The one - line diagram of an unloaded power system is shown in Figure…
Previous year question for Power System-II.
Question
The one - line diagram of an unloaded power system is shown in Figure. Reactance of the two sections of transmission line are shown on the diagram. The generators and transformers are rated as follows:
Generator 1 : $20\text{ MVA}, 13.8\text{ kV}, x'' = 0.20\text{ p.u.}$
Generator 2 : $30\text{ MVA}, 18\text{ kV}, x'' = 0.20\text{ p.u.}$
Generator 3 : $30\text{ MVA}, 20\text{ kV}, x'' = 0.20\text{ p.u.}$
Transformer $\text{T}_1$ : $25\text{ MVA}, 220\text{ Y}/13.8\text{ }\Delta\text{ kV}, x = 10\%$
Transformer $\text{T}_2$ : Single phase units each rated $10\text{ MVA}, 127/18\text{ KV}, x = 10\%$
Transformer $\text{T}_3$ : $35\text{ MVA}, 220\text{ Y}/22\text{ Y KV}, x = 10\%$
Draw the impedance diagram with all reactance marked in per unit. Choose a base of $50\text{ MVA}, 13.2\text{ KV}$ in the circuit of generator 1.
- Year: 2018
- Subject: Power System-II