Tambayar da Gargaɗi na Muhimman Abubuwa Don Ƙoƙari da Ƙananan Kirkiro Mai Tsawo a Faduwar Iya SF6

1 Gaba

Circuit breakers na iya gudanar da kuma kawo karamin karamin hanyar tsohon mulkin gwamnati. Suna iya gudanar da karamin kafin an yi nasara daga wurare masu inganci a lokacin da yake wuya, ko kuma kawo karamin kafin an yi tasfiya a lokacin da yake wuya mai tsawo. Saboda haka, suna da funfwata da kula da kula da kula da kula. A yanzu, akwai zama biyu da suka fi sani a cikin yankin Pingdingshan. A cikin har zuwa, ana bukatar circuit breakers don karamin kafin, karamin karamin, da kuma kofin mafi girma. Circuit breakers mafi girma na SF₆ suna da amfani sosai a cikin substation 110 kV da 220 kV saboda dalilai masu kyau kamar yadda ake gudanar da karamin, lafiya, karin ala, da kuma kalmomin inganci.

Circuit breakers mafi girma suna da muhimmin abubuwa kamar moving contacts, stationary contacts, arc-extinguishing chambers, da kuma conductive parts. Moving da stationary contacts suna cikin arc-extinguishing chamber da ake amfani don kawo karamin. Stationary contact ya dogara, amma moving contact ta shiga aiki a ciki da operating mechanism don in gudanar da circuit breaker da duk kula da kula. Operating mechanism ta shiga aiki a ciki da moving contact ta hanyar transmission mechanism da insulating pull rod.

Akwai amfani sosai a kan circuit breakers mafi girma na SF₆ a yanzu, amma koyaya ba za a iya faru a lokacin da ake yi aiki saboda wahala na gida, yankin, ko abubuwan da ke cikin. A cikin misal, za a bayyana abubuwan da ke faru a lokacin da ake yi aiki da circuit breakers mafi girma na SF₆ a cikin substation 220 kV, da kuma hanyoyin da ake amfani don in taimaka.

2 Bincike da Koyaya Masu Yawanci da Muhimmanci na Operation da Maintenance

Akwai abubuwan da ke faru a lokacin da ake yi aiki a cikin circuit breakers mafi girma na SF₆, kamar operating mechanism, transmission mechanism, arc-extinguishing part, da kuma current-conducting part. A cikin yankin Pingdingshan, akwai wasu abubuwan da ke faru:

• Circuit breakers mafi girma na SF₆ suna bukatar zuwa a lokacin da an samun leakage gas SF₆.

• An samun pressure lockout saboda leakage oil mai girma a hydraulic mechanism, ko kuma energy storage an faru saboda wahala a spring mechanism, saboda haka circuit breakers mafi girma na SF₆ ba zan iya gudanar da karamin kafin.

• Circuit breaker ba zan iya gudanar da karamin kafin saboda wahala a cikin mechanism, kamar control circuit an kasa, saboda haka ba zan iya gudanar da karamin kafin.

• Circuit breakers mafi girma na SF₆ an kasa saboda fracture porcelain insulator.

• Overheating saboda current-conducting issues ya kasa circuit breakers mafi girma na SF₆ ba zan iya gudanar da karamin kafin.

• Circuit breaker an samun damage da ya kasa saboda yankin ko damage a insulation part, saboda haka ba zan iya gudanar da karamin kafin.

Abubuwan da aka bayyana suna iya kasa circuit breakers mafi girma na SF₆ da kuma kawo karamin kafin. A lokacin da ake yi inspection da maintenance, ya kamata a duba waɗannan components da nuna da duniya don in bincike da taimaka don in gudanar da karamin kafin. A nan za a bayyana abubuwan da aka bayyana.

2.1 Arc-Extinguishing Part

Circuit breakers mafi girma na SF₆ na iya da amfani sosai don in gudanar da karamin kafin. Process of arc-extinguishing ya faru a cikin arc-extinguishing chamber, wanda ya da moving da stationary main contacts, moving da stationary arcing contacts, nozzles mai yawa da mai hagu, compression cylinder, da piston. Specifically:

• Main contacts suna da amfani don in gudanar da karamin a lokacin da circuit breaker ya faru.

• Arcing contacts suna da amfani don in gudanar da karamin kafin, suna da amfani don in taimaka main contacts saboda haka ba zan iya kasa.

• Nozzles suna da amfani don in gudanar da direction da speed gas jet don in gudanar da arc-blowing effect da kyau.

• Piston suna da amfani don in gudanar da gas pressure a compression cylinder saboda haka za a iya gudanar da arc-blowing gas pressure da kyau.

A lokacin da ake yi aiki, leakage gas SF₆ za a iya kasa stable operation circuit breaker. Idan gas pressure ta koma da threshold, circuit breaker za a iya faru alarm ko kuma lockout saboda low pressure. A cikin wannan, za a iya faru fault, saboda haka za a iya kasa area outage.

2.2 Mechanical Part

Mechanical performance circuit breakers mafi girma na SF₆ na iya da amfani sosai don in gudanar da karamin kafin. Mechanical part suna da amfani don in gudanar da opening da closing speed. Mechanical part suna da operating mechanism da transmission mechanism. Idan a duba statistics, 63.2% failure circuit breakers a China suna faru saboda operating mechanism.

Operating mechanisms circuit breakers mafi girma na SF₆ a cikin substation 110 kV da uku a yankin Pingdingshan suna da hydraulic mechanisms da spring mechanisms. Spring mechanisms suna da amfani sosai saboda simplicity, easy maintenance, fast response, environmental friendliness, da low cost. Amma a lokacin da ake yi aiki, elasticity spring ta koma, saboda haka za a iya faru failure saboda opening spring ba zan iya store energy, ko kuma reclosing failure saboda closing spring ba zan iya store energy.

Hydraulic mechanisms suna da amfani sosai saboda reliability, safety, da long service life. Idan hydraulic value ta koma da threshold, zero-pressure lockout za a iya faru saboda slow opening. Control system za a iya faru motor don in gudanar da pressure, kafin a set time, time relay za a iya kasa control circuit don in stop pressure increase.

Transmission mechanisms kamar connecting rods, crank arms, da rotating shafts suna da amfani sosai don in gudanar da opening da closing process. Idan a receive signals, opening da closing springs suna da amfani don in gudanar da contacts through transmission mechanisms. Idan connecting rods, crank arms, ko rotating shafts an kasa, za a iya kasa normal transmission during opening da closing circuit breaker.

2.3 Operating Environment

Outdoor-type SF₆ circuit breakers suna da amfani don in duba impact changes a cikin operating environment. Misali, a lokacin da wind ya kafa, lead wires suna da amfani don in swing, ko kuma foreign objects suna da amfani don in catch. Idan lightning strike power grid, over-voltage surges suna da amfani don in trip circuit breaker. A rainy da snowy conditions, surface circuit breaker suna da amfani don in moisture, saboda haka corona discharge suna da amfani. Idan surface an kasa, pollution flashover suna da amfani. A snow accumulation da icing, joints suna da amfani don in overheat. Idan temperature an change, oil level da gas pressure circuit breaker suna da amfani don in change, saboda haka insulation performance suna da amfani don in decrease, saboda haka za a iya kasa opening da closing speed.

2.4 Insulation Part

Insulation part suna da amfani don in isolate equipment from air. Commonly used insulation materials include porcelain insulators, composite insulators, da silicone rubber insulators. Currently, external insulation SF₆ circuit breakers a yankin Pingdingshan suna da amfani don porcelain.

A lokacin da ake yi aiki, insulation performance porcelain insulators suna da amfani don in decline saboda poor quality, unqualified installation, sudden temperature changes, ko kuma over-voltage surges. Idan external insulation SF₆ circuit breakers an stress unevenly during installation, damage to external insulation suna da amfani don in worsen during long-term operation. In severe cases, cracks da breakages suna da amfani don in faru on surface porcelain.

Moreover, sudden changes a cikin external temperature suna da amfani don in reduce bending da tensile strength insulation materials. Idan mechanical forces an apply at this time, insulation part suna da amfani don in kasa da kuma puncture. When external insulation an over-voltage, partial discharge suna da amfani don in trigger. Idan dust da dirt an cika on surface external insulation, da kuma environment an wet, pollution flashover suna da amfani don in occur under high-voltage electric field.

3 Countermeasures

Since there are many outgoing lines in 220 kV substations, and accordingly, a large number of SF₆ circuit breakers, to reduce the occurrence of the above-mentioned problems, a reasonable inspection cycle and maintenance cycle should be formulated, a complete defect handling process and equipment acceptance standard should be established, focusing on accident prevention, and a complete closed-loop management system should be established.

3.1 Formulating a Reasonable Inspection Cycle

The normal operation of circuit breakers depends on the daily inspection by operation and maintenance personnel. By formulating a reasonable inspection cycle, defects in circuit breakers can be detected in a timely manner, preventing the defects from expanding and causing accidents. The following briefly describes the key points to be noted during the inspection of 220 kV high-voltage SF₆ circuit breakers.

• Routine inspections should be carried out at least once a week. This mainly involves routine inspections of the appearance of the circuit breaker, abnormal sounds, equipment leakage, operating environment, and tracking and inspection of defects and potential hazards. Special attention should be paid to checking whether the pressure value and oil level of the high-voltage SF₆ circuit breaker are within the normal range, recording the pressure value, observing whether the oil color is normal, and whether energy storage can be carried out normally.

• Comprehensive inspections should be carried out at least once a month. Based on routine inspections, the cabinet doors of equipment in the substation are opened for inspection. Operating data such as the gas pressure value and oil level value of the circuit breaker are recorded; it is checked whether the cabinet doors of the circuit breaker are tightly closed, whether the holes are well-blocked, and whether the dehumidification and temperature-control devices can operate normally; whether the opening and closing coils have discoloration, abnormal odors, or signs of burning; whether the operating mechanism and transmission mechanism of the circuit breaker are normal; and whether the secondary wiring has overheating, looseness, or breakage.

• Inspection in the dark should be carried out at least once a month. This refers to inspections carried out at night with the lights off, focusing on checking whether the lead wires, joints, and clamps are overheating, and whether there is any discharge on the external insulation.

• Special inspections are carried out to prevent the circuit breaker from malfunctioning, refusing to operate, deforming in structure, suffering insulation damage, discharging, or experiencing pollution flashover due to changes in the external environment or the operation mode of the system, which may affect the normal operation of the circuit breaker. Specific situations have different inspection cycles.

3.2 Formulating a Reasonable Maintenance Cycle

Regular inspections are aimed at better detecting problems, while regular maintenance can better prevent small defects from developing into major accidents. The following are several common maintenance items for circuit breakers.

• Cabinet maintenance is carried out once every six months. It focuses on checking whether the sealing strips, cabinet door hinges, and handles are damaged, whether the cabinet is rusted, and whether the grounding marks are intact.

• Blocking maintenance is carried out once a month. Fire-resistant blocking materials should be used for blocking, and insulating materials such as fire-resistant boards should be used if necessary to ensure tight blocking and prevent the blocking material from collapsing.

• Maintenance of dehumidification and heating devices and lighting devices is carried out once a quarter. It is determined whether the dehumidification and heating devices are operating normally according to environmental changes. At the same time, it is checked whether the lighting devices inside the cabinet are normal, and whether their contact switches and circuit wiring are loose.

3.3 Establishing a Defect Handling Process

Defects found during inspections and maintenance should be recorded, and reported in a timely manner according to their severity. Later, maintenance personnel should promptly conduct experiments and maintenance work. After maintenance, operation and maintenance personnel are responsible for equipment acceptance, and the equipment is put into operation only after it passes the acceptance. Through the whole-process closed-loop management of discovery-filing-reporting-handling-acceptance, not only can the service life of equipment be extended, but also the occurrence of accidents can be reduced, and high-quality electric energy can be better provided to users.

3.4 Precautions for Acceptance

Circuit breakers should be accepted and pass the inspection before being put into operation after new installation or maintenance. During acceptance, it should be ensured that there are no remnants from maintenance on the circuit breaker; the porcelain insulators are clean and undamaged; the SF₆ gas pressure gauge and oil level gauge are normal; the hydraulic mechanism or spring mechanism can store energy normally; the cabinet is well-sealed, and the joints are not loose or deformed; and the position signals and abnormal alarm signals can operate correctly.

4 Conclusion

The operation and maintenance management of circuit breakers is a dynamic process. In daily work, the sense of responsibility of operation and maintenance personnel should be strengthened. They should strictly follow the regulations for corresponding inspections and maintenance, and a reasonable closed-loop management system for equipment should be formulated to ensure the normal operation of equipment and the stable operation of the power grid.