SF6 density relay checking device and checking method thereof

Abstract

The invention discloses an SF6 density relay verification device and a verification method thereof, which realize automatic debugging and calibration in the production process of an SF6 density relay through the combination of manual and automatic pressurization and pressure relief, save time and labor, and improve the accuracy and convenience of adjustment and calibration of the SF6 density relay. The SF6 density relay verification device comprises a box body, the front end face of the box body is provided with an operation panel, the operation panel is provided with a touch display screen, and the right side of the touch display screen is provided with a pressurization button, a pressure release button, a rotary coding switch, a contact state indicating lamp and a power switch. A circuit board, a pressure sensor, a proportional valve, a switching power supply and a temperature transmitter are installed in the box body, and a power socket, a signal aviation plug, a temperature aviation plug, a gas source inlet fast plug, a test port fast plug and an exhaust port fast plug are arranged on the rear end face of the box body.

Description

Technical Field

[0001] The invention relates to the technical field of instrument calibration, and in particular to a SF6 density relay calibration device and a calibration method thereof. Background Art

[0002] SF6 density relay is an important device for monitoring the gas pressure of SF6 circuit breakers in power systems. By real-time monitoring of the gas density in the gas chamber, the normal operation and safety of the equipment can be ensured.

[0003] Currently, in the production process of SF6 density relays, the meter adjustment work usually needs to be carried out in a constant temperature room controlled at 20 degrees Celsius to ensure the accuracy of the relay. Then a calibrated standard pressure gauge is prepared to provide accurate pressure readings. This standard pressure gauge is the benchmark for verifying the accuracy of the SF6 density relay. Then use a gas cylinder filled with nitrogen and connect it to the standard pressure gauge. Connect the standard pressure gauge to the SF6 density relay to be debugged to ensure that the gas can flow from the gas cylinder through the standard pressure gauge and then into the density relay. Open the gas cylinder to allow nitrogen to flow into the system. The meter adjustment master will observe the reading of the standard pressure gauge as a reference. Through mechanical debugging, adjust the contacts and related mechanical components inside the SF6 density relay. These adjustments include adjusting the spring tension, contact gap, etc. The goal is to make the contacts of the SF6 density relay close or open correctly at different pressure points to reflect the actual gas pressure. At each preset pressure point, the meter adjuster will compare the reading of the standard pressure gauge with the contact action of the SF6 density relay. If the contact action does not match the reading of the standard pressure gauge, fine-tuning will be performed until the contacts operate at the correct pressure. This may require repeated adjustments and verifications to ensure the accuracy of the relay over the entire pressure range. After completing the debugging of all pressure points, the meter adjuster will record the debugging results and conduct tests to ensure that the relay can maintain accuracy under various working conditions.

[0004] The nitrogen cylinders used in the existing production process are equipped with mechanical valves. The disadvantage of using the mechanical valves on the cylinders to directly adjust the pressure is that it is difficult to control the intake pressure, which reduces the accuracy of the meter adjustment. The meter adjustment technician needs to perform repeated operations for adjustment, and manual testing is required after the adjustment is completed, which is time-consuming and labor-intensive. Summary of the invention

[0005] The present invention aims to address the technical defects of the prior art and provide an SF6 density relay calibration device and a calibration method thereof. Through the combination of manual and automatic pressurization and pressure release, the automatic debugging and calibration of the SF6 density relay in the production process can be realized, which saves time and labor and improves the accuracy and convenience of SF6 density relay adjustment.

[0006] The present invention provides the following technical solution: an SF6 density relay calibration device, comprising a box, an operation panel is arranged on the front end surface of the box, a touch screen is installed on the operation panel, a pressurization button, a pressure release button, a rotary coding switch, a contact status indicator light and a power switch are arranged on the right side of the touch screen, a circuit board, a pressure sensor, a proportional valve, a switching power supply and a temperature transmitter are installed inside the box, and a power socket, a signal aviation plug, a temperature aviation plug, a gas source inlet quick plug, a test port quick plug and an exhaust port quick plug are arranged on the rear end surface of the box; The power socket is connected to the power switch, the power switch is connected to the switching power supply, and the switching power supply is connected to the circuit board for power supply; the pressurization button, the pressure release button, the rotary coding switch, and the proportional valve are electrically connected to the circuit board respectively; The pressure sensor includes a first pressure sensor and a second pressure sensor, the proportional valve includes an air inlet, a first air outlet and a second air outlet, the air source inlet quick connector is respectively connected to the first pressure sensor and the air inlet of the proportional valve through an air inlet pipe, the first air outlet is respectively connected to the second pressure sensor and the test port quick connector through an air outlet pipe, and the second air outlet is quickly connected to the exhaust port through an air outlet pipe.

[0007] Preferably, the rotary encoding switch is a photoelectric rotary encoding switch, which is used to greatly adjust the test port pressure. The pressure regulation signal is input to the circuit board by rotating, and the circuit board sends a pressure regulation control signal to the proportional valve. The proportional valve adjusts the intake pressure and outputs the pressure to the test port quick plug through the first outlet.

[0008] Preferably, the pressurization button and the pressure release button are fine-tuning buttons for fine-tuning the test port pressure. By pressing the fine-tuning button, a pressure regulating signal is input to the circuit board, and the circuit board sends a pressure regulating control signal to the proportional valve. After the proportional valve adjusts the intake pressure, it outputs the pressure to the test port quick plug through the first outlet.

[0009] Preferably, a 485 aviation plug is also provided on the rear end face of the box body, and the 485 aviation plug is a 4-core aviation plug, wherein two wires are led out from the circuit board and connected to the 485 aviation plug for power supply, and another two wires are led out from the circuit board and connected to the RS232 to RS485 communication module, and the other end of the RS232 to RS485 communication module is connected to the 485 aviation plug to realize 485 communication.

[0010] Preferably, the temperature aviation plug is connected to the input end of the temperature transmitter, and the output end of the temperature transmitter is connected to the circuit board.

[0011] Preferably, a bracket is provided at the bottom of the box, and the bracket includes a bracket body and a connecting end, one end of the connecting end is fixed to both sides of the box, and the other end is provided with a plum blossom groove, and the bracket body is provided with a plum blossom protrusion matching the plum blossom groove; a return spring is provided between the plum blossom groove and the plum blossom protrusion, and when the bracket body is pulled, the plum blossom protrusion is disengaged from the plum blossom groove, and the angle of the bracket is adjusted to the desired position; after releasing the hand, the return spring causes the plum blossom protrusion to automatically engage in the plum blossom groove, thereby fixing the angle of the bracket.

[0012] Preferably, a mounting plate is provided at the bottom of the box, and the circuit board, pressure sensor, proportional valve, switching power supply and temperature transmitter are all fixed on the mounting plate, wherein the pressure sensor is provided with a pressure sensor bracket for fixing the first pressure sensor and the second pressure sensor, and the pressure sensor bracket is configured to be integrally formed and has space for accommodating the first pressure sensor and the second pressure sensor, respectively, and the bottom of the pressure sensor bracket is fixed on the mounting plate.

[0013] The calibration method of the SF6 density relay calibration device is performed as follows: (1) Preparation before calibration: connect the gas source inlet quick plug to the gas source, connect the temperature probe to the temperature plug, connect the signal plug to the SF6 density relay contact, connect the test port quick plug to the SF6 density relay to be tested, connect the exhaust port quick plug to the exhaust pipe, and power on the power socket; (2) Debugging: Turn on the machine and enter the menu interface. Click on manual voltage adjustment to enter the manual voltage adjustment interface. Select the pressure type of the SF6 density relay to be tested. The interface displays contact 1 pressure, contact 2 pressure, contact 3 pressure, control parameters, P pressure, P 20 Pressure can be adjusted manually by rotating the coding switch, pressurization button and pressure release button. 20 Pressure performs mechanical debugging on the SF6 density relay under test, so that the contacts of the SF6 density relay can be correctly closed or opened at different pressure points to reflect the actual gas pressure. After debugging, exhaust the gas source and click Return to return to the menu interface. (3) Automatic test; For ordinary SF6 density relay, click to enter the automatic test interface, select the pressure type of the SF6 density relay to be tested, and the interface displays contact 1 selection, contact 2 selection, contact 3 selection, maximum pressure, and inflation speed. After setting, press the confirmation key to start the automatic test. After the test is completed, the upper cut value of contact 1, the upper cut value of contact 2, the upper cut value of contact 3, the lower cut value of contact 1, the lower cut value of contact 2, and the lower cut value of contact 3 will be displayed. According to the test results, determine whether the readings and actions are accurate. Press the return key to exit the automatic test interface and return to the menu interface; for remote transmission SF6 density relay, click to enter the remote transmission test, select the pressure type of the SF6 density relay to be tested, and after the test is completed, press, temp, and the current P value of the remote transmission table will be displayed. 20, Current address, New address, Atmospheric pressure, P 20 , P, judge whether the readings and actions are accurate based on the test results, press the return key to exit the automatic test interface and return to the menu interface.

[0014] Preferably, the SF6 density relay being tested is a remote transmission type SF6 density relay, and the step further includes connecting the 485 aviation plug to the communication interface of the remote transmission type SF6 density relay.

[0015] Compared with the prior art, the present invention has the following beneficial effects: In the above technical scheme, the SF6 density relay calibration device includes a box body, an operation panel is arranged on the front face of the box body, a touch screen is installed on the operation panel, a pressurization button, a pressure release button, a rotary coding switch, a contact status indicator light and a power switch are arranged on the right side of the touch screen, a circuit board, a pressure sensor, a proportional valve, a switching power supply and a temperature transmitter are installed inside the box body, and a power socket, a signal aviation plug, a temperature aviation plug, a gas source inlet quick plug, a test port quick plug and an exhaust port quick plug are arranged on the rear face of the box body; the power socket is connected to the power switch, the power switch is connected to the switching power supply, and the switching power supply is connected to the circuit board for power supply; the pressurization button, the pressure release button, the rotary coding switch and the proportional valve are electrically connected to the circuit board respectively; the pressure sensor includes a first pressure sensor and a second pressure sensor, the proportional valve includes an air inlet, a first air outlet and a second air outlet, the air source inlet quick plug is respectively connected to the first pressure sensor and the air inlet of the proportional valve through an air inlet pipe, the first air outlet is respectively connected to the second pressure sensor and the test port quick plug through an air outlet pipe, and the second air outlet is connected to the exhaust port quick plug through an air outlet pipe; The present invention discloses an SF6 density relay calibration device. The device is designed as a box-type structure. Through the combination of manual and automatic pressurization and pressure release, the automatic debugging and calibration in the production process of the SF6 density relay is realized. The device has a compact structure and can realize the adjustment of the SF6 density relay anytime and anywhere, saving time and labor and improving the convenience of operation. The device comprises a box body, an operation panel is arranged on the front surface of the box body, a touch display screen is arranged on the operation panel for the operator to perform test operations, a pressurization button and a pressure release button are arranged for fine adjustment of the test port pressure, a rotary coding switch is arranged for large adjustment of the test port pressure, a contact status indicator light indicates the state of the contact, a power switch controls the on and off of the power supply of the entire device, and a power socket is connected to the switch. Turn off the power supply and input AC220V, the switching power supply outputs DC power to the circuit board; the control signal sent by the circuit board is sent to the proportional valve, the proportional valve is set to one inlet and two outlets, the pressure coming in from the air inlet is output to the air outlet through the adjustment of the proportional valve, the first air outlet is connected to the second pressure sensor and the test port quick plug through the air outlet pipe, the adjusted pressure is output to the test port, the pressure sensor tests the pressure of the air outlet, the second air outlet is connected to the exhaust port quick plug through the air outlet pipe, which is used for pressure relief, and can realize manual and automatic pressurization and pressure release, and can obtain the pressure when the contact jumps during the pressure increase and release process, it has the characteristics of fast pressure increase and release process and high pressure measurement accuracy, which improves the accuracy and convenience of SF6 density relay adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of a three-dimensional structure of a specific embodiment of the present invention; Figure 2 for Figure 1 a rear view of the illustrated embodiment; Figure 3 Schematic diagram of the internal structure of the box; Figure 4 is a schematic diagram of the three-dimensional structure of the pressure sensor bracket; Figure 5 It is a schematic diagram of the three-dimensional structure of the operation panel; Figure 6 This is a schematic diagram of the operation interface; Figure 7 This is a schematic diagram of the manual test interface; Figure 8 This is an illustration of the automatic test interface. Figure 1 ; Fig. 9 This is an illustration of the automatic test interface. Figure 2 ; Fig.10 This is a schematic diagram of the remote transmission test interface.

[0017] Description of reference numerals: 1. Touch screen; 2. Pressurization button; 3. Release button; 4. Rotary coding switch; 5. Contact status indicator; 6. Power switch; 7. Box; 8. Bracket; 9. Power socket; 10. Signal plug; 11. Temperature plug; 12. 485 plug; 13. Gas inlet plug; 14. Test port plug; 15. Exhaust port plug; 101. pressure sensor; 102. proportional valve; 103. circuit board; 104. switching power supply; 105. temperature transmitter; 106. pressure sensor bracket. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. All other embodiments obtained by ordinary technicians in the field without making creative work based on the embodiments of the present invention shall fall within the scope of protection of the present invention.

[0019] like Figures 1 to 10 As shown, it shows a specific embodiment of the present invention: Figures 1 to 3 As shown, the SF6 density relay calibration device disclosed in the present invention comprises a box body 7, an operation panel is arranged on the front end face of the box body 7, a touch screen 1 is installed on the operation panel, a pressurization button 2, a pressure release button 3, a rotary coding switch 4, a contact state indicator light 5 and a power switch 6 are arranged on the right side of the touch screen 1, a circuit board 103, a pressure sensor 101, a proportional valve 102, a switching power supply 104 and a temperature transmitter 105 are installed inside the box body 7, and a power socket 9, a signal air plug 10, a temperature air plug 11, an air source inlet quick plug 13, a test port quick plug 14, and an exhaust port quick plug 15 are arranged on the rear end face of the box body 7; The power socket 9 is connected to the power switch 6, the power switch 6 is connected to the switch power supply 104, and the switch power supply 104 is connected to the circuit board 103 for power supply; the pressurization button 2, the pressure release button 3, the rotary coding switch 4, and the proportional valve 102 are electrically connected to the circuit board 103 respectively; The pressure sensor 101 includes a first pressure sensor and a second pressure sensor, the proportional valve 102 includes an air inlet, a first air outlet and a second air outlet, the air source inlet quick connector 13 is respectively connected to the first pressure sensor and the air inlet of the proportional valve 102 through an air inlet pipe, the first air outlet is respectively connected to the second pressure sensor and the test port quick connector 14 through an air outlet pipe, and the second air outlet is connected to the exhaust port quick connector 15 through an air outlet pipe.

[0020] Preferably, Figures 1 to 3As shown, the rotary coding switch 4 is a photoelectric rotary coding switch, which is used to largely adjust the test port pressure. By rotating the input pressure regulation signal to the circuit board 103, the circuit board 103 sends a pressure regulation control signal to the proportional valve 102. The proportional valve 102 adjusts the intake pressure and outputs the pressure through the first outlet to the test port quick plug 14. The photoelectric rotary coding switch is a high-precision, high-resolution detection device that can be used to largely adjust the rotation position and direction. The use of the photoelectric rotary coding switch can achieve a large adjustment of the pressure, saving time and effort, and convenient operation.

[0021] Preferably, Figures 1 to 3 As shown, the pressurization button 2 and the pressure release button 3 are fine-tuning buttons for fine-tuning the test port pressure. By pressing the fine-tuning button, a pressure adjustment signal is input to the circuit board 103, and the circuit board 103 sends a pressure adjustment control signal to the proportional valve 102. The proportional valve 102 adjusts the intake pressure and outputs the pressure to the test port quick plug 14 through the first outlet. The pressurization button 2 and the pressure release button 3 are usually used to fine-tune the air pressure. After the air pressure is greatly adjusted, the pressure is finely adjusted to achieve precise air pressure control, which helps to ensure the accuracy of adjusting the SF6 density relay.

[0022] Preferably, Figures 2-3 As shown, a 485 aviation plug 12 is also provided on the rear end face of the box body 7, and the 485 aviation plug 12 is a 4-core aviation plug, wherein the circuit board 103 leads out 2 wires to connect to the 485 aviation plug 12 for power supply, and the circuit board 103 leads out another 2 wires to connect to the RS232 to RS485 communication module, and the other end of the RS232 to RS485 communication module is connected to the 485 aviation plug 12 to realize 485 communication. A 485 aviation plug 12 interface is set on the rear end face of the box 7 for data communication and power transmission of the remote SF6 density relay, providing a stable and reliable connection method for the equipment; the two wires led out of the circuit board 103 are connected to the 485 aviation plug 12 to power the 485 aviation plug 12, and the other two wires led out of the circuit board 103 are connected to the RS232 to RS485 communication module, which is responsible for converting RS232 format data into RS485 format. Through this conversion, the equipment can achieve compatibility between different communication protocols, so as to better transmit data; this design is to meet the adjustment needs of the remote SF6 density relay. The remote SF6 density relay usually needs to be connected to the 485 communication interface for debugging. Through the 485 communication interface, a connection can be established with the density relay. After the connection is established, relevant instructions can be sent to obtain the status of the density relay, set parameters or perform calibration operations. The ability to debug and set the density meter with wired remote transmission is a good helper for the production of SF6 density relays and remote density relays.

[0023] Preferably, Figure 3As shown, the temperature aerial plug 11 is connected to the input end of the temperature transmitter 105, and the output end of the temperature transmitter 105 is connected to the circuit board 103. A temperature probe is installed on the temperature aerial plug 11, and the resistance value measured by the temperature probe is transmitted to the pressure transmitter. The pressure transmitter converts the resistance value into a current signal and outputs it to the circuit board 103. After receiving the current signal, the circuit board 103 converts it into the corresponding ambient temperature value according to a preset conversion formula, and automatically converts it into a pressure value at 20°C according to the pressure-temperature characteristic relationship of SF6 gas, that is, it can automatically perform dynamic temperature compensation to convert P 20 .

[0024] Preferably, Figure 1 As shown, a bracket 8 is provided at the bottom of the box body 7, and the bracket 8 includes a bracket body and a connecting end. One end of the connecting end is fixed to both sides of the box body 7, and the other end is provided with a plum blossom groove. The bracket body is provided with a plum blossom protrusion matching the plum blossom groove; a return spring is provided between the plum blossom groove and the plum blossom protrusion. When the bracket body is pulled, the plum blossom protrusion is disengaged from the plum blossom groove, and the angle of the bracket 8 is adjusted to the desired position; after releasing the hand, the return spring makes the plum blossom protrusion automatically engage in the plum blossom groove to achieve the fixing of the angle of the bracket 8. This structural design combines the self-locking and angle adjustment functions. Through the action of the return spring, the bracket 8 can be automatically fixed after the angle is adjusted, without the need for manual engagement again. This greatly simplifies the operation process and improves the convenience and stability of use.

[0025] Preferably, Figures 3-4 As shown, a mounting plate is provided at the bottom of the box 7, and the circuit board 103, the pressure sensor 101, the proportional valve 102, the switch power supply 104 and the temperature transmitter 105 are all fixed on the mounting plate, wherein the pressure sensor 101 is provided with a pressure sensor bracket 106 for fixing the first pressure sensor and the second pressure sensor, and the pressure sensor bracket 106 is provided as an integral molding, and is provided with a space for accommodating the first pressure sensor and the second pressure sensor respectively, and the bottom of the pressure sensor bracket 106 is fixed on the mounting plate. The mounting plate is provided for fixing various components in the box 7, and the pressure sensor 101 is provided as two, and the inlet pressure and outlet pressure are tested respectively. The pressure sensor bracket 106 firmly fixes the pressure sensor 101 at the position to be measured, and prevents the pressure sensor 101 from vibrating violently or shifting, which helps to ensure that the measurement data of the sensor is accurate, and ensures the stability and accuracy during the adjustment process. The one-piece design, the targeted design, and the 8-shaped design are adopted to effectively fix the two pressure sensors 101, and a fastening bolt is provided between the two sensors to avoid loosening.

[0026] Preferably, Figures 5 to 10As shown in the figure, it is a specific operation interface of the present invention, wherein each button marked in the figure in each operation interface corresponds to a function, Figure 6 A1-manual voltage regulation; A2-automatic test; A3-remote test; Figure 7 A101-current temperature display bar; A102-gas source pressure display bar; A103-prompt information bar; A104-relative pressure key; A105-gas source exhaust key; A106-empty key; A107-return key; A108-contact 1 pressure; A109-contact 2 pressure; A110-contact 3 pressure; A111-control parameters; A112-current control P pressure value display bar; A113-current control P 20 Pressure value display bar; Figures 8-9 A201-current temperature display bar; A202-gas source pressure display bar; A203-prompt information bar; A204-relative pressure key; A205-inflation speed adjustment key; A206-confirmation key; A207-return key; A208-contact 1 selection; A209-contact 2 selection; A210-contact 3 selection; A211-maximum pressure; A212-minimum pressure; A213-inflation speed display bar; A214-contact 1 upper cut value display bar; A215-contact 2 upper cut value display bar; A216-contact 3 upper cut value display bar; A217-contact 1 lower cut value display bar; A218-contact 2 lower cut value display bar; A219-contact 3 lower cut value display bar; A220-current P pressure value display bar; A221-current P 20 Pressure value display bar; Fig.10 A301-current temperature display bar; A302-gas source pressure display bar; A303-prompt information bar; A304-remote meter current pressure; A305-remote meter current temperature; A306-remote meter current P 20 ; A307-current software version of the remote meter; A308-current atmospheric pressure used by the remote meter; A309-new address to be set for the remote meter; A310-current address of the remote meter; A311-current P pressure value display bar; A312-current P 20 Pressure value display bar; A313-Set address key; A314-Get address key; A315-Read atmospheric pressure value key used by remote meter; A316-Set atmospheric pressure value key used by remote meter; A317-Read remote meter value key; A318-Automatic sensor reading switch key; A319-Relative pressure key; A320-Return key.

[0027] The specific verification method is as follows: The calibration method of the SF6 density relay calibration device is performed as follows: (1) Preparation before calibration: connect the gas source inlet quick plug 13 to the gas source, connect the temperature probe to the temperature air plug 11, connect the signal air plug 10 to the SF6 density relay contact, connect the test port quick plug 14 to the SF6 density relay to be tested, connect the exhaust port quick plug 15 to the exhaust pipe, and power on the power socket 9; (2) Debugging: Turn on the machine and enter the menu interface. Click on manual voltage adjustment to enter the manual voltage adjustment interface. Select the pressure type of the SF6 density relay to be tested. The interface displays contact 1 pressure, contact 2 pressure, contact 3 pressure, control parameters, P pressure, P 20 The pressure is adjusted manually by rotating the coding switch 4, the pressure button 2, and the pressure release button 3. The operator adjusts the pressure manually by P 20 Pressure performs mechanical debugging on the SF6 density relay under test, so that the contacts of the SF6 density relay can be correctly closed or opened at different pressure points to reflect the actual gas pressure. After debugging, exhaust the gas source and click Return to return to the menu interface. (3) Automatic test; For ordinary SF6 density relay, click to enter the automatic test interface, select the pressure type of the SF6 density relay to be tested, and the interface displays contact 1 selection, contact 2 selection, contact 3 selection, maximum pressure, and inflation speed. After setting, press the confirmation key to start the automatic test. After the test is completed, the upper cut value of contact 1, the upper cut value of contact 2, the upper cut value of contact 3, the lower cut value of contact 1, the lower cut value of contact 2, and the lower cut value of contact 3 will be displayed. According to the test results, determine whether the readings and actions are accurate. Press the return key to exit the automatic test interface and return to the menu interface; for remote transmission SF6 density relay, click to enter the remote transmission test, select the pressure type of the SF6 density relay to be tested, and after the test is completed, press, temp, and the current P value of the remote transmission table will be displayed. 20 , Current address, New address, Atmospheric pressure, P 20 , P, judge whether the readings and actions are accurate based on the test results, press the return key to exit the automatic test interface and return to the menu interface.

[0028] Preferably, Figures 5 to 10 As shown, the SF6 density relay under test is a remote SF6 density relay, and step 1 also includes connecting 485 aviation plug 12 to the communication interface of the remote SF6 density relay. 485 aviation plug 12 is connected to the communication interface of the remote SF6 density relay to realize data communication and power supply, thereby realizing manual and automatic adjustment of the remote SF6 density relay, adapting to the adjustment of multiple types of relays in production, with a wide range of applications and convenient operation.

[0029] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the field without departing from the purpose of the present invention. These changes involve related technologies well known to those skilled in the art, which all fall within the scope of protection of the patent of the present invention.

[0030] Many other changes and modifications may be made without departing from the concept and scope of the present invention.It should be understood that the present invention is not limited to the specific embodiments, and the scope of the present invention is defined by the appended claims.

Claims

1. SF6 density relay calibration device, characterized in that: The invention comprises a box (7), wherein an operation panel is arranged on the front face of the box (7), a touch screen (1) is installed on the operation panel, a pressurizing button (2), a pressure releasing button (3), a rotary coding switch (4), a contact state indicator light (5) and a power switch (6) are arranged on the right side of the touch screen (1), a circuit board (103), a pressure sensor (101), a proportional valve (102), a switching power supply (104) and a temperature transmitter (105) are installed inside the box (7), and a power socket (9), a signal air plug (10), a temperature air plug (11), an air source inlet quick plug (13), a test port quick plug (14) and an exhaust port quick plug (15) are arranged on the rear face of the box (7); The power socket (9) is connected to the power switch (6), the power switch (6) is connected to the switch power supply (104), and the switch power supply (104) is connected to the circuit board (103) for power supply; the pressurizing button (2), the pressure releasing button (3), the rotary coding switch (4), and the proportional valve (102) are respectively electrically connected to the circuit board (103); The pressure sensor (101) comprises a first pressure sensor and a second pressure sensor, the proportional valve (102) comprises an air inlet, a first air outlet and a second air outlet, the air source inlet quick connector (13) is respectively connected to the first pressure sensor and the air inlet of the proportional valve (102) via an air inlet pipe, the first air outlet is respectively connected to the second pressure sensor and the test port quick connector (14) via an air outlet pipe, and the second air outlet is connected to the exhaust port quick connector (15) via an air outlet pipe.

2. The SF6 density relay calibration device according to claim 1, characterized in that: The rotary encoding switch (4) is a photoelectric rotary encoding switch used to adjust the test port pressure in a large range. A pressure adjustment signal is input to the circuit board (103) by rotating the switch, and the circuit board (103) sends a pressure adjustment control signal to the proportional valve (102). The proportional valve (102) adjusts the intake pressure and then outputs the pressure to the test port quick connector (14) through the first outlet.

3. The SF6 density relay calibration device according to claim 2, characterized in that: The pressurizing button (2) and the pressure releasing button (3) are fine-tuning buttons for finely adjusting the pressure at the test port. By pressing the fine-tuning button, a pressure regulating signal is input to the circuit board (103), and the circuit board (103) sends a pressure regulating control signal to the proportional valve (102). The proportional valve (102) adjusts the air intake pressure and then outputs the pressure to the test port quick connector (14) through the first air outlet.

4. The SF6 density relay calibration device according to any one of claims 1 to 3, characterized in that: A 485 aviation plug (12) is also provided on the rear end surface of the box body (7), and the 485 aviation plug (12) is a 4-core aviation plug, wherein two wires are led out from the circuit board (103) and connected to the 485 aviation plug (12) for power supply, and another two wires are led out from the circuit board (103) and connected to an RS232 to RS485 communication module, and the other end of the RS232 to RS485 communication module is connected to the 485 aviation plug (12) to realize 485 communication.

5. The SF6 density relay calibration device according to claim 4, characterized in that: The temperature aviation plug (11) is connected to the input end of the temperature transmitter (105), and the output end of the temperature transmitter (105) is connected to the circuit board (103).

6. The SF6 density relay calibration device according to claim 5, characterized in that: A bracket (8) is provided at the bottom of the box body (7), and the bracket (8) comprises a bracket body and a connecting end, one end of the connecting end is fixed to two sides of the box body (7), and the other end is provided with a plum blossom groove, and the bracket body is provided with a plum blossom protrusion matching the plum blossom groove; a return spring is provided between the plum blossom groove and the plum blossom protrusion, and when the bracket body is pulled, the plum blossom protrusion is disengaged from the plum blossom groove, and the angle of the bracket (8) is adjusted to a desired position; after the hand is released, the return spring causes the plum blossom protrusion to automatically snap into the plum blossom groove, thereby achieving the fixing of the angle of the bracket (8).

7. The SF6 density relay calibration device according to claim 5, characterized in that: A mounting plate is provided at the bottom of the box body (7); the circuit board (103), the pressure sensor (101), the proportional valve (102), the switch power supply (104) and the temperature transmitter (105) are all fixed on the mounting plate; the pressure sensor (101) is provided with a pressure sensor bracket (106) for fixing a first pressure sensor and a second pressure sensor; the pressure sensor bracket (106) is integrally formed and is provided with spaces for accommodating the first pressure sensor and the second pressure sensor respectively; and the bottom of the pressure sensor bracket (106) is fixed on the mounting plate.

8. A calibration method for a SF6 density relay calibration device, characterized in that: Using the SF6 density relay calibration device as described in any one of claims 1 to 7, perform the following steps: (1) Preparation before calibration: connect the gas source inlet quick plug (13) to the gas source, connect the temperature probe to the temperature air plug (11), connect the signal air plug (10) to the SF6 density relay contact, connect the test port quick plug (14) to the SF6 density relay to be tested, connect the exhaust port quick plug (15) to the exhaust pipe, and power on the power socket (9); (2) Debugging: Turn on the machine and enter the menu interface. Click on manual voltage adjustment to enter the manual voltage adjustment interface. Select the pressure type of the SF6 density relay to be tested. The interface displays contact 1 pressure, contact 2 pressure, contact 3 pressure, control parameters, P pressure, P 20 The pressure is adjusted manually by rotating the coding switch (4), the pressure increase button (2), and the pressure release button (3). The operator can adjust the pressure manually by pressing the P 20 Pressure performs mechanical debugging on the SF6 density relay under test, so that the contacts of the SF6 density relay can be correctly closed or opened at different pressure points to reflect the actual gas pressure. After debugging, exhaust the gas source and click Return to return to the menu interface. (3) Automatic test; For ordinary SF6 density relay, click to enter the automatic test interface, select the pressure type of the SF6 density relay to be tested, and the interface displays contact 1 selection, contact 2 selection, contact 3 selection, maximum pressure, and inflation speed. After setting, press the confirmation key to start the automatic test. After the test is completed, the upper cut value of contact 1, the upper cut value of contact 2, the upper cut value of contact 3, the lower cut value of contact 1, the lower cut value of contact 2, and the lower cut value of contact 3 will be displayed. According to the test results, determine whether the readings and actions are accurate. Press the return key to exit the automatic test interface and return to the menu interface; for remote transmission SF6 density relay, click to enter the remote transmission test, select the pressure type of the SF6 density relay to be tested, and after the test is completed, press, temp, and the current P value of the remote transmission table will be displayed. 20 , Current address, New address, Atmospheric pressure, P 20 , P, judge whether the readings and actions are accurate based on the test results, press the return key to exit the automatic test interface and return to the menu interface.

9. The calibration method of the SF6 density relay calibration device according to claim 8, characterized in that: The SF6 density relay to be tested is a remote transmission type SF6 density relay, and step (1) further includes connecting the 485 aviation plug (12) to the communication interface of the remote transmission type SF6 density relay.

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