FEMAG Induction machine problems
1982 - 2007
Solution Methods:
- Time stepping VP(t)
- Steady-state complex VP: FEMAG-AC
Problems:
- Time stepping is very time consuming
- FEMAG-AC : B(H) characteristic ?
Induction B and field strength H sinusoidal
Rotor End ring Modeling ? Skewing ?
Harmonics: Leakage, Losses,
Inter bar currents ?
FEMAG Induction machine problems
•
B(H) or
µ (B) characteristic ?
1982 - 2007
FEMAG Induction machine problems
1982 - 2007
• Experiences with FEMAG-AC:
- No Load current > 15 % above reality depending on
saturation level
- Torque: ok
if Rotor bar model ok
- Eff. Rotor bar length:
l eff
π Dr q b σ b
= lb +
Qr q r σ r
1
2 sin 2
πp
Qr
Qr Dr
≈ lb +
2π p 2
FEMAG Induction machine problems
1982 - 2007
FEMAG - AC
No load Current:
- Time Stepping:
- FEMAG-AC:
115 A
133 A