Primary and secondary signals show a topology dependent phase shift.
Y-Y and Delta-Delta configuration:
no phase shift.
Y-Delta configuration / Delta-Y configuration:
shift secondary vs primary voltage is -30deg / +30deg.
PAR-Y configuration:
shift secondary vs primary voltage is adjustable alpha.
Compare:
meter12.alpha_v voltage phase secondary Y-Y topology meter22.alpha_v voltage phase secondary Y-Delta topology meter32.alpha_v voltage phase secondary PAR-Delta topology