PV anti-islanding device

Abstract

The present invention belongs to the technical field of anti-islanding, in particular to a photovoltaic anti-islanding device, which includes an anti-islanding cabinet and a cabinet door hinged to the front side of the anti-islanding cabinet. A PLC controller is fixedly connected to the inner wall of the anti-islanding cabinet. A bottom plate is fixedly connected to the lower side wall of the anti-islanding cabinet. A sealing frame is fixedly connected to the rear side wall of the cabinet door. An airbag frame that contacts the sealing frame is fixedly connected to the inner wall of the anti-islanding cabinet. When the knife switch inside the photovoltaic anti-islanding device is oxidized on the surface due to long-term use, resulting in an increase in contact resistance and temperature rise, the present invention can timely remind the operator. And under the operator's command, it can automatically polish the oxidized part on the surface of the knife switch and apply conductive paste to reduce the resistance at the contact of the knife switch, avoiding the problem of local overheating or even fire caused by the oxidation of the contact of the knife switch.

Description

Technical Field

[0001] The present invention belongs to the technical field of anti-islanding, and particularly relates to a photovoltaic anti-islanding device. Background Art

[0002] When the power grid is operating normally, the power grid and the photovoltaic power generation system supply power to the load together. However, when the power grid is powered off due to maintenance or faults, the system is in a situation where the photovoltaic power generation system supplies power to the load alone. At this time, the system loses the control of the power grid and is in an out-of-control state. This situation where the photovoltaic power generation system supplies power to the load alone is called the islanding effect. Islanding is an inevitable phenomenon in the photovoltaic grid-connected power generation system, and its harm is great. In severe cases, it may even endanger personal safety. Therefore, some anti-islanding devices have emerged continuously. For example, a photovoltaic anti-islanding device proposed in the patent with the publication number CN211377602U.

[0003] During the long-term use of the photovoltaic anti-islanding device, the internal knife switch will be oxidized on the surface due to factors such as frequent on-off of current, resulting in an increase in contact resistance. It is very difficult for maintenance personnel to detect this situation in a timely manner. This will cause the contact part of the knife switch to continuously heat up, further exacerbating the oxidation at the contact. In severe cases, it may cause local overheating or even fire.

[0004] In addition, during the long-term use process, the sealing rubber strip of the door of the anti-islanding cabinet ages and deforms, resulting in poor sealing of the door. This will make it easy for dust, moisture, etc. to enter the cabinet, affecting the normal operation of electrical equipment and reducing the protection level of the cabinet body at the same time.

[0005] Therefore, a photovoltaic anti-islanding device is proposed to solve the above problems. Summary of the Invention

[0006] The purpose of the present invention is to provide a photovoltaic anti-islanding device for the above problems.

[0007] To achieve the above object, the present invention adopts the following technical solutions: A photovoltaic anti-islanding device includes an anti-islanding cabinet and a cabinet door hinged to the front side of the anti-islanding cabinet. A PLC controller is fixedly connected to the inner wall of the anti-islanding cabinet. A bottom plate is fixedly connected to the lower side wall of the anti-islanding cabinet. A sealing frame is fixedly connected to the rear side wall of the cabinet door. An airbag frame in contact with the sealing frame is fixedly connected to the inner wall of the anti-islanding cabinet. It further includes:

[0008] A knife switch mechanism is arranged on the inner wall of the anti-islanding cabinet. The knife switch mechanism includes an insulating plate and a protective cover. Two static contacts are hinged to the side wall of the insulating plate. A knife pole is hinged in each of the two static contacts. The ends of the two knife poles far from the static contacts are fixedly connected to the same handle. A contact clip is fixedly connected to the side wall of the insulating plate.

[0009] A repair component, arranged on the inner wall of the cabinet door, for cleaning the oxide layer on the surface of the knife electrode and the contact clip;

[0010] A temperature reduction component, arranged on the upper side wall of the bottom plate, for cooling the inside of the anti-islanding cabinet;

[0011] A detection component, arranged on the right side wall of the anti-islanding cabinet, for detecting the aging and damage of the airbag frame.

[0012] Preferably, the repair component includes a first small electric push rod and a moving seat. A groove matching the end of the handle is provided on the side wall of the moving seat. The first small electric push rod is fixedly connected to the inner wall of the cabinet door. The moving seat is fixedly connected to the moving end of the first small electric push rod. An installation frame is fixedly connected to the upper side wall of the moving seat. The installation frame is of an inverted L-shaped structure. An infrared probe is fixedly connected to the inner wall of the installation frame, and the infrared probe is electrically connected to the PLC controller. A second small electric push rod is fixedly connected to the upper side wall of the installation frame. The moving end of the second small electric push rod is fixedly connected to a lifting plate. Two cleaning seats are fixedly connected to the lower side wall of the lifting plate. The lower end of the longitudinal section of the cleaning seat is of a pointed structure. First abrasive papers are attached to the front and rear sides of the cleaning seat. A support frame is fixedly connected to the lower side wall of the lifting plate. The support frame is of an inverted U-shaped structure. A first micro motor is fixedly connected to the rear side wall of the support frame. A transmission shaft is rotatably connected to the inner wall of the support frame. The output end of the first micro motor is fixedly connected to the rear end of the transmission shaft. Two rotating plates are fixedly sleeved on the rod wall of the transmission shaft. Cleaning frames are fixedly connected to the lower ends of the two rotating plates. The cleaning frames are of an inverted U-shaped structure. Elastic plates are connected to the inner side walls of the two sides of the cleaning frames through springs. Second abrasive papers are fixedly connected to the side walls of the opposite sides of the two elastic plates. A same coating component is fixedly connected to the upper ends of the two rotating plates.

[0013] Preferably, the coating component includes a storage box fixedly connected to the upper ends of the two rotating plates. Conductive paste is stored in the storage box. Two coating frames are fixedly connected to the side wall of the storage box. The coating frames are of a U-shaped structure. Two coating heads are fixedly connected to the inner wall of the coating frames. A plurality of openings are provided on the surface of the coating heads. A plurality of coating hairs are connected to the surface of the coating heads. The same U-shaped pipe is fixedly communicated between the two coating heads on the same side. A peristaltic pump is fixedly communicated with the upper side wall of the storage box. The discharge end of the peristaltic pump is fixedly communicated with a horizontal pipe. The left and right sides of the horizontal pipe are respectively communicated with the coating heads on both sides.

[0014] Preferably, the temperature reduction component includes a water tank connected above the bottom plate. The water tank is fixedly connected to the bottom plate through a bracket. A plurality of semiconductor refrigeration plates are inserted into the side wall of the water tank. The heat dissipation ends of the plurality of semiconductor refrigeration plates all extend out of the water tank. A micro water pump is fixedly communicated with the upper side wall of the water tank. The liquid outlet end of the micro water pump is fixedly communicated with a refrigeration pipe. A temperature reduction cover is fixedly connected to the upper side wall of the anti-islanding cabinet. The end of the refrigeration pipe away from the micro water pump is arranged in a serpentine structure in the temperature reduction cover. A temperature reduction box is fixedly connected to the rear side wall of the anti-islanding cabinet. The lower end of the refrigeration pipe passes through the temperature reduction box and is communicated with the water tank. The part of the refrigeration pipe located in the temperature reduction box is arranged in a serpentine structure. A blower is fixedly connected to the rear side wall of the anti-islanding cabinet. The air inlet end of the blower is communicated with the temperature reduction box. An air outlet cavity is opened inside the anti-islanding cabinet. A plurality of air outlet holes are opened on the side wall of the air outlet cavity. The air outlet end of the blower is communicated with the air outlet cavity. A plurality of exhaust ports are opened on the side wall of the anti-islanding cabinet, and a dust-proof net is fixedly connected inside the exhaust ports.

[0015] Preferably, an air inlet elbow is fixedly communicated with the upper side wall of the temperature reduction box, and a dust-proof cover is fixedly sleeved on the air inlet end of the air inlet elbow.

[0016] Preferably, the detection component includes a detection box fixedly connected to the right side wall of the anti-islanding cabinet. A short pipe is fixedly communicated with the upper side wall of the detection box. An air outlet pipe is fixedly communicated with the air outlet end of the blower. A first control valve is arranged in the air outlet pipe. A second control valve is arranged at the air outlet end of the blower. The front end of the air outlet pipe is communicated with an air bag frame. The upper end of the short pipe is communicated with the air outlet pipe. A piston plate is connected to the lower inner wall of the detection box through a spring. An exhaust hole is opened on the lower side wall of the detection box. A first trigger switch and a second trigger switch are fixedly connected to the inner wall of the detection box. The first trigger switch and the second trigger switch are respectively located on the upper and lower sides of the piston plate.

[0017] Preferably, a pulling box is fixedly connected to the upper side wall of the insulating plate through a bracket. A winding roller is rotatably connected to the inner wall of the pulling box. A servo motor is fixedly connected to the side wall of the pulling box. The output end of the servo motor is connected to the winding roller. A pulling rope is wound around the winding roller. The end of the pulling rope away from the winding roller extends out of the pulling box and is fixedly connected to a handle. A blocking block is fixedly connected to the front side wall of the protective cover.

[0018] Preferably, a small hydraulic cylinder is fixedly connected to the lower side wall of the pulling box, and a top plate is fixedly connected to the moving end of the small hydraulic cylinder.

[0019] Compared with the existing technology, the advantages of the photovoltaic anti-islanding device are as follows:

[0020] 1. Through the provided repair component and smearing component, when the knife switch inside the photovoltaic anti-islanding device oxidizes on the surface due to long-term use, resulting in an increase in contact resistance and temperature rise, it can promptly remind the operator. And under the operator's command, it can automatically polish the oxidized part on the surface of the knife switch and smear conductive paste to reduce the resistance at the contact of the knife switch, avoiding problems such as local overheating and even fire caused by oxidation at the contact of the knife switch.

[0021] 2. Through the provided detection component, when the airbag frame used for sealing inside the photovoltaic anti-islanding device ages and is damaged, it can promptly remind the operator to replace the aged and damaged airbag frame, avoiding the problem that dust and moisture enter the inside of the photovoltaic anti-islanding device and affect the normal operation of electrical equipment.

[0022] 3. Through the provided cooling component, when the photovoltaic anti-islanding device is used outdoors in summer, it can prevent direct sunlight from shining on the top of the photovoltaic anti-islanding device, avoiding the influence of external temperature on the inside of the photovoltaic anti-islanding device. At the same time, it can timely discharge the heat generated inside the photovoltaic anti-islanding device, avoiding the influence of internal high temperature on the photovoltaic anti-islanding device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of the photovoltaic anti-islanding device provided by the present invention.

[0024] Figure 2 is a schematic internal structural diagram of the anti-islanding cabinet in the photovoltaic anti-islanding device provided by the present invention.

[0025] Figure 3 is the photovoltaic anti-islanding device provided by the present invention Figure 1 right view.

[0026] Figure 4 is the photovoltaic anti-islanding device provided by the present invention Figure 3 enlarged schematic diagram of part A.

[0027] Figure 5 is a schematic diagram of the positional relationship between the cabinet door and the sealing frame in the photovoltaic anti-islanding device provided by the present invention.

[0028] Figure 6 is a schematic diagram of the positional relationship between the anti-islanding cabinet, the airbag frame and the sealing frame in the photovoltaic anti-islanding device provided by the present invention.

[0029] Figure 7 is a schematic structural diagram of the detection component in the photovoltaic anti-islanding device provided by the present invention.

[0030] Figure 8 is a schematic structural diagram of the repair component in the photovoltaic anti-islanding device provided by the present invention.

[0031] Figure 9 It is a schematic structural diagram of the coating component in the photovoltaic anti-islanding device provided by the present invention.

[0032] Figure 10 It is a right view of the cleaning base in the photovoltaic anti-islanding device provided by the present invention.

[0033] Figure 11 It is a schematic structural diagram of the knife switch mechanism in the photovoltaic anti-islanding device provided by the present invention.

[0034] Figure 12 It is a schematic internal structure diagram of the pulling box in the photovoltaic anti-islanding device provided by the present invention.

[0035] In the figure: 1 anti-islanding cabinet, 2 cabinet door, 3 PLC controller, 4 bottom plate, 5 sealing frame, 6 airbag frame, 7 knife switch mechanism, 71 insulating plate, 72 protective cover, 8 static contact, 9 knife pole, 10 handle, 11 contact clip, 12 top plate, 13 repair component, 131 first small electric push rod, 132 moving seat, 14 mounting rack, 15 second small electric push rod, 16 lifting plate, 17 cleaning base, 18 first abrasive paper, 19 support frame, 20 first micro motor, 21 transmission shaft, 22 rotating plate, 23 cleaning frame, 24 elastic plate, 25 second abrasive paper, 26 coating component, 261 storage box, 262 coating frame, 27 coating head, 28 coating hair, 29 U-shaped pipe, 30 peristaltic pump, 31 horizontal pipe, 32 cooling component, 321 water tank, 322 semiconductor refrigeration plate, 33 micro water pump, 34 refrigeration pipe, 35 cooling cover, 36 cooling box, 37 blower, 38 air outlet cavity, 39 air outlet hole, 40 exhaust port, 41 dustproof net, 42 intake elbow pipe, 43 dustproof cover, 44 detection component, 441 detection box, 442 short pipe, 45 air outlet pipe, 46 first control valve, 47 second control valve, 48 piston plate, 49 exhaust hole, 50 first trigger switch, 51 second trigger switch, 52 pulling box, 53 winding roller, 54 servo motor, 55 pull rope, 56 blocking block, 57 small hydraulic cylinder, 58 infrared probe. Detailed implementation manners

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0037] As Figures 1 to 12 shown, a photovoltaic anti-islanding device includes an anti-islanding cabinet 1 and a cabinet door 2 hinged to the front side of the anti-islanding cabinet 1. A PLC controller 3 is fixedly connected to the inner wall of the anti-islanding cabinet 1, a bottom plate 4 is fixedly connected to the lower side wall of the anti-islanding cabinet 1, a sealing frame 5 is fixedly connected to the rear side wall of the cabinet door 2, and an airbag frame 6 in contact with the sealing frame 5 is fixedly connected to the inner wall of the anti-islanding cabinet 1. It further includes:

[0038] The disconnecting switch mechanism 7 is arranged on the inner wall of the anti-islanding cabinet 1. The disconnecting switch mechanism 7 includes an insulating plate 71 and a protective cover 72. Two static contacts 8 are hinged to the side wall of the insulating plate 71. Knife poles 9 are hinged inside both of the two static contacts 8. The ends of the two knife poles 9 far away from the static contacts 8 are fixedly connected to the same handle 10. A contact clip 11 is fixedly connected to the side wall of the insulating plate 71;

[0039] The repair component 13 is arranged on the inner wall of the cabinet door 2 and is used for cleaning the oxide layers on the surfaces of the knife pole 9 and the contact clip 11. The repair component 13 includes a first small electric push rod 131 and a moving seat 132. A groove matching the end of the handle 10 is formed on the side wall of the moving seat 132. The first small electric push rod 131 is fixedly connected to the inner wall of the cabinet door 2. The moving seat 132 is fixedly connected to the moving end of the first small electric push rod 131. An installation frame 14 is fixedly connected to the upper side wall of the moving seat 132. The installation frame 14 is of an inverted L-shaped structure. An infrared probe 58 is fixedly connected to the inner wall of the installation frame 14, and the infrared probe 58 is electrically connected to the PLC controller 3. A second small electric push rod 15 is fixedly connected to the upper side wall of the installation frame 14. A lifting plate 16 is fixedly connected to the moving end of the second small electric push rod 15. Two cleaning seats 17 are fixedly connected to the lower side wall of the lifting plate 16. The lower end of the longitudinal section of the cleaning seat 17 is of a pointed structure. First polishing sandpapers 18 are attached to both the front and rear sides of the cleaning seat 17. A support frame 19 is fixedly connected to the lower side wall of the lifting plate 16. The support frame 19 is of an inverted U-shaped structure. A first micro motor 20 is fixedly connected to the rear side wall of the support frame 19. A transmission shaft 21 is rotatably connected to the inner wall of the support frame 19. The output end of the first micro motor 20 is fixedly connected to the rear end of the transmission shaft 21. Two rotating plates 22 are fixedly sleeved on the rod wall of the transmission shaft 21. Cleaning frames 23 are fixedly connected to the lower ends of the two rotating plates 22. The cleaning frames 23 are of an inverted U-shaped structure. Elastic plates 24 are connected to both the inner side walls of the cleaning frames 23 through springs. Second polishing sandpapers 25 are fixedly connected to the side walls of the opposite sides of the two elastic plates 24. A coating component 26 is fixedly connected to the upper ends of the two rotating plates 22. When the disconnecting switch inside the photovoltaic anti-islanding device is oxidized due to long-term use, resulting in an increase in contact resistance and temperature rise, it can timely remind the operator, and under the operator's command, it can automatically polish the oxidized parts on the surface of the disconnecting switch;

[0040] The cooling component 32 is arranged on the upper side wall of the bottom plate 4 and is used for cooling the inside of the anti-islanding cabinet 1. The cooling component 32 includes a water tank 321 connected above the bottom plate 4. The water tank 321 is fixedly connected to the bottom plate 4 through a bracket. A plurality of semiconductor refrigeration plates 322 are inserted into the side wall of the water tank 321. The heat dissipation ends of the plurality of semiconductor refrigeration plates 322 all extend out of the water tank 321. A micro water pump 33 is fixedly communicated with the upper side wall of the water tank 321. The liquid outlet end of the micro water pump 33 is fixedly communicated with a refrigeration pipe 34. A cooling cover 35 is fixedly connected to the upper side wall of the anti-islanding cabinet 1. The end of the refrigeration pipe 34 far from the micro water pump 33 is arranged in a serpentine structure in the cooling cover 35. A cooling box 36 is fixedly connected to the rear side wall of the anti-islanding cabinet 1. The lower end of the refrigeration pipe 34 passes through the cooling box 36 and is communicated with the water tank 321. The part of the refrigeration pipe 34 located in the cooling box 36 is arranged in a serpentine structure. A blower 37 is fixedly connected to the rear side wall of the anti-islanding cabinet 1. The air inlet end of the blower 37 is communicated with the cooling box 36. An air outlet cavity 38 is opened inside the anti-islanding cabinet 1. A plurality of air outlet holes 39 are opened on the side wall of the air outlet cavity 38. The air outlet end of the blower 37 is communicated with the air outlet cavity 38. A plurality of exhaust ports 40 are opened on the side wall of the anti-islanding cabinet 1, and a dust-proof net 41 is fixedly connected inside the exhaust ports 40. When the photovoltaic anti-islanding device is used outdoors in summer, it can prevent direct sunlight from shining on the top of the photovoltaic anti-islanding device, avoid the influence of external temperature on the inside of the photovoltaic anti-islanding device, and at the same time can timely discharge the heat generated inside the photovoltaic anti-islanding device, avoiding the influence of the internal high temperature on the photovoltaic anti-islanding device;

[0041] The detection component 44 is arranged on the right side wall of the anti-islanding cabinet 1 and is used for detecting the aging and damage of the airbag frame 6. The detection component 44 includes a detection box 441 fixedly connected to the right side wall of the anti-islanding cabinet 1. A short pipe 442 is fixedly communicated with the upper side wall of the detection box 441. The air outlet end of the blower 37 is fixedly communicated with an air outlet pipe 45. A first control valve 46 is arranged in the air outlet pipe 45. A second control valve 47 is arranged at the air outlet end of the blower 37. The front end of the air outlet pipe 45 is communicated with the airbag frame 6. The upper end of the short pipe 442 is communicated with the air outlet pipe 45. The lower inner wall of the detection box 441 is connected with a piston plate 48 through a spring. An exhaust hole 49 is opened on the lower side wall of the detection box 441. A first trigger switch 50 and a second trigger switch 51 are fixedly connected to the inner wall of the detection box 441. The first trigger switch 50 and the second trigger switch 51 are respectively located on the upper and lower sides of the piston plate 48. When the airbag frame 6 used for sealing inside the photovoltaic anti-islanding device is aged and damaged, it can timely remind the operator to replace the aged and damaged airbag frame 6, avoiding the problem that dust and moisture enter the inside of the photovoltaic anti-islanding device and affect the normal operation of electrical equipment.

[0042] The smearing component 26 includes a storage box 261 fixedly connected to the upper ends of two rotating plates 22. The storage box 261 stores conductive paste. Two smearing frames 262 are fixedly connected to the side wall of the storage box 261. The smearing frames 262 are of U-shaped structure. Two smearing heads 27 are fixedly connected to the inner wall of the smearing frames 262. The surface of the smearing heads 27 is provided with a plurality of openings. A plurality of smearing hairs 28 are connected to the surface of the smearing heads 27. The same U-shaped tube 29 is fixedly communicated between the two smearing heads 27 on the same side. The upper side wall of the storage box 261 is fixedly communicated with a peristaltic pump 30. The discharging end of the peristaltic pump 30 is fixedly communicated with a horizontal tube 31. The left and right sides of the horizontal tube 31 are respectively communicated with the smearing heads 27 on both sides, and the conductive paste can be smeared at the grinding part of the knife electrode 9.

[0043] The upper side wall of the cooling box 36 is fixedly communicated with an intake elbow 42. The intake end of the intake elbow 42 is fixedly covered with a dust-proof cover 43, which can prevent dust from entering the intake elbow 42.

[0044] The upper side wall of the insulating plate 71 is fixedly connected with a pulling box 52 through a bracket. A winding roller 53 is rotatably connected to the inner wall of the pulling box 52. A servo motor 54 is fixedly connected to the side wall of the pulling box 52. The output end of the servo motor 54 is connected to the winding roller 53. A pull rope 55 is wound around the winding roller 53. One end of the pull rope 55 far from the winding roller 53 extends out of the pulling box 52 and is fixedly connected to the handle 10. A blocking block 56 is fixedly connected to the front side wall of the protective cover 72, which can control the rotation of the knife electrode 9.

[0045] The lower side wall of the pulling box 52 is fixedly connected with a small hydraulic cylinder 57. The moving end of the small hydraulic cylinder 57 is fixedly connected with a top plate 12, which can push the knife electrode 9.

[0046] Now, the operation principle of the present invention is described as follows: When the knife switch mechanism 7 inside the photovoltaic anti-islanding device is oxidized on the surface due to frequent on-off of the current, the resistance between the contact clip 11 and the knife electrode 9 inside the knife switch mechanism 7 will increase, resulting in abnormal temperature at the contact position between the contact clip 11 and the knife electrode 9. After the infrared probe 58 detects the abnormal temperature at the contact position between the contact clip 11 and the knife electrode 9, the infrared probe 58 will send an electrical signal to the PLC controller 3. After receiving this electrical signal, the PLC controller 3 will feedback this situation to the receiving end through the communication module. After the operator in front of the receiving end sees this situation, when the photovoltaic anti-islanding device is overhauled next time, the oxidation layer on the surface of the knife switch mechanism 7 can be polished;

[0047] When the operator performs maintenance on the PV anti-islanding device, the current needs to be disconnected, and an electrical signal is sent to the PLC controller 3 through an external operation panel. After receiving the electrical signal, the PLC controller 3 will control the servo motor 54 to rotate forward, and at the same time, it will also control the small hydraulic cylinder 57 to work. The small hydraulic cylinder 57 will push the handle 10 through the top plate 12, causing the handle 10 to drive the knife electrode 9 and the contact clip 11 to separate. And the servo motor 54 will drive the winding roller 53 to rotate, so that the pulling rope 55 wound on the surface of the winding roller 53 is relaxed. The knife electrode 9 and the handle 10 will continue to rotate under the action of gravity until the blocking block 56 supports the knife electrode 9. At this time, the knife electrode 9 is in a horizontal state. After the servo motor 54 works for five seconds, the knife electrode 9 will be laid flat. After the servo motor 54 works for five seconds, the PLC controller 3 will control the first small electric push rod 131 to work. The first small electric push rod 131 will drive the moving seat 132 to move to a set distance close to the handle 10, so that the protrusion on the surface of the handle 10 is inserted into the groove on the surface of the moving seat 132, and the positions of the handle 10 and the knife electrode 9 can be fixed. Then the PLC controller 3 controls the second small electric push rod 15 to work. The second small electric push rod 15 will drive the lifting plate 16 to move up and down reciprocally. The lifting plate 16 drives the transmission shaft 21, the rotating plate 22, the cleaning frame 23 and the elastic plate 24 to move up and down reciprocally together through the support frame 19. The ends of the two elastic plates 24 on the same side close to the knife electrode 9 are arc-shaped structures and can separate to both sides when contacting the knife electrode 9 (the elastic plate 24 is connected to the cleaning frame 23 through a guide chute and a guide slider, which increases the stability of the movement of the elastic plate 24). Thus, the oxide layer on the surface of the knife electrode 9 is polished by the second abrasive paper 25 between the two elastic plates 24. At the same time, the lifting plate 16 will also drive the first abrasive paper 18 to move inside the inner wall of the contact clip 11 through the cleaning seat 17, and the oxide layer on the inner wall of the contact clip 11 is polished by the first abrasive paper 18. After the polishing work is carried out for one minute, the PLC controller 3 will control the first micro-motor 20 to work. The first micro-motor 20 will drive the transmission shaft 21 to rotate clockwise by 180 degrees, so that the coating frame 262 is placed downward. Then the PLC controller 3 controls the peristaltic pump 30 to work. The peristaltic pump 30 transports the conductive paste in the storage box 261 to the four coating heads 27 through the horizontal pipe 31 and the U-shaped pipe 29, and the conductive paste is polished on the polished part of the knife electrode 9 by the coating heads 27, thereby reducing the resistance at the contact of the knife switch mechanism 7 and avoiding the problem that the knife switch mechanism 7 causes local overheating and even fire due to oxidation at the contact;

[0048] When the grinding of the disconnecting switch mechanism 7 is completed, the PLC controller 3 will control the buzzer module inside to emit a prompt sound. After the operator hears this prompt sound, an electrical signal can be sent to the PLC controller 3 through the operation panel. After receiving this electrical signal, the PLC controller 3 will control the first control valve 46 to open, and the gas inside the airbag frame 6 will be discharged through the air outlet pipe 45, the first control valve 46, the blower 37, the cooling box 36, and the intake elbow 42 (the blower 37 is of a non-closed structure, and the gas can be discharged through the blower 37). Then the operator can open the cabinet door 2 to repair the components inside the anti-islanding cabinet 1. After the repair is completed, the operator closes the cabinet door 2 and controls the blower 37 and the first control valve 46 to work through the operation panel and the PLC controller 3. The blower 37 conveys the external gas to the airbag frame 6 through the air outlet pipe 45 and conveys the gas to the detection box 441 through the short pipe 442, increasing the gas above the piston plate 48. Under the action of air pressure, the piston plate 48 will move downward. When the air pressure above the airbag frame 6 and the piston plate 48 reaches the set air pressure (3 atmospheres), the piston plate 48 will squeeze the second trigger switch 51, and the second trigger switch 51 will control the blower 37 to stop working and control the first control valve 46 to close through the PLC controller 3. When the airbag frame 6 is damaged due to aging or other reasons, the gas inside the airbag frame 6 and the detection box 441 will be slowly discharged to the outside. Under the action of the spring elasticity, the piston plate 48 will move upward until it squeezes the first trigger switch 50, and the first trigger switch 50 will send an electrical signal to the PLC controller 3. After receiving this electrical signal, the PLC controller 3 will feedback this situation to the receiving end through the communication module. After learning this situation through the receiving end, the operator needs to replace the damaged airbag frame 6 in time to avoid the problem that dust and moisture enter the photovoltaic anti-islanding device and affect the normal operation of electrical equipment;

[0049] When the temperature is relatively high in summer and this situation is detected by the temperature sensor externally installed on the anti-islanding cabinet 1 (the temperature sensor is not shown in the figure), the temperature sensor will control the semiconductor refrigeration plate 322 and the micro water pump 33 to work simultaneously through the PLC controller 3. The semiconductor refrigeration plate 322 cools the liquid inside the water tank 321, and the cooled liquid is transported into the refrigeration pipe 34 by using the micro water pump 33. The liquid enters the cooling cover 35 through the refrigeration pipe 34, and the heat inside the cooling cover 35 can be absorbed (using the cooling cover 35 to block the sunlight for cooling). Moreover, the liquid will also be transported into the cooling box 36 through the refrigeration pipe 34. When the PLC controller 3 controls the blower 37 to work, the gas with a relatively high external temperature will enter the cooling box 36 through the intake elbow 42. After being cooled by the refrigeration pipe 34, the cold air will be transported to the air outlet cavity 38 and discharged through the air outlet hole 39, so that the heat inside the anti-islanding cabinet 1 is discharged through the exhaust port 40, avoiding the influence of high temperature on the photovoltaic anti-islanding device.

[0050] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Photovoltaic anti-islanding device, including an anti-islanding cabinet and a cabinet door hinged to the front side of the anti-islanding cabinet. A PLC controller is fixedly connected to the inner wall of the anti-islanding cabinet. A bottom plate is fixedly connected to the lower side wall of the anti-islanding cabinet. A sealing frame is fixedly connected to the rear side wall of the cabinet door. An airbag frame in contact with the sealing frame is fixedly connected to the inner wall of the anti-islanding cabinet. It is characterized in that, It further includes: A knife switch mechanism is arranged on the inner wall of the anti-islanding cabinet. The knife switch mechanism includes an insulating board and a protective cover. Two static contacts are hinged to the side wall of the insulating board. Knife poles are hinged in both of the two static contacts. The ends of the two knife poles away from the static contacts are fixedly connected to the same handle. A contact clip is fixedly connected to the side wall of the insulating board; A repair component is arranged on the inner wall of the cabinet door for cleaning the oxide layers on the surfaces of the knife poles and the contact clips. The repair component includes a first small electric push rod and a moving seat. A groove matching the end of the handle is formed in the side wall of the moving seat. The first small electric push rod is fixedly connected to the inner wall of the cabinet door. The moving seat is fixedly connected to the moving end of the first small electric push rod. An installation frame is fixedly connected to the upper side wall of the moving seat. The installation frame is of an inverted L-shaped structure. An infrared probe is fixedly connected to the inner wall of the installation frame, and the infrared probe is electrically connected to a PLC controller. A second small electric push rod is fixedly connected to the upper side wall of the installation frame. The moving end of the second small electric push rod is fixedly connected to a lifting plate. Two cleaning seats are fixedly connected to the lower side wall of the lifting plate. The lower end of the longitudinal section of the cleaning seat is of a pointed structure. First abrasive papers are attached to the front and rear sides of the cleaning seat. A support frame is fixedly connected to the lower side wall of the lifting plate. The support frame is of an inverted U-shaped structure. A first micro motor is fixedly connected to the rear side wall of the support frame. A transmission shaft is rotatably connected to the inner wall of the support frame. The output end of the first micro motor is fixedly connected to the rear end of the transmission shaft. Two rotating plates are fixedly sleeved on the rod wall of the transmission shaft. Cleaning frames are fixedly connected to the lower ends of the two rotating plates. The cleaning frames are of an inverted U-shaped structure. Elastic plates are connected to the inner side walls of both sides of the cleaning frames through springs. Second abrasive papers are fixedly connected to the side walls of the opposite sides of the two elastic plates. A coating component is fixedly connected to the upper ends of the two rotating plates; A cooling component is arranged on the upper side wall of the bottom plate for cooling the inside of the anti-islanding cabinet; A detection component is arranged on the right side wall of the anti-islanding cabinet for detecting the aging and damage conditions of the airbag frame.

2. The PV anti-islanding device according to claim 1, wherein, The coating component includes a storage box fixedly connected to the upper ends of the two rotating plates. Electrically conductive paste is stored in the storage box. Two coating frames are fixedly connected to the side wall of the storage box. The coating frames are of a U-shaped structure. Two coating heads are fixedly connected to the inner wall of the coating frames. A plurality of openings are formed on the surface of the coating head. A plurality of coating hairs are connected to the surface of the coating head. The same U-shaped pipe is fixedly communicated between the two coating heads on the same side. A peristaltic pump is fixedly communicated with the upper side wall of the storage box. The discharge end of the peristaltic pump is fixedly communicated with a transverse pipe. The left and right sides of the transverse pipe are respectively communicated with the coating heads on both sides.

3. The photovoltaic anti-islanding device according to claim 1, characterized in that The cooling component includes a water tank connected above the bottom plate. The water tank is fixedly connected to the bottom plate through a bracket. A plurality of semiconductor refrigeration plates are inserted into the side wall of the water tank, and the heat dissipation ends of the plurality of semiconductor refrigeration plates all extend out of the water tank. The upper side wall of the water tank is fixedly communicated with a micro water pump. The liquid outlet end of the micro water pump is fixedly communicated with a refrigeration pipe. The upper side wall of the anti-islanding cabinet is fixedly connected with a cooling cover. The end of the refrigeration pipe away from the micro water pump is arranged in a serpentine structure in the cooling cover. The rear side wall of the anti-islanding cabinet is fixedly connected with a cooling box. The lower end of the refrigeration pipe passes through the cooling box and is communicated with the water tank. The part of the refrigeration pipe located in the cooling box is arranged in a serpentine structure. The rear side wall of the anti-islanding cabinet is fixedly connected with a blower. The air inlet end of the blower is communicated with the cooling box. An air outlet cavity is formed inside the anti-islanding cabinet. A plurality of air outlet holes are formed in the side wall of the air outlet cavity. The air outlet end of the blower is communicated with the air outlet cavity. A plurality of exhaust ports are formed in the side wall of the anti-islanding cabinet, and a dust-proof net is fixedly connected inside the exhaust ports.

4. The PV anti-islanding device according to claim 3, wherein, The upper side wall of the cooling box is fixedly communicated with an intake elbow pipe, and a dust-proof cover is fixedly sleeved at the intake end of the intake elbow pipe.

5. The PV anti-islanding device according to claim 3, characterized in that, The detection component includes a detection box fixedly connected to the right side wall of the anti-islanding cabinet. The upper side wall of the detection box is fixedly communicated with a short pipe. The air outlet end of the blower is fixedly communicated with an air outlet pipe. A first control valve is arranged in the air outlet pipe. A second control valve is arranged at the air outlet end of the blower. The front end of the air outlet pipe is communicated with an airbag frame. The upper end of the short pipe is communicated with the air outlet pipe. The lower inner wall of the detection box is connected with a piston plate through a spring. An exhaust hole is formed in the lower side wall of the detection box. A first trigger switch and a second trigger switch are fixedly connected to the inner wall of the detection box. The first trigger switch and the second trigger switch are respectively located on the upper and lower sides of the piston plate.

6. The PV anti-islanding device according to claim 1, wherein, The upper side wall of the insulating plate is fixedly connected with a pulling box through a bracket. A winding roller is rotatably connected to the inner wall of the pulling box. A servo motor is fixedly connected to the side wall of the pulling box. The output end of the servo motor is connected to the winding roller. A pulling rope is wound around the winding roller. The end of the pulling rope away from the winding roller extends out of the pulling box and is fixedly connected with a handle. A blocking block is fixedly connected to the front side wall of the protective cover.

7. The PV anti-islanding device according to claim 6, characterized in that, The lower side wall of the pulling box is fixedly connected with a small hydraulic cylinder, and the moving end of the small hydraulic cylinder is fixedly connected with a top plate.

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