Portable Containerised MV 11kV Substations

[JezNZ]

Hi,

We have a project on-going where we will design-build a containerised portable substation for 11kV vaccuum switchgear. We have built several in the past but not been directly involved in the design.

The feedback from speaking to the project managers involved in these works is that the movement of the portable buildings and the subsequent deflection puts undue stress on the switchgear leading to early failures of bushings etc. An obvious solution is to load the gear in-situ, however this negates the usefulness of a portable sub.

Have enquired with the building manufacturer regarding costs to stiffen the building to keep deflection to 1mm/m (typical of the allowed deflection by many manufacturers), but advised the steel costs will be astronomical.

Another option is to require the busbars, all cables, and bolted connections between panels to be decoupled prior to each move, and reconnected after.

Interested to get some thoughts from similar experiences?

Thanks

 

[bacon4life]

I am not sure why mobile switchgear would be a problem. Lots places have mobile transformers with a 15 kV low side breaker. I suspect that manufacturers such as Delta Star that regularly build mobile equipment select many of the components based on component's ability to withstand the stresses of transport. Rather than designing for extreme stiffness, perhaps consider designs that have flexible connections? There may also be vibration modes excited during transport that stationary gear would not need to be designed to accommodate.

 

[cranky108]

In addition to containerized, have you look at skid mounted substations? I have seen a couple of those, the last manufactured by Cooper (15 kV class), with step down transformer, with high side protection, and pad mounted, three pad mounted regulators, and two pad mounted reclosers.

 

[LittleInch]

I've seen switchgear inside modular buildings transported before now, but with the bus bar and other solid connections loosened off with big warning notices that they need to be torqued back up again to prevent this sort of damage.

Unless the units are themselves rigidly connected, anything which spans between one item and another should either be unbolted or shipped in a "loose" state.

Or as said use some sort of flexible cable or connector.

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