lab sheet 6 performance analysis of a three phase induction motor obje

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Lab Sheet 6: Performance Analysis of a Three-Phase Induction Motor
Objective:
Analyze and calculate various performance parameters of a three-phase, 4-pole, 200V, 400Hz induction motor. Understand the effects of electrical properties on motor performance using MATLAB, Python, or Excel.
Equipment and Software:
MATLAB, Python, or Excel
Calculator for manual verification
Motor Specifications:
Type: Three-phase, 4-pole induction motor
Rated Voltage: 200V
Frequency: 400Hz
Stator Resistance (π π Rs ): 1.71 ohms
Stator Reactance (ππ Xs ): 0.12 ohms
Rotor Resistance (π πRr ): 0.5 ohms
Rotor Reactance (ππβ²Xiβ² ): 0.3 ohms
Magnetizing Reactance (ππXm ): 32 ohms
Slip (π s): 2.5%
Friction Losses: 100W
Negligible Core Losses
Tasks:
Calculate the Synchronous Speed:
Use the formula: ππ =120Γππns =P120Γf
Where πf is the frequency, and πP is the number of poles.
Calculate the Motor Speed at Full Load:
Considering the slip (π s), use the formula: π=ππ Γ(1βπ )n=ns Γ(1βs)
Determine the Total Impedance:
Combine stator impedance, rotor impedance referred to the stator, and magnetizing impedance. Use parallel and series combinations as applicable.
Calculate the Stator Current and Power Factor:
Use Ohmβs law and impedance to find the current: πΌπ =ππβππ‘ππ‘ππIs =Ztotal Vph
Determine the power factor from the impedance phase angle.
Compute Stator and Rotor Copper Losses:
ππ ππ’=3ΓπΌπ 2Γπ π Pscu =3ΓIs2 ΓRs
ππππ’=3ΓπΌπ2Γπ πPrcu =3ΓIr2 ΓRr
Calculate the Air Gap Power:
ππππ=ππππ’/π
Determine the Developed Power and Torque:
Subtract rotor copper losses from the air gap power for developed power.
Calculate the torque using the developed power and motor speed.
Assess Input and Output Power:
Input power calculation incorporating power factor.
Output power considering friction losses.
Evaluate Motor Efficiency:
Ratio of output power to input power, expressed as a percentage.
Instructions:
Students may choose MATLAB, Python, or Excel to perform the calculations.
Document all steps, formulas, and intermediate values.
Discuss the impact of slip, stator, and rotor resistances on motor performance.
Submission:
Submit all calculations, code (if applicable) and a discussion on the implications of your findings on motor design and operation.
Lab Sheet for Session 5
Objective:
Analyse DC motor operations using MATLAB and perform a comprehensive load analysis for an aircraft's electrical system using Excel.
Materials:
MATLAB software
Microsoft Excel
Exercise 1: DC Motor Analysis Using MATLAB
A DC shunt motor connected to a 460-V supply has an armature resistance of 0.15 β¦. Calculate:
(a) The back e.m.f when the armature current is 120 A.
(b) The armature current when the back e.m.f. is 447.4 V.
A DC shunt motor connected to a 460-V supply takes an armature current of 120 A on full load. Calculate the back e.m.f. at this load given the armature resistance of 0.25 β¦.
A 4-pole DC shunt motor takes an armature current of 150 A at 440 V, with an armature resistance of 0.15 β¦. Calculate the back e.m.f. at this load.
A 28 V DC motor with an armature resistance of 0.3 ohm, rated at 800 rpm and 5 A, is used to drive a pump. Calculate the no-load speed.
Exercise 2: Load Analysis Using Excel
Using the provided aircraft electrical data and load profiles, compute the following using Excel:
The electrical data for a military aircraft is as follows:
Number of generators : 2 (split bus)
Number of inverter (for emergency use only) : 1
Number of Transformer Rectifier Unit : 2
Number of battery : 1
Specs:
Generator
Voltage
115
Frequency
400
Power Factor
0.8
Configuration
WYE
Max Continuous Power Rating (kVA)
15
Interval Rating (5 s β KVA
24
Interval Rating (5 min β kVA)
18
Inverter Emergency
Rating (kVA)
15
Voltage (AC)
115
Frequency
400
Power Factor
0.8
Configuration
WYE
TRU
Rating (amps)
150
Output Voltage (DC)
28
Max Continuous Power Rating (kVA)
150
Interval Rating (5 s β KVA
600
Interval Rating (5 min β kVA)
225
Battery
Rating (AH)
40
Output Voltage (DC)
28
There are seven flight profiles.
G1 : Start-Up
G2 : Taxi
G3 : Take Off and Climb
G4: Cruise
G5 : Landing
G6: Ground Alert
G7: Double Gen Failure
The various AC Loads are as follows:
LRU
Consumption (VA)
Profiles Used
Operating Time
Fuel Booster Pump
1800
G1, G6
Continuous
Fuel Transfer Pump
1628
G1, G6,G7
Continuous
Amplifier
10
G1, G3,G7
Continuous
Oxygen
9
G2, G3,G4,G7
Continuous
Cabin Control
23
G2, G3,G5,G6
Continuous
Cockpit Lighting
167
G2, G4,G5,G6
Continuous
Heat
270
G1, G2, G5,G6
Continuous
Radar
2500
G1, G4, G6
Continuous
Avionics Computer
170
G1,G3, G4,G6,G7
Continuous
Avionics Sys 1
2700
G3, G7
Continuous
Avionics Sys 2
870
G5,G7
Continuous
HUD
235
G3,G4,G5
Continuous
Fuel Measurement
28
G4,G5
Continuous
Weapon System
400
G2, G6
Continuous
EW System
3410
G1,G2, G6,G7
Continuous
Nav 1`
132
G1,G2, G4,G6,G7
Continuous
Nav 2
85.7
G1,G5, G4,G6,G7
Continuous
GPS
98.9
G5,G6,G7
Continuous
26 V transformer
82
G2,G5
Continuous
Others
4300
G3
Continuous
The various DC Loads are as follows:
LRU
Consumption (Amps)
Profiles Used
Operating Time
VOR/ILS
2
G1, G7
Continuous
EW1
5.5
G5, G7
Continuous
EW2
1.52
G2, G5,G7
Continuous
Controller
0.1
G2, G5, G6
Continuous
J Box
0.5
G2, G4,G5,G6
Continuous
Air Con
1.8
G3, G4,G5
Continuous
Cockpit Lights
4.7
G2, G3,G5,G6,G7
Continuous
Anti-Collision Lights
3.4
G1, G4, G3
Continuous
Formation Light
0.2
G7, G4, G3
Continuous
Landing Light
16.1
G6
Continuous
EFIS
2.33
G6,G7
Continuous
ADAHRS
0.6
G2
Continuous
Transmitter
14.28
G4,G5,G6,G7
Continuous
Receiver
3.57
G2, G3,G5,G6,G7
Continuous
Standby
4
G3,G5,G6,G4
Continuous
Comms Panel
0.3
G4, G3,G5,G6,G7
Continuous
AWS
6.9
G2, G5,G7
Continuous
SMD
5
G7
Continuous
Master Comp
1
G7
Continuous
Others
122
G1
Continuous
AC Load Analysis: For each flight profile, compute the total consumption in VA.
DC Load Analysis: For each flight profile, compute the total consumption in Amps.
Evaluate whether the provided generators, inverter, and TRU can cater to these loads under different flight profiles.
Questions:
How does the back e.m.f. affect the performance of a DC motor?
What is the impact of varying the load conditions on the electrical system of an aircraft?
Can the aircraft's electrical system handle all operational scenarios without overloading any component?
Lab Sheet for Session 4
Objective:
Explore the Fourier series representation of square waves and perform detailed harmonic power analysis for inverters in electrical circuits.
Materials:
Microsoft Excel software
Exercise 1: Fourier Series Analysis of a Square Wave
Given a square wave of amplitude 3 V and frequency 50 Hz, use MATLAB to compute the Fourier series coefficients up to the 25th harmonic. Sum up to 12th harmonics and up to 2th 5 harmonics plot the two resulting waveform. Observe which waveform (12 vs 25 harmonics) looks more like the original square wave.
Questions:
Which waveform resembles the original square wave more closely, and why?
How does increasing the number of harmonics affect the approximation of the square wave?
Exercise 2: Power Analysis for Inverter Circuits Using Excel
Using Microsoft Excel, perform a detailed power analysis for a half-bridge and a full-bridge inverter under the following conditions:
Load = 20 ohms, DC voltage = 20V, frequency of switching = 200 Hz.
Calculate up to the 100th harmonic.
Columns: Harmonic Number, Frequency, Voltage at the Harmonic, Resistance, Inductive Reactance, Impedance, Current, Power Factor, and Power.
Compute Total Power, Fundamental Power, Total Harmonic Power, and Total Harmonic Distortion (THD).
Repeat for the two inverters for
Load = 20 ohms, L = 159 mH, DC voltage = 20V, frequency of switching = 200 Hz.
Questions:
How does the addition of inductance affect the power distribution across the harmonics?
What implications do your findings have for the design and operation of inverter systems?