Unit 5: Rotating Field Theory Flashcards
(6 cards)
1
Q
What producing a rotating magnetic field?
A
Balanced 3-phase supply with frequency ‘fs’ applied to symmetric 3-phase winding.
2
Q
Voltages in the 3-phase winding
A
Va = Vmax * sin(ωt)
Vb = Vmax * sin(ωt - 2π/3)
Vc = Vmax * sin(ωt + 2π/3)
3
Q
Summed Voltages in the 3-phase winding
A
Va + Vb + Vc = 0
4
Q
Conditions [3]
A
- Each pole accommodates all 3 phases
- Displacement between adjacent phases is 120⁰
- Start & Finish of each phase is 180⁰
5
Q
Electrical Angle
A
θ = (P/2)*θmechanical
5
Q
Synchronous Speed (Ns)
A
Ns = (120*fs)/P [rpm]
