In the infinite grid connection structure for a single DFIG, [Z.sub.eq-k] is jointed into the grounding transformer
and the middle-voltage bus; then, the terminal voltage dip threshold is redetermined by means of the method in Section 2.3.
The REF relay operates for phaseto-ground faults of a grounded winding and also of the delta winding if a grounding transformer
is installed between the delta winding and the current transformers (CTs) .
Pacific Crest Transformers, a leader in the design and construction of liquid-filled distribution transformers, announces that it provides grounding transformers
ideal for the renewable energy market.