A three-phase transmission line is feeding from a 400-MVA, 240/24 kV transformer at its sending end. The line has an impedance of 0.6 + jl.20 per phase while the transformer has an equivalent impedance of 1.2 + jl.6 Q referred to the HV side. If the base to be used is 100 MVA, 20 kV for the transmission line, find the per-unit values to be used for the transformer and line impedances A single-phase transformer is rated 15 MVA, 66/11.5 kV. With the 11.5 kV winding short-circuited, rated current flows when the applied voltage to the primary is 5.5 kv. The power input is read as 100 kW. Determine the per unit equivalent impedance of the transformer.

A three-phase transmission line is feeding from a 400-MVA, 240/24 kV transformer at its sending end. The line has an impedance of 0.6 + jl.20 per phase while the transformer has an equivalent impedance of 1.2 + jl.6 Q referred to the HV side. If the base to be used is 100 MVA, 20 kV for the transmission line, find the per-unit values to be used for the transformer and line impedances A single-phase transformer is rated 15 MVA, 66/11.5 kV. With the 11.5 kV winding short-circuited, rated current flows when the applied voltage to the primary is 5.5 kv. The power input is read as 100 kW. Determine the per unit equivalent impedance of the transformer.

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.41P: Consider the single-line diagram of the power system shown in Figure 3.38. Equipment ratings are...

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PowerWorid Simulator case Problem 3_60 duplicates Example 3.13 except that a resistance term of 0.06 per unit has been added to the transformer and 0.05 per unit to the transmission line. Since the system is no longer lossless, a field showing the real power losses has also been added to the oneline. With the LTC tap fixed at 1.05, plot the real power losses as the phase shift angle is varied from 10 to +10 degrees. What value of phase shift minimizes the system losses?
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