MR type R switch. 4 resistors. Example Canada 3.4 and 6 Ohms. Phase shifting transformer 840 MVA 240kV. MCa - Main contact (copper) opening. First region. MSCa - Main switching contact opens. Adding resistance – current drops. Second region – subtracting turns.
MR type R switch
Phase shifting transformer 840 MVA 240kV
MSCa - Main switching contact opens
Adding resistance – current drops
TCa2 - Transition contact closes
Connecting onto the contact at “potential” and lower resistance
Connecting onto the contact with potential at lower resistance
Influence of L
More or less turns
4th segment influenced
OLTC problem ?
Double tap changer
windings in parallel
Is it because two parallel windings and two parallel OLTCS tested at the same time?