If the line-to-line primary voltage and line current is 1.0 at 0 degrees, what is the secondary line- to-line voltage for the following three-phase transformers? Assume a turns ratio of N = 10. Express answer in polar form. a. Delta-to-Delta: b. Delta-to-Wye: c. Wye-to-Delta: d. Wye-to-Wye:

What do the connection angles and groups show in transformers? For example, where are the Yy0 , Dy5 ,Yd5, Yz5 group transformers used?

2. Given three identical ideal single-phase transformers with each rated at 100KVA and 7kV/3.5kV, they are connected as a three-phase transformer bank. The three-phase transformer has high voltage side connected in delta and the low voltage side is connected in wye. A three-phase 200KVA, wye connected load is connected at the low voltage side of the transformer. Calculate the following: a. Rated line-to-line voltage on each side b. Line current on each side of the transformer