Hi All,
We have a project where we are free issued stainless steel earth (grounding) bars. The copper down-conductors from lightning terminals (in the air) are run to this earth bar, and all of the copper conductors which connect to earthing electrodes buried in the native soil are also...
Hi Guys,
In summary the question is: is it ever deemed a more economical solution to parallel PV modules before the combiner box (i.e. series AND parallel connections in a 'string' of PV panels) for a large scale solar PV project?
Some more detail:
When designing a large scale solar...
I am working on a project which requires either 2 x 300MVA, 500kV/115kV three phase transformers or alternatively 2 x 3 x (~100MVA?) single phase 500kV/sqrt(3) / 115kV/sqrt(3) transformers.
Single phase transformers are being explored as an option due to complications in transporting such a...
Hi,
I have received a fault study document. Using this document, I am trying to work out the maximum fault current which actually travels through the earthing system and returns to the upstream star point.
Typically I use the worst case single line to ground fault current for this purpose...
I am performing some basic pre-commissioning tests on a 132kV transmission line shortly. The line is around 40km in length and is earthed at both ends with portable earths. Several medium voltage and high voltage lines run parallel or intersect this transmission line over the route.
I am...
Hi All,
Recently I have had a discussion with a fellow engineer in relation to the choice of winding configuration for a 132/33kV transformer in a wind farm application.
His sentiments were that a Yyn(d)0 (buried delta) should be used. I was proposing a Dyn1 transformer as I assume it will be...
I'm performing some calculations for a substation and have been presented with the following system information at the point of connection:
3ph fault (5.53kA phase & positive sequence), X1/R1=4.8, R1=0.016pu, X1=0.077pu
2ph-G fault (6.75kA, 6.99kA phase), (3.2kA, 4.4kA, 1.2KA, zero, pos...
Hi,
I have a supply substation with an earth grid, and a long cable (e.g. 10km) which supplies some equipment sitting on its own earth grid. I have a good understanding of the earth grid impedances of both the feeding substation and the remote equipment earth grid.
The cable which feeds the...
Hi,
It is typical to use copper for an earthing conductor and also to bond it to the reinforcing steel of a large concrete structure such as a power transformer foundation.
Some consultants have informed me that a passivating film will form over the reinforcing steel as a result of the...
I have a problem with a new substation which is fed from an unrestricted 11kV feed. The substation upstream has an 11kV fault level of approx 7kA and is located 200m away.
I want to reduce the fault current so that the touch voltages within the new substation comply with IEC/AS standards...
Hi All,
I am looking at a large solar farm in Australia.
The current design is for several 33kV to 415V Dyn11 step up transformers with LV supply from approx 15 x 60kW 3 phase inverters per transformer (inverters will be mounted on or adjacent to large solar panels).
My question is- Do we...
