Tests for VT

[Arevaengineer]

My client is asking for tests on a 400kV VT.The tests includes magnetizing curve for the VT.Can anyone tell me how its done as I have never encountered such request before.

Thanks to all for help.

 

[scottf]

With the primary winding open circuited, apply a voltage across the secondary winding and measure the current that is drawn. Plot the voltage versus current and this is the magentizing curve.

Don't exceed the rated secondary voltage by more than the short-time over-voltage rating.

Caution...a high voltage will be present on the primary winding. The voltage present will be a function of the VT ratio. Make sure the primary terminal is not connected to anything.

 

[040358]

Generally magnetizing curve is plotted on logarithmic scale

 

[RalphChristie]

Logarithmic?
I would use a normal scale for both current and voltage.

 

[scottf]

Yes...if you put the X axis in mA or micro-Amps and the Y axis in volts, the graph will be fine plotted normally.