AIS变电站

We're fabricating the tubular aluminum busbars for the 220 kV yard — 120 mm diameter, 8 mm wall thickness, 6,800 mm per section. We have 18 sections to weld into three continuous runs. The welding process is TIG (GTAW) with argon shielding. I need you to witness the first weld procedure qualification today.

Let me check the WPS (Welding Procedure Specification). Aluminum TIG welding — 5356 filler rod, preheat to 150°C, argon flow rate 15 L/min. Joint preparation: V-groove at 60° included angle with a 2 mm root face. The welder qualification certificate — he's certified for aluminum TIG, valid until next year. Good. Let him run the first weld and I'll inspect visually, then we'll do radiography on it.

Weld complete. The visual appearance is good — smooth, even bead, no cracks or undercut. Radiography will take 2 hours for processing. After the WPS is qualified, we'll weld all 18 sections over the next 3 days. Once welded, we sand and polish the weld zone, then install on the post insulators using the sliding clamp system. The busbar must be perfectly straight within 5 mm over 20 meters — we use a laser alignment tool for this.

We're designing a new 132/33 kV substation for the industrial park. The available land is tight — only 80 by 60 meters. The client's initial spec called for AIS, but I'm concerned about the footprint. What are our real options?

A standard 132 kV AIS with a double busbar scheme needs about 100 by 80 meters minimum — we can't fit it. We have three options. Option one: compact AIS with a single busbar scheme and vertical-break disconnectors — slimmer but with reduced operational flexibility. It can fit in 80 by 45 meters. Option two: indoor GIS — fits in a building of 30 by 15 meters, freeing up the rest of the land for other uses. Equipment cost is about 30% higher than AIS, but total lifecycle cost may be lower because of reduced maintenance and land savings. Option three: a hybrid — outdoor GIS for the 132 kV side and AIS for the 33 kV side. Let me show you the comparison matrix.

The hybrid sounds pragmatic. But does the client's O&M team have GIS experience? GIS maintenance requires specialized training and SF6 handling equipment. If they've never touched a GIS, we could be creating an operational problem.

Good catch. Let me check their capability before we finalize the recommendation. If they lack GIS experience, compact AIS might be safer despite the larger footprint. I've seen too many projects where advanced technology sits unused because the O&M team can't handle it.