Teknologi na ɗaya da Kyauko mai Tsirrai na Riga Mai Zama na Kashi na Ilimin Kirkiro da Bincike

1 Introduction​
An kwallon tsohon insula ɗin RMUs (Ring Main Units) na 10kV masu tsari mai yawa sun haɗa da insula na gas, insula na kayan aikin, da insula na hawa.
• Insula na gas yana amfani da SF₆ a matsayin babban insula. Amma, wani ƙaramin SF₆ yana taimaka waɗanda yake ƙarfin birnin duka 25,000 daga wani ƙaramin CO₂, kuma SF₆ yana zama a tsakiyar sama ta 3,400 shekaru, wanda yake taimaka da abubuwa mai yawa ga zamantakewa. RMUs masu tsari mai yawa suka ci gaba, saboda haka, ya zama abin da ba a tabbas ba da kuma mai girma a kan samun SF₆ idan ake yi shi da jin daidai.
• Insula na hawa yana bukatar fushi mai yawa, wanda ba ya iya kawo girman zaɓin gine.

A lokacin da tashar kula na mafi girma ta gida yake ci gaba, abubuwa kamar gwamnatin bincike da sassan rayuwarsu sun neman ƙwarewa mai kyau a cikin RMUs - wadannan sun haɗa da girman kusa, inganci da dalilin kuɗi, kuma inganci da al'adu da zamantakewa. RMUs masu insula na kayan aiki sun zama yadda ake faruwa a kasar.

RMUs masu insula na kayan aiki na 10kV sun amfani da teknologi na insula na kayan aiki, ba gas na SF₆. Girman kusa su ne kawai 30% daga zaɓin gine masu insula na hawa, wanda ke taimaka da insula mai inganci da kuma al'umma da mutanen ƙasashe suka bayyana.

​2 Kayan Aikin da Kallamuwar Insula​
Babu ƙarin bayanin sauli sun nuna cewa kallamuwar insula na RMUs masu insula na kayan aiki yana ci 40% daga kudin gine. Zan iya zabi kayan aikin da ke fi, kallamuwar insula masu ƙarfi, da kuma hanyoyin insula masu daidai suna taimaka da ƙwarewa RMU.

Idan an samu a nan a 1930, resin epoxy yana ci gaba da yawan additin da ke taimaka da ita. Ita ce mafi karfi a tsari, mafi karfi a tsari, tana ci gaban darasi a lokacin da ake so, da kuma yana da ƙarin lafiya don kallamuwar ma'adin. Saboda haka, muna amfani da ita a matsayin kayan aiki mafi yawan insula na RMUs masu tsari mai yawa, da additin da ke taimaka da ita, kamar hardeners, toughening agents, plasticizers, fillers, da pigments, don samun resin epoxy mai karfi. Yadda ake taimaka da ita a tsari, tana taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, wanda yake taimaka da ita a tsari, da kuma tana taimaka da ita a tsari, w......

​3 Kallamuwar Insula na RMUs Masu Insula Na Kayan Aiki​
Interrupters vacuum, disconnectors, grounding switches, da kuma dukkan abubuwa masu ƙarfi suna fi sanya a cikin molds. Ana samun resin epoxy mai karfi da yawan gelation pressure automation. Medium na ƙarfin arc yana ci vacuum, da insula tana ci resin epoxy.

Kallamuwar cabinet yana amfani da kallamuwar modular don yakin mass production. Dukkan bayi na RMU suka fi kwallon metal partitions saboda haka, fault arcs zai zaune a cikin moduluwa guda guda. Ana amfani da busbar connectors da contact connectors masu integration. Main busbar yana ci segmented, enclosed insulated busbars connected by telescopic integrated connectors for convenient on-site installation and commissioning. Cabinet door features an internal arc-proof design and allows breaker closing, opening, and grounding (three-position operation) with the door closed. Switch status is visible through observation windows, ensuring safe and reliable operation.

​4 Advantages and Type Testing Analysis of Medium-Voltage Solid-Insulated RMUs​
​4.1 Key Advantages:​​
(1) Uses high-performance epoxy resin for reliable insulation and low partial discharge.
(2) Fully insulated and sealed structure with no exposed live parts. Unaffected by dust or contaminants. Suitable for diverse environments (high/low temperatures, high altitudes, explosion/contamination-prone areas). Eliminates issues like SF₆ gas pressure fluctuations during high-temperature operation or liquefaction in extreme cold. Offers distinct advantages in high-salt-fog coastal areas.
(3) SF₆-free and contains no hazardous gases—an eco-friendly product. Leak-proof design eliminates regular maintenance. Enhanced explosion resistance suits hazardous locations. The fully insulated three-phase structure prevents phase-to-phase faults, ensuring safety and reliability.
(4) Occupies only 30% of the space required by air-insulated RMUs—an ultra-compact solution.

​4.2 Type Testing Analysis​
Based on these advantages, comprehensive type testing was conducted, including:

• Insulation tests (42kV/48kV withstand voltage)
• Partial discharge measurement (≤ 5pC)
• High/low temperature tests (+80°C / -45°C)
• Condensation test (Class II pollution)
• Internal arc test (0.5s)
  Test results confirmed the product fully meets specifications, validating all stated advantages.

Additional national standard tests were performed:

• Temperature rise test
• Main circuit resistance measurement
• Rated peak withstand current and short-time withstand current tests
• Rated short-circuit making capacity test
• Rated short-circuit breaking capacity test
• Electrical endurance test
• Mechanical test
• Earth-fault test (phase-to-phase)
• Rated active load current switching test
• Rated capacitive current switching test
  All results comply with national standards.

​5 Key Construction Points​
① When pouring concrete, pour beams and columns first, followed by slabs. Pour layer-by-layer along the direction of the formwork tubes, distributing concrete onto the CBM self-stabilizing formwork before vibrating downward. Deposit the first layer of concrete to half the height of the formwork, vibrate symmetrically on both sides. Use vibrators ≤35mm diameter (typically 30mm) for uniform penetration and vibration. Avoid gaps, under-vibration, or contact with the formwork. Spacing ≤25cm, duration ≤3s per point. After confirming compaction, vibrate the surface layer again with a screed vibrator before initial setting, followed by leveling and compaction with a wood float.
② Water/electricity conduits should run within the ribs between CBM self-stabilizing formwork units. If passing through a unit, use a smaller formwork size. During formwork installation and concrete pouring, construct working platforms. Position concrete pump pipe supports on these platforms. Personnel must not walk directly on the formwork, and materials must not be stacked directly on it.

​6 Engineering Performance of CBM Self-Stabilizing Formwork​
① Increased Clear Height
Compared to conventional beam-slab systems, the two projects using hollow-core slabs reduced structural thickness per floor by 30–50cm, increasing clear height. CBM self-stabilizing formwork is ideal for large-span, heavy-load industrial/public structures. It ensures uniform force distribution and allows flexible placement of partition walls.
② Reduced Costs
The CBM hollow-core slab system features a grid-like orthogonal "I"-shaped lattice and hidden closely-spaced ribs, enabling balanced force transfer. Based on the two projects, it reduced reinforcement steel by 27%, concrete volume by 29%, and formwork area by 46% compared to conventional RC frame structures. Overall construction costs decreased by 26.3%.
③ Simplified Construction
CBM formwork offers high strength, light weight, impact resistance, and integrated support frames for easy installation. With hidden beams, the slab bottom remains flat, simplifying formwork/shoring operations.
④ Lighter Weight, Optimized Performance
CBM hollow-core slabs reduce structural self-weight by 27.6% based on calculations, optimizing the design of beams, slabs, columns, and foundations.

​7 Discussion on CBM Formwork Construction Issues​
① Ensuring lower flange concrete compaction is challenging. Leakage in CBM hollow-core slabs is difficult to remedy.
Unlike conventional slabs where concrete is placed directly on a single surface, CBM slabs have upper and lower flanges. Achieving compaction in the lower flange requires meticulous vibration using small-diameter vibrators and external vibrators. After this, the hidden beams and top slab are poured, demanding great care and dedicated QC oversight.
Crack frequency in CBM slabs is comparable to or slightly lower than conventional slabs. However, leaks occurred in the basement roofs and roof slabs of both projects. Identifying the cause is difficult—potential sources include cracks in the upper flange, water seepage through adjacent formwork, or conduits within the ribs. Per leak, repair effort/cost is 5–8 times higher than for conventional slabs.
② Construction Joints & Expansion Strips Require Detailed Design
Structural expansion joint locations are typically specified by design codes. However, the dual-flange nature of CBM slabs complicates pouring if a joint abuts a formwork unit: ensuring bond between new/old concrete in the lower flange and containing grout is difficult. On-site, joint locations should be adjusted based on formwork layout to ensure joints fall within ribs between formwork units. Resizing adjacent units may be necessary.
With CBM slabs typically covering large areas, designers often overlook construction joint placement. To ensure proper bonding within the initial setting time, the site team must determine joint locations considering pour width limits and resource capabilities. Joints must meet code requirements and be placed within ribs.
③ Difficult Mitigation of Formwork Buoyancy
If formwork buoyancy occurs during pouring, the existing countermeasures (removing top reinforcement, clearing concrete, re-fixing formwork) are impractical and often ineffective. Currently, the only solution is breaking/removing the floated unit, placing additional reinforcement, and pouring solid concrete there. Rigorous onsite monitoring of formwork securing and anti-buoyancy measures is essential during construction.