these are easy questions please answer alll questions for like either dislike is readyplease answer all subparts....please... 1. Three 3.33 Q resistance are connected in delta across 220 V, 3 phase supply. The equivalent wye connectedresistance isa. 1.110c. 6.7 0d. 10 0b. 20 03. The primary of 34.5/13.8 kV, 75 MVA transformer is wye grounded. The three primary currents are:I, = 69522094 = 7202 – 30Determine the neutral currentI = 710488a. 42.39417.34b. 57.812 - 15.21c. 30.2220.51d. 14.132 - 12.31----- -.6. The line current of unbalanced delta connected load are:I, = 40240Detemine the phase b zero sequence componentb. 45 - j2.9la = 5020I = 45.84130.9a. 0c. 16 + j17.25d. 5- j2.97. Three identical resistors are connected in delta across a balance, 3-phase source. If one of the resistors isоpen,.a. power will become doubleb. power is reduced to 33%c. power will become three times the originald. power will increase to 66%

In this question, Choose the correct options What is equivalent of the resistance R in the star.…

1. Three 3.33 Q resistance are connected in delta across 220 V, 3 phase supply. The equivalent wye connected resistance is a. 1.110 c. 6.7 0 d. 10 0 b. 20 0 3. The primary of 34.5/13.8 kV, 75 MVA transformer is wye grounded. The three primary currents are: la = 7202 - 30 Determine the neutral current I, = 6952209 I = 710488 a. 42.39417.34 b. 57.812- 15.21 c. 30.2220.51 d. 14.134- 12.31 ----- -. 6. The line current of unbalanced delta connected load are: I, = 40240 Detemine the phase b zero sequence component b. 45 - j2.9 a = 5020 I = 45.84130.9 a. 0 c. 16 + j17.25 d. 5-j2.9 7. Three identical resistors are connected in delta across a balance, 3-phase source. If one of the resistors is open, a. power will become double b. power is reduced to 33% c. power will become three times the original d. power will increase to 66%

1. Three 3.33 Q resistance are connected in delta across 220 V, 3 phase supply. The equivalent wye connected resistance is a. 1.110 c. 6.7 0 d. 10 0 b. 20 0 3. The primary of 34.5/13.8 kV, 75 MVA transformer is wye grounded. The three primary currents are: la = 7202 - 30 Determine the neutral current I, = 6952209 I = 710488 a. 42.39417.34 b. 57.812- 15.21 c. 30.2220.51 d. 14.134- 12.31 ----- -. 6. The line current of unbalanced delta connected load are: I, = 40240 Detemine the phase b zero sequence component b. 45 - j2.9 a = 5020 I = 45.84130.9 a. 0 c. 16 + j17.25 d. 5-j2.9 7. Three identical resistors are connected in delta across a balance, 3-phase source. If one of the resistors is open, a. power will become double b. power is reduced to 33% c. power will become three times the original d. power will increase to 66%

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

Chapter2: Fundamentals

Section: Chapter Questions

Problem 2.45P: Two balanced Y-connected loads, one drawing 10 kW at 0.8 power factor lagging and the other IS kW at...

See similar textbooks

Similar questions

An infinite bus, which is a constant voltage source, is connected to the primary of the three-winding transformer of Problem 3.53. A 7.5-MVA,13.2-kV synchronous motor with a sub transient reactance of 0.2 per unit is connected to the transformer secondary. A5-MW,2.3-kV three-phase resistive load is connected to the tertiary Choosing a base of 66 kV and 15 MVA in the primary, draw the impedance diagram of the system showing per-unit impedances. Neglect transformer exciting current, phase shifts, and all resistances except the resistive load.
Three single-phase transformers, each rated 10MVA,66.4/12.5kV,60Hz, with an equivalent series reactance of 0.1 per unit divided equally between primary and secondary, are connected in a three-phase bank. The high-voltage windings are V-connected and their terminals are directly connected to a 115-kV three-phase bus. The secondary terminals are all shorted together. Find the currents entering the high-voltage terminals and leaving the low-voltage terminals if the low-voltage windings are (a) Y-connected and (b) - connected.
Consider the three single-phase two-winding transformers shown in Figure 3.37. The high-voltage windings are connected in Y. (a) For the low-voltage side, connect the windings in , place the polarity marks, and label the terminals a, b, and c in accordance with the American standard. (b) Relabel the terminals a, b, and c such that VAN is 90 out of phase with Va for positive sequence.
Rework Example 3.12 for a+10 tap, providing a 10 increase for the high-voltage winding.
(a) An ideal single-phase two-winding transformer with turns ratio at=N1/N2 is connected with a series impedance Z2 across winding 2. If one wants to replace Z2, with a series impedance Z1 across winding 1 and keep the terminal behavior of the two circuits to be identical, find Z1 in terms of Z2. (b) Would the above result be true if instead of a series impedance there is a shunt impedance? (c) Can one refer a ladder network on the secondary (2) side to the primary (1) side simply by multiplying every impedance byat2 ?
A two-winding single-phase transformer rated 60kVA,240/1200V,60Hz, has an efficiency of 0.96 when operated at rated load, 0.8 power factor lagging. This transformer is to be utilized as a 1440/1200-V step-down autotransformer in a power distribution system. (a) Find the permissible kVA rating of the autotransformer if the winding currents and voltages are not to exceed the ratings as a two-winding transformer. Assume an ideal transformer. (b) Determine the efficiency of the autotransformer with the kVA loading of part (a) and 0.8 power factor leading.
Consider the single-line diagram of the power system shown in Figure 3.38. Equipment ratings are Generator 1: 1000MVA,18kV,X=0.2perunit Generator 2: 1000MVA,18kV,X=0.2p.u. Synchronous motor 3: 1500MVA,20kV,X=0.2p.u. Three-phase -Y transformers T1,T2,T3,T4,: 1000MVA,500kV,Y/20kV,X=0.1p.u. Three-phase YY transformer T5: 1500MVA,500kV,Y/20kVY,X=0.1p.u. Neglecting resistance, transformer phase shift, and magnetizing reactance, draw the equivalent reactance diagram. Use a base of 100 MA and 500 kV for the 50-ohm line. Determine the per-unit reactances.
Two balanced Y-connected loads, one drawing 10 kW at 0.8 power factor lagging and the other IS kW at 0.9 power factor leading, are connected in parallel and supplied by a balanced three-phase Y-connected, 480-V source. (a) Determine the source current. (b) If the load neutrals are connected to the source neutral by a zero-ohm neutral wire through an ammeter, what will the ammeter read?
Rework Problem 3.14 if the transformer is delivering rated load at rated secondary voltage and at (a) unity power factor, (b) 0.8 power factor leading. Compare the results with those of Problem 3.14. -
With generator conyention, where the current leaves the positive terminal of the circuit element, if P is positive then positive real power is delivered. (a) False (b) True
An open-delta three-phase transformer system has one transformer center-tapped to provide a neutral for single-phase voltages. If the voltage from line to center tap is 277 V, what is the high-leg voltage?
Reconsider Problem 3.64 with the change that now Tb includes both a transformer of the same turns ratio as Ta and a regulating transformer with a 4 phase shift. On the base of Ta, the impedance of the two comp onents of Tb is jO.1 per unit. Determine the complex power in per unit transmitted to the load through each transformer. Comment on how the transformers share the real and reactive pors.