Ukosefu wa Kuvutia kwa SL400 Vacuum Contactor? Miongozo na Matumizi ya Kutafuta Sababu na Suluhisho

Katika mfumo wa umeme wa kusaidizi wa kiwango cha juu wa mashirika ya kutengeneza umeme, vifaa vya mikakati vya vakuum vinatumika kama vifaa vya mikakati vya mikakati kwa majinzi ya kiwango cha juu, mabadiliko, wavu za uhamiaji na vifaa vingine vya umeme. Hii inawezesha mikakati mbali na utendaji wa mara kwa mara, kwa hivyo kuipata matumizi mengi. Ikiwa hitilafu za vifaa vya vakuum hazitosolve kwa haraka, itaweza kuboresha usalama na utendaji wa fedha wa makabili ya tenganeko katika mashirika ya kutengeneza umeme.

Kati ya vifaa vya vakuum vya mfumo wa umeme wa kusaidizi wa kiwango cha juu wa Makabili 3 na 4 ya chakula cha moto, 60 ni vifaa vya vakuum vya aina ya SL400 400A. Kutoka wakati wa ufunguzi wao mwaka 2015 hadi mwisho wa mwaka 2016, vifaa vingine vya vakuum katika mfumo wa upanaji wa chakula cha moto walipata hitilafu kama kutokujitokeza kwa mtazamo wa kutofunga, kuvunjika kwa shamba la kutofunga, na kutolewa kwa ishara ya "kutofunguka kwa njia ya mikakati" kutokufungua, kwa hivyo kuwasilisha kwa vifaa vyenye ukosefu wa kutofungua. Tangu upande mmoja wa shamba la kutofunga unahusiana moja kwa moja na electrode hasi, linaweza pia kusababisha grounding moja kwa moja ya DC negative, kusababisha silaha ya usalama kutokufanya kazi na kutathmini hatari kali kwa usalama wa utendaji. Pia, hitaji wa kutofunga manufaa kwenye eneo la kituo wakati vifaa vya vakuum havijitokeze, huchangia hatari kali kwa wafanyakazi wa utendaji.

1. Sera ya Kazi ya Mikakati

Mikakati ya vifaa vya vakuum aina ya SL-400 iliyochaguliwa na chakula cha moto ni mikakati ya kudumisha kwa njia ya muundo. Waktu shamba la kutofunga la vifaa vya vakuum linalopewa nguvu, chombo cha kutofunga kilichorudi hutoa mikakati ya msingi ili kubadilika chini ya nguvu ya elektromagnetiki. Roller katika chombo cha kutofunga kilichorudi hukutana na kizuizi cha kutofunga, ikifunga komponente ya kutofunga ili kukubalika vifaa vya vakuum vya kutofunga. Pia, spring inachomwa ili kupanda nguvu ya kutofunga, na kizuizi cha kutambua na penyelewezo la kutofunga cha electromagnet limeweza kushuka ili kupanga kutofunga.

Wakati shamba la kutofunga likapewa nguvu ya pulse, chombo cha kutofunga kilichorudi hutarajiwa na penyelewezo la kutofunga cha electromagnet liko chini. Penyelewezo hilo litakatifu kizuizi cha kutambua, kutofautiana na maeneo ya kutofunga yaliyotengenezwa na roller na kizuizi cha kutofunga. Chini ya nguvu ya spring, kutofunga kinaweza kutofautiana haraka. Chombo cha kutofunga kilichorudi, kilichopewa nguvu na spring ya kutofunga, hurudi na msingi mkuu mpaka sehemu ya limit plate na kukwepa, kutokamilisha mchakato wa kutofunga.

2. Uchanganuzi wa Sababu

2.1 Aina ya Umeme

Utafutaji wa njia ya kutofunga ulionyesha kwamba upimaji wa resistance wa plug wa pili, contacts za msingi za position vacuum contactor, na contacts za operation handle zilikuwa sahihi. Umeme wa tofauti ulikuwa karibu 110V, na hakukuwa na hali ya umeme wenye wingi wenye wingi kwenye shamba la kutofunga. Hakukuwa na tabia kama kupungua insulation ground katika njia ya mikakati au mitundu yoyote yenye wingi.

Kutofunguka kwa njia ya mikakati ni ishara ya kutokufungua kutokufungua kutokufungua kwa shamba la kutofunga la umeme wa mikakati kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokufungua kutokuf......

2.2 Aina ya Muundo

Ukosefu wa ustawi wa chombo cha kutambua: Vyanzo vya asili vya kizuizi cha kutofunga, penyelewezo la electromagnet na chombo cha kutambua vilikuwa ni carbon steel, ambayo ina magnetic inayokubwa. Baada ya mara nyingi za kutambua na kutofunga, penyelewezo hilo na chombo cha kutambua lilianza kupewa magnetic kutokana na magnetic field iliyotengenezwa na shamba la coil wakati wa kutofunga, kusababisha nguvu magnetiki zinazohusiana na kuongeza uchunguzi wa kutofunga. Ikiwa hitilafu ya kutofunga itatofautiana na utendaji wa mara kwa mara, shamba la kutofunga litavunjika.

Magnetic remaining after energization of the tripping coil: This leads to a decrease in the magnetic flux of the tripping coil, resulting in insufficient tripping torque and unreliable tripping. Frequent tripping operations cause the tripping coil to be energized for a long time, generating heat and eventually burning out.

Mechanical jamming between the tripping detent and the positioning roller: The rotating parts lack lubricating grease. Burrs in the movable parts of the bending plate positioning hole and positioning rod, or deviation of the positioning hole due to wear, cause jamming. After multiple operations of the tripping electromagnet, the tripping friction resistance gradually increases, leading to overload and burnout of the tripping coil.

Frequent startup and shutdown of equipment: Coal handling belt conveyors and coal crushers are equipment that start and shut down frequently. When the tripping refusal fault occurs, these devices have already operated more than 500 times. The tripping coil is often energized and generates heat, which accelerates the insulation aging of the coil to a certain extent.

3. Handling Methods

Material replacement for key components: Replace the material of the tripping detent connecting piece from carbon steel to non-magnetic stainless steel, and replace the fixed screws from galvanized carbon steel to copper screws. This prevents the connecting piece from being magnetized, significantly reduces the mechanical resistance of tripping, and thereby reduces the consumption of tripping energy.

Demagnetization of core components: Demagnetize the tripping electromagnet base plate and bending plate using the tapping method before installation. This further reduces the attractive resistance between these components and the tripping detent connecting piece, increases the tripping force margin, and ensures reliable closing and tripping of the contactor.

Localization transformation of the original coil: Replace the original coil with one with a resistance of approximately 20Ω, increase the number of coil turns to enhance magnetic flux, and maintain the electromagnetic force of the coil operation above a certain value. At the same time, the increased resistance of the tripping circuit reduces the circuit current, lowers the heat generation of the coil during energization, slows down the coil aging rate, and effectively reduces the tripping refusal phenomenon caused by the decrease in tripping coil voltage due to increased contact resistance from burnout and oxidation of auxiliary contacts.

Lubrication and maintenance of mechanical parts: Apply lubricating grease to the tripping detent and positioning roller of the vacuum contactor, as well as the rotating parts of the tripping detent. Polish and trim the burrs and worn parts in the movable parts of the bending plate positioning hole, and perform lubrication and maintenance on the rotating parts of the tripping detent connecting piece. After the minimum tripping action voltage test, the action value is basically controlled between 45V and 55V, keeping the tripping mechanism in good condition and greatly improving the safety and reliability of tripping.

4. Preventive Measures

• Regular maintenance and testing: Conduct minor maintenance once a year and major maintenance once every five years after normal operation, and properly perform mechanism maintenance and preventive tests.

• Strict equipment selection and acceptance: Ensure proper selection of vacuum contactor equipment, and strictly control the quality of commissioning, handover, and acceptance.

• Real-time operation monitoring: Strengthen monitoring during operation to promptly identify and handle problems.

• Optimize maintenance procedures: Further grasp the actual conditions of the equipment, and revise and improve the maintenance process procedures based on fault handling methods and experience.

• Strengthen inspection and management of frequently operated equipment: Enhance the inspection and management intensity of vacuum contactors in frequently operated equipment.

• Focus on mechanical part inspection: Pay attention to inspecting the vacuum contactor's mechanical parts, including checking whether the operating mechanism is well-lubricated, operates flexibly, and has no jamming. Special attention should be paid to checking for jamming between the tripping electromagnet bending plate and the tripping detent connecting piece.

• Utilize unit shutdown periods for maintenance: Make full use of the unit shutdown and standby periods to perform maintenance on the vacuum contactor mechanism and conduct preventive tests such as the closing and tripping coil action voltage test. This helps grasp the deterioration trend and promptly adjust and handle potential issues.

5. Conclusion

The vacuum contactors after handling have been put into operation for nearly one year without any faults such as tripping refusal or coil burnout. The power plant once again inspected the vacuum contactors in the coal handling system that had newly accumulated 500 to 1,000 operations and conducted the minimum tripping action voltage test. The results showed that the DC resistance and insulation of the tripping coils were in good condition, the action voltage value did not increase significantly, and the on-site/remote electric tripping tests were accurate and reliable. This has greatly improved the health level and reliability of the equipment, while reducing maintenance workload and saving maintenance costs.