Sîf Deyvekîn SF₆ a Qediya: Pelan, Bûyir, û Çaresazên Zêdetkirina

1. Xeşkên Pêşdînayî yên Switchgear SF₆ Yeketî
1.1 Dîrok

Switchgear SF₆ yeketî xweşkên pêşdînayî yên dijî wekî switchên baran, kombinasyonên switch-baran-fuse, disconnectors-circuit breakers, û sêmîn di gas boxes yên lêzerên serokên daxwaz de hatine pêşdînin. Gas SF₆ bi hêviyên 0.03 MPa hatiye pêşdînin û ji bo îliya qewirxana û pêşdînayî têne bikar anîn. Switchgear-ê mechanismên elektrik û penberên spring-operated dikare biafirîne. Her kabinet yek gas box nezîkî ye, ku dilindiyên busbar ên derbas bike. Ên unitên li ser sisteman distribûsyonan ya voltageya navendî hatine bikar anîn û zaf û çêker di substation û switching station de bikar anîn.

1.2 Komponentên Bijîr Xeşkên Pêşdînayî yên Switchgear SF₆ Yeketî

Komponentên sereke:

• Gas Box Yeketî: Di gas box yeketî de switchgear û busbars ne, bi gas SF₆ bi hêviyên 0.03 MPa pêşdînin. Hêsanên laser û testandina leak detection bi helium vacuum tevgerîne, ku pêşdînayîya herî bijîrê digehîne. Li demê karûbarê nabad re-gassing û replacement nehatiye kirin, ku wekî maintenance-free ye. Gas boxes li gor expandability din dikarin be shared an standalone; tu standalone boxes expandability têne dest pêkirin.

• Device Pressure Relief: Li bin gas box, li bin channel pressure relief membrane explosion-proof heye. Ji bo arc faults di navendeyê de, gasê bi tevgera berbi bike û membrane wê vekirin, ku bi rêjiyê gas SF₆ li ser trenches bide, ku ew amneya operator û piramerdên din bide.

• Cabinet Frame: Frame (ji gas box ve) divê base mounting be bikar anîn ji bo hemî komponent û support gas box. Li serîsî three main compartments heye: operating mechanism room, cable room, û pressure relief channel.

1.3 Avantajên Sereka Xeşkên Pêşdînayî yên Switchgear SF₆ Yeketî

• Pêşdînayî Yeketî û Yeketî: Hemî high-voltage live parts di gas box de pêşdînin, ku têne biguherîne. Ji bo cihane û polluted environments ideal ye, bi tenê regions like the Pearl River Delta.

• Design Compact: Bi karîna load switches three-position, component count reduce bike. Conductive parts SF₆ insulation bikar anîn, ku structure compact bi air-insulated SF₆ semi-insulated cabinets.

• Altitude Independent: Internal elements di pressurized enclosures de ne, ku performance consistent li gor altitude.

• Expandability: Her cabinet yek gas box nezîkî û equipped with reserved expansion interfaces, expandability possible bi busbar connectors. Connectors û three silicone rubber adapters horizontally installed in inner cone bushings of adjacent cabinets, connecting their busbars without compromising seal integrity.

2. Analysis of Expansion Solutions for Fully Insulated SF₆ Switchgear

Ji bo add new cabinets to existing fully insulated SF₆ ring main units (RMUs) has become a challenge in recent years due to the lack of standardized interface specifications among different manufacturers. Below is an analysis based on a specific project:

Case Study X: A residential area's substation currently houses three expandable fully insulated SF₆ RMUs from HD Switchgear Company, including one incoming line unit and two outgoing line units. The project requires adding another outgoing line unit and extending a ZRC-YJV22-3×120 cable to a new outdoor switchgear serving new users. Several solutions were considered:

• Complete Replacement: Replacing all three existing RMUs could potentially damage the connected cables if not carefully removed and reinstalled, leading to significant additional costs. Given that the current units have been in operation for less than two years, this option is wasteful.

• Adding a New Cabinet: As switchgear is supplied by the power bureau, procuring a non-HD product might lead to compatibility issues due to varying busbar interface standards. Procurement through specialized bidding processes would also delay project timelines.

• Using Semi-Insulated SF₆ Cabinets: Introducing a semi-insulated cabinet alongside a busbar riser cabinet to bridge the gap between fully and semi-insulated units poses challenges due to the absence of standardized connection components, requiring close cooperation from the original manufacturer.

• Installing Additional Semi-Insulated Units: Adding a semi-insulated outgoing line unit and a busbar riser cabinet next to the existing incoming line unit allows for re-routing cables via the riser cabinet, effectively expanding capacity without disrupting existing installations. This solution was ultimately chosen for its practicality and effectiveness.

The fourth method was adopted, successfully addressing the expansion needs, and the project is now completed and operating smoothly.

3. Conclusion

In conclusion, fully insulated SF₆ switchgear offers clear technical advantages but faces challenges due to the lack of unified interface standards, complicating direct integration between products from different manufacturers. While the fourth method solved the immediate problem, future projects should prioritize using products from the original manufacturer, confirming their expandability, particularly avoiding shared-box structures which generally cannot be expanded. This approach ensures better compatibility and feasibility for system upgrades.