Optimizatio methodorum de terreo connectendo ad nucleum et fibulas transformatoris electricitatis

Praesidia ad terram transformatoris dividuntur in duos typos: Primus est praesidium ad terram puncti neutri. Hoc praesidium impedit declinationem tensionis puncti neutri propter inaequabilitatem oneris tria-phalangeae durant operationem transformatoris, faciens ut praesidia citius disjungant et reducens currentes circuitus breves. Hoc consideratur praesidium functionale ad terram pro transformatore. Secundum praesidium est praesidium ad terram nucleique et clavarum.

Hoc praesidium prohibet tensiones inducendas quae oriuntur super superficies nucleique et clavarum propter campos magneticos internos durant operationem, quae possunt ducere ad defectus partialis discursus. Hoc consideratur praesidium protectivum ad terram pro transformatore. Ut securitatem et fiduciam operationis transformatoris confirmet, hic articulus analysat et optimat methodos praesidiorum ad terram specialiter pro nucleo et clavis transformatoris.

1.Importantia Praesidii ad Terram Nuclei et Clavorum

Principes componentes interni transformatoris includunt: spires, nucleus, et clavas. Spira formant circuitum electricum transformatoris, nucleus constituit circuitum magneticum, et clavae principaliter usurae sunt ad fixandum spiras et lamellas silicis ferrei. Durante operatione normali, spira prima et secunda generant campos magnetics cum currentibus per eas fluentibus. Sub hoc ambiente magnetico, tensiones inducuntur super superficies nucleique et clavorum. 

Cum roboramento campi magnetici, fluxus magneticus gradatim crescens, causans tensiones inducendas progressu crescentes. Propter distributionem inaequalitatis campi magnetici, tensiones inducendae non uniformes creant differentias potentialis, resultantes in discursu continuo super superficies nucleique et clavorum, ducendo ad defectus internos transformatoris. Haec tensio causans defectus discursus internos in transformatoribus nominatur "tensio flottans." Ergo, durante operatione, nucleus et clavae transformatoris debent ad unum punctum terrari ut reducant et eliminant tensiones inducendas.

Quando terratur nucleus et clavae transformatoris, solum unum punctum terrationis permittitur ut prohibeat circulationes currentium inter nucleus et clavas. Si duo vel plures puncti terrationis existunt, differentiae potentialis causabunt circulationes currentium inter nucleus et clavas, ducendo ad incrementa abnormalia caloris interni transformatoris. Hoc directe laedit insulationem solidam internam et accelerat senectutem olei insulantis, affectans vitam normalis servitii transformatoris.

2. Methodi Praesidiorum ad Terram Nuclei et Clavorum et Approaches Optimorum

In designis transformatorum hodiernis Sinensibus, praesidium ad terram nuclei et clavorum principaliter efficitur per connexiones ductas per parvos bushings vel bullas insulatas ad exteriorem dolium transformatoris antequam terrantur. Haec methodus praesidii dividitur in duas methodos:

Prima methodus praesidii (Figura 1) connectit nucleus et clavas per bushings vel bullas insulatas, tunc directe short-circuitas simul antequam terrantur. Durante operatione normali transformatoris, haec methodus praesidii exhibet tres vias currentium fluendi, notatas I1, I2, et I3:

• I1: Nucleus → Terminale terrationis → Terra

• I2: Clavae → Terminale terrationis → Terra

• I3: Nucleus → Terminale terrationis → Terra → Clavae

Secunda methodus praesidii (Figura 2) ductat nucleus et clavas per bushings vel bullas insulatas ad puncta terrationis separata. Haec methodus praesidii quoque exhibet tres vias currentium fluendi durante operatione normali:

• I1: Nucleus → Punctum terrationis nucleique → Terra

• I2: Clavae → Punctum terrationis clavorum → Terra

• I3: Nucleus → Punctum terrationis nucleique → Terra → Punctum terrationis clavorum → Clavae

Ex duabus methodis praesidiorum supra mentionatis, currentes terrationis inducendi I1 et I2 repraesentant conditiones normales. Tamen, currentes terrationis inducendi I3 differunt significanter:

In methodo praesidii ostensa in Figura 1, currentes inducendi fluunt per viam: nucleus → terminale terrationis → clavae, creantes "circulationem currentium" inter nucleus et clavas transformatoris. Sub effectu caloris huius currentis, temperies interna transformatoris abnormiter crescens. Alta temperies directe causat degradatio insulationis solidae et senescens olei insulantis. In additionem, propter influentiam circulationis currentium, systemata monitoria online non potest accurate mensurare currentes terrationis nucleique et clavorum, ducendo ad misdiagnosi quando defectus equipmenti occurrunt. Ergo, prima methodus praesidii habet defectus significantes.

Contrario, in methodo praesidii ostensa in Figura 2, currentes inducendi ductantur per: nucleus → terra nucleique → terra → terra clavorum → clavae. Quoniam currentes per terram alta-resistiva transibunt, "circulatio currentium" non potest formari inter nucleus et clavas. Hoc prohibet incrementum abnormaliter caloris transformatoris et permitte systemata monitoria online accurate mensurare currentes terrationis nucleique et clavorum (secundum DL/T 596-2021 Codem Preventivum Testis Electrici, currentes terrationis nucleique non debent excedere 0.1 A et currentes terrationis clavorum non debent excedere 0.3 A durante operationem transformatoris). Hoc affert probam fidelem determinandi si defectus interni existunt in transformatore.

Pro transformatore xx-223000/500 sine-excitatione regulante potentia, nucleus et clavae terrantur per methodum ostensam in Figura 1, quae praebet varias difficultates operationis:

(1) Durante operatione, "circulatio currentium" facile formatur inter nucleus internus et clavas. Effectus calorificus causat incrementum abnormaliter caloris, accelerans degradatio insulationis solidae et senescens olei insulantis, reductans vitam servitii transformatoris.

(2) Owing to the influence of "circulating current," online monitoring systems cannot accurately measure the grounding currents of the core and clamps, making it impossible to provide conclusive evidence for determining internal faults.

(3) The induced grounding currents of the core and clamps can be continuously measured and compared with leakage currents monitored by the online system to verify the monitoring system's accuracy.

(4) During transformer maintenance and repair, when measuring insulation resistance between core/clamps and ground, external grounding leads must be disconnected. Since this transformer model uses M10 copper bolts (insulated from ground) for core and clamp connections, which have excellent conductivity but low mechanical strength and are prone to breakage. During field operations, confined spaces and unbalanced forces can easily cause copper bolt fractures. Given the transformer's compact internal structure, addressing this fault requires lifting the tank cover for replacement, affecting normal maintenance cycles and operational efficiency.

Considering these four issues, to ensure accurate detection of core and clamp induced grounding currents during operation, extend transformer service life, eliminate "circulating currents," and prevent maintenance operations from causing damage that expands repair scope, it is recommended to optimize the transformer's core and clamp grounding method from the Figure 1 configuration to the Figure 2 configuration.

3.Conclusion

Through detailed introduction of transformer internal components and functions, along with scientific analysis of discharge faults occurring during operation, modifications to defective parts have been successfully implemented. This approach achieves extended equipment service life, improved power grid safety, and reduced equipment maintenance costs.