Polarity test for Capacitive voltage transformer

[Powerykh]

When we carry out polarity test or flick test for Current transformer and inductive voltage transformer, we can use a lantern battery to complete the test.
When come to 132kV CVT (outdoor type,Trench TEVF138 ) , the lantern battery yield no result (due to the capacitor divider C1 and C2?). With a 5kV insulation tester, i can see the slight flicking at the analog meter. Have you guys carried out the polarity test for CVT using any other methods?

 

[DTR2011]

You can use an AC Source, such as a variac and a phase angle meter.

 

[scottf]

If your CVT has a potential ground switch (PGS), there is a way to do the DC flicker polarity test.

Put the PGS in the grounded position
Disconnect the HF terminal from ground
This puts the HV side of the intermediate transformer primary winding at the potential of the tank
Apply the voltage to the HF terminal (between the HF terminal and the tank), which will be the neutral end of the intermediate transformer primary winding

Note that since you're applying DC voltage to the neutral end of the primary winding, you will need to look for reverse polarity.

Hopefully that makes sense.

 

[Powerykh]

Thank you DTR2011 and scottf for your valuable suggestion.