A 3-ph transformer having line voltage ratio of 0.43 kV/11 kV is connected in star-delta and protective transformers onthe 430 V side have a current ratio of 400/5. What must be the ratio of the protective transformers on the 11 kV side?O 1.8 by 1O8.66 by 15.63O 15.63 by 5O Non of the optionQuestion 7 ofClick Submit to complete this assessment.1:35 AIO a ) ENG5/11/2O Type here to searchovoPrtScInsertDeleteF10F11F12F7F8F9F3F5&BackspaceNumLock%232434.567V89.201くT.YU1DEFGYH iJ.KEnte143山

given a transformer 0.43/11 KV connected in star delta for differential protection, CT are…

3-ph transformer having line voltage ratio of 0.43 kV/11 kV is connected in star-delta and protective transformers on he 430 V side have a current ratio of 400/5. What must be the ratio of the protective transformers on the 11 kV side? O 1.8 by 1 O8.66 by 15.63 15.63 by 5 Non of the option Question 7 ot Click Submit to complete this assessment. 1:35 A A D d) ENG 5/11/2 P Type here to search Delete **- F11 **+ F12 Prisc Insert F9 F10 F7 F8 F3 F4 F5 Num Lock Backspace

3-ph transformer having line voltage ratio of 0.43 kV/11 kV is connected in star-delta and protective transformers on he 430 V side have a current ratio of 400/5. What must be the ratio of the protective transformers on the 11 kV side? O 1.8 by 1 O8.66 by 15.63 15.63 by 5 Non of the option Question 7 ot Click Submit to complete this assessment. 1:35 A A D d) ENG 5/11/2 P Type here to search Delete - F11 + F12 Prisc Insert F9 F10 F7 F8 F3 F4 F5 Num Lock Backspace

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 3.32MCQ

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.
A single-phase step-down transformer is rated 13MVA,66kV/11.5kV. With the 11.5 kV winding short-circuited, rated current flows when the voltage applied to the primary is 5.5 kV. The power input is read as 100 kW. Determine Req1andXeq1 in ohms referred to the high-voltage winding.
Rework Example 3.12 for a+10 tap, providing a 10 increase for the high-voltage winding.
How many transformers are needed to make an open-delta connection?
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.
Two transformers rated at 100 kVA each are connected in an open-delta connection. What is the total output power that can be supplied by this bank?
Does an open- operation, the kVA rating compared to that of the original thr-phase bank is (a) 2/3 (b) 58 (c) 1
For an ideal transformer, the efficiency is (a) 0 (b) 100 (c) 50
All values of a transformer are proportional to its __________________ ___________________.
The ratings of a three-phase three-winding transformer are Primary(1): Y connected 66kV,15MVA Secondary (2): Y connected, 13.2kV,10MVA Tertiary (3): A connected, 2.3kV,5MVA Neglecting winding resistances and exciting current, the per-unit leakage reactances are X12=0.08 on a 15-MVA,66-kV base X13=0.10 on a 15-MVA,66-kV base X23=0.09 on a 10-MVA,13.2-kV base (a) Determine the per-unit reactances X1,X2,X3 of the equivalent circuit on a 15-MVA,66-kV base at the primary terminals. (b) Purely resistive loads of 7.5 MW at 13.2 kV and 5 MW at 2.3kV are connected to the secondary and tertiary sides of the transformer, respectively. Draw the per- unit impedance diagram, showing the per-unit impedances on a 15-MVA,66-kV base at the primary terminals.
(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 ?
Question 1. The primary of a 1000 kVA, 11 / 3.3 kV three-phase transformer is connected in star and the secondary in delta. The resistances per phase of these windings are given as 0.375 Ω for the primary winding, 0.095 Ω for the secondary winding, and the leakage reactances per phase are given as 9.5 Ω for the primary winding and 2 Ω for the secondary winding. Calculate the voltage value and input power that must be applied to the primary when the secondary winding ends of the transformer are short-circuited. (In case of short circuit, the middle arm in the equivalent circuit will be neglected.)