Terminatio Cabilis MV & HV ad Apparatum & Iuncturas
Problema Generalia et Considerationes in Terminatione Electrica
Cum ad terminandum conexiones electricas in apparatibus commutationis indoor, motoribus electricis, transformatoribus potentiae, transformatoribus instrumentorum, et aliis apparatibus medio - voltai (MV, ubi ambitus tensionis est（1 kV<V<60 kV) et alto - voltai (HV, cum V≥60 kV) pertinet, plures difficultates emergunt. Haec saepe ex complexitate designorum terminationum, praesertim quae ad apparatuos commutationis pertinent, oriuntur. Ut haec effectuose tractentur, arcta coordinatio cum manufactoribus apparatorum non solum consilii sed necessaria est.
Factorum Consideratio in Terminatione Machinarum Electricarum et Transitionibus Cabelorum Subterraneorum ad Aereos
Factores in Terminatione Machinarum Electricarum
Cum machinas electricas terminamus, completus factorum set debet diligenter considerari ut operatio secura, fidelis, et efficientia assequatur:
Bus et Structurae Sustinentes: Design, materia, et robor mensurae busbarum et earum structurarum sustinentium sunt cruciales. Illae debent resistere currentibus electricis, stressibus mechanicis, et fortibus circuitorum brevium dum rectam alinementum et stabilitatem retinent.
Structura Insulationis Interruptoris Circuiti: Integritas insulationis intra interruptores circuiti vitalis est ad praeveniendum disiectamenta electrica. Illa debet poterit tolerare tensionem nominalem, overvoltages transitorias, et conditiones ambientales sine defectu.
PD (Partial Discharge) Analyse: Effectuando analysin partial discharge signa primitiva degradatio insulationis deteguntur. Partial discharges possunt indicare potentialia infirma in systemate insulationis, quae, si non curantur, ad casus catastrophicos ducere possunt.
Materia Insulationis: Electio materiae insulationis, sive olei, sulfur hexafluoride (SF6), vel vacui, magnam impactum habet. Quaeque materia suas proprias virtutes et limites in termis fortitudinis insulationis, capacitate arc - quenching, impacto ambientali, et requisitis maintenance habet.
Condicio Systematis Wedging: Systema wedging, quod partes in loco fixat, debet bono statu esse. Systema wedging defensum coniunctiones laxas, resistentiam electricam maiorem, et calorem superfluum potest generare.
Typus Gas Refrigerae: Pro machinis quae gas - based refrigeratione utuntur, typus gas refirigerae affectat dissipationem caloris et performance totalem. Diversi gase varias conductivitates thermicas et capacitatis caloris portandi habent.
Proximitas Componentium Grounded ad Conductores Alto - Voltai: Locatio componentium grounded in relatione ad conductores alto - voltai est critica. Proximitas magna periculum electrale leakage, flashovers, vel interferences augit, necessitans properam insulationem et spatium.
Terminationes pro Transitions Cabelorum Subterraneorum ad Lineas Aereas
Terminationes pro transitionibus cabelorum subterraneorum ad lineas aereas, communiter OH/OG terminationes dictae, partem clavem in rete distributionis electricae agunt. Hae terminationes saepe designantur pro systematibus cum tensionibus nominatis usque ad 36 kV. Eorum functiones primarias includunt connexionem systematis distributionis ad apparatuos commutationis indoor vel outdoor praeparatos et facilitationem routing electricae potentiae dum necesse non est ut lineae aereae urbana transirent.
OH/OG terminationes compatibiles sunt cum ambos oleo - charta et cross - linked polyethylene (XLPE) insulated cables, qui possunt unico - core vel tri - core esse. Instalantur foris et montantur in structuris metallicis firmis ad poles lineae aereae factis e ligno, betono, vel metallo, ut in Figura 1 illustratur.
Requisitum essentiale pro OH/OG terminationibus est ut structurae metallicae eorum recte ground sint. Hoc grounding servit ad protegendum contra shocks electricos, dissipandum currents fault, et assecurandum security electricam totalem systematis.
Requiritia pro Structuris Metallicis et Installationibus Cabelorum OH/OG, et Elbow Terminations
Requiritia pro Structuris Metallicis et Installationibus Cabelorum OH/OG
Altura structurae metallicae OH/OG (Overhead/Underground) non est arbitraria; stricta ad minimum distance insulation safety ad terram definita per standards industriales relevantes adhaerere debet. Haec compliance crucialis est ad assecurandum security hominum, equipment, et systematis electrici totius, prevenendo pericula electrica sicut contactus accidentales vel arcing ad terram.
Cum cables pro terminationibus OH/OG instalamus, ipsi debent positi esse in latere pole quod facit ab oncoming traffic. Haec positio minuit periculum damni a vehiculis, ita augmentans reliability et longevitatem infrastructure electricae. Praeterea, per totum processum installationis et postquam cables in sua ultima positione sunt, imperativum est ut non sint flexi ultra minimam radius internam flexionem manufacturer - specified. Defectus huius requirementi potest causare damnum internum ad insulationem et conductores cable, potentiando ad failures electricas. In aliquibus casibus, ut minimum radius flexionis teneatur, poles altiores necessarii esse possunt, addens considerationem extra in phase planning et installationis. Praeterea, terminationes OH/OG debent designari cum measure animal - proofing in loco. Haec tutatur cables ab damno ab animantibus, quod aliter potest resultare in power outages et pericula security.
Elbow Terminations
Cable terminations communiter ad connexiones cables ad terminals diversorum equipment, including transformers, motors, and pre - assembled switchgears, utuntur. Tamen, propter conditiones specificas installationis electricae vel naturam terminals equipment, sunt tempora ubi connexio cable ad bushings sigillanda sit. In talibus situatibus, elbow terminations, ut in Figura 2 depictae, sunt optima electio. Haec specialia terminationes non solum connexionem electricam securem provident sed etiam functionality sealing necessarium, protectantes systema electricum ab elementis ambientalibus et assecurantes operationem eius stabiliter.
Elbow Terminations et Eorum Applicatio in Ring Main Units (RMUs)
Elbow terminations munus cruciale et specializatum servant, praesertim quando ad connexiones cables ad bushings Ring Main Units (RMUs) pertinet. RMUs sunt compacta, self - contained, et fully insulated switchgear systems quae solito sulfur hexafluoride (SF6) ut medium insulationis utilitant. Largiter in networkibus distributionis secundariis employant, haec unitates partem vitalem in management et distributione potentiae electricae ad level local agunt.
Una ex key feature RMUs est design eorum pro internal arc withstand, quod security et reliability systematis electrici augescit. Partes vivae RMUs ingeniantur ut maintenance - free sint, reducendo necessitatem interventionum frequentium et minimizando downtime. Praeterea, natura eorum modularis expansionem facilem in loco installationis permittit, systema ad adaptandum ad mutandas demandas potentiae temporis permissum.
Functiones switching et protectionis in RMUs per usum switch - disconnectors in combination cum fuses vel circuit breakers efficiuntur. Haec configuratio assecurat ut systema electricum secure isolate possit, faultes celeriter detecti et eliminati, et integritas network distributionis conservetur.
Elbow terminations non solum utiles sunt ad connexiones cables ad bushings RMU sed etiam applicationem inveniunt quando plures cables ad idem bushing equipment electrici connectendi sunt. Ut in Figura 3 illustratur, haec terminationes solutionem practicam et fidem dignam pro tali complexa connectione cable - to - equipment praebent, facilitantes distributionem efficientem potentiae electricae dum integritas et security systematis totius conservantur.
Elastimold Cable Joints & Terminations
Elastimold est brand notabilis quae offerit range comprehensivum equipment et accessory pro splicing et termination cabling, designata pro rated voltages usque ad 36 kV.
Elastimold cable terminations in both single - piece et modular designs veniunt. Haec versatilia models apta sunt pro variis applicationibus, including the transition from underground cables to bare overhead conductors, connections to live - front equipment, et elbow connections, making them adaptable for both indoor et outdoor use. Possunt integrari seamless into oil, SF6, et air - insulated high - voltage switchgear, as well as transformers, motors, et capacitors.
Designs productorum Elastimold incorporant advanced silicone rubber insulating materials. Haec materiae provide essential resistance against creep, electrical strikes, weathering, et contamination, assecurantes performance reliable etiam in conditionibus severissimis. Compactness et levis nature units Elastimold facilis installationem in spaces confinis et enable free - hanging applications.
Devices Elastimold etiam ATEX - certified sunt. ATEX, derived from the French title of the 94/9/EC (European Commission) directive "Appareils destinés à être utilisés en ATmosphères Explosibles" (Equipment to be installed in explosive atmospheres), these high - voltage bushings are suitable for use within oil or air - insulated switchgear and transformers in hazardous areas, sicut in industria petrolio, gas, et petrochemicalia reperiuntur. Fabrication Elastimold equipment adheret ad standards internationales a IEC (International Electrotechnical Commission), ANSI/IEEE (American National Standards Institute/Institute of Electrical and Electronics Engineers), et CENELEC (European Committee for Electrotechnical Standardization) constitutas.
Elastimold offers several specialized devices for specific applications:
Separable Elbow Connectors and Accessories: Haec sunt load - break connectors qui convenientem modum offerunt ad connexiones et disjunctiones cables et equipment in systematibus distributionis potentiae. Load - break elbows designantur pro operatione energized using standard hot - stick tools, enabling load make/break operations et providing a visible disconnect. The components can be isolated using insulated caps, plugs, et parking bushings.
Metal Oxide Varistor (MOV) Surge Arresters: Hi arresters sunt fully shielded et fully - submersible, designati pro overvoltage protection. Feature 200 A separable connector interfaces for easy attachment to other Elastimold accessories. Elastimold arresters offer high - voltage protection against lightning et switching surges for transformers, cables, equipment, et alia componentia in systematibus distributionis subterraneis reperientia. Proper placement, voltage selection, et coordination with riser pole arresters significantly enhance protective margins et minimize damaging surge voltages. Typical applications include installing arresters at the end of a radial system vel at both ends of an open point on a loop system, with additional arresters added at strategic upstream locations for optimal protection.
Fused Elbows: Hi combine replaceable current - limiting fuses for current protection in OH/OG cable terminations with 200 A separable connector interfaces for compatibility with other Elastimold accessories.
Raychem is another commonly recognized brand in the field of cable splicing and termination equipment.
Terminations for GIS (Gas Insulated Substations)
When the available space for substation installation is limited or environmental conditions are extremely harsh, a Gas Insulated Substation (GIS) is often the preferred solution. GIS is a compact, multi - component assembly housed within a grounded metallic enclosure. It contains bus bars, circuit breakers, isolators, and instrument transformers, with compressed sulfur hexafluoride (SF6) gas serving as the primary insulation medium, ensuring reliable phase - to - ground insulation. While GIS are typically installed indoors, outdoor models are also available.
GIS units are equipped with cable termination enclosures where cable terminations are installed. According to IEC Standard 60859, both the enclosures and cable terminations must meet specific dimension requirements to ensure interchangeability. Cable terminations for GIS are suitable for gas, oil - paper, and XLPE - insulated cables and share many components with the cable joints previously discussed.
Features of GIS Cable Terminations
The main features of GIS cable terminations include:
Cable Lug: Facilitates the connection between the cable conductor and the termination.
Box Body: Typically made of aluminium alloy or a similar material, providing structural support and protection.
Reliable Support Insulator: High - grade, non - tracking epoxy insulators offer excellent mechanical and electrical properties. These insulators are compatible with SF6 gas by - products, ensuring a long service life for the termination. Their design also allows for an optional cable shield break.
Filling Compound: Such as transformer oil, polybutene oil, or similar substances, which help in insulation and stress relief.
Stress Control Cone with Bundle Tape: Manages electrical stress at the cable insulation - termination interface.
Rigid Cable Support: The connector is securely locked in place by a threaded hood at the top of the support insulator. This design ensures that the electrical connection between the GIS and the termination is not subjected to mechanical forces from the cable.
Positive Sealing System: A double "O" ring sealing system is employed to seal the termination oil compartment from the GIS SF6 compartment. Fully retained gaskets are compressed to prevent the ingress of atmospheric elements into the termination interior.
Earthing Clamp: Provides a secure connection for earthing purposes.
Figure 4 illustrates a schematic of a GIS cable termination. Some models available on the market do not require the use of oil, eliminating the need for an oil housing.
Sealing, Connection, and Installation Requirements for GIS Cable Terminations
Sealing System
The sealing system of GIS cable terminations is of paramount importance and must be meticulously designed. Its primary function is to prevent the leakage of oil or gas into the GIS. A compromised seal could lead to insulation failures, gas loss, and potential safety hazards. By ensuring a robust and reliable sealing mechanism, the integrity of the GIS environment and the overall electrical system is maintained.
Mating Connection Piece
The GIS supplier is responsible for providing a mating connection piece that is specifically designed to be fitted to the cable end. This component is crucial for establishing a secure and electrical connection between the cable and the GIS. The precise design and compatibility of the mating connection piece are essential to ensure seamless integration and optimal performance of the cable - GIS interface.
Isolation and Testing Facilities
To guarantee the safety and reliability of the electrical system, proper facilities must be provided to safely isolate a feeder cable. This isolation capability is necessary during maintenance, repairs, or fault - finding operations. Additionally, provisions should be made to connect a high - voltage test cable to either the GIS or the cable itself. These testing facilities enable routine inspections and diagnostic tests to assess the condition of the cable and the GIS, helping to identify potential issues before they escalate into major problems.
Required Tools and Accessories for GIS Termination Installation
For the successful installation of GIS cable terminations, a specific set of proper tools and accessories is indispensable:
Panduit Pliers: These pliers are specifically designed for installing bundle tape around the stress cone. The accurate application of the bundle tape is crucial for managing electrical stress and ensuring the long - term reliability of the termination.
Circlip Pliers: Used for the installation of the top fitting, circlip pliers provide the necessary grip and precision to secure this important component in place.
Adapter Flange: The adapter flange plays a key role in facilitating the connection between different components, ensuring a proper fit and alignment within the GIS termination system.
Top Fitting Removal Kit: This kit is essential for maintenance and repair operations, allowing for the safe and efficient removal of the top fitting when required.
Re - assembly Kit: The re - assembly kit contains all the necessary components and hardware to put the termination back together after maintenance or repairs, ensuring that all parts are replaced correctly.
Earthing Kit: An earthing kit is vital for establishing a secure electrical connection to the ground, which is essential for the safety of the electrical system and personnel.
Screen Connection: The screen connection ensures the proper grounding and shielding of the cable, reducing electromagnetic interference and enhancing the overall performance of the cable - GIS system.
