Energization of 150 MVA transformer. Inrush current issue
Energization of 150 MVA transformer. Inrush current issue
(OP)
I am looking into limiting the inrush current as much as possible.
The 150 MVA transformer is 33/150 kV and is to be energized from the 33kV side. The transformer is energized for testing purposes only and will never be loaded.
It is being energized from a relatively week grid, through a small(10MVA) 50/33 kV transformer.
I have looked into solutions such as sequential phase switching to hit the optimal point in the voltage curve resulting in reduced inrush.
But I am very interested in a solution of serial connection of resistors, around 100 ohm. This should effectively reduce inrush current. The resistors can remain in series connection as the transformer should never be loaded (only no load losses of transformer). Can anyone see a fundamental error in this setup or advise if components such as 33kV (3-10kW) are readily available?
any hints/tips greatly apreciated.
The 150 MVA transformer is 33/150 kV and is to be energized from the 33kV side. The transformer is energized for testing purposes only and will never be loaded.
It is being energized from a relatively week grid, through a small(10MVA) 50/33 kV transformer.
I have looked into solutions such as sequential phase switching to hit the optimal point in the voltage curve resulting in reduced inrush.
But I am very interested in a solution of serial connection of resistors, around 100 ohm. This should effectively reduce inrush current. The resistors can remain in series connection as the transformer should never be loaded (only no load losses of transformer). Can anyone see a fundamental error in this setup or advise if components such as 33kV (3-10kW) are readily available?
any hints/tips greatly apreciated.






RE: Energization of 150 MVA transformer. Inrush current issue
RE: Energization of 150 MVA transformer. Inrush current issue
RE: Energization of 150 MVA transformer. Inrush current issue
Could there be any other reasons for not using a permanent series resistor in this setup?
RE: Energization of 150 MVA transformer. Inrush current issue
How do you know that 100 ohms is enough?
RE: Energization of 150 MVA transformer. Inrush current issue
An 100ohm resistor was choses a bit arbitrary and a quick EMT simulation shows inrush current is almost completely removed. Resulting in something like 15A peak current that is already dampened after 1 period to the level of transformer no load current. So actually a 500W resistors would be sufficient.
RE: Energization of 150 MVA transformer. Inrush current issue
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