2.29 Three 10, 100 kVA, 2300/460 V, 60 Hz transformers are connected to form a 30, 2300/460 V trans- former bank. The equivalent impedance of each transformer referred to its low-voltage side is 0.045 +10.16 2. The transformer is connected to a 36 source through 30 feeders, the impedance of each feeder being 0.5 +j1.5 2. The transformer delivers full load at 460 V and 0.85 power factor lagging. (a) Draw a schematic diagram showing the transformer connection. (b) Determine the single-phase equivalent circuit. (c) Determine the sending end voltage of the 30 source. (d) Determine the transformer winding currents.

Ql-phase step down transformer 1250 KVA, 10002200 V, 50 Hz The resistance /phase and leakage reactanceiphase of the primary winding are 0.78 2 and 4.82 and the corresponding values for the secondary winding are 0.012 and 0.002 respectively if the primary winding is connected in delta and secondary in star calculate: )The voltage to be applied at normal frequency to the primary to circulate full-load through it when the secondary is short-circuited li) The full load copper loss

When the transformer is loaded in a balanced fashion up to its nominal rating (10 MVA), calculate the high side line-to-line phasor voltages (ab, bc, ca). and low side phasor voltages both line-to-line and line-to-neutral (ab, bc, ca, a, b,c). as a reference for calculations the low side A line to neutral voltage is 7620V at an angle of 0 degrees when the transformer is at rated power.  The transformer has the following characteristics: V: 138kV delta high side/ 13.2 kV wye low side 9% impedance X/R ratio of 20