Metal shell type SF 6 Internal insulation damage warning and early fault removal method for high-voltage circuit breakers

Abstract

The present invention relates to the technical field of circuit breakers, specifically a method for warning of internal insulation damage and early fault removal in a metal-enclosed SF6 high-voltage circuit breaker, including: determining the SF6 leakage rate; predicting the insulation breakdown time; presetting the device tripping and alarm strategy; designing and constructing an insulation monitoring system. The present invention can solve the problems that the reaction time of manual handling is insufficient for the sudden drop of SF6 gas pressure in metal-enclosed high-voltage circuit breakers such as tank circuit breakers, GIS, and HGIS, and it is powerless to prevent the internal insulation breakdown from damaging the equipment. It can trip adjacent circuit breakers by starting the corresponding breaker failure protection before the insulation breakdown and remove the faulty equipment in advance; solve the problem that the severity of SF6 leakage cannot be measured and manual on-site inspection and verification are required; solve the problem of false signals related to SF6 gas pressure caused by poor insulation in a single circuit. Compared with the prior art, it has great advantages.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit breakers, specifically to a method for warning of internal insulation damage and early fault removal of a metal - shell - type SF 6 high - voltage circuit breaker Background Technique

[0002] In 1988, the professional standard of the Ministry of Machinery and Electronics Industry, "General Technical Conditions for Sulfur Hexafluoride Circuit Breakers" (ZBK43001 - 88), required in 4.6 zero - gauge - pressure withstand voltage: the metal - shell - type circuit breaker should withstand 1.1 to 1.3 times the highest power - frequency phase voltage for 5 minutes with respect to the ground. This requirement was cancelled in the 1999 revised version (JB / T9694 - 1999). Currently, neither national standards nor industry standards have the requirement for the "zero - gauge - pressure power - frequency withstand voltage test" of circuit breakers. Therefore, for SF 6 insulated tank - type circuit breakers, GIS (Gas Insulated Switchgear), HGIS (Hybrid Gas Insulated Switchgear, with a structure basically the same as GIS, but the busbar is not installed in the SF 6 gas chamber), etc. high - voltage electrical equipment, a large number of them adopt miniaturized and compact designs. When the SF 6 gas pressure drops suddenly and approaches zero gauge pressure, the internal insulation margin is insufficient, and the conductive part will discharge and break down through the metal shell. Specifically, the following problems exist:

[0003] (1) There is no disposal measure for the equipment burned out due to insulation breakdown discharge caused by rapid SF 6 leakage: When the SF 6 gas pressure drops, it first alarms, and then locks the opening and closing when the pressure further decreases. Although it can avoid serious accidents such as explosion caused by opening and closing the circuit breaker when the arc - extinguishing ability is insufficient, it cannot avoid the problem that the artificial response time is insufficient due to the too - fast drop of the SF 6 gas pressure, and the internal insulation can only break down and discharge to burn out the equipment. The short - circuit fault will cause a large number of equipment to be involved and power outages, and at the same time, normal equipment such as main transformers will also be impacted by the short - circuit fault current in the near area.

[0004] (2) The severity of SF 6 leakage cannot be measured: Even if SF 6 leakage does occur, its severity cannot be measured. It is necessary for personnel to go to the site to check and verify the SF 6 pressure value and its decreasing trend. During the process of inspection and verification, it is possible that due to the rapid SF 6 leakage, the insulation has broken down and short - circuited to the ground (the shell), and it is impossible to quickly take appropriate disposal measures according to different leakage degrees to prevent the further expansion of the accident.

[0005] (3) SF 6The accuracy of the abnormal signal cannot be determined: Due to the humid environment, the insulation of the secondary circuit is poor, and it often misissues signals such as SF 6 pressure reduction alarm, etc. The credibility of the signals of a single circuit is extremely low, and no rash disposal measures can be taken. It is necessary to conduct on-site inspections to verify the authenticity of the signals. To avoid human poisoning, it is necessary to follow relevant regulations such as wearing SF 6 protective clothing and approaching the leaking equipment from the upwind. Depending on the distance, it takes 15 - 30 minutes. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for warning of internal insulation damage and early fault removal of a metal - shell - type SF 6 high - voltage circuit breaker to solve the problems raised in the above - mentioned background technology.

[0007] To solve the above - mentioned technical problems, one of the purposes of the present invention is to provide a method for warning of internal insulation damage and early fault removal of a metal - shell - type SF 6 high - voltage circuit breaker, including the following steps:

[0008] S1. Determine the SF 6 leakage rate according to the time difference between the issuance of the "SF 6 leakage alarm" signal of the circuit breaker and the issuance of the "SF 6 total block 1" or "SF 6 total block 2" signal;

[0009] S2. Predict the insulation breakdown time according to the SF 6 leakage rate;

[0010] S3. Calculate the actual time required for each circuit breaker to take different disposal measures, inversely calculate the corresponding total block time setting value, and implant it into the protection device;

[0011] S4. When it is predicted that the insulation breakdown time is extremely short and there is no time for manual disposal, adopt the "early fault removal" strategy, start the malfunction protection circuit of the corresponding circuit breaker to trip the adjacent circuit breaker, and remove the fault before the insulation breakdown;

[0012] S5. When it is predicted that the insulation breakdown time is only enough to take the measure of "directly disconnecting the adjacent circuit breaker without adjusting the operation mode", issue the "SF 6 pressure level - I alarm" signal, and at the same time start the accident total unlocking of the monitoring machine, manually disconnect the adjacent circuit breakers one by one, or preset the "isolate circuit breaker XXX" program operation combined order on the monitoring machine to save time;

[0013] S6: When it is predicted that the insulation breakdown time is sufficient to take the measure of "disconnecting the disconnectors on both sides of the faulty circuit breaker without voltage after adjusting the operation mode", send SF 6Level II pressure alarm. According to the principle of dealing with the failure of circuit breaker locking for opening, isolate the faulty circuit breaker after adjusting the operation mode.

[0014] Preferably, in the step S1, taking the time t 6 when the "SF 告警 leakage alarm" signal is sent as the starting point, calculate the time t 6 when the "SF 6 total lockout 1" signal (or the "SF 总闭锁 total lockout 2" signal, which theoretically acts simultaneously) is sent. The difference "SF 6 total lockout time t bs " is used to determine the leakage rate. The formula is:

[0015] t bs = t 总闭锁 - t 告警 (1)

[0016] Preferably, in the step S1, the equipment for detecting the leakage rate using the pressure change method includes but is not limited to pressure gauges, density meters, or specialized pressure change detectors, leakage rate monitoring systems.

[0017] Preferably, in the step S2, multiply the "SF 6 total lockout time t bs " by a specific proportionality coefficient k jc to predict the insulation breakdown time (i.e., the remaining manual handling response time). The formula is:

[0018] t cz = k jc ·t bs = k jc (t 总闭锁 - t 告警 ) (2)

[0019] where k jc is the proportionality coefficient between the "insulation breakdown time" when the SF 6 pressure drops to the breakdown pressure under the condition that 30% of the area of the circuit breaker's maximum probability explosion-proof film ruptures and the "SF 6 total lockout time t bs ".

[0020] Preferably, in the step S3, measure the actual manual handling time required for each circuit breaker, including: 1) the handling time t cz1 required to directly disconnect the adjacent circuit breaker without adjusting the operation mode after verifying the signal; 2) the handling time t cz2 required to open the disconnectors on both sides of the faulty circuit breaker under no voltage after adjusting the operation mode after verifying the signal. And calculate the corresponding total lockout time setting value inversely. The formula is:

[0021] t ck1 = t cz1 / k jc (3)

[0022] t ck2 = t cz2 / k jc (4)

[0023] Preferably, in the step S4, the determination condition for adopting the "early fault excision" strategy is SF 6 Total blocking time t bs < t ck1 , that is, there is not enough time to directly disconnect the adjacent circuit breakers, so the automatic device is used for excision, or the control word can be used or the link is set to select only signal sending without tripping.

[0024] Preferably, in the step S4, the failure protection circuit of the corresponding circuit breaker includes but is not limited to: 1) When the 3 / 2 wiring mode is adopted, the failure of the circuit breaker trips the side circuit breaker + remotely trips the opposite side of the line (or the failure trips the three sides of the main transformer); 2) When the 3 / 2 wiring mode is adopted, the failure of the side circuit breaker starts the failure of the corresponding bus + trips the intermediate circuit breaker + remotely trips the opposite side of the line (or the failure trips the three sides of the main transformer); 3) When the double-bus wiring mode is adopted, the failure of the line circuit breaker starts the failure of the corresponding bus + remotely trips the opposite side; 4) The failure of the main transformer circuit breaker starts the failure of the corresponding bus + the failure interlocks and trips the three sides of the main transformer; 5) The failure of the bus-tie (sectionalizing) circuit breaker starts the failure of the corresponding bus.

[0025] Preferably, in the step S5, the determination condition for adopting the measure of "directly disconnecting the adjacent circuit breakers without adjusting the operation mode" is t ck1 ≤ t bs < t ck2 , that is, the insulation breakdown time is only enough to take the measure of "directly disconnecting the adjacent circuit breakers without adjusting the operation mode", but not enough to adjust the operation mode and open the disconnectors on both sides of the faulty circuit breaker without voltage;

[0026] Preferably, in the step S5, the total accident unlocking can be automatically started after the monitoring computer receives the "SF 6 Gas pressure level I alarm" signal, or can be manually started.

[0027] Preferably, in the step S5, the monitoring computer presets the program operation combined order of "isolating the XXX circuit breaker". The program operation task executed by this station is exactly the same as the failure start of this circuit breaker to trip the adjacent circuit breaker, but the control circuits of each target circuit breaker are used for simultaneous opening; if the circuit breaker on the opposite side of the line is ordered by the dispatcher, it is operated by the opposite side to disconnect.

[0028] Preferably, in the step S6, the determination condition for adopting the measure of "opening the disconnectors on both sides of the faulty circuit breaker without voltage after adjusting the operation mode" is t ck2 ≤ tbs , that is, the manual handling reaction time is sufficient, and the faulty circuit breaker can be isolated after adjusting the operation mode according to the principles for handling the circuit breaker's locked trip fault.

[0029] The second object of the present invention is to provide a metal shell type SF 6 device for early warning of internal insulation damage and early fault removal of high-voltage circuit breakers, characterized in that: a control circuit board is provided inside the warning and removal device, and the circuit board includes a CPU core control unit, a power supply module, an MMI module, a communication module, optoelectronic isolation, a switch input circuit, and a switch output circuit.

[0030] As a further improvement of this technical solution, in addition to programming with microcomputer protection for the composition of the device, a traditional relay can also be used to form a protection circuit. Any equivalent changes or modifications made according to the principles and design ideas disclosed in the present invention are within the protection scope of the present invention.

[0031] Preferably, the power supply module is connected to a DC 220V DC power supply, and is converted into a working voltage that can be used by the microprocessor through a voltage stabilizing circuit and output to the CPU core control unit.

[0032] Preferably, the switch input circuit is connected to the microswitches of "SF 6 leakage alarm", "SF 6 total lockout 1", and "SF 6 total lockout 2". After the DC 220V switch input signal is optically isolated, it is converted into a weak electrical signal that can be received by the microprocessor and connected to the CPU core control unit.

[0033] Preferably, the switch output circuit uses a switch output module and adopts optoelectronic isolation measures to output three passive contacts of "start malfunction trip adjacent circuit breaker", "SF 6 gas pressure level I alarm", and "SF 6 gas pressure level II alarm". The "start malfunction trip adjacent circuit breaker" circuit is connected to the corresponding protection device after expanding the number of contacts for starting the malfunction. At the same time, the three output circuits are connected to the measurement and control device for sending action signals, and the common terminal (positive electricity) of the corresponding signals is provided by the connected protection and measurement and control devices.

[0034] Preferably, the communication module adopts an Ethernet communication interface A, an Ethernet communication interface B, and an RS485 communication interface. The MMI module is connected to the CPU module through a signal line, and the MMI man-machine dialogue module is specifically a liquid crystal touch screen.

[0035] A third object of the present invention is to provide a computer-readable storage medium storing a computer program corresponding to a tripping and warning strategy, and when the computer program is executed by a CPU core control unit processor, the above-mentioned method for warning internal insulation damage of a metal-enclosed SF 6 high-voltage circuit breaker and pre-removing faults realizes all steps.

[0036] Preferably, for GIS, HGIS and all other SF 6 gas-insulated electrical equipment, the same method can be used for warning internal insulation damage and pre-removing faults. Any equivalent changes or modifications made according to the principles and design ideas disclosed in the present invention are within the protection scope of the present invention.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] 1. The method for warning internal insulation damage of a metal-enclosed SF 6 high-voltage circuit breaker and pre-removing faults isolates the faulty equipment before the insulation breakdown burns out the equipment: when SF 6 leaks sharply and the system judges that the reaction time for manual disposal is insufficient, the adjacent circuit breaker is tripped before the insulation breakdown to pre-remove the faulty equipment, avoiding damage to internal components such as the tank body and the conducting rod, preventing a large number of equipment from being affected and powered off, and preventing normal equipment such as the main transformer from being impacted by the short-circuit fault current in the near area.

[0039] 2. The method for warning internal insulation damage of a metal-enclosed SF 6 high-voltage circuit breaker and pre-removing faults can measure the severity of SF 6 leakage: by calculating the time difference between "circuit breaker SF 6 leakage" and "circuit breaker SF 6 total block", it is used to distinguish the severity of SF 6 leakage, and trip isolation measures are taken or different signals are sent. When "SF 6 gas pressure level I warning" occurs, the adjacent circuit breaker is manually disconnected to remove the fault, avoiding being classified as a serious-level accident event. When "SF 6 gas pressure level II warning" occurs, the operation mode is adjusted and then the fault is isolated, and the normal equipment is not powered off or the power-off range is small.

[0040] 3. The method for warning internal insulation damage of a metal-enclosed SF 6 high-voltage circuit breaker and pre-removing faults improves the accuracy of SF 6 gas pressure abnormal signals: the probability of mis-sending signals in a single loop is relatively large, while in this system, "SF 6 start failure trip", "SF6 gas pressure level I warning", "SF 6For any one of the output signals of the "Level II Pressure Alarm" to actuate, it is necessary for one of the two total blocking signals, namely "Circuit Breaker SF 6 Leakage" and "Circuit Breaker SF 6 Total Blocking 1", "Circuit Breaker SF 6 Total Blocking 2", to actuate, and the mutual verification has a relatively high credibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings are used to provide a further understanding of the present invention and form a part of the specification. Together with the embodiments of the present invention, they are further explained in detail, but do not constitute a limitation to the present invention.

[0042] Figure 1 Schematic diagram of the internal structure of the exemplary metal - enclosed SF 6 High - voltage tank - type circuit breaker in the present invention;

[0043] Figure 2 Schematic diagram of the SF gas monitoring of the exemplary metal - enclosed high - voltage circuit breaker in the present invention 6 ;

[0044] Figure 3 Schematic diagram of the structure of the exemplary density relay in the present invention;

[0045] Figure 4 Flowchart of the method for warning of internal insulation damage and early fault removal of the exemplary metal - enclosed SF 6 High - voltage circuit breaker in the present invention;

[0046] Figure 5 Logic block diagram of the warning of internal insulation damage and early fault removal protection of the exemplary metal - enclosed SF 6 High - voltage circuit breaker in the present invention;

[0047] Figure 6 Schematic diagram of the exemplary system structure in the present invention;

[0048] Figure 7 Exemplary appearance view in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0049] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention and the drawings of the specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0050] Embodiment

[0051] The internal structure of the metal - enclosed SF 6 High - voltage tank - type circuit breaker is asFigure 1 As shown, it includes a circuit breaker tank body with a sealing structure. A pressure gauge and an SF density relay for monitoring the internal pressure of the circuit breaker tank body are also externally connected to the circuit breaker tank body. 6 Density relay.

[0052] The circuit breaker should operate at the rated SF density. When the density is lower than the minimum operating density, the insulation and arc extinguishing capabilities cannot be guaranteed. For a metal shell type SF high-voltage circuit breaker 6 The SF gas monitoring system is as 6 shown in. Each phase of the tank body is a closed gas chamber, and each phase gas chamber is monitored by the following components: a check valve, a density relay B4, gas filling and test connectors W1 and W2, and connecting pipes. 6 The SF density inside the circuit breaker is monitored by a density relay B4, and the structure of the density relay is as Figure 2 shown. The density relay B4 compares the SF gas density in the gas chamber with the standard gas density of the standard gas chamber sealed in its inner cavity. The gases in the two chambers are in the same ambient temperature, and the influence of temperature on pressure can be ignored. Thus, the density difference can be converted into the pressure difference between the two systems.

[0053] Furthermore, the SF density relay includes a microswitch arranged inside the housing. When the SF gas in the circuit breaker leaks, the bellows in the standard gas chamber will extend, driving the microswitch of the density relay to act, and different contacts will be connected to send out different signals such as "SF leakage warning", "SF total lockout 1", "SF total lockout 2", etc. 6 As shown in, this embodiment provides a method for warning of internal insulation damage and early removal of faults in a metal shell type SF high-voltage circuit breaker, including the following steps: Figure 3 shown. The density relay B4 compares the SF gas density in the gas chamber with the standard gas density of the standard gas chamber sealed in its inner cavity. The gases in the two chambers are in the same ambient temperature, and the influence of temperature on pressure can be ignored. Thus, the density difference can be converted into the pressure difference between the two systems. 6 The gases in the two chambers are in the same ambient temperature, and the influence of temperature on pressure can be ignored. Thus, the density difference can be converted into the pressure difference between the two systems.

[0054] Furthermore, 6 the SF density relay includes a microswitch arranged inside the housing. When the SF gas in the circuit breaker leaks, the bellows in the standard gas chamber will extend, driving the microswitch of the density relay to act, and different contacts will be connected to send out different signals. 6 When the SF gas in the circuit breaker leaks, the bellows in the standard gas chamber will extend, driving the microswitch of the density relay to act, and different contacts will be connected to send out different signals such as "SF 6 leakage warning", 6 "SF 6 total lockout 1",

[0055] As Figure 4 shown, this embodiment provides a method for warning of internal insulation damage and early removal of faults in a metal shell type SF 6 high-voltage circuit breaker, including the following steps:

[0056] S1. Determine the SF 6 leakage rate according to the time difference between the issuance of the "SF 6 leakage warning" signal and the issuance of the "SF 6 total lockout 1" or "SF 6 total lockout 2" signal of the circuit breaker;

[0057] S2. Predict the insulation breakdown time according to the SF 6 leakage rate;

[0058] S3. Measure the actual time required for each circuit breaker to take different disposal measures, inversely calculate the corresponding total blocking time setting value, and implant it into the protection device;

[0059] S4. Predict that the insulation breakdown time is extremely short and there is no time for manual disposal. Adopt the strategy of "removing the fault in advance", start the malfunction protection circuit of the corresponding circuit breaker to trip the adjacent circuit breakers, and remove the fault before the insulation breakdown;

[0060] S5. Predict that the insulation breakdown time is only enough to take the measure of "directly disconnecting the adjacent circuit breakers without adjusting the operation mode". Send out the "SF 6 gas pressure level I alarm" signal, and at the same time start the total accident unlocking of the monitoring machine, manually disconnect the adjacent circuit breakers one by one, or preset the "isolate circuit breaker XXX" program operation combined order in the monitoring machine to save time;

[0061] S6: Predict that the insulation breakdown time is enough to take the measure of "disconnecting the isolating switches on both sides of the faulty circuit breaker after adjusting the operation mode". Send out the SF 6 gas pressure level II alarm, and isolate the faulty circuit breaker after adjusting the operation mode according to the principle of handling the circuit breaker locking trip fault.

[0062] In this embodiment, taking the time t 6 when the "SF 告警 leakage alarm" signal is sent as the starting point, calculate the time t 6 when the "SF 6 total blocking 1" signal (or the "SF 总闭锁 total blocking 2" signal, which theoretically acts simultaneously) is sent. The difference is the "SF 6 total blocking time t bs ", to determine the leakage rate. The formula is:

[0063] t bs = t 总闭锁 - t 告警 (1)

[0064] Further, multiply the "SF 6 total blocking time t bs " by a specific proportionality coefficient k jc to predict the insulation breakdown time (i.e., the remaining manual disposal response time). The formula is:

[0065] t cz = k jc · t bs = k jc (t 总闭锁 - t 告警 ) (2)

[0066] where k jc is the condition for 30% of the area of the circuit breaker's maximum probability explosion-proof membrane to rupture. Under the condition of SF6 The "insulation breakdown time" when the pressure drops to the breakdown pressure and the "SF 6 Total blocking time t bs The proportionality coefficient between ". The proportionality coefficients k of circuit breakers of different models jc are different. For example, the actual value of the 500 kV 3AP2 DT-FI type circuit breaker is 82.801 / 1.394 = 59.398 ≈ 60.

[0067] In addition, measure the actual manual handling time required for each circuit breaker, including: 1) The handling time t cz1 required to directly disconnect the adjacent circuit breaker without adjusting the operation mode after verifying the signal; 2) The handling time t cz2 required to open the isolating switches on both sides of the faulty circuit breaker without voltage after adjusting the operation mode after verifying the signal. And calculate the corresponding total blocking time setting value inversely. The formula is:

[0068] t ck1 = t cz1 / k jc (3)

[0069] t ck2 = t cz2 / k jc (4)

[0070] When it is predicted that the SF 6 total blocking time t bs < t ck1 , that is, there is not enough time to directly disconnect the adjacent circuit breaker, use the automatic device to cut off, or you can also use the control word or set the link to select only sending a signal without tripping. The corresponding failure protection circuits of the above circuit breakers include but are not limited to: 1) When the circuit breaker fails in the 3 / 2 wiring mode, trip the side circuit breaker + remote trip the opposite side of the line (or trip the three sides of the main transformer when the circuit breaker fails); 2) When the side circuit breaker fails in the 3 / 2 wiring mode, start the failure of the corresponding bus + trip the intermediate circuit breaker + remote trip the opposite side of the line (or trip the three sides of the main transformer when the circuit breaker fails); 3) When the line circuit breaker fails in the double-bus wiring mode, start the failure of the corresponding bus + remote trip the opposite side; 4) When the main transformer circuit breaker fails, start the failure of the corresponding bus + failure interlock trip the three sides of the main transformer; 5) When the bus coupler (sectionalizing) circuit breaker fails, start the failure of the corresponding bus.

[0071] When it is predicted that the SF 6 total blocking time is between t ck1 and t ck2 , that is, t ck1 ≤ t bs < t ck2 , take the measure of "directly disconnecting the adjacent circuit breaker without adjusting the operation mode". And when the monitoring machine receives "SF 6After receiving the "Level I Pressure Alarm" signal, the accident total unlocking can be automatically activated, or manually activated. At the same time, use the monitoring computer to preset the "Isolate XXX Circuit Breaker" program to operate the comprehensive order and disconnect the adjacent circuit breakers.

[0072] When predicting SF 6 Total locking time t bs ≥t ck2 Take the measure of "Pull the isolating switches on both sides of the faulty circuit breaker without voltage after adjusting the operation mode". According to the principle of handling the fault of the circuit breaker with locked trip, isolate the faulty circuit breaker after adjusting the operation mode.

[0073] This embodiment also provides a method for operating a platform device, that is, a metal shell type SF 6 Internal insulation damage warning and early fault removal device for high-voltage circuit breakers. The system structure is as Figure 6 shown, and the exemplary device panel is as Figure 7 shown. The device includes a control circuit board, and the circuit board includes a CPU core control unit, a power module, an MMI module, a communication module, optoelectronic isolation, a switch input circuit, and a switch output circuit.

[0074] Among them, the power module is connected to a DC 220V DC power supply, and is converted into a working voltage that can be used by the microprocessor through a voltage stabilizing circuit, and output to the CPU core control unit.

[0075] The switch input circuit is connected to the density relay "SF 6 Leakage Alarm", "SF 6 Total Lock 1", "SF 6 Total Lock 2" microswitches. After the DC 220V switch input signal is optically isolated, it is converted into a weak electrical signal that can be received by the microprocessor and connected to the CPU core control unit.

[0076] The switch output circuit uses a switch output module and adopts optoelectronic isolation measures to output three passive contacts: "Start Malfunction Trip Adjacent Circuit Breaker", "SF 6 Level I Pressure Alarm", "SF 6 Level II Pressure Alarm". The "Start Malfunction Trip Adjacent Circuit Breaker" circuit is connected to the corresponding protection device after expanding the number of contacts for starting the malfunction. At the same time, the three output circuits are connected to the measurement and control device for sending action signals, and the corresponding signal common terminal (positive power) is provided by the connected protection and measurement and control devices.

[0077] The communication module uses Ethernet communication interface A, Ethernet communication interface B, and RS485 communication interface. The MMI module is connected to the CPU module through a signal line, and the MMI man-machine dialogue module is specifically a liquid crystal touch screen.

[0078] This embodiment provides a computer-readable storage medium, which stores a computer program corresponding to a tripping and warning strategy, and its action logic is as Figure 5 shown. When the computer program is executed by a CPU core control unit processor, all steps of the above method for early warning of internal insulation damage and early fault removal of a metal-enclosed SF 6 high-voltage circuit breaker are implemented.

[0079] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only preferred examples of the present invention and do not limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. Metal - shell type SF 6 Internal insulation damage warning and early fault removal method for high - voltage circuit breakers, It is characterized in that It includes the following steps: S1. Determine the SF leakage rate based on the time difference between the issuance of the "SF leakage alarm" signal and the issuance of the "SF total block 1" or "SF total block 2" signal. 6 Leakage alarm" signal is sent to "SF 6 Total block 1" or "SF 6 Total block 2" signal is sent to determine the SF 6 Leakage rate; S2. Predict the insulation breakdown time according to SF 6 Leakage rate; S3. Measure the actual time required for each circuit breaker to take different disposal measures, inversely calculate the corresponding total blocking time setting value, and implant it into the protection device; S4. Predict that the insulation breakdown time is extremely short and there is no time for manual disposal, adopt the "fault pre-removal" strategy, start the malfunction protection circuit of the corresponding circuit breaker to trip the adjacent circuit breaker, and remove the fault before the insulation breakdown; S5. When the predicted insulation breakdown time is only enough to take the measure of "directly disconnecting the adjacent circuit breaker without adjusting the operation mode", send out the "SF 6 gas pressure level I alarm" signal, and at the same time start the total accident unlocking of the monitoring machine, manually disconnect the adjacent circuit breakers one by one, or preset the "isolate circuit breaker XXX" program operation combined order on the monitoring machine to save time; S6: Predict that the insulation breakdown time is sufficient to take the measure of "opening the disconnectors on both sides of the faulty circuit breaker without voltage after adjusting the operation mode", and send SF 6 The SF6 gas pressure level II alarm is given. According to the principle of handling the fault of the circuit breaker with blocked opening, isolate the faulty circuit breaker after adjusting the operation mode.

2. The metal shell type SF according to claim 1 6 Early warning of internal insulation failure and method for early removal of faults of high - voltage circuit breakers It is characterized in that: In the step S1, taking "SF 6 the time t when the "leakage alarm" signal is sent 告警 as the starting point, calculate the time t when the "SF 6 total block 1" signal or the "SF 6 total block 2" signal is sent 总闭锁 the difference "SF 6 total blocking time t bs ", to determine the leakage rate. The formula is: t bs = t 总闭锁 -t 告警 (1) 3. According to claim 2, the metal housing type SF 6 Internal insulation failure warning and early fault removal method for high-voltage circuit breakers, It is characterized in that: In the step S1, the pressure change method is used to detect the leakage rate, and the equipment includes but is not limited to a pressure gauge, a densitometer, or a dedicated pressure change detector, a leakage rate monitoring system.

4. According to claim 3, the metal shell type SF 6 Method for warning of internal insulation damage and early removal of faults in high-voltage circuit breakers It is characterized in that: In the step S2, use "SF 6 Total blocking time t bs " multiplied by a specific proportionality coefficient k jc , to predict the insulation breakdown time. The formula is: t cz = k jc ·t bs = k jc (t 总闭锁 - t 告警 ) (2) where k jc is the proportionality coefficient between the "insulation breakdown time" when the SF 6 pressure drops to the breakdown pressure under the condition that 30% of the area of the maximum probability explosion-proof film of the circuit breaker ruptures and the "total locking time t 6 ". bs ​ 5. The method for warning of internal insulation failure and early removal of faults in a metal - enclosed SF 6 high - voltage circuit breaker according to claim 4 It is characterized in that: In the step S3, measure the actual manual handling time required for each circuit breaker, including: 1) the handling time t required to directly disconnect the adjacent circuit breaker without adjusting the operation mode after verifying the signal cz1 ; 2) the handling time t required to open the disconnectors on both sides of the faulty circuit breaker without voltage after adjusting the operation mode after verifying the signal cz2 , and inversely calculate the corresponding total blocking time setting value. The formula is: t ck1 = t cz1 / k jc (3) t ck2 = t cz2 / k jc (4) 6. The method for warning of internal insulation breakdown and early removal of faults of the metal case type SF 6 high voltage circuit breaker according to claim 5 It is characterized in that: In the said step S4, the determination condition for adopting the "fault pre-removal" strategy is SF 6 Total blocking time t bs < t ck1 , that is, when there is not enough time to directly disconnect the adjacent circuit breaker, the failure protection circuit of the corresponding circuit breaker is activated to trip the adjacent circuit breaker, or the control word or link can be used to select only signal sending without tripping; Among them, the malfunction protection circuit of the circuit breaker includes but is not limited to: 1) When the 3 / 2 wiring mode is adopted, the circuit breaker malfunction trips the side circuit breaker + remotely trips the opposite side of the line or the malfunction trips the three sides of the main transformer; 2) When the 3 / 2 wiring mode is adopted, the side circuit breaker malfunction starts the corresponding busbar malfunction + trips the intermediate circuit breaker + remotely trips the opposite side of the line or the malfunction trips the three sides of the main transformer; 3) When the double-bus wiring mode is adopted, the line circuit breaker malfunction starts the corresponding busbar malfunction + remotely trips the opposite side; 4) The main transformer circuit breaker malfunction starts the corresponding busbar malfunction + the malfunction interlocks and trips the three sides of the main transformer; 5) The bus-coupler circuit breaker malfunction starts the corresponding busbar malfunction.

7. The method for warning of internal insulation damage and early removal of faults in a metal - enclosed SF 6 high - voltage circuit breaker according to claim 6 It is characterized in that: In the said step S5, the judgment condition for taking the measure of "directly disconnecting the adjacent circuit breakers without adjusting the operation mode" is t ck1 ≤t bs <t ck2 , that is, the insulation breakdown time is only enough to take the measure of "directly disconnecting the adjacent circuit breakers without adjusting the operation mode", but not enough to adjust the operation mode and open the disconnectors on both sides of the faulty circuit breaker without voltage; at the same time, the total accident unlocking can be automatically started after the monitoring machine receives the "SF 6 gas pressure level I alarm" signal, or can also be manually started.

8. The method for warning of internal insulation failure and early removal of faults in a metal - enclosed SF 6 high - voltage circuit breaker according to claim 7, It is characterized in that: In the step S5, the monitoring machine presets the program operation combined order of "isolating the XXX circuit breaker". The program operation task executed by this station is exactly the same as that of the circuit breaker malfunction starting to trip the adjacent circuit breaker, but the control circuits of each target circuit breaker are used for simultaneous opening; if the circuit breaker on the opposite side of the line is ordered by the dispatcher, it is operated and disconnected by the opposite side.

9. According to claim 8, the metal shell type SF 6 Early warning of internal insulation failure and method for early removal of faults in high-voltage circuit breakers It is characterized in that: In the said step S6, the determination condition for taking the measure of "opening the disconnectors on both sides of the faulty circuit breaker without voltage after adjusting the operation mode" is t ck2 ≤t bs , that is, the manual handling response time is sufficient, and the faulty circuit breaker can be isolated after adjusting the operation mode according to the fault handling principle of circuit breaker locking for opening.

10. Metal enclosure type SF 6 Internal insulation damage warning and early fault removal device for high-voltage circuit breaker, used for the metal enclosure type SF described in any one of claims 1-9 6 Internal insulation damage warning and early fault removal method for high-voltage circuit breaker It is characterized in that: A control circuit board is arranged in the warning eliminator. The circuit board includes a CPU core control unit, a power supply module, an MMI module, a communication module, optoelectronic isolation, a switch input loop, and a switch output loop. Specifically: The power supply module accesses the DC 220V DC power supply, converts it into the working voltage that can be used by the microprocessor through a voltage stabilizing circuit, and outputs it to the CPU core control unit; The digital input circuit is connected to the micro switches of the density relay "SF 6 Leakage alarm", "SF 6 Total blocking 1", "SF 6 Total blocking 2". After the DC 220V digital input signal is optically isolated, it is converted into a weak electrical signal that can be accepted by the microprocessor and then connected to the CPU core control unit; The switch output loop uses a switch output module and adopts optoelectronic isolation measures to output three passive contacts: "start malfunction trip adjacent circuit breaker", "SF 6 gas pressure level I alarm", "SF 6 gas pressure level II alarm". The "start malfunction trip adjacent circuit breaker" loop is connected to the corresponding protection device through the expanded contact quantity for starting malfunction. At the same time, the three output loops are connected to the measurement and control device for sending action signals, and the common terminal of the corresponding signals is provided by the connected protection and measurement and control devices. The communication module adopts an Ethernet communication interface A, an Ethernet communication interface B, and an RS485 communication interface. The MMI module is connected to the CPU module through a signal line. The MMI man-machine dialogue module is specifically a liquid crystal touch screen.

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