pros and cons of two different transformer configurations
pros and cons of two different transformer configurations
(OP)
Originally the plan was to use four 6.6/0.4 kVA and grouped generators totaling 2 MW and have four distribution panel. We have already purchased the generators and the transformers. Recently city power starting upgrading the grid to 20 kV and it is a lot more stable so and thereformer want to upgrade too. We are now considering two options.
Option 1:
Two 20/0.4 kV each 2000 kVA. Connect one 20/0.4 to two 6.6/0.4 xformers. We plan to have four manual change over to select between the two with the 20/0.4 being the priority.
Option 2:
Two 20/6.6 kV each 2000 kVA. They will be connected in parralel. The four 6.6/0.4 will be connected to a common busbar. The output of the parallel configuration will be the busbar.
i want to know what are any technical advantages and disadvantages of each of the configs. Thank you.
Option 1:
Two 20/0.4 kV each 2000 kVA. Connect one 20/0.4 to two 6.6/0.4 xformers. We plan to have four manual change over to select between the two with the 20/0.4 being the priority.
Option 2:
Two 20/6.6 kV each 2000 kVA. They will be connected in parralel. The four 6.6/0.4 will be connected to a common busbar. The output of the parallel configuration will be the busbar.
i want to know what are any technical advantages and disadvantages of each of the configs. Thank you.






RE: pros and cons of two different transformer configurations
Is there any reason you can't go with a single 20 kV / 0.4 kV 2000 kVA transformer? The generators could then all be connected to the 400 V bus. This is a lot simpler arrangement.
I'm assuming the generators are all rated 400 V and not 6.6 kV. Correct?
RE: pros and cons of two different transformer configurations
priority 1: 20/0.4 kV
priority 2: 6.6/0.4 kV
priority 3: gensets
I just want to know if there are any technical difficulties/challenges/advantages of either option.
RE: pros and cons of two different transformer configurations
It's a much cleaner and lss expensive arrangement going from 20 kV to 400 V. If you don't, you pay a penalty in having 2 transformations. It gives you higher losses and more voltage drop.
I'd either sell or the 6.6 kV to 0.4 kV transformers or use them somewhere else. At this point, it's a sunk cost, so it shouldn't bias your decision in light of the fact that 20 kV is now introduced.
I'll shut up and let others chime in.