Consider the system below. The nominal voltage is 138 kV, and the positive sequence impedances for the various elements are given. The maximum load is 120 MVA. The available relays can be set from 0.2 to 10 2 or 0.5 to 40 2, whichever is required. The angle of maximum torque can be adjusted to 75° or 80°. The CT and VT ratios are respectively 500:5 and 1150:1. Neglect line resistances and suppose relay Rab is a directional comparison blocking relay using directional mho relays for tripping and reversed mho relays, without offset, for blocking. The carrier trip settings for the phase relays of line AB and BC are respectively equal to 602, 80° and 802, 80°. Assuming a PF of 0.8, then the maximum Loadability of relays Rab and Rbc would be respectively equal to: A (3+j40) с Rab * B (2+150) F2 (0+19) Select one: a. 120MVA, 381 MVA O b. 381MVA, 508 MVA О с. 120MVA, 508 MVA O d. 381MVA, 381 MVA

Consider the system below. The nominal voltage is 138 kV, and the positive sequence impedances for the various elements are given. The maximum load is 120 MVA. The available relays can be set from 0.2 to 10 2 or 0.5 to 40 2, whichever is required. The angle of maximum torque can be adjusted to 75° or 80°. The CT and VT ratios are respectively 500:5 and 1150:1. Neglect line resistances and suppose relay Rab is a directional comparison blocking relay using directional mho relays for tripping and reversed mho relays, without offset, for blocking. The carrier trip settings for the phase relays of line AB and BC are respectively equal to 602, 80° and 802, 80°. Assuming a PF of 0.8, then the maximum Loadability of relays Rab and Rbc would be respectively equal to: A (3+j40) с Rab * B (2+150) F2 (0+19) Select one: a. 120MVA, 381 MVA O b. 381MVA, 508 MVA О с. 120MVA, 508 MVA O d. 381MVA, 381 MVA

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 3.47P: Consider the oneline diagram shown in Figure 3.40. The three-phase transformer bank is made up of...

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