What a great visit by Tortech Engineers to discuss with UNSW team, some new Impulse testing techniques for voltage transformers! Thank-you to Professor Toan and Lab engineer Liu from UNSW for this opportunity.
On our visit we tested a 11kV to 240v single phase voltage transformer. It was an indoor VT and it was epoxy cast. We impulse tested at 125kV peak. It was a full wave impulse test.
Resistive current shunt testing was performed to detect failure in impulse testing. Multiple impulse shots were performed on the VT and the voltage and current waveforms were compared for each shot.
Conclusion was that the resistive shunt was not very sensitive and that capacitive shunt detection for the current wave form would be more sensitive.
Read related article High voltage testing on VT Transformers here.
