliding guide rail is fixedly connected to the bottom of the grounding device base.
[0019] The grounding side status switches at the aforementioned multiple transformers correspond to different address numbers on the communication module. The communication module sends the status of different address numbers to the remote host computer. The host computer simultaneously receives the status signals of the transformer-side status switches. By comparing the address number status of the grounding side status switches on the host computer with the status signals of the transformer-side status switches, it can be determined which transformer has a ground wire installed.
[0020] The grounding method for the temporary grounding system of the giant hydropower station's auxiliary transformer, as described above, includes grounding installation and removal steps, and strictly follows the operational sequence of installing the grounding terminal first and then the transformer-side conductor terminal, and removing the transformer-side conductor terminal first and then the grounding terminal: I. Grounding Installation Steps 1) Moving and positioning: Move the grounding device base along the sliding guide rail of the grounding sliding base to the corresponding grounding position of the transformer to be repaired; 2) Installing the grounding terminal: Flip the grounding device from the vertical storage state to the horizontal unfolded state by 90°. Drive the rotating surface gear of the rotary locking device to rotate through the transmission gear set, so that the grounding locking contact extends and is embedded in the locking cavity of the grounding sliding base, making reliable contact with the grounding locking conductor to complete the installation of the grounding terminal. At the same time, the grounding side status switch is triggered to send a grounding terminal in place signal. 3) Mechanical locking: By operating the locking device, the transmission gear set is locked to the grounding device, so that the grounding device is fixed in the current position and cannot be slid. 4) Installing the transformer-side conductor end: After confirming that the transformer under maintenance is de-energized, release the piston locking device from locking the piston rod. The piston rod slowly extends under the slow release action of the telescopic spring and the damping air tube, so that the grounding guide seat of the telescopic end is in contact with the grounding contact on the transformer side. 5) Contact locking: When the grounding guide seat compresses the buffer spring to the limit position, the locking pin automatically falls into the transformer grounding lock hole to complete the mechanical locking, and at the same time triggers the transformer side status switch to send a conductor end grounding success signal; 6) Status Confirmation: Both the grounding side status switch and the transformer side status switch signals are uploaded to the host computer to confirm that the grounding is complete; II. Grounding Removal Procedures 1) Remove the transformer-side conductor end: Pull out the locking pin to release the locking of the transformer-side grounding contact, push the piston rod back into the piston chamber and lock it through the piston locking device to separate the grounding guide seat from the transformer-side grounding contact and reset the transformer-side status switch; Remove the grounding terminal: Release the locking device from the transmission gear set, rotate the grounding device from the horizontal unfolded state to the vertical storage state by 90°, drive the rotating surface gear to rotate through the transmission gear set, so that the grounding locking contact retracts and separates from the grounding locking conductor, thus completing the removal of the grounding terminal and resetting the grounding side status switch; 3) Reset: The grounding device base returns to a sliding state and moves away or to the next transformer to be repaired along the sliding guide rail.
[0021] The above-mentioned grounding method involves short-circuiting the three grounding lock conductors corresponding to the three phases through copper busbars or grounding flat irons to achieve three-phase short-circuit grounding when grounding a three-phase transformer.
[0022] The temporary grounding system and method for a giant hydropower station power plant transformer mentioned in this invention have the following beneficial effects: 1. The device is lightweight and portable, and can be operated by a single person, greatly reducing labor intensity; 2. Automatic docking and locking are achieved, eliminating the need for manual contact with live parts and significantly improving operational safety; 3. It has mechanical interlocking and enforces the standard procedure of grounding the terminal before the conductor terminal and conductor terminal before the grounding terminal; 4. Dual-state switch for real-time monitoring, allowing remote monitoring of grounding status to prevent misoperation and incorrect bay selection; 5. A single system can serve multiple transformers, making it highly versatile and reducing the cost of grounding wire configuration. Attached Figure Description
[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 The structure of the transformer temporary grounding system of the present invention Figure 1 The grounding device is in a horizontally deployed state; Figure 2 The structure of the transformer temporary grounding system of the present invention Figure 2 The grounding device is in a vertically stored state; Figure 3 This is a schematic diagram of the grounding device of the present invention in a retracted, ungrounded state; Figure 4 This is a schematic diagram of the grounding device of the present invention in the extended grounding state; Figure 5 This is a schematic diagram of the rotating locking device of the present invention; Figure 6 This is a partial structural schematic diagram of the rotary locking device of the present invention; Figure 7 This is a schematic diagram of a preferred embodiment of the present invention; Figure 8This is a schematic diagram of the arrangement of the temporary grounding system for the transformer of the present invention.
[0024] The components include: 1. Transformer; 2. Grounding device base; 3. Grounding device; 31. Grounding base; 32. Piston chamber; 33. Piston rod; 34. Grounding telescopic end; 35. Grounding guide seat; 36. Follow-up grounding wire; 37. Damping air pipe; 38. Piston locking device; 39. Locking groove; 4. Transmission gear set; 5. Rotary locking device; 51. Rotary surface gear; 52. Telescopic slide; 53. Grounding locking contact; 54. Guide plate; 6. Grounding sliding base; 7. Sliding guide rail; 8. Grounding locking conductor; 9. Grounding connection wire; 10. Actuating locking device; 11. Grounding side status switch; 12. Transformer side grounding contact; 13. Transformer grounding lock hole; 14. Telescopic spring; 15. Transformer side status switch; 16. Locking pin; 17. Sliding lever; 18. Wire roller; 19. Locking cavity; 20. Detection contact; 21. Buffer spring. Detailed Implementation
[0025] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0026] The temporary grounding system for the power plant transformers of a giant hydropower station includes multiple transformers 1 and a grounding device base 2 on one side of the transformer 1. The transformer 1 is equipped with a transformer-side grounding contact 12 for grounding operation. The bottom of the grounding device base 2 is slidably connected to the grounding sliding base 6. The grounding sliding base 6 is equipped with a grounding structure. The grounding device base 2 is equipped with a grounding device 3, a transmission gear set 4 and a rotary locking device 5. The grounding device 3 is equipped with a grounding wire 36. The grounding wire 36 extends from the rear end of the grounding device 3 and is electrically connected to the rotary locking device 5. The grounding device 3 can switch between a horizontal state and a vertical state. When the grounding device 3 is in a horizontal state, it can be locked and electrically connected to the transformer-side grounding contact 12 to make the transformer-side grounding contact 12 conduct with the grounding conductor 36. When the grounding device 3 is in a vertical state, it can be stored in the grounding device base 2. The grounding device 3 is connected to the bottom rotating locking device 5 through the transmission gear set 4. When the grounding device 3 is switched between horizontal and vertical states, the rotating locking device 5 can be driven to lock or release the grounding sliding base 6. When the drive rotation locking device 5 is locked with the grounding sliding base 6, the grounding wire 36 can be connected to the grounding structure on the grounding sliding base 6, thereby grounding the transformer 1. When the drive rotation locking device 5 and the grounding sliding base 6 are released, the grounding device base 2 can slide on the grounding sliding base 6 along the arrangement direction of the transformer 1.
[0027] The system consists of a transformer 1, a grounding device base 2, a grounding sliding base 6, a grounding device 3, a transmission gear set 4, and a rotary locking device 5. The grounding device 3 can be flipped to switch between horizontal and vertical states. The flipping action is linked to the rotary locking device 5 via the transmission gear set 4, realizing the locking / unlocking of the grounding end and the sliding / fixing of the base. This achieves integrated storage and deployment of the grounding device, with linkage control between the grounding end and the conductor end, meeting the requirements for mobility, shared use, and storage.
[0028] The structure for locking or releasing the aforementioned rotary locking device 5 and the grounded sliding base 6 is as follows: The system includes a rotating surface gear 51 that meshes with the transmission gear set 4. The rotating surface gear 51 has a telescopic groove 52 that arcs outward from the center of the rotating surface gear 51. A grounding locking contact 53 is axially mounted on the rotating surface gear 51 and electrically connected to the grounding wire 36. A sliding lever 17 on the grounding locking contact 53 extends into the telescopic groove 52. Guide plates 54 on both sides of the grounding locking contact 53 guide its extension and retraction. When the transmission gear set 4 drives the rotating surface gear 51 to rotate, the sliding lever 17 moves within the telescopic groove 52, driving the grounding locking contact 53 to slide along the guide plates 54. This converts the flipping motion into a linear telescopic motion, resulting in a compact structure, reliable transmission, and automatic grounding connection.
[0029] The grounding structure on the aforementioned grounding sliding base 6 is as follows: the part of the grounding sliding base 6 that contacts and locks with the grounding locking contact 53 is connected to the earth. This ensures reliable grounding upon insertion of the grounding terminal, with a short conduction path and low impedance, meeting the requirements for safe grounding.
[0030] The structure in which the grounding sliding base 6 and the grounding locking contact 53 are in contact and locked together is connected to the ground as follows: The grounding sliding base 6 is provided with a locking cavity 19 corresponding to each transformer 1 along the arrangement direction of the multiple transformers 1. The inner surface of the locking cavity 19 is provided with a grounding locking conductor 8 of matching shape, which is electrically connected to the grounding connection line 9. The locking cavity 19 and the grounding locking conductor 8 have trapezoidal cross sections, which realizes the position locking of the grounding device base 2 and the grounding sliding base 6 while connecting the grounding conductor 36 to the earth. The locked position puts the grounding device 3 in the preparatory position for connecting the grounding contact 12 on the transformer side, realizing fixed-point grounding. Grounding can only be completed when the designated transformer position is reached, preventing accidental grounding.
[0031] Each transformer 1 has a locking cavity 19, one on each side of the grounding device base 2, forming a pair. Two telescopic grooves 52 are evenly distributed on the rotating gear 51. Two grounding locking contacts 53 are symmetrically arranged radially along the rotating gear 51, and the end shape of the grounding locking contacts 53 matches the inner cavity of the grounding locking conductor 8. This double-contact redundant grounding ensures reliable conduction even with poor contact on one side, improving grounding safety. Furthermore, the locking on both sides makes the grounding device base 2 more securely fixed.
[0032] A grounding-side status switch 11 is provided on one side of the aforementioned grounding locking conductor 8. A detection contact 20 is provided at the end of the grounding-side status switch 11, extending into the inner cavity of the grounding locking conductor 8. When the grounding locking contact 53 locks with the inner cavity of the grounding locking conductor 8, it pushes the detection contact 20 to actuate, causing the grounding signal of the grounding-side status switch 11 to change its state. The grounding-side status switch 11 is equipped with a power supply, a status indicator light, and a communication module. The communication module can transmit the status of the grounding-side status switch 11. This enables remote monitoring and indication of the grounding terminal status, allowing for real-time determination of whether the grounding terminal is in place.
[0033] In the preferred embodiment, the transmission ratio between the aforementioned transmission gear set 4 and the rotating surface gear 51 is 1:1, ensuring that when the grounding device 3 switches between horizontal and vertical states (i.e., rotates 90 degrees), the rotating surface gear 51 also rotates 90 degrees. The flipping angle and extension / retraction action precisely correspond, the mechanical logic is clear, and jamming and malfunctions are avoided.
[0034] In a preferred embodiment, the aforementioned transmission gear set 4 includes a first gear fixedly connected to the grounding device 3, and the grounding device base 2 is provided with a lever locking device 10 for locking the first gear. When unfolded, it can be mechanically locked to prevent the grounding device 3 from falling back, ensuring a stable and safe operation.
[0035] The aforementioned grounding device 3 includes a grounding base 31, inside which is a controllable telescopic piston rod 33. The extended end of the piston rod 33 has a telescopic end 34, and the telescopic end 34 contains a sliding grounding guide seat 35. The rear end of the grounding guide seat 35 is fixedly connected to a grounding wire 36, which passes through the piston rod 33. A buffer spring 21 is also provided at the rear end of the grounding guide seat 35, abutting against the telescopic end 34. The front end of the grounding guide seat 35 matches the shape of the transformer-side grounding contact 12. This allows for flexible conductor connection, buffering and compensating for installation errors, and ensuring stable contact pressure.
[0036] The controllable telescopic structure of the piston rod 33 described above is as follows: The grounding base 31 has a piston chamber 32 inside, and the rear end of the piston rod 33 is located in the piston chamber 32. The rear end of the piston chamber 32 has a locking groove 39. The grounding base 31 is equipped with a piston locking device 38, the end of which extends into the piston chamber 32. The piston chamber 32 is equipped with a telescopic spring 14 fixed to the rear end of the piston rod 33. When the piston rod 33 is at its rear end limit position, the end of the piston locking device 38 engages with the locking groove 39 to lock it. The piston rod can store energy and is ready to extend automatically upon unlocking, without the need for continuous manual force.
[0037] The aforementioned grounding base 31 is equipped with a damping air pipe 37 to connect the front of the piston chamber 32 with the external atmosphere, so that the gas in the piston chamber 32 becomes a slow-release damping when the piston rod 33 extends. The piston rod extends slowly and uniformly, avoiding impact damage to the contacts and improving docking stability and safety.
[0038] The aforementioned telescopic end 34 is equipped with a sliding locking pin 16, and the transformer-side grounding contact 12 is equipped with a transformer grounding locking hole 13. When the piston rod 33 extends to connect the transformer-side grounding contact 12 with the grounding guide seat 35, the grounding guide seat 35 compresses the buffer spring 21 to its limit, aligning the transformer grounding locking hole 13 with the locking pin 16. The locking pin 16 then falls into the transformer grounding locking hole 13 to lock the transformer-side grounding contact 12. This achieves mechanical anti-disengagement locking of the conductor end, preventing grounding failure due to vibration or collision.
[0039] The aforementioned telescopic end 34 is equipped with a transformer-side status switch 15. When the locking pin 16 locks the transformer-side grounding contact 12, the locking pin 16 passes through the transformer grounding lock hole 13 and triggers the transformer-side status switch 15. The transformer-side status switch 15 is equipped with a power supply, a status indicator light, and a communication module. The communication module can send the status of the transformer-side status switch 15. Real-time monitoring of whether the conductor end is reliably connected forms a double confirmation logic of grounding end + conductor end.
[0040] The aforementioned grounding device base 2 is equipped with a wire roller 18 for guiding and constraining the grounding wire 36 when the grounding device 3 switches between horizontal and vertical states. This prevents the wire from tangling, pulling, or wearing, and ensures smooth flipping and extension movements.
[0041] The aforementioned grounding sliding base 6 is equipped with a sliding guide rail 7, and the slider of the sliding guide rail 7 is fixedly connected to the bottom of the grounding device base 2. The base moves smoothly and is guided accurately, allowing for rapid repositioning along the transformer column.
[0042] The grounding-side status switches 11 at the aforementioned multiple transformers correspond to different address numbers on the communication module. The communication module sends the status of these different address numbers to a remote host computer. Simultaneously, the host computer receives the status signals from the transformer-side status switches 15. By comparing the address numbers of the grounding-side status switches 11 and the status signals of the transformer-side status switches 15 on the host computer, it can determine which transformer has a ground wire installed. This allows for precise identification of which transformer is grounded, effectively preventing incorrect wiring.
[0043] The grounding method for the temporary grounding system of the giant hydropower station's auxiliary transformer, as described above, includes grounding installation and removal steps, and strictly follows the operational sequence of installing the grounding terminal first and then the transformer-side conductor terminal, and removing the transformer-side conductor terminal first and then the grounding terminal: I. Grounding Installation Steps 1. Move and position: Move the grounding device base 2 along the sliding guide rail 7 of the grounding sliding base 6 to the corresponding grounding position of the transformer 1 to be inspected; 2. Install the grounding terminal: Flip the grounding device 3 from the vertical storage state to the horizontal unfolded state by 90°. Drive the rotating surface gear 51 of the rotating locking device 5 through the transmission gear set 4 to rotate, so that the grounding locking contact 53 extends out and is embedded in the locking cavity 19 of the grounding sliding base 6, and makes reliable contact with the grounding locking conductor 8 to complete the grounding terminal installation. At the same time, the grounding side status switch 11 is triggered to send a grounding terminal in place signal. 3 Mechanical locking: By moving the locking device 10, the transmission gear set 4 and the grounding device 3 are locked together, so that the grounding device 3 is fixed in the current position and cannot slide. 4. Install the transformer-side conductor end: After verifying that the transformer 1 under maintenance is de-energized, release the piston locking device 38 from locking the piston rod 33. The piston rod 33 slowly extends under the slow release action of the telescopic spring 14 and the damping air tube 37, so that the grounding guide seat 35 of the telescopic end 34 is in contact with the transformer-side grounding contact 12. 5. Contact locking: When the grounding guide seat 35 compresses the buffer spring 21 to the limit position, the locking pin 16 automatically falls into the transformer grounding lock hole 13 to complete the mechanical locking, and at the same time triggers the transformer side status switch 15 to send a conductor end grounding success signal. 6. Status Confirmation: Signals from both the grounding side status switch 11 and the transformer side status switch 15 are uploaded to the host computer to confirm that the grounding is complete; II. Grounding Removal Procedures 1. Remove the transformer-side conductor end: Pull out the locking pin 16 to release the locking of the transformer-side grounding contact 12, push the piston rod 33 back into the piston chamber 32 and lock it through the piston locking device 38, so that the grounding guide seat 35 is separated from the transformer-side grounding contact 12, and the transformer-side status switch 15 is reset. 2. Remove the grounding terminal: Release the locking device 10 from locking the transmission gear set 4, rotate the grounding device 3 from the horizontal unfolded state to the vertical storage state by 90°, drive the rotating surface gear 51 to rotate through the transmission gear set 4, so that the grounding locking contact 53 retracts and separates from the grounding locking conductor 8, thus completing the removal of the grounding terminal and resetting the grounding side status switch 11. 3. Reset: The grounding device base 2 returns to a sliding state and moves away or to the position of the next transformer 1 to be repaired along the sliding guide rail 7.
[0044] The above-described grounding method, when grounding the three-phase transformer 1, involves short-circuiting the three corresponding grounding locking conductors 8 through copper busbars or grounding flat irons to achieve three-phase short-circuit grounding. This three-phase short-circuit grounding meets electrical maintenance safety standards and prevents hazards from induced current and residual charge.
Claims
1. A temporary grounding system for a power plant transformer in a giant hydropower station, characterized in that, Includes multiple transformers (1) and a grounding device base (2) on one side of the transformer (1). The transformer (1) is provided with a transformer-side grounding contact (12) for grounding operation. The bottom of the grounding device base (2) is slidably connected to the grounding sliding base (6). The grounding sliding base (6) is provided with a grounding structure. The grounding device base (2) is provided with a grounding device (3), a transmission gear set (4), and a rotary locking device (5). The grounding device (3) is provided with a grounding wire (36). The grounding wire (36) extends from the rear end of the grounding device (3) and is electrically connected to the rotary locking device (5). The grounding device (3) can be switched between a horizontal state and a vertical state. When the grounding device (3) is in a horizontal state, it can be locked and electrically connected to the transformer-side grounding contact (12) so that the transformer-side grounding contact (12) is connected to the grounding conductor (36). When the grounding device (3) is in a vertical state, it can be stored in the grounding device base (2). The grounding device (3) is connected to the rotating locking device (5) at the bottom via a transmission gear set (4). When the grounding device (3) is switched between horizontal and vertical states, the rotating locking device (5) can be driven to lock or release the grounding sliding base (6). When the drive rotation locking device (5) locks with the grounding sliding base (6), the grounding wire (36) can be connected to the grounding structure on the grounding sliding base (6) to realize the grounding of the transformer (1); When the drive rotation locking device (5) and the grounding sliding base (6) are released, the grounding device seat (2) can slide on the grounding sliding base (6) along the arrangement direction of the transformer (1).
2. The temporary grounding system for the power plant transformer of a giant hydropower station according to claim 1, characterized in that, The structure for locking or releasing the rotary locking device (5) and the grounded sliding base (6) is as follows: The gear includes a rotating surface gear (51) that meshes with the transmission gear set (4). The rotating surface gear (51) is provided with a telescopic groove (52). The telescopic groove (52) extends outward in an arc along the center of the rotating surface gear (51). The rotating surface gear (51) is provided with a grounding locking contact (53) that is electrically connected to the grounding wire (36) in the axial direction. The grounding locking contact (53) is provided with a sliding lever (17) that extends into the telescopic groove (52). The grounding locking contact (53) is provided with guide plates (54) on both sides for telescopic guidance. When the transmission gear set (4) drives the rotating surface gear (51) to rotate, the sliding lever (17) moves in the telescopic groove (52) to drive the grounding locking contact (53) to slide along the guide plate (54).
3. The temporary grounding system for the power plant transformer of a giant hydropower station according to claim 2, characterized in that, The grounding structure on the grounding sliding base (6) is as follows: the part of the grounding sliding base (6) that is in contact with and locked by the grounding locking contact (53) is connected to the earth.
4. The temporary grounding system for the power plant transformer of a giant hydropower station according to claim 3, characterized in that, The structure in which the grounding sliding base (6) and the grounding locking contact (53) are in contact and locked together is connected to the ground: The grounding sliding base (6) is provided with a locking cavity (19) corresponding to each transformer (1) along the arrangement direction of the multiple transformers (1). The inner surface of the locking cavity (19) is provided with a grounding locking conductor (8) with matching shape. The grounding locking conductor (8) is electrically connected to the grounding connection line (9).
5. The temporary grounding system for the power plant transformer of a giant hydropower station according to claim 4, characterized in that, Each transformer (1) has a locking cavity (19) on each side of the grounding device base (2) to form a pair. There are two telescopic slides (52) evenly distributed on the rotating surface gear (51). The two grounding locking contacts (53) are arranged radially symmetrically along the rotating surface gear (51). The shape of the end of the grounding locking contact (53) matches the inner cavity of the grounding locking conductor (8).
6. The temporary grounding system for the power plant transformer of a giant hydropower station according to claim 5, characterized in that, The grounding locking conductor (8) is provided with a grounding side status switch (11) on one side. The end of the grounding side status switch (11) is provided with a detection contact (20) that extends into the inner cavity of the grounding locking conductor (8). When the grounding locking contact (53) locks with the inner cavity of the grounding locking conductor (8), the detection contact (20) is pushed to change the grounding signal of the grounding side status switch (11). The grounding side status switch (11) is provided with a power supply, a status indicator light and a communication module. The communication module can send the status of the grounding side status switch (11).
7. The temporary grounding system for the power plant transformer of a giant hydropower station according to claim 6, characterized in that, The transmission ratio between the transmission gear set (4) and the rotating surface gear (51) is 1:1, so that when the grounding device (3) switches between horizontal and vertical states, i.e., rotates 90 degrees, the rotating surface gear (51) also rotates 90 degrees.
8. The temporary grounding system for the power plant transformer of a giant hydropower station according to claim 6, characterized in that, The transmission gear set (4) includes a first gear fixedly connected to the grounding device (3), and the grounding device base (2) is provided with a lever locking device (10) for locking the first gear.
9. The temporary grounding system for the power plant transformer of a giant hydropower station according to claim 6, characterized in that, The grounding device (3) includes a grounding seat (31), inside which is a controllable telescopic piston rod (33), the extended end of the piston rod (33) is provided with a telescopic end (34), inside the telescopic end (34) is a sliding contact grounding guide seat (35), the rear end of the grounding guide seat (35) is fixedly connected to the grounding wire (36), the grounding wire (36) passes through the piston rod (33), the rear end of the grounding guide seat (35) is also provided with a buffer spring (21) that abuts against the telescopic end (34), and the front end of the grounding guide seat (35) matches the shape of the transformer side grounding contact (12).
10. The temporary grounding system for the power plant transformer of a giant hydropower station according to claim 9, characterized in that, The controllable telescopic structure of the piston rod (33) is as follows: The grounding base (31) has a piston chamber (32) inside. The rear end of the piston rod (33) is located in the piston chamber (32). The rear end of the piston chamber (32) has a locking groove (39). The grounding base (31) has a piston locking device (38). The end of the piston locking device (38) extends into the piston chamber (32). The piston chamber (32) has a telescopic spring (14) fixed to the rear end of the piston rod (33). When the piston rod (33) is at the rear end limit position, the end of the piston locking device (38) is embedded in the locking groove (39) to lock.
11. The temporary grounding system for the power plant transformer of a giant hydropower station according to claim 10, characterized in that, The grounding base (31) is provided with a damping air pipe (37) to connect the front of the piston chamber (32) with the external atmosphere, so that the gas in the piston chamber (32) becomes a slow-release damping when the piston rod (33) extends.
12. The temporary grounding system for the power plant transformer of a giant hydropower station according to claim 11, characterized in that, The telescopic end (34) is provided with a locking pin (16) that can slide up and down, and the transformer side grounding contact (12) is provided with a transformer grounding lock hole (13). When the piston rod (33) extends to connect the transformer side grounding contact (12) with the grounding guide seat (35), the grounding guide seat (35) compresses the buffer spring (21) to the limit, the transformer grounding lock hole (13) aligns with the locking pin (16), and the locking pin (16) falls into the transformer grounding lock hole (13) to lock the transformer side grounding contact (12).
13. The temporary grounding system for the power plant transformer of a giant hydropower station according to claim 12, characterized in that, The telescopic end (34) is provided with a transformer-side status switch (15). When the locking pin (16) locks the transformer-side grounding contact (12), the locking pin (16) passes through the transformer grounding lock hole (13) and triggers the transformer-side status switch (15). The transformer-side status switch (15) is provided with a power supply, a status indicator light and a communication module. The communication module can send the status of the transformer-side status switch (15).
14. The temporary grounding system for the power plant transformer of a giant hydropower station according to claim 6, characterized in that, The grounding device base (2) is provided with a wire roller (18) for guiding and constraining the grounding wire (36) when the grounding device (3) is switched between horizontal and vertical states.
15. The temporary grounding system for the power plant transformer of a giant hydropower station according to claim 6, characterized in that, The grounding sliding base (6) is provided with a sliding guide rail (7), and the slider of the sliding guide rail (7) is fixedly connected to the bottom of the grounding device seat (2).
16. The temporary grounding system for the power plant transformer of a giant hydropower station according to claim 14, characterized in that, The grounding side status switches (11) at the multiple transformers correspond to different address numbers on the communication module. The communication module sends the different address number statuses to the remote host computer. The host computer simultaneously receives the status signals of the transformer side status switches (15). By using the address number status of the grounding side status switches (11) and the status signals of the transformer side status switches (15) on the host computer, it can be determined which transformer has a ground wire installed.
17. A grounding method using the temporary grounding system of a giant hydropower station service transformer as described in any one of claims 1-16, characterized in that, This includes both grounding installation and removal procedures, and strictly adheres to the following operational sequence: during installation, install the grounding terminal first, then the transformer-side conductor terminal; during removal, remove the transformer-side conductor terminal first, then the grounding terminal. I. Grounding Installation Steps 1) Moving and positioning: Move the grounding device base (2) along the sliding guide rail (7) of the grounding sliding base (6) to the corresponding grounding position of the transformer (1) to be repaired; 2) Installing the grounding terminal: Flip the grounding device (3) from the vertical storage state to the horizontal unfolded state by 90°. Drive the rotating surface gear (51) of the rotating locking device (5) to rotate through the transmission gear set (4), so that the grounding locking contact (53) extends out and is embedded in the locking cavity (19) of the grounding sliding base (6), and makes reliable contact with the grounding locking conductor (8) to complete the installation of the grounding terminal. At the same time, the grounding side status switch (11) is triggered to send a grounding terminal in place signal. 3) Mechanical locking: By moving the locking device (10), the transmission gear set (4) and the grounding device (3) are locked, so that the grounding device (3) is fixed in the current position and cannot slide; 4) Install the transformer side conductor end: After the transformer (1) under maintenance is tested and confirmed to be de-energized, release the piston locking device (38) from locking the piston rod (33). The piston rod (33) slowly extends under the slow release action of the telescopic spring (14) and the damping air tube (37), so that the grounding guide seat (35) of the telescopic end (34) is in contact with the transformer side grounding contact (12). 5) Contact locking: When the grounding guide seat (35) compresses the buffer spring (21) to the limit position, the locking pin (16) automatically falls into the transformer grounding lock hole (13) to complete the mechanical locking, and at the same time triggers the transformer side status switch (15) to send a conductor end grounding success signal; 6) Status confirmation: The signals from the grounding side status switch (11) and the transformer side status switch (15) are both uploaded to the host computer to confirm that the grounding is completed; II. Grounding Removal Procedures 1) Remove the transformer-side conductor end: Pull out the locking pin (16) to release the locking of the transformer-side grounding contact (12), push the piston rod (33) back into the piston chamber (32) and lock it through the piston locking device (38) to separate the grounding guide seat (35) from the transformer-side grounding contact (12) and reset the transformer-side status switch (15). 2) Remove the grounding terminal: Release the locking device (10) from locking the transmission gear set (4), rotate the grounding device (3) from the horizontal unfolded state to the vertical storage state by 90°, drive the rotating surface gear (51) to rotate through the transmission gear set (4), so that the grounding locking contact (53) retracts and separates from the grounding locking conductor (8), and the grounding terminal is removed. The grounding side status switch (11) is reset. 3) Reset: The grounding device base (2) is restored to a sliding state and moved away or moved to the position of the next transformer (1) to be repaired along the sliding guide rail (7).
18. The grounding method according to claim 17, characterized in that, When grounding a three-phase transformer (1), the three grounding locking conductors (8) corresponding to the three phases are short-circuited through copper busbars or grounding flat iron to achieve three-phase short-circuit grounding.