1. Technical Report
General Design Data of a
Three Phase Induction Machine 90kW – Squirrel
Cage Rotor
Tasos Lazaridis
Electrical Engineer – CAD/CAE Engineer
tasoslazaridis13@gmail.com
2. Three-Phase Induction Machine Design
GENERAL DATA
Given Output Power (kW): 90
Rated Voltage (V): 380
Winding Connection: Wye
Number of Poles: 4
Given Speed (rpm): 1463
Frequency (Hz): 50
Stray Loss (W): 1620
Frictional Loss (W): 1000
Windage Loss (W): 2500
Operation Mode: Motor
Type of Load: Constant Power
Operating Temperature (C): 75
STATOR DATA
Number of Stator Slots: 48
Outer Diameter of Stator (mm): 349
Inner Diameter of Stator (mm): 235
Type of Stator Slot: 1
Stator Slot
hs0 (mm): 0.5
hs2 (mm): 21
bs0 (mm): 3
bs1 (mm): 9.3
bs2 (mm): 11.4
Top Tooth Width (mm): 6.72953
Bottom Tooth Width (mm): 7.38096
Length of Stator Core (mm): 300
Stacking Factor of Stator Core: 0.95
Type of Steel: D23_50
Number of lamination sectors 0
Press board thickness (mm): 2
Magnetic press board Yes
Number of Parallel Branches: 1
Type of Coils: 21
Coil Pitch: 4
Number of Conductors per Slot: 8
Number of Wires per Conductor: 1
Wire Diameter (mm): 4.62
Wire Wrap Thickness (mm): 0
Wedge Thickness (mm): 0
Slot Liner Thickness (mm): 0.3
Layer Insulation (mm): 0.3
Slot Area (mm^2): 303.35
Net Slot Area (mm^2): 251.069
3. Slot Fill Factor (%): 68.0113
Limited Slot Fill Factor (%): 75
Wire Resistivity (ohm.mm^2/m): 0.0217
Conductor Length Adjustment (mm): 0
End Length Correction Factor 1
End Leakage Reactance Correction Factor 1
ROTOR DATA
Number of Rotor Slots: 38
Air Gap (mm): 0.7
Inner Diameter of Rotor (mm): 70
Type of Rotor Slot: 1
Rotor Slot
hs0 (mm): 0.5
hs2 (mm): 22.5
bs0 (mm): 1.5
bs1 (mm): 7
bs2 (mm): 7
Cast Rotor: Yes
Half Slot: Yes
Length of Rotor (mm): 300
Stacking Factor of Rotor Core: 0.95
Type of Steel: D23_50
Skew Width: 0
End Length of Bar (mm): 0
Height of End Ring (mm): 32
Width of End Ring (mm): 23
Resistivity of Rotor Bar
at 75 Centigrade (ohm.mm^2/m): 0.0263158
Resistivity of Rotor Ring
at 75 Centigrade (ohm.mm^2/m): 0.0263158
Magnetic Shaft: Yes
MATERIAL CONSUMPTION
Armature Copper Density (kg/m^3): 8900
Rotor Bar Material Density (kg/m^3): 2689
Rotor Ring Material Density (kg/m^3): 2689
Armature Core Steel Density (kg/m^3): 7820
Rotor Core Steel Density (kg/m^3): 7820
Armature Copper Weight (kg): 23.3299
Rotor Bar Material Weight (kg): 3.01416
Rotor Ring Material Weight (kg): 2.49448
Armature Core Steel Weight (kg): 85.2642
Rotor Core Steel Weight (kg): 78.6141
Total Net Weight (kg): 192.717
Armature Core Steel Consumption (kg): 181.997
Rotor Core Steel Consumption (kg): 96.6668
4. RATED-LOAD OPERATION
Stator Resistance (ohm): 0.0674703
Stator Resistance at 20C (ohm): 0.0554998
Stator Leakage Reactance (ohm): 0.126467
Rotor Resistance (ohm): 0.0270918
Rotor Leakage Reactance (ohm): 0.282897
Resistance Corresponding to
Iron-Core Loss (ohm): 86.3582
Magnetizing Reactance (ohm): 3.12506
Stator Phase Current (A): 196.241
Current Corresponding to
Iron-Core Loss (A): 2.253
Magnetizing Current (A): 62.2595
Rotor Phase Current (A): 169.394
Copper Loss of Stator Winding (W): 7794.93
Copper Loss of Rotor Winding (W): 2332.14
Iron-Core Loss (W): 1315.06
Frictional and Windage Loss (W): 3502.88
Stray Loss (W): 1620
Total Loss (W): 16565
Input Power (kW): 106.558
Output Power (kW): 89.9932
Mechanical Shaft Torque (N.m): 587.205
Efficiency (%): 84.4545
Power Factor: 0.812457
Rated Slip: 0.0243366
Rated Shaft Speed (rpm): 1463.5
NO-LOAD OPERATION
No-Load Stator Resistance (ohm): 0.0674703
No-Load Stator Leakage Reactance (ohm): 0.126973
No-Load Rotor Resistance (ohm): 0.0270573
No-Load Rotor Leakage Reactance (ohm): 0.288555
No-Load Stator Phase Current (A): 67.8374
No-Load Iron-Core Loss (W): 1535.74
No-Load Input Power (W): 7785.61
No-Load Power Factor: 0.13809
No-Load Slip: 0.000754578
No-Load Shaft Speed (rpm): 1498.87
BREAK-DOWN OPERATION
Break-Down Slip: 0.08
Break-Down Torque (N.m): 941.169
Break-Down Torque Ratio: 1.60279
Break-Down Phase Current (A): 418.008
LOCKED-ROTOR OPERATION
Locked-Rotor Torque (N.m): 474.54
5. Locked-Rotor Phase Current (A): 679.546
Locked-Rotor Torque Ratio: 0.808134
Locked-Rotor Current Ratio: 3.46282
Locked-Rotor Stator Resistance (ohm): 0.0674703
Locked-Rotor Stator
Leakage Reactance (ohm): 0.115617
Locked-Rotor Rotor Resistance (ohm): 0.0616147
Locked-Rotor Rotor
Leakage Reactance (ohm): 0.193633
DETAILED DATA AT RATED OPERATION
Stator Slot Leakage Reactance (ohm): 0.0881042
Stator End-Winding Leakage
Reactance (ohm): 0.0201604
Stator Differential Leakage
Reactance (ohm): 0.018202
Rotor Slot Leakage Reactance (ohm): 0.152883
Rotor End-Winding Leakage
Reactance (ohm): 0.00686664
Rotor Differential Leakage
Reactance (ohm): 0.123145
Skewing Leakage Reactance (ohm): 0
Stator Winding Factor: 0.478831
Stator-Teeth Flux Density (Tesla): 1.70722
Rotor-Teeth Flux Density (Tesla): 1.16603
Stator-Yoke Flux Density (Tesla): 1.87124
Rotor-Yoke Flux Density (Tesla): 0.588304
Air-Gap Flux Density (Tesla): 0.753862
Stator-Teeth Ampere Turns (A.T): 190.167
Rotor-Teeth Ampere Turns (A.T): 16.1044
Stator-Yoke Ampere Turns (A.T): 521.959
Rotor-Yoke Ampere Turns (A.T): 4.31289
Air-Gap Ampere Turns (A.T): 478.047
Correction Factor for Magnetic
Circuit Length of Stator Yoke: 0.246496
Correction Factor for Magnetic
Circuit Length of Rotor Yoke: 0.7
Saturation Factor for Teeth: 1.43149
Saturation Factor for Teeth & Yoke: 2.53236
Induced-Voltage Factor: 0.886832
Stator Current Density (A/mm^2): 11.7062
Specific Electric Loading (A/mm): 102.071
Stator Thermal Load (A^2/mm^3): 1194.86
Rotor Bar Current Density (A/mm^2): 8.33598
Rotor Ring Current Density (A/mm^2): 3.38302
Half-Turn Length of
Stator Winding (mm): 407.209
6. WINDING ARRANGEMENT
The 3-phase, 2-layer winding can be arranged in 12 slots as: AAAAZZZZBBBB
Angle per slot (elec. degrees): 15
Phase-A axis (elec. degrees): 52.5
First slot center (elec. degrees): 0
TRANSIENT FEA INPUT DATA
For one phase of the Stator Winding:
Number of Turns: 64
Parallel Branches: 1
Terminal Resistance (ohm): 0.0674703
End Leakage Inductance (H): 6.04158e-005
For Rotor End Ring Between Two Bars of One
Side:
Equivalent Ring Resistance (ohm): 5.92974e-007
Equivalent Ring Inductance (H): 3.99331e-009
2D Equivalent Value:
Equivalent Model Depth (mm): 300
Equivalent Stator Stacking Factor: 0.963333
Estimated Rotor Inertial Moment (kg m^2): 0.68408