Electrical Engineering (EE) Exam > Electrical Engineering (EE) Questions > Consider two single-phase transformers in par...
Start Learning for Free
Consider two single-phase transformers in parallet: Transformer-1: 300 kVA, 6600/440 V. Z. = (1.5 j4.25)% Transformer-2:400 kVA, 6600/420 V, Z, = (1.75 j4)% The HV sides are parallelly fed from a 6600 V bus. 4) Estimate the no-load circulating current (secondary side, in A) 5) Estimate the ohmic loss (in W) caused by the no-load circulating current. 6) Estimate the no-load LV side terminal voltage (in V)?
Most Upvoted Answer
Consider two single-phase transformers in parallet: Transformer-1: 300...
Estimating No-Load Circulating Current:
To estimate the no-load circulating current, we need to calculate the equivalent impedance seen by the secondary side of the transformers when they are connected in parallel.
1. Calculate the equivalent impedance of Transformer-1:
Given: Z1 = (1.5 + j4.25)%
Impedance in per-unit: Z1_pu = Z1 / 100 = (0.015 + j0.0425) pu
Base impedance: Zbase = (Vbase^2) / Sbase = (440^2) / 300000 = 0.6453 ohms
Equivalent impedance of Transformer-1: Zeq1 = Z1_pu * Zbase = (0.015 + j0.0425) * 0.6453 = (0.00968 + j0.02742) ohms
2. Calculate the equivalent impedance of Transformer-2:
Given: Z2 = (1.75 + j4)%
Impedance in per-unit: Z2_pu = Z2 / 100 = (0.0175 + j0.04) pu
Equivalent impedance of Transformer-2: Zeq2 = Z2_pu * Zbase = (0.0175 + j0.04) * 0.6453 = (0.01129 + j0.02577) ohms
3. Calculate the total equivalent impedance:
Total equivalent impedance: Zeq_total = (Zeq1 * Zeq2) / (Zeq1 + Zeq2) = (0.00968 + j0.02742) * (0.01129 + j0.02577) / ((0.00968 + j0.02742) + (0.01129 + j0.02577)) = (0.0002677 + j0.0006127) ohms
4. Calculate the no-load circulating current:
No-load circulating current, I_circ = V_secondary / |Zeq_total| = 440 / sqrt((0.0002677)^2 + (0.0006127)^2) = 440 / 0.0006761 = 650,392 A
Estimating Ohmic Loss:
To estimate the ohmic loss caused by the no-load circulating current, we need to calculate the resistance component of the equivalent impedance.
5. Calculate the resistance component of the equivalent impedance:
Resistance component, R_eq = Re(Zeq_total) = Re(0.0002677 + j0.0006127) = 0.0002677 ohms
6. Calculate the ohmic loss:
Ohmic loss, P_loss = (I_circ^2) * R_eq = (650,392^2) * 0.0002677 = 113,922 W
Estimating No-Load LV Side Terminal Voltage:
To estimate the no-load LV side terminal voltage, we need to consider the voltage drop across the equivalent impedance and the transformer turns ratio.
7. Calculate the voltage drop across the equivalent impedance:
Voltage drop, V_drop = I_circ * Re(Zeq_total) = 650,392 * 0.0002677 = 173.89 V
8. Calculate the no-load LV side terminal voltage:
No-load LV side terminal voltage
To estimate the no-load circulating current, we need to calculate the equivalent impedance seen by the secondary side of the transformers when they are connected in parallel.
1. Calculate the equivalent impedance of Transformer-1:
Given: Z1 = (1.5 + j4.25)%
Impedance in per-unit: Z1_pu = Z1 / 100 = (0.015 + j0.0425) pu
Base impedance: Zbase = (Vbase^2) / Sbase = (440^2) / 300000 = 0.6453 ohms
Equivalent impedance of Transformer-1: Zeq1 = Z1_pu * Zbase = (0.015 + j0.0425) * 0.6453 = (0.00968 + j0.02742) ohms
2. Calculate the equivalent impedance of Transformer-2:
Given: Z2 = (1.75 + j4)%
Impedance in per-unit: Z2_pu = Z2 / 100 = (0.0175 + j0.04) pu
Equivalent impedance of Transformer-2: Zeq2 = Z2_pu * Zbase = (0.0175 + j0.04) * 0.6453 = (0.01129 + j0.02577) ohms
3. Calculate the total equivalent impedance:
Total equivalent impedance: Zeq_total = (Zeq1 * Zeq2) / (Zeq1 + Zeq2) = (0.00968 + j0.02742) * (0.01129 + j0.02577) / ((0.00968 + j0.02742) + (0.01129 + j0.02577)) = (0.0002677 + j0.0006127) ohms
4. Calculate the no-load circulating current:
No-load circulating current, I_circ = V_secondary / |Zeq_total| = 440 / sqrt((0.0002677)^2 + (0.0006127)^2) = 440 / 0.0006761 = 650,392 A
Estimating Ohmic Loss:
To estimate the ohmic loss caused by the no-load circulating current, we need to calculate the resistance component of the equivalent impedance.
5. Calculate the resistance component of the equivalent impedance:
Resistance component, R_eq = Re(Zeq_total) = Re(0.0002677 + j0.0006127) = 0.0002677 ohms
6. Calculate the ohmic loss:
Ohmic loss, P_loss = (I_circ^2) * R_eq = (650,392^2) * 0.0002677 = 113,922 W
Estimating No-Load LV Side Terminal Voltage:
To estimate the no-load LV side terminal voltage, we need to consider the voltage drop across the equivalent impedance and the transformer turns ratio.
7. Calculate the voltage drop across the equivalent impedance:
Voltage drop, V_drop = I_circ * Re(Zeq_total) = 650,392 * 0.0002677 = 173.89 V
8. Calculate the no-load LV side terminal voltage:
No-load LV side terminal voltage
Attention Electrical Engineering (EE) Students!
To make sure you are not studying endlessly, EduRev has designed Electrical Engineering (EE) study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Electrical Engineering (EE).
|
Explore Courses for Electrical Engineering (EE) exam
|
|
Similar Electrical Engineering (EE) Doubts
Top Courses for Electrical Engineering (EE)View all
Consider two single-phase transformers in parallet: Transformer-1: 300 kVA, 6600/440 V. Z. = (1.5 j4.25)% Transformer-2:400 kVA, 6600/420 V, Z, = (1.75 j4)% The HV sides are parallelly fed from a 6600 V bus. 4) Estimate the no-load circulating current (secondary side, in A) 5) Estimate the ohmic loss (in W) caused by the no-load circulating current. 6) Estimate the no-load LV side terminal voltage (in V)?
Question Description
Consider two single-phase transformers in parallet: Transformer-1: 300 kVA, 6600/440 V. Z. = (1.5 j4.25)% Transformer-2:400 kVA, 6600/420 V, Z, = (1.75 j4)% The HV sides are parallelly fed from a 6600 V bus. 4) Estimate the no-load circulating current (secondary side, in A) 5) Estimate the ohmic loss (in W) caused by the no-load circulating current. 6) Estimate the no-load LV side terminal voltage (in V)? for Electrical Engineering (EE) 2024 is part of Electrical Engineering (EE) preparation. The Question and answers have been prepared according to the Electrical Engineering (EE) exam syllabus. Information about Consider two single-phase transformers in parallet: Transformer-1: 300 kVA, 6600/440 V. Z. = (1.5 j4.25)% Transformer-2:400 kVA, 6600/420 V, Z, = (1.75 j4)% The HV sides are parallelly fed from a 6600 V bus. 4) Estimate the no-load circulating current (secondary side, in A) 5) Estimate the ohmic loss (in W) caused by the no-load circulating current. 6) Estimate the no-load LV side terminal voltage (in V)? covers all topics & solutions for Electrical Engineering (EE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Consider two single-phase transformers in parallet: Transformer-1: 300 kVA, 6600/440 V. Z. = (1.5 j4.25)% Transformer-2:400 kVA, 6600/420 V, Z, = (1.75 j4)% The HV sides are parallelly fed from a 6600 V bus. 4) Estimate the no-load circulating current (secondary side, in A) 5) Estimate the ohmic loss (in W) caused by the no-load circulating current. 6) Estimate the no-load LV side terminal voltage (in V)?.
Consider two single-phase transformers in parallet: Transformer-1: 300 kVA, 6600/440 V. Z. = (1.5 j4.25)% Transformer-2:400 kVA, 6600/420 V, Z, = (1.75 j4)% The HV sides are parallelly fed from a 6600 V bus. 4) Estimate the no-load circulating current (secondary side, in A) 5) Estimate the ohmic loss (in W) caused by the no-load circulating current. 6) Estimate the no-load LV side terminal voltage (in V)? for Electrical Engineering (EE) 2024 is part of Electrical Engineering (EE) preparation. The Question and answers have been prepared according to the Electrical Engineering (EE) exam syllabus. Information about Consider two single-phase transformers in parallet: Transformer-1: 300 kVA, 6600/440 V. Z. = (1.5 j4.25)% Transformer-2:400 kVA, 6600/420 V, Z, = (1.75 j4)% The HV sides are parallelly fed from a 6600 V bus. 4) Estimate the no-load circulating current (secondary side, in A) 5) Estimate the ohmic loss (in W) caused by the no-load circulating current. 6) Estimate the no-load LV side terminal voltage (in V)? covers all topics & solutions for Electrical Engineering (EE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Consider two single-phase transformers in parallet: Transformer-1: 300 kVA, 6600/440 V. Z. = (1.5 j4.25)% Transformer-2:400 kVA, 6600/420 V, Z, = (1.75 j4)% The HV sides are parallelly fed from a 6600 V bus. 4) Estimate the no-load circulating current (secondary side, in A) 5) Estimate the ohmic loss (in W) caused by the no-load circulating current. 6) Estimate the no-load LV side terminal voltage (in V)?.
Solutions for Consider two single-phase transformers in parallet: Transformer-1: 300 kVA, 6600/440 V. Z. = (1.5 j4.25)% Transformer-2:400 kVA, 6600/420 V, Z, = (1.75 j4)% The HV sides are parallelly fed from a 6600 V bus. 4) Estimate the no-load circulating current (secondary side, in A) 5) Estimate the ohmic loss (in W) caused by the no-load circulating current. 6) Estimate the no-load LV side terminal voltage (in V)? in English & in Hindi are available as part of our courses for Electrical Engineering (EE).
Download more important topics, notes, lectures and mock test series for Electrical Engineering (EE) Exam by signing up for free.
Here you can find the meaning of Consider two single-phase transformers in parallet: Transformer-1: 300 kVA, 6600/440 V. Z. = (1.5 j4.25)% Transformer-2:400 kVA, 6600/420 V, Z, = (1.75 j4)% The HV sides are parallelly fed from a 6600 V bus. 4) Estimate the no-load circulating current (secondary side, in A) 5) Estimate the ohmic loss (in W) caused by the no-load circulating current. 6) Estimate the no-load LV side terminal voltage (in V)? defined & explained in the simplest way possible. Besides giving the explanation of
Consider two single-phase transformers in parallet: Transformer-1: 300 kVA, 6600/440 V. Z. = (1.5 j4.25)% Transformer-2:400 kVA, 6600/420 V, Z, = (1.75 j4)% The HV sides are parallelly fed from a 6600 V bus. 4) Estimate the no-load circulating current (secondary side, in A) 5) Estimate the ohmic loss (in W) caused by the no-load circulating current. 6) Estimate the no-load LV side terminal voltage (in V)?, a detailed solution for Consider two single-phase transformers in parallet: Transformer-1: 300 kVA, 6600/440 V. Z. = (1.5 j4.25)% Transformer-2:400 kVA, 6600/420 V, Z, = (1.75 j4)% The HV sides are parallelly fed from a 6600 V bus. 4) Estimate the no-load circulating current (secondary side, in A) 5) Estimate the ohmic loss (in W) caused by the no-load circulating current. 6) Estimate the no-load LV side terminal voltage (in V)? has been provided alongside types of Consider two single-phase transformers in parallet: Transformer-1: 300 kVA, 6600/440 V. Z. = (1.5 j4.25)% Transformer-2:400 kVA, 6600/420 V, Z, = (1.75 j4)% The HV sides are parallelly fed from a 6600 V bus. 4) Estimate the no-load circulating current (secondary side, in A) 5) Estimate the ohmic loss (in W) caused by the no-load circulating current. 6) Estimate the no-load LV side terminal voltage (in V)? theory, EduRev gives you an
ample number of questions to practice Consider two single-phase transformers in parallet: Transformer-1: 300 kVA, 6600/440 V. Z. = (1.5 j4.25)% Transformer-2:400 kVA, 6600/420 V, Z, = (1.75 j4)% The HV sides are parallelly fed from a 6600 V bus. 4) Estimate the no-load circulating current (secondary side, in A) 5) Estimate the ohmic loss (in W) caused by the no-load circulating current. 6) Estimate the no-load LV side terminal voltage (in V)? tests, examples and also practice Electrical Engineering (EE) tests.
|
|
Explore Courses for Electrical Engineering (EE) exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup