Bincike da Tafakka ta Kula da Koyarwa na Ma'aikatar SF6

A cikin gwamnatin substation, haɗin kasa mai sauki suna da wasu wurare masu iya kan waƙoƙi na tsarin kasa. Daga cikinsu, SF₆ circuit breakers sun fi yawa a tafiya. Waɗannan circuit breakers sun amfani da gasar SF₆ a matsayin babban muhimmanci masu inganta. Saboda tasiri na energy na arc, ana yi amfani da SF₆ compressed gas don in kama tsakiyar arc, kuma don haka in iya kan waƙoƙi na rated current da fault current, ta kiyaye masana'antu da yanayin elektroni da za su iya kasancewa. An samun system mai karatu na duka, wanda zai iya gyaran circuit breaker ta hanyar opening da closing operations, kuma yana da kyakkyawan abubuwa.

SF₆ circuit breakers suna da muhimmanci sosai don hanyar gudanar da substation. Idan SF₆ circuit breaker ya jawo nasara, zai iya tabbatar da tasirin ga hanyar gudanar da substation. Wannan ya nuna muhimmancin koyarwa da kiyaye waɗannan SF₆ circuit breakers. A nan, tushen bayanan nasarorin da kuma tushen koyarwa na SF₆ circuit breakers yana da muhimmanci mai yawa.

1 Bayanin Nasarorin Yawan SF₆ Circuit Breakers
1.1 Kadan Pressure na Gas SF₆

Idan ake yi amfani da SF₆ circuit breakers a cikin tashin, ya kamata a faru nasarar kadan pressure na gas SF₆. Idan nasara wannan ya faru, zaɓon pressure a cikin SF₆ pressure gauge zai zama da ita da rated pressure value. A cikin remote control, background management system zai bude alarm don in ba ma'a shugaban kwallon kasa wajen magana cewa pressure na gas SF₆ yana da ita.

Wannan nasara na iya zama saboda temperature na yankin da ke da ita, ko kuma akwai leakage na gas a cikin system na SF₆, ko kuma reading na pressure gauge yana da kuskure, wanda yake zama saboda SF₆ density relay ya jawo nasara, kuma ya zama saboda kadan pressure na gas SF₆, wanda ya jawo nasara a cikin SF₆ circuit breaker.

1.2 Nasara ta Closing ko Opening na SF₆ Circuit Breaker

A cikin tashin SF₆ circuit breaker, idan an faru command ta closing ko opening a cikin tashin manual, SF₆ circuit breaker bai canza ba, kuma ya zama saboda nasara ta closing ko opening na SF₆ circuit breaker.

Abubuwan da suka zama sabbin nasara wannan nasarorin sun haɗa uku. Kafin, spring energy-storage system ya jawo nasara, kuma bai iya ba da energy da power don tashin closing ko opening na SF₆ circuit breaker. Ta farko, control circuit ya kasance, kuma ya zama saboda open circuit, wanda ya kawo ƙungiyar tashin closing ko opening. Uku, akwai nasara ta mechanical linkage. Idan command an faru, saboda nasara ko damage na mechanical components, command an faru bai iya jin Hausa ba.

1.3 Nasara ta False Opening na SF₆ Circuit Breaker

Nasara ta false opening yana cikin nasarorin yawan SF₆ circuit breakers. Yana nufin ƙarfin da SF₆ circuit breaker ya zama ta opening ta hanyar baya, kuma ya zama saboda SF₆ circuit breaker ya kasance ta out of control, kuma ya zama saboda tashin substation.

Sababbin nasara wannan nasarorin sun haɗa misoperation na mutane ko accidental touch. Zai iya zama saboda false opening saboda mechanical vibration na waje. Nasarorin elektroni zai iya zama sabon automatic opening na SF₆ circuit breaker, kuma yana nufin incorrect protection actions da setting values. A cikin two-point grounding na DC system, idan positive da negative power supplies suka faru, signal na relay protection zai bude da ƙungiya, kuma zai zama saboda incorrect actions. Da kuma nasarorin mechanical kamar failure na closing bracket da displacement na positioning screw zai iya zama sabon false opening na SF₆ circuit breaker.

1.4 Nasara ta False Closing na SF₆ Circuit Breaker

Nasara ta false closing yana cikin nasarorin yawan SF₆ circuit breakers. Yana nufin ƙarfin da SF₆ circuit breaker ya zama ta closing ta hanyar baya, kuma ya zama saboda SF₆ circuit breaker ya kasance ta out of control, kuma ya zama saboda tashin substation.

Sababbin nasara wannan nasarorin sun haɗa da yadda positive da negative contacts a cikin DC circuit ba su faru, amma suka faru ta ground, kuma an yi closing control circuit, kuma ya zama saboda closing fault; resistance na closing contactor coil yana da ita, kuma ya kawo starting voltage, kuma ya zama saboda momentary pulse a cikin DC system, kuma ya zama saboda closing fault; da kuma damage na opening latch support zai iya zama sabon false closing na SF₆ circuit breaker.

2 Tushen Koyarwa na Nasarorin SF₆ Circuit Breaker
2.1 Tushen Koyarwa na Nasara ta Kadan Pressure na Gas SF₆

Idan nasara ta kadan pressure na gas SF₆ ya faru, maintenance personnel ya kamata a rubuta zaɓon pressure gauge na SF₆ circuit breaker a lokacin daidai, kuma a yi conversion zuwa zaɓon pressure a standard temperature don in neman cewa pressure na gas a cikin SF₆ circuit breaker yana da kyau. Idan pressure yana ci, za a yi diagnosis a cikin leakage na gas a cikin SF₆ circuit breaker.

Ba da charging na SF₆ circuit breaker zuwa rated pressure, ka ƙunshi ƙarin pressure gauge. Yi amfani da SF₆ leak detector don in neman duk parts na SF₆ circuit breaker, sama da connecting parts, sealing rubber rings, da position na pressure gauge joint. Daga cikin halin da aka faru, ka fada soapy water zuwa parts da aka sani da leakage don in neman location na leakage.

A cikin tashin leakage, ka yi repair welding zuwa parts na leakage. Ka fitowa leaking da damaged parts da kuma usage na each part. A cikin practice, saboda failure na density relay zai iya zama sabon system ta bude low-pressure alarm, maintenance personnel zai iya yi ƙarin nemo density relay, musamman indicator light da switch parts, don in koyarwa switch adhesion ko short-circuit, kuma ka fitowa damaged relay a baya don in koyarwa nasara.

2.2 Tushen Koyarwa na Nasara ta Failure to Close or Open na SF₆ Circuit Breaker

Idan nasara ta failure to close or open na SF₆ circuit breaker ya faru, ka koyar nasara zuwa sababin da aka faru.

Don nasara ta failure to close or open na SF₆ circuit breaker saboda failure na spring energy-storage system, maintenance personnel ya kamata a neman tashin auxiliary switch da energy-storage motor na spring energy-storage system, kuma ka fitowa components da ke da burnt-out marks a outer surface a baya. Idan appearance yana da kyau, ka jiye motor wires da ka test resistance na energy-storage motor da auxiliary switch don in neman cewa zai iya tashin da kyau. Idan energy storage yana da kyau a baya closing kuma motor yana ci, za a yi determination cewa energy-storage auxiliary switch bai iya disconnect circuit a baya saboda moisture-induced adhesion ko contact burnout, kuma ya zama saboda nasara ta SF₆ circuit breaker. Maintenance personnel ya kamata a manually disconnect energy-storage power switch don in koyar components da ke da ita saboda long-term operation na motor, ka fitowa auxiliary switch, ka neman cewa entire equipment ba su iya yin moisture ko water seepage, kuma ka yi timely moisture-proof da seepage-proof measures don in koyar recurrence na nasara ta SF₆ circuit breaker.

Don nasara ta failure to close or open na SF₆ circuit breaker saboda blockage na control circuit, maintenance personnel ya kamata a neman working state na opening da closing coils na circuit breaker, ka neman cewa control wires ba su faru, kuma ka koyar looseness ko disconnection na wiring terminals da auxiliary switch nodes. Kafin, maintenance personnel ya kamata a neman cewa opening da closing coils ba su overheated ko burnt out, kuma ka fitowa damaged opening da closing coils a baya. Sannan, according to wiring diagram na SF₆ circuit breaker, ka yi amfani da multimeter don in neman connectivity na circuit breaker circuit, kuma ka koyar broken wires ko loose connections a baya don in ensure locking circuit yana da kyau. Idan abnormality ya faru, fault point zai iya zama saboda immediate, kuma ka koyar fault.

Don nasara ta failure to close or open na SF₆ circuit breaker saboda mechanical linkage failure, maintenance personnel ya kamata a stop using SF₆ circuit breaker kuma ka report mechanical failure zuwa superior leader. Generally, mechanical failures include problems such as mechanism jamming, loose opening latch, and detachment of the transmission connecting rod. Maintenance personnel ya kamata a disassemble mechanically faulty components, restore original mechanical components zuwa their original positions according to factory instruction manual, ka fitowa damaged mechanical components, clean dust on components, add appropriate lubricating oil, and eliminate mechanism jamming problem to achieve fault elimination.

2.3 Tushen Koyarwa na Nasara ta False Opening na SF₆ Circuit Breaker

Don nasara ta false opening saboda human misoperation ko accidental touch, maintenance personnel ya kamata a neman signal display na SF₆ circuit breaker, ka koyar switch fault, kuma ka restart SF₆ circuit breaker don in supply power. Don nasara ta false opening saboda electrical faults, maintenance personnel ya kamata a neman signal da setting value na SF₆ circuit breaker, ka neman fault point, analyze cause of fault, and timely eliminate and repair faulty components. For components affected by moisture due to poor sealing, replace sealing components and install heating device for moisture-proof and dehumidification to eliminate fault problem. For false opening fault caused by mechanical faults, maintenance personnel should disassemble mechanical part, re-correct position of positioning screw, replace or repair closing bracket, eliminate false opening fault, and thus ensure normal operation of SF₆ circuit breaker.

2.4 Tushen Koyarwa na Nasara ta False Closing na SF₆ Circuit Breaker

In treatment of false closing fault of SF₆ circuit breaker, maintenance personnel should clarify main cause of false closing fault of SF₆ circuit breaker and adopt targeted treatment methods to eliminate fault. Maintenance personnel should regularly check moisture-proof situation of each component of SF₆ circuit breaker. If closing is caused by simultaneous grounding of positive and negative contacts in DC circuit and it is judged that it is caused by moisture of secondary circuit, moisture-proof and dehumidification device can be installed in moisture-affected parts, and water-seepage holes can be blocked in time to eliminate fault. At same time, maintenance personnel should check all secondary circuits, replace defective or damaged components in time, and eliminate fault. In addition, maintenance personnel should check opening latch component, replace damaged opening latch component, and eliminate fault.

3 Case Analysis
3.1 Fault Phenomenon

A LW15 - 252 type SF₆ circuit breaker was put into operation as early as 2007. After the circuit breaker tripped, the latch was still in an over-position, and there was an abnormal spacing of about 10mm between the latch and the closing trigger, with abnormal contact. However, after the closing pulse power supply was provided, the coil and the trigger worked normally, but the latch still could not be disengaged for closing. After manually disengaging the latch, the switch still could not close.

3.2 Fault Analysis

Through the analysis of the operation data records of this circuit breaker, it was found that the circuit breaker had interrupted the current 132 times during operation. When the current is interrupted, a large amount of heat is generated, and the high-temperature arc will promote the accumulation of chemical reaction substances. Especially for the interruption of large currents, a catalytic effect is formed, accelerating the chemical reaction of internal substances and increasing a large amount of dust.

Therefore, the initial diagnosis of this circuit breaker fault is that the arc decomposition products caused by current interruption react chemically with the silicone grease in the sealed environment, forming a large amount of substances such as SiF₄ and Si(CH₃)₂F₂. The solidified substances stay in the braking seal rod, hindering the transmission of the braking seal rod, resulting in a jamming phenomenon and causing the closing failure of the SF₆ circuit breaker.

3.3 Fault Elimination

The maintenance personnel disassembled the faulty circuit breaker body. In the external inspection, it was found that the braking seal rod was obviously dirty, and there was a large amount of silicone grease on the sealing ring in the braking seal system, adhering to the surface of the braking seal rod, increasing the friction between the braking seal rod and the sealing ring during the transmission process, resulting in the inability of the braking seal rod to transmit normally and causing jamming. Replacing the components of the braking system could not fundamentally solve the fault problem, which only addressed the symptoms but not the root cause.

In the internal inspection, the switch body was disassembled, and a large amount of gray-white powder was found adhering to the inner wall of the arc-extinguishing chamber porcelain bushing, the braking seal rod, and the insulating pull rod. These powders are mainly solidified substances such as SiF₄ and Si(CH₃)₂F₂ formed under the high-temperature arc. Once accumulated to a certain extent, it may cause insulation breakdown accidents.

4 Conclusion

In summary, during daily management, administrators should be familiar with the common faults of SF₆ circuit breakers and develop practical solutions. Once a fault occurs, the fault point should be promptly identified and the fault eliminated, removing potential hazards, reducing power-outage time, preventing the occurrence of out-of-sequence tripping, and thereby enhancing the safety and stability of power supply in substations.

Therefore, in addition to replacing the components of the braking system, the maintenance personnel also need to replace the sealing components and arc-extinguishing components, clean the dust in the arc-extinguishing chamber. After the fault was eliminated, the circuit breaker was restarted and operated normally.