Aiki na Insuladi na Kafa SF₆: Faifai, Mafi Girma da Kowa da Zaɓuɓɓukaƙi

1. Muhimmanci na Fasahar Jirgin Kirkiro SF₆ Da Duk Kafin Yadda Ake Zama
1.1 Bayanai

Fasahar jirgin kirkiro SF₆ da duk kafin yadda ake zama na iya haɗa dukkan birnin fasahar jirgin kirkiro kamar load switches, load switch-fuse combinations, disconnectors-circuit breakers, wanda suka zama da suka kusa a cikin gas boxes da ke ƙare tsarin kasuwa da suka kusa da gas SF₆ da suka fiye. Wannan gas ya kunshi mafi harkokin jirgin kirkiro da kuma mafi harkokin tashin hankali. Fasahar jirgin kirkiro suna amfani da masana'antu mai shirya ko kuma masana'antu mai shirya da kiyaye. Har zuwa babban kasa ne ƙasar gas box da yake da ita, wanda ya yi tasiri don in yi kudeta da kuma busbar connectors a kan baya da kima. Su na iya amfani da shi a cikin systemen fasahar jirgin kirkiro da suka fiye, kuma su suna amfani da shi a cikin substation da switching stations don in yi abubuwan fasahar jirgin kirkiro.

1.2 Muhimmancin Birni na Fasahar Jirgin Kirkiro SF₆ Da Duk Kafin Yadda Ake Zama

Muhimman birnin suka haɗa:

• Gas Box Da Kafin Yadda Ake Zama: A cikin gas box da kafin yadda ake zama ana iya haɗa fasahar jirgin kirkiro da kuma busbars, da suka kusa da gas SF₆ da suka fiye da suka zama da suka kusa da pressure da suka zama 0.03 MPa. Advanced laser welding da kuma vacuum helium leak detection suna bayyana mafi harkokin kafin yadda ake zama. Babu lafiya da za a yi re-gassing ko kuma replacement a kan lokacin da za a yi amfani da shi, saboda haka ta zama free-maintenance. Idan an yi kudeta, gas boxes suka iya zama shared ko standalone; kawai gas boxes da suka zama standalone su na iya samun kudeta.

• Pressure Relief Device: A cikin gas box, a kan kasa, akwai pressure relief channel da ke ƙare explosion-proof membrane. Idan an yi matsaloli a cikin gas box, zai yi gas expansion da zai kawo membrane open, don in kawo pressure rauni da kuma kawo gas SF₆ a kan trenches don in taimakawa operators da kuma abubuwan fasahar jirgin kirkiro suka zama safe.

• Cabinet Frame: Frame (babu gas box) ya kunshi mounting base don dukkan birnin fasahar jirgin kirkiro da kuma support gas box. Tana ƙunshi uku compartments: operating mechanism room, cable room, da kuma pressure relief channel.

1.3 Muhimmancin Fa'idon na Fasahar Jirgin Kirkiro SF₆ Da Duk Kafin Yadda Ake Zama

• Fully Sealed and Insulated: Dukkan high-voltage live parts suka zama da kafin yadda ake zama a cikin gas box, wanda ya kunshi mafi harkokin tashin hankali. Ideal for humid or polluted environments, especially suitable for regions like the Pearl River Delta.

• Compact Design: Amfani da three-position load switches ya ƙara component count. Conductive parts use SF₆ insulation, resulting in a more compact structure compared to air-insulated SF₆ semi-insulated cabinets.

• Altitude Independent: Internal elements are housed in pressurized enclosures, ensuring consistent performance regardless of altitude.

• Expandability: With each cabinet being an independent gas box and equipped with reserved expansion interfaces, expansion is possible using busbar connectors. These connectors consist of three silicone rubber adapters installed horizontally in the inner cone bushings of adjacent cabinets, connecting their busbars without compromising the seal integrity.

2. Analysis of Expansion Solutions for Fully Insulated SF₆ Switchgear

How to 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.