Bistable permanent magnet ground wire disconnecting link for switching between ice melting state and lightning protection state

Abstract

A vacuum arc-extinguishing chamber, an insulating mechanism and a driving mechanism are sequentially connected, the first end, deviating from the insulating mechanism, of the vacuum arc-extinguishing chamber is connected with an iron tower to be deiced through a conducting rod, the other end of the vacuum arc-extinguishing chamber is connected with a ground wire, the inner end of the conducting rod is connected with a static contact, and the inner end of the conducting rod is connected with a power supply. One end, facing the vacuum arc-extinguishing chamber, of a movable iron core of the driving mechanism penetrates through the insulating mechanism to be connected with the movable contact, and through a magnet and a coil surrounding the movable iron core in the driving mechanism, after the coil is electrified, the movable iron core is driven by magnetic force to drive the movable contact to move, so that the static contact is separated from or contacted with the movable contact; the driving mechanism drives the closing movable contact and the closing static contact in the vacuum arc-extinguishing chamber to be closed or opened, so that automatic switching of closing and opening is realized, a worker does not need to climb a tower on site to carry out manual operation, the misoperation risk is reduced, the potential safety hazard is reduced, and the operation efficiency, safety and reliability are improved.

Description

Technical Field

[0001] The invention relates to the technical field of deicing of transmission lines, in particular to a bistable permanent magnetic ground wire switch for switching between ice melting and lightning protection states. Background Art

[0002] During the cold autumn and winter seasons, power transmission lines are susceptible to icing. If artificial ice-melting measures are not taken in time, major accidents are likely to occur, leading to regional power supply interruptions, affecting residents' lives, industrial production and public safety.

[0003] Therefore, ice-melting measures should be taken in time in the heavy ice area. During the ice-melting work, if the line is equipped with an ice-melting ground wire knife switch, the ice-melting time can be shortened and the ice-melting efficiency can be greatly improved. Therefore, in the anti-icing and anti-icing work of the power grid, the ice-melting ground wire knife switch plays an important role. At the same time, as an electrical safety device, the ground wire knife switch can ensure the safety of the maintenance personnel when the line is shut down for maintenance; it can be closed in thunderstorm weather to introduce the lightning impulse current into the ground, which can effectively ensure the stable operation of the transmission line.

[0004] However, the traditional grounding switch has a single function, which is limited to one of the lightning protection grounding or ice melting operations. It cannot be switched quickly and conveniently to meet these two important needs, which brings great inconvenience to the actual production operation. In addition, this type of switch usually requires workers to climb the tower on site for manual operation, which is difficult to operate in bad weather, has low work efficiency, and there is a risk of misoperation other than the operator's operation, which poses a great safety hazard. Summary of the invention

[0005] The purpose of the present invention is to provide a bistable permanent magnetic ground switch for switching between ice melting and lightning protection states, so as to realize the automatic switching of lightning protection grounding and ice melting operations, without the need for staff to climb the tower on site for manual operation, thereby reducing the risk of misoperation, reducing safety hazards, and improving operational efficiency, safety and reliability.

[0006] To solve the above technical problems, an embodiment of the present invention provides a bistable permanent magnetic ground switch for switching between ice melting and lightning protection states, including a vacuum arc chamber, an insulating mechanism, a driving mechanism and a spring mechanism connected in sequence, wherein the first end of the vacuum arc chamber away from the insulating mechanism is used to connect to the iron tower to be de-iced, and the end of the vacuum arc chamber facing the insulating mechanism is connected to the ground wire, the outer end of the conductive rod of the vacuum arc chamber is connected to the iron tower to be de-iced, and a static contact is provided at the inner end, the end of the moving iron core of the driving mechanism facing the vacuum arc chamber passes through the insulating mechanism and is connected to the moving contact, the driving mechanism includes a magnet and a coil surrounding the moving iron core, and the coil is used to drive the moving iron core to drive the moving contact to move through the magnetic force generated by the change of the magnetic field after power is turned on, so as to separate or contact the static contact with the moving contact.

[0007] It also includes an outer magnetic yoke of a cylindrical structure arranged in the driving mechanism, the magnet is a permanent magnet arranged on the side wall of the outer magnetic yoke, and the coil is arranged in the outer magnetic yoke between the permanent magnet and the spring mechanism.

[0008] Among them, it also includes a spring mechanism arranged at one end of the driving mechanism away from the insulating mechanism, the spring mechanism includes a accommodating cylinder and an opening spring, a closing spring and a driving rod arranged in the accommodating cylinder, the driving rod is connected to the moving iron core, the driving rod is connected to the closing spring through a T-shaped spring pressure head, the T-shaped spring pressure head is embedded in the closing spring, the opening spring is sheathed on the driving rod and is located between the outer yoke and the T-shaped spring pressure head, and the elastic coefficient of the closing spring is greater than the elastic coefficient of the opening spring.

[0009] It also includes a spring positioning column coaxially arranged at the bottom of the accommodating tube, one end of the closing spring is sleeved on the spring positioning column, and one end of the driving rod is coaxially fixedly connected to the moving iron core.

[0010] Wherein, the ratio of the elastic coefficient of the closing spring to the elastic coefficient of the opening spring is 1.5-4.

[0011] Wherein, it also includes a spring state detection device arranged in the spring mechanism, which is used to detect the position of the T-shaped spring pressure head in the spring mechanism and calculate and output the corresponding spring state information of the spring mechanism according to the position of the T-shaped spring pressure head in the spring mechanism.

[0012] Among them, the vacuum arc extinguishing chamber includes an insulating shell and a shielding cover arranged in the insulating shell, the conductive rod, the static contact and the moving contact are arranged in the vacuum arc extinguishing chamber, the static contact and the moving contact are arranged in the shielding cover, and the shielding cover is used to shield the metal vapor and metal droplets generated in the process of the static contact and the moving contact breaking the current.

[0013] It also includes a bellows arranged between the moving contact and the insulating shell, the bellows is sleeved on the part of the moving iron core extending into the vacuum arc extinguishing chamber, and the bellows is used to be elongated or shortened along the axial direction of the bellows under the action of external force.

[0014] Wherein, the bellows is an alloy elastic bellows, and the shape of the tube wall of the bellows is corrugated.

[0015] It also includes a magnetic conductive block arranged on the inner side of the permanent magnet facing the moving iron core, and the magnetic conductive block is aligned with the permanent magnet at both ends of the axial direction of the outer magnetic yoke.

[0016] The bistable permanent magnetic ground wire switch for ice melting and lightning protection state switching provided in the embodiment of the present invention has the following advantages compared with the prior art:

[0017] The bistable permanent magnetic grounding knife switch for switching between ice melting and lightning protection states provided in the embodiment of the present invention is provided by sequentially connecting a vacuum arc chamber, an insulating mechanism, and a driving mechanism. The first end of the vacuum arc chamber away from the insulating mechanism is connected to the iron tower to be de-iced through a conductive rod, and the other end is connected to the ground wire. The inner end of the conductive rod is connected to the static contact. The end of the moving iron core of the driving mechanism facing the vacuum arc chamber passes through the insulating mechanism and is connected to the moving contact. Through the permanent magnet and coil surrounding the moving iron core in the driving mechanism, after the coil is energized, the magnetic force generated by the change in the magnetic field drives the moving iron core to drive the moving contact to move, so as to separate or contact the static contact and the moving contact. The closing moving contact and the closing static contact in the vacuum arc chamber are driven to close or open by the driving mechanism, so as to realize the automation of closing and opening, and the automatic switching. There is no need for staff to climb the tower on site for manual operation, which reduces the risk of misoperation, reduces safety hazards, and improves operating efficiency, safety and reliability. Through remote precise control and intelligent and fast switching of working modes, the convenience and safety of operation are greatly improved, which can significantly reduce manual on-site intervention in severe ice disasters, reduce operation and maintenance costs, and improve the ability of transmission lines to respond to ice disasters, which is in line with the development trend of intelligent automation of high-voltage power transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of the overall structure of an embodiment of a bistable permanent magnetic ground switch for switching between ice melting and lightning protection states provided by the present invention;

[0020] Figure 2 A schematic diagram of the structure of a vacuum interrupter in one embodiment of a bistable permanent magnetic ground switch for switching between ice melting and lightning protection states provided by the present invention;

[0021] Figure 3 A schematic diagram of a driving mechanism in an embodiment of a bistable permanent magnetic ground switch for switching between ice melting and lightning protection states provided for the implementation of the present invention;

[0022] Figure 4 A schematic diagram of an implementation flow in one embodiment of a bistable permanent magnetic ground switch for switching between ice melting and lightning protection states provided for the implementation of the present invention;

[0023] Among them, 10-vacuum interrupter, 20-insulating mechanism, 30-driving mechanism, 40-spring mechanism, 11-insulating shell, 12-conductive rod, 13-shielding cover, 14-bellows, 15-static contact, 16-moving contact, 31-moving iron core, 32-coil, 33-magnet is a permanent magnet, 34-magnetic block, 35-external magnetic yoke, 42-opening spring, 43-closing spring, 41-T-shaped spring pressure head. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Please refer to Figure 1-Figure 4 , Figure 1 A schematic diagram of the overall structure of an embodiment of a bistable permanent magnetic ground switch for switching between ice melting and lightning protection states provided by the present invention; Figure 2 A schematic diagram of the structure of a vacuum interrupter in one embodiment of a bistable permanent magnetic ground switch for switching between ice melting and lightning protection states provided by the present invention; Figure 3 A schematic diagram of a driving mechanism in an embodiment of a bistable permanent magnetic ground switch for switching between ice melting and lightning protection states provided for the implementation of the present invention; Figure 4 A schematic diagram of an implementation flow in one embodiment of a bistable permanent magnetic ground switch for switching between ice melting and lightning protection states provided for the implementation of the present invention.

[0026] In a specific embodiment, the bistable permanent magnetic ground switch for switching between ice melting and lightning protection states includes a vacuum arc chamber 10, an insulating mechanism 20, a driving mechanism 30 and a spring mechanism 40 connected in sequence, the first end of the vacuum arc chamber 10 away from the insulating mechanism 20 is used to connect to the iron tower to be de-iced, the end of the vacuum arc chamber 10 facing the insulating mechanism 20 is connected to the ground wire, the outer end of the conductive rod 12 of the vacuum arc chamber 10 is connected to the iron tower to be de-iced, and a static contact 15 is provided at the inner end, the moving iron core 31 of the driving mechanism 30 faces the vacuum arc chamber 10 and passes through the insulating mechanism 20 to be connected to the moving contact 16, the driving mechanism 30 is surrounded by a magnet and a coil 32, and the coil 32 is used to drive the moving iron core 31 to drive the moving contact 16 to move through the magnetic force generated by the change of the magnetic field after power is turned on, so as to separate or contact the static contact 15 with the moving contact 16.

[0027] The vacuum interrupter 10, the insulating mechanism 20 and the driving mechanism 30 are connected in sequence. The first end of the vacuum interrupter 10 away from the insulating mechanism 20 is connected to the iron tower to be de-iced through the conductive rod 12, and the other end is connected to the ground wire. The inner end of the conductive rod 12 is connected to the static contact 15. The end of the moving iron core 31 of the driving mechanism 30 facing the vacuum interrupter 10 passes through the insulating mechanism 20 and is connected to the moving contact 16. Through the permanent magnet and the coil 32 surrounding the moving iron core 31 in the driving mechanism 30, after the coil 32 is energized, the magnetic force generated by the change in the magnetic field drives the moving iron core 31 to drive the moving contact 16 to move, so that the static contact 15 is separated from or in contact with the moving contact 16. The driving mechanism 30 drives the closing moving contact 16 and the closing static contact 15 in the vacuum interrupter 10 to close or open, thereby realizing the automation of closing and opening, and the automatic switching. There is no need for staff to climb the tower on site for manual operation, which reduces the risk of misoperation, reduces safety hazards, and improves operation efficiency, safety and reliability. Through remote precise control and intelligent and fast switching of working modes, the convenience and safety of operation are greatly improved, which can significantly reduce manual on-site intervention in severe ice disasters, reduce operation and maintenance costs, and improve the ability of transmission lines to respond to ice disasters, which is in line with the development trend of intelligent automation of high-voltage power transmission.

[0028] In order to further improve the reliability of the driving mechanism 30, reduce its volume, and improve the installation efficiency, in one embodiment, the bistable permanent magnetic ground switch that switches between the ice melting and lightning protection states also includes an outer magnetic yoke 35 of a cylindrical structure arranged in the driving mechanism 30, and the magnet is a permanent magnet 33, which is arranged on the side wall of the outer magnetic yoke 35, and the coil 32 is arranged in the outer magnetic yoke 35 between the permanent magnet and the spring mechanism 40.

[0029] By setting an outer magnetic yoke 35 with a cylindrical structure and using a permanent magnet, the permanent magnet is set on the side wall of the outer magnetic yoke 35, and the coil 32 is set between the permanent magnet and the spring mechanism 40 in the outer magnetic yoke 35, the moving iron core 31 can move freely in the coil 32. After power is turned on, the moving iron core 31 can move freely. The force direction can be changed by changing the direction of the current to drive the moving iron core 31 to move. The moving iron core 31 is set between the permanent magnet and the spring mechanism 40 so that a smaller current can be used for driving during closing, thereby improving the driving efficiency.

[0030] The present application includes but is not limited to the structure of the driving mechanism 30 described above.

[0031] In order to further improve the stability of moving parts during ice melting and lightning protection, in one embodiment, the bistable permanent magnetic ground wire knife switch for switching between ice melting and lightning protection states also includes a spring mechanism 40 arranged at one end of the driving mechanism 30 away from the insulating mechanism 20, the spring mechanism 40 includes a accommodating cylinder and a disconnecting spring 42, a closing spring 43 and a driving rod arranged in the accommodating cylinder, the driving rod is connected to the moving iron core 31, the driving rod is connected to the closing spring 43 through a T-shaped spring pressure head 41, the T-shaped spring pressure head 41 is embedded in the closing spring 43, the disconnecting spring 42 is sheathed on the driving rod and is located between the outer yoke 35 and the T-shaped spring pressure head 41, and the elastic coefficient of the closing spring 43 is greater than the elastic coefficient of the disconnecting spring 42.

[0032] By setting the spring mechanism 40, the elastic coefficient of the closing spring 43 is greater than the elastic coefficient of the opening spring 42, so that in the natural state, the knife switch is naturally in the closed state. At this time, the closing spring 43 is in a released state, but not completely released, and still retains a certain amount of compression. Therefore, the closing spring 43 applies a left elastic force to the moving iron core 31. The elastic force of the closing spring 43 and the static holding force of the driving mechanism 30 work together to keep the closing moving contact 16 in the vacuum arc chamber 10 closed with the closing static contact 15, that is, the closed state. At this time, the opening spring 42 is in a compressed state, and the elastic coefficient of the closing spring 43 is greater than the elastic coefficient of the opening spring 42, so it has little effect on the closed state of the closing moving contact 16 and the closing static contact 15, thereby ensuring the reliability of the closing.

[0033] The use of the opening spring 42 and the closing spring 43 can simplify the drive mechanism 30 to a single coil type. When closing and opening, only a small current in the opposite direction needs to be passed through the single coil, and the opening and closing process can be realized with the action of the spring. The energy for opening and closing is provided by the spring and the permanent magnet. If a telescopic device is used and the drive mechanism 30 is used to directly drive the opening and closing, if a bistable state is to be achieved, a double-coil drive mechanism 30 needs to be used.

[0034] Compared with the double-coil drive mechanism 30, the single-coil drive mechanism 30 lacks one coil 32 and its corresponding control circuit and connection device, making the structure more compact and lighter, and reducing the manufacturing cost.

[0035] The energy for opening and closing the single-coil drive mechanism 30 is provided by a spring and a permanent magnet. Therefore, under the same conditions, the peak current passing through the coil of the single-coil drive mechanism 30 is relatively small, and the requirements for power supply capacity and control part are also relatively low, which is conducive to simplifying system design and reducing costs.

[0036] The control logic of the single-coil drive mechanism 30 is relatively simple. It only needs to control the on / off state and current of one coil to realize the closing and opening operation. However, the dual-coil drive mechanism 30 needs to control the working state of the two coils 32 separately, and the control process is relatively complicated. Therefore, the control system of the single-coil drive mechanism is easier to realize and maintain, and improves the accuracy and reliability of the operation.

[0037] Directly pushing by the driving mechanism 30 may have the following disadvantages:

[0038] During the opening process, the switch requires a higher opening speed for the operating mechanism, which requires a larger current to be passed at the beginning of the stroke. In addition, during the opening process, the working air gap becomes smaller and smaller, and the force generated by the excitation current becomes larger and larger. The permanent magnet changes its original obstructive effect on the opening speed to a driving effect, further accelerating the opening speed of the switch, causing the movement speed to be too high at the end of the stroke, causing a great impact, which will not only affect the life of the switch, but also cause a large opening rebound, causing the switch to be severely broken down after disconnection, and ultimately leading to opening failure.

[0039] The opening characteristic is not easy to adjust and can only be achieved by changing the current of the opening coil 32. For a certain mechanism, once the coil 32 has been processed and its parameters are certain, if the voltage of the power supply is certain, then the current of the coil 32 will not change and the opening characteristic cannot be changed.

[0040] Therefore, by adopting the above-mentioned opening spring 42 and closing spring 43 structure, the overall device structure can be greatly reduced, the current required to drive the knife switch state change can be reduced, and the control capability and control efficiency can be improved.

[0041] The present application includes but is not limited to the above-mentioned opening spring 42 and closing spring 43 structures, and other structures besides the spring mechanism 40 may also be used. The present application includes but is not limited to the above-mentioned spring mechanism 40.

[0042] In order to further facilitate the fixation of the spring, in one embodiment, the bistable permanent magnetic ground switch for switching between ice melting and lightning protection states also includes a spring positioning column coaxially arranged at the bottom of the accommodating tube, one end of the closing spring 43 is sleeved on the spring positioning column, and one end of the driving rod is coaxially fixedly connected to the moving iron core 31.

[0043] By coaxially arranging a spring positioning column, one end of the closing spring 43 is sleeved on the spring positioning column, and one end of the driving rod is coaxially fixedly connected to the moving iron core 31, it can be ensured that the corresponding driving force and the spring elastic force are in the same direction, thereby improving the reliability of equipment operation.

[0044] The structure of the spring positioning column is not limited in this application.

[0045] In the present application, there is no limitation on the value and ratio of the elastic coefficient of the closing spring 43 to the elastic coefficient of the opening spring 42 . The ratio of the elastic coefficient of the closing spring 43 to the elastic coefficient of the opening spring 42 is 1.5-4.

[0046] In order to further improve the feedback detection of the closing state, in one embodiment, the bistable permanent magnetic ground switch for switching between ice melting and lightning protection states also includes a spring state detection device arranged in the spring mechanism 40, which is used to detect the position of the T-shaped spring pressure head 41 in the spring mechanism 40 and calculate and output the corresponding spring state information of the spring mechanism 40 according to the position of the T-shaped spring pressure head 41 in the spring mechanism 40.

[0047] By setting up a spring state detection device, it is only necessary to detect the position of the T-shaped spring pressure head 41 in the spring mechanism 40 to determine the actual position of the moving iron core 31 and whether the moving contact 16 and the static contact 15 are in contact, and compare them with the applied current parameters of the drive mechanism 30. If the states of the two are consistent, it means that the two are working normally. Otherwise, one of them must be in a faulty state. It may be that the spring of the spring mechanism 40 is faulty, or that the moving iron core 31 drives the conductive rod 12 or the conductive rod 12 to the moving contact 16 is faulty. The actual state of the conductive rod 12 can be obtained by detecting whether it is performing ice melting operations and grounding, thereby realizing state detection of the spring mechanism 40 and achieving rapid maintenance.

[0048] The present application does not limit the structure of the spring state detection device. It can be a photoelectric device for detection to detect the intensity of reflected light, or a reflective layer can be set on the side wall of the driving rod to detect whether specific light is detected. A detection rod can also be set at the outer end of the driving rod, and a fluorescent layer can be set on the part of the detection rod that is exposed outside the spring mechanism 40. The position detection can be achieved by irradiating it to detect whether the position of the driving rod is driven into place, or other position detection devices can be used.

[0049] The vacuum interrupter 10 in the present application is mainly used to prevent discharge during the closing and opening processes and reduce damage to the equipment. The present application does not limit the structure of the vacuum interrupter 10.

[0050] In one embodiment, the vacuum arc chamber 10 includes an insulating shell and a shielding cover 13 arranged in the insulating shell 11, the conductive rod 12, the static contact 15 and the moving contact 16 are arranged in the vacuum arc chamber 10, the static contact 15 and the moving contact 16 are arranged in the shielding cover 13, and the shielding cover 13 is used to shield the metal vapor and metal droplets generated in the process of the static contact 15 and the moving contact 16 breaking the current.

[0051] An insulating shell is arranged on the whole exterior to confine possible discharge within the insulating shell 11, thereby reducing or avoiding the impact or damage to external equipment. A shielding cover 13 is arranged inside the insulating shell 11, and the static contact 15 and the moving contact 16 are arranged inside the shielding cover 13, thereby further reducing the metal vapor and metal droplets generated during the current breaking process of the static contact 15 and the moving contact 16, reducing the damage to the static contact 15 and the moving contact 16 during the gate opening process, and improving the safety and reliability of the equipment.

[0052] In the present application, there is no limitation on the shape, size, material, etc. of the insulating shell and the shielding cover 13 disposed in the insulating shell 11, which can be determined according to the specific voltage level and environment.

[0053] In order to further realize electromagnetic shielding and reduce the leakage phenomenon of the moving iron core 31 or the moving iron core 31 driving components during entry and exit, in one embodiment, the bistable permanent magnetic ground wire switch for switching between ice melting and lightning protection states also includes a bellows 14 arranged between the moving contact 16 and the insulating shell, and the bellows 14 is sleeved on the part of the moving iron core 31 extending into the vacuum arc extinguishing chamber 10, and the bellows 14 is used to lengthen or shorten along the axial direction of the bellows 14 under the action of external force.

[0054] By arranging a bellows 14 between the moving contact 16 and the insulating shell, the bellows 14 is sleeved on the part of the moving iron core 31 extending into the vacuum arc extinguishing chamber 10 or the connecting rod driven by the moving iron core 31. The bellows 14 is used to be elongated or shortened along the axial direction under the action of external force, so as to support the shielding cover 13. Moreover, when the air pressure in the shielding cover 13 increases, it can also be released through the bellows 14 and restored after cooling, thereby ensuring the reliability of use.

[0055] The material, size, installation method, etc. of the bellows 14 are not limited in the present application. The bellows 14 is an alloy elastic bellows 14 , and the shape of the wall of the bellows 14 is corrugated.

[0056] In order to further improve the utilization efficiency of the permanent magnet, in one embodiment, the bistable permanent magnetic ground switch for switching between ice melting and lightning protection states also includes a magnetic block 34 arranged on the inner side of the permanent magnet facing the moving iron core 31, and the magnetic block 34 is aligned with the permanent magnet at both ends of the axial direction of the outer magnetic yoke 35.

[0057] By providing the magnetic conductive block 34 and aligning the magnetic conductive block 34 with the permanent magnet at both ends of the axial direction of the outer magnetic yoke 35, the magnetism of the permanent magnet can be amplified, the driving current in the driving process can be reduced, and the control efficiency can be improved.

[0058] The present application does not limit the material, size, installation method, etc. of the magnetic conductive block 34 .

[0059] In one embodiment, the bistable permanent magnetic ground wire switch for switching between ice melting and lightning protection states realizes the mechanical action of closing and closing the switch by driving the switch through the permanent magnetic mechanism, and moving to the right is opening the switch, and moving to the left is closing the switch. The permanent magnetic mechanism is then connected to the vacuum interrupter 10 through an insulating connector, and the left end of the vacuum interrupter 10 is connected to the iron tower, and the right end is connected to the ground wire.

[0060] The vacuum interrupter 10 is composed of an insulating shell, a bellows 14, contacts, a conductive rod 12, a shielding cover 13 and other parts. The contacts are divided into a closing static contact 15 and a closing moving contact 16. The shell of the vacuum interrupter 10 is both a vacuum container and an insulator between the moving and static contacts. The bellows 14 is an alloy elastic element, and its tube wall is corrugated, which can be stretched or shortened along its axis under the action of external force. The main function of the shielding cover 13 is to shield the metal vapor and metal droplets generated in the process of breaking the current, otherwise the arc products will be deposited on the insulating shell and destroy the insulation of the shell.

[0061] The bistable permanent magnet mechanism includes a top coil 32, a moving iron core 31, an outer magnetic yoke 35 of a cylindrical structure, and a connecting rod for connecting the closing moving contact 16 and the moving iron core 31. The top coil 32 is located at the connecting rod of the closing moving contact 16 inside the outer magnetic yoke 35, and the moving iron core 31 is inserted into the top coil 32 and can move back and forth in a single degree of freedom in the coil 32.

[0062] A spring mechanism 40 for providing auxiliary force for opening and closing is also provided below the moving iron core 31. The spring mechanism 40 is located outside the bottom of the outer magnetic yoke 35 and is fixedly connected to the moving iron core 31. The spring mechanism 40 includes an opening spring 42, a closing spring 43, a driving rod, and a receiving tube for accommodating the opening spring 42 and the closing spring 43. A spring positioning column is coaxially provided at the bottom of the receiving tube. One end of the closing spring 43 is sleeved on the spring positioning column. One end of the driving rod is coaxially fixedly connected to the moving iron core 31, and the other end passes through the bottom of the outer magnetic yoke 35 and penetrates into the receiving tube. The driving rod is connected to the closing spring 43 through a T-shaped spring pressure head 41. The T-shaped spring pressure head 41 is embedded in the closing spring 43. The opening spring 42 is sleeved on the driving rod and is located between the outer magnetic yoke 35 and the T-shaped spring pressure head 41.

[0063] Working principle:

[0064] Natural state: naturally in the closed state. At this time, the closing spring 43 is in a released state, but not completely released, and still retains a certain amount of compression. Therefore, the closing spring 43 applies a left elastic force to the moving iron core 31. The elastic force of the closing spring 43 and the static holding force of the permanent magnet mechanism work together to keep the closing moving contact 16 in the vacuum arc extinguishing chamber 10 closed with the closing static contact 15, that is, the closed state. At this time, the opening spring 42 is in a compressed state, and the elastic coefficient of the closing spring 43 is greater than the elastic coefficient of the opening spring 42. Therefore, it has little effect on the closed state of the closing moving contact 16 and the closing static contact 15, thereby ensuring the reliability of the closing.

[0065] In static state, there is no current in the coil 32, and the closed state is maintained by the closing spring 43 and the suction force of the permanent magnet on the left end of the moving iron core 31. The elastic coefficients of the closing spring 43 and the opening spring 42 do not have fixed universal standard values, and their specific values ​​are affected by many factors.

[0066] The spring coefficient of the closing spring 43 is affected by factors such as the voltage and current, the contact pressure requirements, and the closing speed requirements. Under the working requirements of high voltage and high current, large contact pressure, and fast closing speed, the closing spring 43 needs to provide a large elastic force to ensure the reliability of closing, and its spring coefficient is relatively large. The spring coefficient of the opening spring 42 is affected by factors such as the opening speed requirements and the contact opening distance. Under the working requirements of fast opening speed and large contact opening distance, the spring coefficient of the opening spring 42 is relatively large. In general, the elastic coefficient of the closing spring 43 is larger than that of the opening spring 42, and the ratio may be about 1.5-4 times.

[0067] Opening process: A positive voltage is applied to both ends of the coil 32 to control the coil 32 to generate a magnetic field. The corresponding magnetic field is opposite to the original magnetic field of the permanent magnet, weakening the attraction of the permanent magnet to the left on the moving iron core, and the magnetic force generated by the corresponding magnetic field acts on the moving iron core 31, and cooperates with the elastic force accumulated by the opening spring 42 in the closed state. The two forces work together to make the moving iron core 31 overcome the elastic force of the closing spring 43 and the static holding force of the permanent magnet to move to the right, realizing the opening movement of the closing moving contact 16 and the closing static contact 15, ensuring the reliability of the opening. During the opening process, the closing spring 43 is continuously compressed, and at the same time plays a role in accumulating elastic potential energy for closing.

[0068] Closing process: A negative voltage is applied to both ends of the bottom coil 32 to control the magnetic field generated by the top coil 32 to be opposite to the direction of the permanent magnet magnetic field, offsetting the permanent magnet's suction force on the moving iron core to the right, and the corresponding magnetic field generates a magnetic force acting on the moving iron core 31, which cooperates with the elastic force accumulated by the closing spring 43 in the open state, so that the moving iron core 31 overcomes the elastic force of the opening spring 42 and the static holding force of the permanent magnet mechanism to realize the closing movement of the switch. The opening spring 42 plays a buffering role in the closing process.

[0069] The bistable state in the present application means that the moving iron core 31 can be maintained in the closing and opening positions without the aid of external energy or locks, that is, the stability of the two states of ice melting and lightning protection.

[0070] In a specific embodiment of the above device, the practical process is as follows:

[0071] Collect line environment data;

[0072] Select the working mode of the ground switch according to the status of the transmission line;

[0073] If it is thunderstorm weather, a lightning protection status switching signal is sent to the knife switch to close the ground wire knife switch to protect the safety of the transmission line.

[0074] If ice melting operation is required, an insulation state switching signal is sent to the knife switch to open the ground wire knife switch to ensure the normal progress of the ice melting operation.

[0075] The above-mentioned knife switch can quickly switch to the grounding mode during thunderstorm weather, effectively guiding the lightning current into the ground and protecting the power system from damage caused by lightning strikes; during the ice melting operation, it can be converted to an insulating state to form an ice melting circuit to ensure stable ice melting of the power grid.

[0076] Intelligent control system can avoid manual work and improve work efficiency.

[0077] To summarize, the bistable permanent magnetic grounding knife switch for switching between ice melting and lightning protection states provided by the embodiment of the present invention is provided by sequentially connecting a vacuum arc chamber, an insulating mechanism, and a driving mechanism. The first end of the vacuum arc chamber away from the insulating mechanism is connected to the iron tower to be de-iced through a conductive rod, and the other end is connected to the ground wire. The inner end of the conductive rod is connected to the static contact. The end of the moving iron core of the driving mechanism facing the vacuum arc chamber passes through the insulating mechanism and is connected to the moving contact. Through the permanent magnet and coil surrounding the moving iron core in the driving mechanism, after the coil is energized, the magnetic force generated by the change in the magnetic field drives the moving iron core to drive the moving contact to move, so as to separate or contact the static contact and the moving contact. The closing moving contact and the closing static contact in the vacuum arc chamber are driven to close or open by the driving mechanism, so as to realize the automation of closing and opening, and the automatic switching. There is no need for staff to climb the tower on site for manual operation, which reduces the risk of misoperation, reduces safety hazards, and improves operating efficiency, safety and reliability. Through remote precise control and intelligent and fast switching of working modes, the convenience and safety of operation are greatly improved, which can significantly reduce manual on-site intervention in severe ice disasters, reduce operation and maintenance costs, and improve the ability of transmission lines to respond to ice disasters, which is in line with the development trend of intelligent automation of high-voltage power transmission.

[0078] The above is a detailed introduction to the bistable permanent magnetic ground switch for ice melting and lightning protection state switching provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A bistable permanent magnetic ground switch for switching between ice melting and lightning protection states, characterized in that: It comprises a vacuum arc extinguishing chamber, an insulating mechanism, a driving mechanism and a spring mechanism connected in sequence, wherein the first end of the vacuum arc extinguishing chamber facing away from the insulating mechanism is used to connect to the iron tower to be de-iced, the end of the vacuum arc extinguishing chamber facing the insulating mechanism is connected to the ground wire, the outer end of the conductive rod of the vacuum arc extinguishing chamber is connected to the iron tower to be de-iced, and the inner end is provided with a static contact, the end of the moving iron core of the driving mechanism facing the vacuum arc extinguishing chamber passes through the insulating mechanism and is connected to the moving contact, the driving mechanism is surrounded by a magnet and a coil around the moving iron core, and the coil is used to drive the moving iron core to drive the moving contact to move through the magnetic force generated by the change of the magnetic field after power is turned on, so as to separate or contact the static contact with the moving contact.

2. The bistable permanent magnetic ground switch for switching between ice melting and lightning protection states as claimed in claim 1, characterized in that: It also includes an outer magnetic yoke of a cylindrical structure arranged in the driving mechanism, the magnet is a permanent magnet arranged on the side wall of the outer magnetic yoke, and the coil is arranged in the outer magnetic yoke between the permanent magnet and the spring mechanism.

3. The bistable permanent magnetic ground switch for switching between ice melting and lightning protection states as claimed in claim 2, characterized in that: It also includes a spring mechanism arranged at one end of the driving mechanism away from the insulating mechanism, the spring mechanism includes a accommodating cylinder and an opening spring, a closing spring and a driving rod arranged in the accommodating cylinder, the driving rod is connected to the moving iron core, the driving rod is connected to the closing spring through a T-shaped spring pressure head, the T-shaped spring pressure head is embedded in the closing spring, the opening spring is sheathed on the driving rod and is located between the outer yoke and the T-shaped spring pressure head, and the elastic coefficient of the closing spring is greater than the elastic coefficient of the opening spring.

4. The bistable permanent magnetic ground switch for switching between ice melting and lightning protection states as claimed in claim 3, characterized in that: It also includes a spring positioning column coaxially arranged at the bottom of the accommodating tube, one end of the closing spring is sleeved on the spring positioning column, and one end of the driving rod is coaxially fixedly connected to the moving iron core.

5. The bistable permanent magnetic ground switch for switching between ice melting and lightning protection states as claimed in claim 4, characterized in that: The ratio of the elastic coefficient of the closing spring to the elastic coefficient of the opening spring is 1.5-4.

6. The bistable permanent magnetic ground switch for switching between ice melting and lightning protection states as claimed in claim 1, characterized in that: It also includes a spring state detection device arranged on the spring mechanism, which is used to detect the position of the T-shaped spring pressure head in the spring mechanism and calculate and output the corresponding spring state information of the spring mechanism according to the position of the T-shaped spring pressure head in the spring mechanism.

7. The bistable permanent magnetic ground switch for switching between ice melting and lightning protection states as claimed in claim 1, characterized in that: The vacuum interrupter chamber includes an insulating shell and a shielding cover arranged in the insulating shell, the conductive rod, the static contact and the moving contact are arranged in the vacuum interrupter chamber, the static contact and the moving contact are arranged in the shielding cover, and the shielding cover is used to shield the metal vapor and metal droplets generated in the process of the static contact and the moving contact breaking the current.

8. The bistable permanent magnetic ground switch for switching between ice melting and lightning protection states as claimed in claim 1, characterized in that: It also includes a bellows arranged between the moving contact and the insulating shell, the bellows is sleeved on the part of the moving iron core extending into the vacuum arc extinguishing chamber, and the bellows is used to be elongated or shortened along the axial direction of the bellows under the action of external force.

9. The bistable permanent magnetic ground switch for switching between ice melting and lightning protection states as claimed in claim 8, characterized in that: The bellows is an alloy elastic bellows, and the shape of the tube wall of the bellows is corrugated.

10. The bistable permanent magnetic ground switch for switching between ice melting and lightning protection states as claimed in claim 3, characterized in that: It also includes a magnetic conductive block arranged on the inner side of the permanent magnet facing the moving iron core, and the magnetic conductive block is aligned with the permanent magnet at both ends of the axial direction of the outer magnetic yoke.

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