CN115483666A - SF with metal shell 6 Method for early warning of internal insulation damage of high-voltage circuit breaker and early fault removal - Google Patents

Abstract

The invention relates to the technical field of circuit breakers, in particular to SF with a metal shell ₆ The method for early warning of internal insulation damage of the high-voltage circuit breaker and early fault removal comprises the following steps: determination of SF ₆ A leak rate; preparation ofMeasuring the insulation breakdown time; presetting device tripping and alarming strategies; an insulation monitoring system is designed and constructed. The invention can solve the problem of metal case type high voltage circuit breaker SF such as tank type circuit breaker, GIS, HGIS and the like ₆ The problem that the response time of manual handling of air pressure sudden drop is not enough, and the equipment is damaged by internal insulation breakdown but cannot be used as the power is solved, the corresponding breaker failure protection is started before the insulation breakdown to jump off the adjacent breaker, and the fault equipment is cut off in advance; solving the problem of SF ₆ The severity of the leakage cannot be measured, and manual on-site inspection and verification are required; solve the problems of poor insulation of a single loop and SF fault ₆ Air pressure related signal problems. Compared with the prior art, the method has great advantages.

Description

SF with metal shell 6 Method for early warning of internal insulation damage of high-voltage circuit breaker and early fault removal

Technical Field

The invention relates to the technical field of circuit breakers, in particular to SF with a metal shell ₆ A method for early warning and early fault removal of internal insulation damage of a high-voltage circuit breaker.

Background

The professional standard of the department of mechanical and electronic industry, sulfur hexafluoride breaker general technical conditions (ZBK 43001-88) 4.6 zero gauge pressure withstand requirement in 1988: the metal-enclosed circuit breaker is to withstand correspondingly 1.1 to 1.3 times the highest phase voltage at power frequency of 5min, which was cancelled by the 1999 revision (JB/T9694-1999). At present, the national standard and the standard of the action have no requirement of a circuit breaker for zero gauge pressure power frequency withstand test. Thus SF ₆ The structure of the Insulated tank circuit breaker, the Gas Insulated Switchgear (GIS), the Gas Insulated Switchgear (HGIS), and the composite Gas Insulated Switchgear (GIS) is basically the same as that of the GIS, but the bus bar is not installed in the SF ₆ Air chamber) and the like are largely designed in a miniaturized and compact manner, and SF ₆ When the air pressure dip approaches zero gauge pressure, the internal insulation margin is insufficient, and the conductive part discharges and breaks down the metal shell. The following problems are specifically present:

(1)SF ₆ the quick leakage causes the insulation breakdown to discharge and burn out the apparatus has no treatment: SF ₆ The alarm is firstly carried out when the air pressure is reduced, the opening and closing are locked after the pressure is further reduced, although serious accidents such as explosion and the like caused by the opening and closing of the breaker under the condition of insufficient arc extinguishing capacity can be avoided, SF (sulfur hexafluoride) cannot be avoided ₆ The reaction time of manual treatment is not enough when the air pressure is reduced too fast, and the equipment can only be burnt by the internal insulation breakdown discharge. The short-circuit fault can cause a large amount of equipment to be involved and power failure occurs, and meanwhile, normal equipment such as a main transformer can flow short-circuit fault current in a near area to be impacted.

(2)SF ₆ The severity of the leak cannot be measured: even if SF does occur ₆ Leakage, the severity of which is also not measurable, is verified by manual to field inspection of SF ₆ The pressure value and the descending trend thereof may be caused by SF in the process of checking and verifying ₆ The rapid leakage causes the insulation breakdown to be short-circuited to the ground (the shell), and the rapid collection according to different leakage degrees cannot be realizedAnd taking proper measures to prevent the accident from further expanding.

(3)SF ₆ The accuracy of the abnormal signal cannot be determined: the secondary circuit is poor in insulation due to the humidity of the environment, and SF is frequently mistakenly sent ₆ The air pressure reduction alarm and other related signals have extremely low signal reliability of a single loop, cannot adopt treatment measures without trade, and needs to check and verify the authenticity of the signals on site. In order to avoid poisoning of human body, the wearing of SF must be followed in the process ₆ The related regulations of protective clothing, the equipment which is close to the leakage from the upper air inlet and the like consume 15-30 minutes according to the distance.

Disclosure of Invention

The invention aims to provide a metal shell type SF ₆ A method for early warning of internal insulation damage of a high-voltage circuit breaker and early fault removal aims to solve the problems in the background technology.

To solve the above problems, an object of the present invention is to provide a metal-enclosed SF ₆ The method for early warning of internal insulation damage of the high-voltage circuit breaker and early fault removal comprises the following steps:

s1, according to breaker' SF ₆ Leakage alarm signal to SF ₆ Total latch-up 1 'or' SF ₆ Determination of the time difference of the emission of the Total latch 2 "Signal ₆ A leak rate;

s2 according to SF ₆ Predicting the insulation breakdown time by the leakage rate;

s3, measuring and calculating the time actually required by each breaker to take different treatment measures, reversely calculating the corresponding total blocking time fixed value, and implanting a protection device;

s4, predicting that the insulation breakdown time is too short to be manually handled, adopting a strategy of 'removing faults in advance', starting a failure protection circuit of a corresponding circuit breaker to jump off an adjacent circuit breaker, and removing the faults before the insulation breakdown;

s5, predicting the insulation breakdown time only by taking a measure of directly disconnecting adjacent circuit breakers without adjusting the operation mode, and sending out' SF ₆ An air pressure I-level alarm signal, simultaneously starting a monitoring machine to totally unlock the accident, manually disconnecting adjacent circuit breakers one by one,or a program operation comprehensive command of 'isolating XXX breaker' is preset in the monitoring machine so as to save time;

s6: predicting insulation breakdown time, and performing 'adjusting operation mode and then opening isolation switches at two sides of fault circuit breaker without voltage', and then generating SF ₆ And (4) giving an alarm at the air pressure level II, and isolating the fault circuit breaker after adjusting the operation mode according to the circuit breaker locking and opening fault handling principle.

Preferably, in the step S1, the term "SF" is used ₆ Time t of signal sending of leakage alarm _{Alarm system} As a starting point, "SF" is calculated ₆ Total latch 1 "signal (or" SF ₆ Total latch 2 "signal, theoretically acting simultaneously) is emitted for a time t _{Total latch} The difference "" SF " ₆ Total latch-up time t _bs ", to determine the leak rate, the formula is:

t _bs ＝t _{total latch} -t _{Alarm device} (1)

Preferably, in step S1, the device for detecting the leakage rate by using the pressure variation method includes, but is not limited to, a pressure gauge, a densitometer, a special pressure variation detector, and a leakage rate monitoring system.

Preferably, in step S2, the term "SF" is used ₆ Total latch-up time t _bs "multiplying by a specific scaling factor k _jc To predict the insulation breakdown time (i.e., the remaining manual treatment response time), the formula is:

t _cz ＝k _jc ·t _bs ＝k _jc (t _{total latch} -t _{Alarm system} ) (2)

Wherein k is _jc SF is the maximum probability of the explosion-proof membrane of the circuit breaker under the condition of 30 percent area rupture ₆ Dielectric breakdown time and SF of pressure drop to breakdown pressure ₆ Total latch-up time t _bs "the proportionality coefficient between.

Preferably, the step S3 of measuring and calculating the manual handling time actually required for each breaker includes: 1) After verifying the signal, the handling time t required to directly disconnect the adjacent circuit breaker without adjusting the operating mode _cz1 (ii) a 2) Verification signalThen, adjusting the processing time t required by non-pressure pulling of disconnecting switches on two sides of the fault circuit breaker in the operation mode _cz2 . And reversely calculating a corresponding total locking time fixed value, wherein the formula is as follows:

t _ck1 ＝t _cz1 /k _jc (3)

t _ck2 ＝t _cz2 /k _jc (4)

preferably, in step S4, the determination condition of the "early failure removal" policy is SF ₆ Total latch-up time t _bs ＜t _ck1 The adjacent circuit breakers can not be directly disconnected, an automatic device is adopted for cutting, and control words or connecting sheets can be used for selecting to send signals and not trip.

Preferably, in step S4, the failure protection circuit of the corresponding circuit breaker includes, but is not limited to: 1) The three sides of the three-way circuit breaker are connected in a 3/2 connection mode, namely a failed side-jumping circuit breaker and a far-jumping circuit opposite side (or a failed main-jumping side main transformer); 2) The 3/2 connection mode is that when the breaker fails to start, the corresponding bus fails, the mid-jump breaker and the opposite side of the long-jump line (or three sides of the failure main-jump main transformer) are started; 3) The double-bus connection mode line breaker fails and starts a corresponding bus failure + remote tripping opposite side; 4) The main transformer breaker fails and starts three sides of a corresponding bus failure and a failure combined tripping main transformer; 5) And the bus-coupled (segmented) circuit breaker fails to start and corresponds to the bus failure.

Preferably, in the step S5, the determination condition for taking the measure of directly disconnecting the adjacent circuit breaker without adjusting the operation mode is t _ck1 ≤t _bs ＜t _ck2 Namely, the insulation breakdown time is only enough to adopt the measure of directly disconnecting adjacent circuit breakers without adjusting the operation mode, but is not enough to adjust the operation mode and pull open the disconnecting switches at two sides of the fault circuit breaker without pressure;

preferably, in step S5, the accident total unlocking may be received by "SF" at the monitoring machine ₆ The air pressure I-level alarm signal is automatically started, and can also be manually started.

Preferably, in the step S5, the monitor presets a "isolation XXX circuit breaker" program operation comprehensive command, and the program operation task executed by the station is completely consistent with that of the circuit breaker failure starting trip adjacent circuit breaker, but the control loops of the target circuit breakers are used for simultaneous opening; if the circuit breaker on the opposite side of the line is commanded by the dispatching, the circuit breaker on the opposite side is operated and disconnected.

Preferably, in the step S6, the determination condition for taking the measure of 'opening the disconnecting switches at both sides of the fault circuit breaker without pressure after adjusting the operation mode' is t _ck2 ≤t _bs Namely, the manual handling reaction time is sufficient, and the fault circuit breaker can be isolated after the operation mode is adjusted according to the fault handling principle of circuit breaker locking and opening.

The second purpose of the present invention is to provide a metal shell SF ₆ Inside dielectric breakdown early warning of high voltage circuit breaker and device of clearing fault in advance, its characterized in that: the early warning resectoscope is internally provided with a control circuit board, and the circuit board comprises a CPU core control unit, a power supply module, an MMI module, a communication module, a photoelectric isolator, a switching value input circuit and a switching value output circuit.

As a further improvement of the technical scheme, besides the microcomputer protection for programming, the device can also use the traditional relay to form a protection loop. All equivalent changes and modifications made in accordance with the principles and concepts disclosed herein are intended to be included within the scope of the present invention.

Preferably, the power module is connected to a DC 220V direct current power supply, converts the DC 220V direct current power supply into a working voltage which can be used by the microprocessor through a voltage stabilizing circuit, and outputs the working voltage to the CPU core control unit.

Preferably, the switching value input circuit is connected with a density relay' SF ₆ Leak alarm "," SF ₆ Total latch-up 1"," SF ₆ The total locking 2' micro switch is connected, and after the DC 220V switching value input signal is subjected to photoelectric isolation, the input signal is converted into a weak current signal which can be accepted by a microprocessor and is accessed to a CPU core control unit.

Preferably, the switching value output circuit uses a switching value output module, adopts a photoelectric isolation measure and outputs ' start failure tripping adjacent circuit breakers ' and ' SF ₆ Air pressure I-level alarm and SF ₆ Air pressure level II alarm' three passive contacts. The circuit of the 'starting failure jump adjacent circuit breaker' is connected with the corresponding protection device after the number of the extended contacts is increased for starting failure, meanwhile, the three output circuits are connected with the measurement and control device for sending action signals, and the corresponding signal public end (positive electricity) is provided by the connected protection and measurement and control device.

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 with the CPU module through a signal line, and the MMI man-machine conversation module is specifically a liquid crystal touch screen.

It is a further object of the present invention to provide a computer readable storage medium storing a computer program corresponding to a trip and alarm strategy, wherein the computer program when executed by a CPU core control unit processor implements the above-mentioned SF ₆ And all steps of the method for early warning the internal insulation damage of the high-voltage circuit breaker and removing the fault in advance.

Preferably, for GIS, HGIS and all other SF ₆ The gas insulated electric equipment can use the same method to carry out the early warning of the internal insulation damage and the early fault removal, and all the equivalent changes or modifications made according to the principle and the design thought disclosed by the invention are within the protection scope of the invention.

Compared with the prior art, the invention has the beneficial effects that:

1. the metal shell type SF ₆ The method for early warning of internal insulation damage of the high-voltage circuit breaker and early fault removal comprises the following steps of isolating fault equipment before insulation breakdown burning equipment: SF ₆ The rapid leakage, when the system judges that the response time of manual treatment is not enough, the adjacent circuit breakers are tripped before insulation breakdown, fault equipment is cut off in advance, internal elements such as the tank body and the conducting rod are prevented from being damaged, power failure caused by the fact that a large amount of equipment is involved is avoided, and the situation that normal equipment such as a main transformer is impacted due to the fact that short-circuit fault current flows through a near area is avoided.

2. The metal shell type SF ₆ The method for early warning the internal insulation damage of the high-voltage circuit breaker and removing the fault in advance can measure SF ₆ Severity of leak: by passingCalculating' Circuit breaker SF ₆ Leakage and breaker SF ₆ Time difference of total latch-up for distinguishing SF ₆ The severity of the leak, take trip isolation measures or signal differently. And is "SF ₆ Manually disconnecting adjacent circuit breakers to remove faults during air pressure level I warning to avoid accident events characterized as severe levels,' SF ₆ And when the air pressure II level alarm is performed, the fault is isolated after the operation mode is adjusted, and the normal equipment is not powered off or the power failure range is smaller.

3. The metal shell type SF ₆ The method for early warning the internal insulation damage of the high-voltage circuit breaker and removing the fault in advance improves SF ₆ Accuracy of the air pressure abnormality signal: the probability of signal error in a single loop is greater, and the SF of the system ₆ Start failure trip, SF6 air pressure I-level alarm and SF ₆ Air pressure II level alarm 'any one output signal needs to act, and' breaker SF is needed ₆ Leakage and breaker SF ₆ Total latch 1"," circuit breaker SF ₆ Total latch 2' one of the two total latch signals acts, and the mutual authentication reliability is higher.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

FIG. 1 is an exemplary metal housing SF according to the present invention ₆ The internal structure schematic diagram of the high-voltage tank type circuit breaker;

fig. 2 is an exemplary metal-enclosed high-voltage circuit breaker SF of the present invention ₆ A gas monitoring map;

FIG. 3 is a schematic diagram of an exemplary density relay configuration of the present invention;

FIG. 4 is an exemplary metal can SF according to the present invention ₆ A flow chart of a method for early warning of internal insulation damage of a high-voltage circuit breaker and early fault removal;

FIG. 5 is an exemplary metal can SF according to the present invention ₆ A logic block diagram of early warning of internal insulation damage of the high-voltage circuit breaker and early cutting protection;

FIG. 6 is a schematic diagram of an exemplary system configuration of the present invention;

fig. 7 is an exemplary external view of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely in the following description with reference to the embodiments of the present invention and the accompanying drawings, and it is to be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

Examples

SF with metal shell ₆ The internal structure of the high-voltage tank type circuit breaker is shown in figure 1, and comprises a circuit breaker tank body adopting a sealing structure, wherein the circuit breaker tank body is externally connected with a pressure gauge and an SF (sulfur hexafluoride) for monitoring the internal pressure of the circuit breaker tank body ₆ A density relay.

The breaker should be rated SF ₆ The operation is carried out under the density, and the insulation and arc extinguishing capability can not be ensured when the operation density is lower than the minimum operation density. SF with metal shell ₆ High-voltage circuit breaker SF ₆ Gas monitoring system as shown in fig. 2, each phase of the tank is a closed gas cell, and each phase of the gas cell is monitored by the following components: a check valve, a density relay B4, inflation and test connectors W1 and W2, and connecting pipes.

SF inside circuit breaker ₆ The density is monitored by a density relay B4, which is structured as shown in fig. 3. The density relay B4 converts SF in the air chamber ₆ The gas density is compared to the standard gas density of a standard gas cell sealed in its interior cavity. The gases in both chambers are at the same ambient temperature and the temperature has a negligible effect on the pressure. This converts the difference in density into a difference in pressure between the two systems.

Further, SF ₆ The density relay comprises a microswitch arranged in an outer shell, and SF in the circuit breaker ₆ When gas leaks, the corrugated pipe in the standard gas chamber extends to drive the micro switch of the density relay to act without leakageThe same contact is connected to emit' SF ₆ Leak alarm "," SF ₆ Total latch-up 1"," SF ₆ Total latch 2", etc.

As shown in FIG. 4, the present embodiment provides a metal-enclosed SF ₆ The method for early warning of internal insulation damage of the high-voltage circuit breaker and early fault removal comprises the following steps:

s1, according to breaker' SF ₆ Leakage alarm signal to SF ₆ Total latch-up 1 'or' SF ₆ Determination of the time difference of the emission of the Total latch 2 "Signal ₆ A leak rate;

s2, according to SF ₆ Predicting the insulation breakdown time by the leakage rate;

s3, measuring and calculating the time actually required by each breaker to take different treatment measures, reversely calculating the corresponding total blocking time fixed value, and implanting a protection device;

s4, predicting that the insulation breakdown time is too short to be manually handled, adopting a strategy of removing faults in advance, starting a failure protection circuit of a corresponding circuit breaker to jump off an adjacent circuit breaker, and removing the faults before the insulation breakdown;

s5, predicting the insulation breakdown time only by taking a measure of directly disconnecting adjacent circuit breakers without adjusting the operation mode, and sending out' SF ₆ An air pressure I-level alarm signal is sent, meanwhile, a monitoring machine is started to perform total unlocking in case of accidents, adjacent circuit breakers are disconnected one by one manually, or a program operation comprehensive command of 'isolating XXX circuit breakers' is preset in the monitoring machine, so that the time is saved;

s6: predicting the insulation breakdown time to be enough to adopt 'adjusting the operation mode and then opening isolation switches at two sides of the fault circuit breaker without pressure', and sending SF ₆ And (4) giving an alarm at the air pressure level II, and isolating the fault circuit breaker after adjusting the operation mode according to the circuit breaker locking and opening fault handling principle.

In this example, the term "SF ₆ Leakage alarm signal sending time t _{Alarm system} As a starting point, "SF" is calculated ₆ Total latch 1 "signal (or" SF ₆ Total latch-up 2 "signal, theoretically acting simultaneously) is issued at time t _{Total latch} The difference "" SF " ₆ Total latch-up time t _bs ", to determine the leak rate, the formula is:

t _bs ＝t _{total latch} -t _{Alarm device} (1)

Further, with "SF ₆ Total latch-up time t _bs "multiplying by a specific scaling factor k _jc To predict the dielectric breakdown time (i.e., the remaining manual treatment response time), the formula is:

t _cz ＝k _jc ·t _bs ＝k _jc (t _{total latch} -t _{Alarm device} ) (2)

Wherein k is _jc SF is the maximum probability of the breaker under the condition that the rupture membrane has 30 percent of area rupture ₆ Insulation breakdown time and SF of pressure drop to breakdown pressure ₆ Total latch-up time t _bs "the proportionality coefficient between. Proportional coefficient k of circuit breakers of different models _jc The actual value of a 500kV 3ap2 DT-FI type circuit breaker is, for example, 82.801/1.394=59.398 ≈ 60.

In addition, the step of re-measuring and calculating the manual handling time actually required by each breaker comprises the following steps: 1) After verifying the signal, the handling time t required for directly disconnecting the adjacent circuit breaker without adjusting the operation mode _cz1 (ii) a 2) After the signal is verified, the processing time t required for opening the disconnecting switches on two sides of the fault circuit breaker without voltage is adjusted _cz2 . And reversely calculating a corresponding total locking time fixed value, wherein the formula is as follows:

t _ck1 ＝t _cz1 /k _jc (3)

t _ck2 ＝t _cz2 /k _jc (4)

when prejudging SF ₆ Total latch-up time t _bs ＜t _ck1 The adjacent circuit breakers are not immediately switched off, an automatic device is adopted for cutting off, and a control word or a connecting sheet is also used for selecting to send signals and not trip. The failure protection circuit of the corresponding circuit breaker includes but is not limited to: 1) The three sides of the three-way circuit breaker are connected in a 3/2 connection mode, namely a failed side-jumping circuit breaker and a far-jumping circuit opposite side (or a failed main-jumping side main transformer); 2) 3/2 connectionThe line mode side circuit breaker fails to start the corresponding bus failure, the middle jumping circuit breaker and the opposite side of the long-jump line (or the three sides of the failure main jumping transformer); 3) The double-bus connection mode line breaker fails to start and corresponds to the bus failure + the far trip opposite side; 4) The main transformer breaker fails and starts three sides of a corresponding bus failure and a failure combined tripping main transformer; 5) And the bus tie (section) breaker is started in case of failure and corresponds to bus failure.

When prejudging SF ₆ Total latch-up time between t _ck1 To t _ck2 Between, i.e. t _ck1 ≤t _bs ＜t _ck2 And meanwhile, measures of directly disconnecting adjacent circuit breakers without adjusting the operation mode are taken. And receives the SF at the monitor ₆ The accident total unlocking can be automatically started after the air pressure I-level alarm signal, or manually started. Meanwhile, a program operation comprehensive order of 'isolating XXX circuit breaker' is preset by the monitoring machine, and adjacent circuit breakers are disconnected.

When prejudging SF ₆ Total latch-up time t _bs ≥t _ck2 The method adopts the measure of opening the isolating switches at two sides of the fault circuit breaker without pressure after the operation mode is adjusted, and can isolate the fault circuit breaker after the operation mode is adjusted according to the treatment principle of the locking and opening faults of the circuit breaker.

The embodiment also provides a method operation platform device, namely a metal shell type SF ₆ The system structure of the device for early warning of the internal insulation damage and early fault removal of the high-voltage circuit breaker is shown in fig. 6, and the panel of an exemplary device is shown in fig. 7. The device comprises a control circuit board, wherein the circuit board comprises a CPU core control unit, a power supply module, an MMI module, a communication module, a photoelectric isolation, a switching value input circuit and a switching value output circuit.

The power module is connected with a DC 220V direct-current power supply, converts the direct-current power supply into working voltage which can be used by the microprocessor through the voltage stabilizing circuit and outputs the working voltage to the CPU core control unit.

Switching value input loop and density relay SF ₆ Leak alarm "," SF ₆ Total latch-up 1"," SF ₆ The total locking 2' micro switch is connected, the DC 220V switching value input signal is converted into a weak current signal which can be accepted by a microprocessor after being subjected to photoelectric isolation, and the weak current signal is accessed to the CPU core controlAnd (4) units.

The switching value output circuit uses a switching value output module, adopts a photoelectric isolation measure and outputs ' starting failure tripping adjacent circuit breakers ' and ' SF ₆ Air pressure I-level alarm and SF ₆ Air pressure II level alarm' three passive contacts. The loops of the 'startup failure tripping adjacent circuit breakers' are connected with corresponding protection devices through the number of the extended contacts for startup failure, meanwhile, the three output loops are connected with the measurement and control devices for sending action signals, and the corresponding signal public terminals (positive electricity) are 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 with the CPU module through a signal line, and the MMI man-machine conversation module is specifically a liquid crystal touch screen.

The embodiment provides a computer readable storage medium, which stores a computer program corresponding to the trip and alarm policy, and the action logic of the computer program is as shown in fig. 5. The computer program realizes the metal shell type SF when being executed by a CPU core control unit processor ₆ And all steps of the method for early warning the internal insulation damage of the high-voltage circuit breaker and removing the fault in advance.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention, and that various changes and modifications may be made without departing from the spirit and scope of the present invention, which fall within the scope of the claimed invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (10)

1. SF with metal shell ₆ The method for early warning of internal insulation damage of the high-voltage circuit breaker and early fault removal is characterized by comprising the following steps of:

s1, according to breaker' SF ₆ Leakage alarm signal to SF ₆ Total latch-up 1 'or' SF ₆ Determination of the time difference of the overall latch-up 2 "signal emission SF ₆ A leak rate;

s2 according to SF ₆ Predicting the insulation breakdown time by the leakage rate;

s3, measuring and calculating the time actually required by each breaker to take different treatment measures, reversely calculating a corresponding total locking time fixed value, and implanting a protection device;

s4, predicting that the insulation breakdown time is too short to be manually handled, adopting a strategy of removing faults in advance, starting a failure protection circuit of a corresponding circuit breaker to jump off an adjacent circuit breaker, and removing the faults before the insulation breakdown;

s5, predicting the insulation breakdown time only by taking a measure of directly disconnecting adjacent circuit breakers without adjusting the operation mode to send out SF ₆ An air pressure I-level alarm signal is sent, the monitoring machine is started to perform accident total unlocking at the same time, adjacent circuit breakers are disconnected one by one manually, or a program operation comprehensive command of 'isolating XXX circuit breaker' is preset in the monitoring machine, so that the time is saved;

s6: predicting insulation breakdown time, and performing 'adjusting operation mode and then opening isolation switches at two sides of fault circuit breaker without voltage', and then generating SF ₆ And (4) giving an alarm at the air pressure level II, and isolating the fault circuit breaker after adjusting the operation mode according to the circuit breaker locking and opening fault handling principle.

2. The metal-encased SF according to claim 1 ₆ The method for early warning of internal insulation damage of the high-voltage circuit breaker and early fault removal is characterized by comprising the following steps of: in said step S1, with "SF ₆ Time t of signal sending of leakage alarm _{Alarm device} As a starting point, "SF" is calculated ₆ Total latch 1 "signal (or" SF ₆ Total latch-up 2 "signal, theoretically acting simultaneously) is issued at time t _{Total latch} The difference "" SF " ₆ Total latch-up time t _bs ", to determine the leak rate, the formula is:

t _bs ＝t _{total latch} -t _{Alarm system} (1) 。

3. According to claimThe metal-enclosed SF of claim 2 ₆ The method for early warning of internal insulation damage of the high-voltage circuit breaker and early fault removal is characterized by comprising the following steps of: in step S1, the leakage rate is detected by using a pressure variation method, and the apparatus includes, but is not limited to, a pressure gauge, a densitometer, or a special pressure variation detector, and a leakage rate monitoring system.

4. Metal-enclosed SF according to claim 3 ₆ The method for early warning of internal insulation damage of the high-voltage circuit breaker and early fault removal is characterized by comprising the following steps of: in said step S2, use "SF ₆ Total latch-up time t _bs "multiplying by a specific scaling factor k _jc To predict the insulation breakdown time (i.e., the remaining manual treatment response time), the formula is:

t _cz ＝k _jc ·t _bs ＝k _jc (t _{total latch} -t _{Alarm system} ) (2)

Wherein k is _jc SF is the maximum probability of the breaker under the condition that the rupture membrane has 30 percent of area rupture ₆ Insulation breakdown time and SF of pressure drop to breakdown pressure ₆ Total latch-up time t _bs "coefficient of proportionality between.

5. Metal-enclosed SF according to claim 4 ₆ The method for early warning of internal insulation damage of the high-voltage circuit breaker and early fault removal is characterized by comprising the following steps of: in step S3, calculating the manual handling time actually required by each breaker includes: 1) After verifying the signal, the handling time t required to directly disconnect the adjacent circuit breaker without adjusting the operating mode _cz1 (ii) a 2) After the signal is verified, the processing time t required by pulling the disconnecting switches on two sides of the fault circuit breaker without pressure in the operation mode is adjusted _cz2 . And reversely calculating a corresponding total locking time fixed value, wherein the formula is as follows:

t _ck1 ＝t _cz1 /k _jc (3)

t _ck2 ＝t _cz2 /k _jc (4) 。

6. metal-enclosed SF according to claim 5 ₆ The method for early warning of internal insulation damage of the high-voltage circuit breaker and early fault removal is characterized by comprising the following steps of: in the step S4, the judgment condition of adopting the strategy of 'removing the fault in advance' is SF ₆ Total latch-up time t _bs ＜t _ck1 The adjacent circuit breakers can be tripped by starting the failure protection circuit of the corresponding circuit breaker without taking measures of directly disconnecting the adjacent circuit breakers, and the control words or the connecting sheets can be used for selecting to send signals and not trip.

Among them, the failure protection circuit of the circuit breaker includes but is not limited to: 1) The three sides of the three-way circuit breaker are connected in a 3/2 connection mode, namely a failed side-jumping circuit breaker and a far-jumping circuit opposite side (or a failed main-jumping side main transformer); 2) The 3/2 connection mode is that when the breaker fails to start, the corresponding bus fails, the mid-jump breaker and the opposite side of the long-jump line (or three sides of the failure main-jump main transformer) are started; 3) The double-bus connection mode line breaker fails and starts a corresponding bus failure + remote tripping opposite side; 4) The main transformer breaker fails and starts three sides of a corresponding bus failure and a failure combined tripping main transformer; 5) And the bus tie (section) breaker is started in case of failure and corresponds to bus failure.

7. Metal-enclosed SF according to claim 6 ₆ The method for early warning of internal insulation damage of the high-voltage circuit breaker and early fault removal is characterized by comprising the following steps of: in the step S5, the judgment condition for taking the measure of directly disconnecting adjacent circuit breakers without adjusting the operation mode is t _ck1 ≤t _bs ＜t _ck2 Namely, the insulation breakdown time is only enough to adopt the measure of directly disconnecting adjacent circuit breakers without adjusting the operation mode, but is not enough to adjust the operation mode and pull open the disconnecting switches at two sides of the fault circuit breaker without pressure; meanwhile, the accident total unlocking can receive 'SF' at the monitoring machine ₆ The air pressure I-level alarm signal is automatically started, and can also be manually started.

8. The metal-encased SF according to claim 7 ₆ The method for early warning of internal insulation damage of the high-voltage circuit breaker and early fault removal is characterized by comprising the following steps of: in the step S5, the monitoring machine presets a program operation comprehensive order of 'isolating XXX breaker', namelyThe program operation task executed by the station is completely consistent with the fault starting jump of the adjacent circuit breaker, but the control loop of each target circuit breaker is used for simultaneous opening; if the circuit breaker on the opposite side of the line is ordered by the dispatching, the circuit breaker on the opposite side is disconnected by the operation.

9. The metal-encased SF according to claim 8 ₆ The method for early warning of internal insulation damage of the high-voltage circuit breaker and early fault removal is characterized by comprising the following steps of: in the step S6, the judgment condition of taking the measure of 'non-pressure pulling open the disconnecting switches at two sides of the fault circuit breaker after adjusting the operation mode' is t _ck2 ≤t _bs Namely, the manual handling reaction time is sufficient, and the fault circuit breaker can be isolated after the operation mode is adjusted according to the fault handling principle of circuit breaker locking and opening.

10. SF with metal shell ₆ High voltage circuit breaker internal insulation destroys early warning and cuts off trouble device in advance, its characterized in that: the early warning resectoscope is internally provided with a control circuit board, and the circuit board comprises a CPU core control unit, a power supply module, an MMI module, a communication module, a photoelectric isolator, a switching value input circuit and a switching value output circuit. The method comprises the following specific steps:

the power supply module is connected with a DC 220V direct-current power supply, converts the direct-current power supply into working voltage which can be used by the microprocessor through a voltage stabilizing circuit and outputs the working voltage to the CPU core control unit;

switching value input loop and density relay SF ₆ Leak alarm "," SF ₆ Total latch-up 1"," SF ₆ The general lock 2' micro switch is connected, DC 220V switching value input signals are converted into weak current signals which can be accepted by a microprocessor after photoelectric isolation, and the weak current signals are accessed to a CPU core control unit;

the switching value output circuit uses a switching value output module, adopts a photoelectric isolation measure and outputs ' starting failure tripping adjacent circuit breakers ' and ' SF ₆ Air pressure I-level alarm and SF ₆ Air pressure level II alarm' three passive contacts. The loop of the 'startup failure jump adjacent circuit breaker' is connected with the corresponding protection device for startup failure after the number of the extended contacts,meanwhile, the three output loops are connected with the measurement and control device and used for sending action signals, and the corresponding signal public end (positive electricity) is provided by the connected protection and measurement and control device;

the communication module adopts an Ethernet communication interface A, an Ethernet communication interface B and an RS485 communication interface, the MMI module is connected with the CPU module through a signal line, and the MMI man-machine conversation module is specifically a liquid crystal touch screen.

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