Lab_10
.pdf
keyboard_arrow_up
School
Douglas College *
*We aren’t endorsed by this school
Course
4435
Subject
Electrical Engineering
Date
Apr 3, 2024
Type
Pages
9
Uploaded by SuperHumanRiver3417 on coursehero.com
Seyed Nikan Hossein Attar A01230368 ELEX 2105: Circuit Analysis 2 Page 1 of 9
The original document was provided by Mark Lane and Norm Cousins Lab 10: 3-Phase systems, Wye-loads
Objective •
Verify the voltage magnitude and phase relationships for a 4-wire, 3-phase supply. •
Verify the voltage, current and power relationships for balanced and unbalanced wye loads. Introduction The lab is supplied by a 208/120 V, 4-wire system. For safety reasons we do not use these voltages. The 3-
phase “box” on the bench:
a)
‘Plugs in’ to the 208 V lab system.
b)
Contains 3 transformers. c)
Steps the lab voltages down to 28/16 V. d)
Isolates the output voltages from ground. Identify the output terminals on the 3-phase box: Green
ground (earth) –
connects to the metal chassis and to the 208/120 V system ground through the grounding pin of the power plug. Red
Line A –
from the low voltage side of the transformer bank. Black
Line B –
from the low voltage side of the transformer bank. Blue
Line C –
from the low voltage side of the transformer bank. White
Neutral –
from the low voltage side of the transformer bank. This terminal is ISOLATED from the 208 V lab system.
Seyed Nikan Hossein Attar A01230368 ELEX 2105: Circuit Analysis 2 Page 2 of 9
The original document was provided by Mark Lane and Norm Cousins Preparation 1.
Draw a diagram for a 3-phase, 4-wire
, balanced resistive load Y-Y system. Use capital letters for the generator side and small letters for the load side to label the nodes. Put a 1 ohm current sampling resister on line A and a 10 ohm sampling resistor to measure the current in the neutral line. Use 4 channels of the scope to measure the phase voltages on the generator side as well the current in line A (the voltage drop across the 1 ohm sampling resistor). 2.
Redraw the diagram for a 3-wire
system similar to the previous one. The load wye-point is now disconnected —
name this node ‘y’.
Seyed Nikan Hossein Attar A01230368 ELEX 2105: Circuit Analysis 2 Page 3 of 9
The original document was provided by Mark Lane and Norm Cousins 3.
Prepare the following table for the supply voltage. VAN VBN VCN VAB VCA θVAN
- θVBN
θVAN
- θVCN
θVBN
- θVCN
θVAB
- θVCA
θVAB
- θVBC
16 16 16 16 28.4 27.3 120 -120 120
Seyed Nikan Hossein Attar A01230368 ELEX 2105: Circuit Analysis 2 Page 4 of 9
The original document was provided by Mark Lane and Norm Cousins 4.
Prepare the following table for the measurements Balanced 4-wire Balanced 3-wire Unbalanced 4-wire Unbalanced 3-wire Van/ay 16 15.8 15.7 17.4 Vbn/by 16 16.3 15.9 10.5 Vcn/cy 16 16.1 15.8 21.2 Ia 0.02875 0.02821 0.02804 0.03107 Ib 0.02875 0.02875 0.1325 0.0875 Ic 0.02857 0.02875 0.07182 0.09636 Vab 28.4 28.2 28.1 27.5 IAa 0.02875 0.02821 0.02804 0.03107 In 0 n/a 0.0769 n/a θVab
-
θIa
30 28.7 30 10.3 Vyn N/A 0.151 N/A 6.14 Pt (1st method) 1.38289 1.37729 3.68164 3.5023 Pt (2nd method) 1.22475 1.20879 Pre-lab requirements: •
Two schematics showing all the probes. •
One table for the measured values at the source side •
One table to record the measurements of the load side. •
No prediction or calculation is needed.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
Related Questions
A 500 kVA, 1100 V, 50 hz, wye-connected 3-phasehas armature resistance of 0.1 02/phase and
synchronous reactance/phase of 1.502. (i) What is voltage regulation if the load pf is 0.9 lagging
? (ii) what is voltage regulation
if the load pf is 0.8 leading?
arrow_forward
Q4/For the three-phase power network shown in Figure. the various components are:
GI: 100 MVA, 0.30 pu reactance.
G2: 60 MVA, 0.18 pu reactance.
Transformers (cach): 50 MVA, 0.10 pu reactance.
Inductive reactor X: 0.20 pu on a base of 100 MVA.
Lines (each): 80 ohms (reactive); neglect resistance.
with the network initially unloaded and a line voltage of 110 kV, a symmetrical short circuit
occurs at midpoint E of line 2. Calculate the short circuit MVA to be interrupted by the circuit
breakers A and B at the ends of the line.
T3
38
L1
L2
G2
Bas
12
T4
Bus
arrow_forward
The recommended limit of voltage drop on a power circuit for a single-phase supply as per IEE Wiring regulations is equal to 12 V. Then the value of supply voltage is
a.
200 V
b.
400 V
c.
240 V
d.
230 V
arrow_forward
Power factor correction is usually done by adding _________ to the load circuit.Select the correct response:a. switchb. capacitorc. inductive loads
arrow_forward
In a given system of base power of 250 MW, and bus 3 is taken as reference. The per-unit reactances are X12 = 0.2 p.u., X13 = X23 = 0. 1
p.u. The power flow in the system is given as: PF12 = 50 MW, PF13 = 150 MW, PF23 = 50 MW. Based on readings from 2 meters (not
including M12 meter), M13 = 145 MW (not calibrated), and M23 = 50 MW (well calibrated), deduce the flow on line 1-2.
Select one:
O a. PF12 = - 47.5 MW.
O b. None of these
O c. PF12 = 67.5 MW.
O d.
PF12 = 47.5 MW.
O e. PF12 =- 57.5 MW.
O f.
PF12 = 57 MW.
arrow_forward
A three-phase balanced load of 15A per phase is supplied by a steel wire armoured cable with a c.s.a. of 2.5mm². The voltage drop for this cable is 15mv/A/m and the circuit is 40m long. Calculate the voltage drop in the cable.
arrow_forward
Q2 (a) Three-phase generator consist of three set of single-phase generators, with voltages equal
in magnitude but differing in phase angle by 120° apart.
(i)
Sketch phasor diagram of the three-phase voltages VA, VB and Vc
(ii)
Plot the three-phase voltages waveform in Q2(a)(i) in single plot.
arrow_forward
What is the main direct cause of reactive power in AC system?A. Resistance of transmission linesB. Inductance and capacitance in the loadsC. Ideal transformer connected in the systemD. Power produced by generator2. “Reactive power in a system is dissipated generally as thermal energy?”A. TRUEB. FALSE3. Which of the following statements are correct for three phase circuit:A. Sum of all the three phase currents is zero in unbalanced networkB. Total power transfer to load is constant with timeC. Neutral conductor is same size in terms of material used as in single phase conductorsD. Net apparent power consumed is equal to real power
arrow_forward
What is the main direct cause of reactive power in AC system?A. Resistance of transmission linesB. Inductance and capacitance in the loadsC. Ideal transformer connected in the systemD. Power produced by generator
arrow_forward
Qa1. The three phases of a generator can be connected in either delia (D) or wye (Y) connection. List two advantages of three phase system over a single phase system. Also write mathematical relationship between the phase voltage and the ine voltage, and the phase current and the line current for both delia (D) and wye (Y) connections.
Please answer in typing format please..
arrow_forward
The section bus-bars A and B are linked by a bus-bar reactor rated at 6000 kVA with 12% reactance. On bus-bar-A, there are two generators each of 10 MVA with 8% reactance and on bus-bar-B, two generators each of 6000 kVA with 10% reactance.
Find the steady MVA fed into a dead short circuit all phases on B with bus-bar reactor in the circuit.
arrow_forward
Power in a three phase delta system with balanced load is equal to
(Sqrt (3)) (VL) (IL) (p.f.)
(Sqrt (3)) (Vph) (Iph) (p.f.)
(Sqrt (3)) (VL) (Iph) (p.f.)
O (Sqrt (3)) (Vph) (IL) (p.f.)
arrow_forward
Table Q2a
Time (hours)
0-6
6-12
12-14
14-18
18-24
Load (MW)
45
90
135
150
75
Referring to the Table Q2a;
i)
Draw the load curve and the load duration curve [Use the graph paper
provided]
ii)
Indicate the base load and the peak load on the graph. Determine the
values for both loads.
iii)
Choose the suitable generating units to supply the load and list their
operating schedules. Later, compute the total installed capacity.
iv)
Calculate the load factor and the plant capacity factor. Discuss the
impact on the operating schedule if the plant capacity factor increases
to 0.9.
arrow_forward
2) The one-line diagram of a three-phase power system is as shown in Figure. Impedance are marked in per-unit on a
100-MVA, 400-kV base. The load at bus 2 is S2=15.93 MW - j33.4 Mvar, and at bus 3 is S3-77 MW + j14 Mvar. It
is required to hold the voltage at bus 3 at ...L0 kV. Working in per-unit, determine the voltage at buses 2 and 1.
(Please determine the voltage magnitude within the specified limits: 410-450 V. By considering the voltage magnitude
value you determined yourself, solve the question.)
V₁
j0.5 pu
V₂
j0.4 pu
S₂
Figure
V3
S3
arrow_forward
Differentiate Wye and Delta Connection in Three Phase System and Relate it with Computer Engineering
arrow_forward
6.5%
ans
ex A so kvA. 2o00/20 V, So He single-phase transformar has
impedance drof of8% and resistance drop of 4%.
Caleulate. The Requlation of the Thams former at full- Load o8 P.s
Legging. also find The Power factor at which Voltage requlation will
Be Zero.
Sols
0.5 leading.
s alculate The % Noltege Requlation af atransformar in w hich the
Percantage resistance drof is 1% and Percentage dre is 6% when
The Power fador is
0.8 lagging
) > unity
aMS 38 %
ans 1 %
(シ→
0.8 leading . amS - 2.2%
arrow_forward
In the system shown in Figure 1, the transformers are connected star-star with both star points grounded and the generators are connected in
star with thier star points grounded. The system base is 15 MVA. The transformers all have reactances of 0.04 p.u. on this 15 MVA base. The
reactances of all other elements are given in Table 1 (in 2) and the voltage levels are given in Table 2.
p.u.
G1
p.u.
T1
jö
Per-Unit
Convert all values to p.u. on a 15 MVA base.
Xa=
p.u.
Xc₂=
XL =
V BABE
G1
2
X
9
T3
Figure 1: A section of the distribution system
T1
L
Table 1: Sequence reactances (2)
3
G1 L G2
0.3 0.59 0.01
4
L
9/10 10
Fault Voltage
What is the voltage at bus 3 (in Volts) after the fault has occurred?
Vp=
V
T2
5
T2
34
10/4
Table 2: Voltage bases (kV)
G2
4
T3
10/9
|
G2
Fault Current
A three-phase fault with a fault reactance of 0.01 p.u. occurs at bus 3. Calculate the fault current flowing at the fault point in KA.
Ip=-j
KA
So
arrow_forward
Problem 1 - Series en Parallel AC networks [19]
Look at the circuit in Figure 1 and
determine the following:
(a) Total Admittance.
(b) Total Impedance.
(c) Total Current (l:).
(d) Current (I1) through impedance Z2.
(e) Current (12) through impedance Z3.
(f) Current (I3) through impedance Z4.
(g) Is this an inductive or capacitive
circuit?
A.
B Zs
220V;50HZ
Figure 1
(h) Voltage across Z1.
(i) Voltage across A and B.
G) Voltage across Zs.
Z1 = 3 + j5 ohm
Z2 = 10 + jo ohm
Z3 = 5 + j15 ohm
Z4 = 10 – j30 ohm
Zs = 20 – j30 ohm
Admittance and Impedance in
rectangular notation.
All currents and voltage in polar
notation.
Take voltage as reference.
arrow_forward
Write an introduction about:
LOAD BALANCING in 3-Phase System
arrow_forward
Combination circuit
what is
PT?
RT?
IT?
Voltage Across each load?
arrow_forward
I- Purely Inductive Load
1. Sketch a three-phase 100VAC RMS phase-voltage, Wye (Y) Connected power supply with a
Wye (Y) Connected load with purely inductive j3002 per phase.
2. Assume the phase-voltage of phase-A at the source side has an angle of zero. Calculate both
magnitudes and phase-angles for phase voltage, line voltage, phase current, and line current
at the load side. Also, compute load real power, apparent Power, and power factor.
Ve V VLine_V l A ILine.
V.A. P.F.
(lagging or leading)
arrow_forward
2. A single-phase are distributor AB is fed from end A and has a total impedance of (0.3-0.3) ohm. At the far end, the voltage V-240V and the current is 100A at a p.f. of 0, 8 lagging. At the mid-point M. a current of 100 A is tapped at a p... of 0.6 lagging with reference to the voltage V_{M} at the midi-point. Calculate the supply voltage V Lambda j sending current I_{N} and the phase angle between V_{A} and V_{E}
arrow_forward
Can we improve a leading load pf using a synchronous condenser? Explain briefly your answerin one(1) sentence.
arrow_forward
Two 7970-V:230-V single-phase transformers with impedance with respect to their secondaries
of 1.5 + j3 and 2 + j4.5 ohms are connected in parallel to a 7900-V source. Their secondaries are
supplying a common load of 30 + j40 ohms.
A. What is the magnitude of the voltage across the load in volts? (2 decimal places)
B. What is the magnitude of the total current supplied by the 7900-V source in amperes? (3
decimal places)
C. What is the efficiency of the parallel transformers combined in percent? ( 1 decimal
place)
arrow_forward
Using Kirchhoff's Law, determine the load currents. All The possible current and voltage equations.
With complete solutions
arrow_forward
e = 0
Q1: What does happen if we change two currents?
a.
Q2: What does happen if we have a three-phase four poles machine?
Q3: What does happen if we have a two-phase two poles machine?
e = 0
Q4: What does happen if we apply a capacitance in phase b and then use same
voltage for both phase.
Dr. Ali Ki. pw --
arrow_forward
A single phase a. C distributor AB 300mts long if fed from end A is loaded as under a) 100amps at 0.707 p.f lagging 200mts from pointA(b) 200amps at 0.8p.f lagging 300mts from point A. The total resistance and the Reactance and the distributor is0. 2ohms and0. 1ohms per km respectively. Calculate the total voltage drop in the distributor. The load power factors refer to the voltage at the far end
arrow_forward
Explain the concept of FACTS (Flexible Alternating Current Transmission Systems) devices. How do they enhance the control and stability of power systems? Provide examples of FACTS devices and their applications.
arrow_forward
SEE MORE QUESTIONS
Recommended textbooks for you
Power System Analysis and Design (MindTap Course ...
Electrical Engineering
ISBN:9781305632134
Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma
Publisher:Cengage Learning
Related Questions
- A 500 kVA, 1100 V, 50 hz, wye-connected 3-phasehas armature resistance of 0.1 02/phase and synchronous reactance/phase of 1.502. (i) What is voltage regulation if the load pf is 0.9 lagging ? (ii) what is voltage regulation if the load pf is 0.8 leading?arrow_forwardQ4/For the three-phase power network shown in Figure. the various components are: GI: 100 MVA, 0.30 pu reactance. G2: 60 MVA, 0.18 pu reactance. Transformers (cach): 50 MVA, 0.10 pu reactance. Inductive reactor X: 0.20 pu on a base of 100 MVA. Lines (each): 80 ohms (reactive); neglect resistance. with the network initially unloaded and a line voltage of 110 kV, a symmetrical short circuit occurs at midpoint E of line 2. Calculate the short circuit MVA to be interrupted by the circuit breakers A and B at the ends of the line. T3 38 L1 L2 G2 Bas 12 T4 Busarrow_forwardThe recommended limit of voltage drop on a power circuit for a single-phase supply as per IEE Wiring regulations is equal to 12 V. Then the value of supply voltage is a. 200 V b. 400 V c. 240 V d. 230 Varrow_forward
- Power factor correction is usually done by adding _________ to the load circuit.Select the correct response:a. switchb. capacitorc. inductive loadsarrow_forwardIn a given system of base power of 250 MW, and bus 3 is taken as reference. The per-unit reactances are X12 = 0.2 p.u., X13 = X23 = 0. 1 p.u. The power flow in the system is given as: PF12 = 50 MW, PF13 = 150 MW, PF23 = 50 MW. Based on readings from 2 meters (not including M12 meter), M13 = 145 MW (not calibrated), and M23 = 50 MW (well calibrated), deduce the flow on line 1-2. Select one: O a. PF12 = - 47.5 MW. O b. None of these O c. PF12 = 67.5 MW. O d. PF12 = 47.5 MW. O e. PF12 =- 57.5 MW. O f. PF12 = 57 MW.arrow_forwardA three-phase balanced load of 15A per phase is supplied by a steel wire armoured cable with a c.s.a. of 2.5mm². The voltage drop for this cable is 15mv/A/m and the circuit is 40m long. Calculate the voltage drop in the cable.arrow_forward
- Q2 (a) Three-phase generator consist of three set of single-phase generators, with voltages equal in magnitude but differing in phase angle by 120° apart. (i) Sketch phasor diagram of the three-phase voltages VA, VB and Vc (ii) Plot the three-phase voltages waveform in Q2(a)(i) in single plot.arrow_forwardWhat is the main direct cause of reactive power in AC system?A. Resistance of transmission linesB. Inductance and capacitance in the loadsC. Ideal transformer connected in the systemD. Power produced by generator2. “Reactive power in a system is dissipated generally as thermal energy?”A. TRUEB. FALSE3. Which of the following statements are correct for three phase circuit:A. Sum of all the three phase currents is zero in unbalanced networkB. Total power transfer to load is constant with timeC. Neutral conductor is same size in terms of material used as in single phase conductorsD. Net apparent power consumed is equal to real powerarrow_forwardWhat is the main direct cause of reactive power in AC system?A. Resistance of transmission linesB. Inductance and capacitance in the loadsC. Ideal transformer connected in the systemD. Power produced by generatorarrow_forward
- Qa1. The three phases of a generator can be connected in either delia (D) or wye (Y) connection. List two advantages of three phase system over a single phase system. Also write mathematical relationship between the phase voltage and the ine voltage, and the phase current and the line current for both delia (D) and wye (Y) connections. Please answer in typing format please..arrow_forwardThe section bus-bars A and B are linked by a bus-bar reactor rated at 6000 kVA with 12% reactance. On bus-bar-A, there are two generators each of 10 MVA with 8% reactance and on bus-bar-B, two generators each of 6000 kVA with 10% reactance. Find the steady MVA fed into a dead short circuit all phases on B with bus-bar reactor in the circuit.arrow_forwardPower in a three phase delta system with balanced load is equal to (Sqrt (3)) (VL) (IL) (p.f.) (Sqrt (3)) (Vph) (Iph) (p.f.) (Sqrt (3)) (VL) (Iph) (p.f.) O (Sqrt (3)) (Vph) (IL) (p.f.)arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Power System Analysis and Design (MindTap Course ...Electrical EngineeringISBN:9781305632134Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. SarmaPublisher:Cengage Learning
Power System Analysis and Design (MindTap Course ...
Electrical Engineering
ISBN:9781305632134
Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma
Publisher:Cengage Learning