Transmission of Electricity

[raylewis]

Des 56 you forgot the Hope....this was interesting.....
This was not a comment but a question
Will re frase other to the way it was meant....... Electricians common mistake
Not here to be sarcastic just here to help
Anyway I appologise if it was taken the wrong way,as it wasnt meant
that way.
Only here to learn and help

Your quite right Terrell the higher the HV the worst the insulation problems with other things
Was privelaged to help design and work on 768KV line from J'berg to Capetown in South Africa and a DC
line from Pretoria to Mosambique.The main problem is with insulation not so much overhead but at ground
level in switching.


Regards

Ray

 

[sheppy]

Thanks for that

 

[mechelec]

Delta-Delta HV transformers are use because you dont need a neutral phase in transmission.


You do need a earthed star point for protection of the grid network though, that is why electricity is transformed delta - star eg. Grid transformer primary (delta) fed via three wire 132KV and feeds out star 11KV with neutral point earthed through neutral earth resistor (earth required by electricity distribution regs), 11KV distributed three wire to substation tx primary delta with secondary line voltage 400V wired in star. This means that each section of the network (any voltage) is fed from a star connected feeder with earth faults going back to that point (origin) where the protection of that feeder will be.