typical Locked rotor/Nominal current ratio for synchronous motor
typical Locked rotor/Nominal current ratio for synchronous motor
(OP)
I have no vendor data yet and I need to model a synchronous motor, so I need a Typical Ilr/In ratio and reactance for 4500HP motor





RE: typical Locked rotor/Nominal current ratio for synchronous motor
Expect around 5.7 kVA/HP (Code G) for a motor 4,500 HP. This will result in
25,600 kVA starting at full voltage.
For 4160 volts, I start = 25,600/(1.732*4.16) = 3560 amperes.
The synchronous reactance depend on the PF design (1.0 or 0.8)
Typical reactance values are:
Xd =1.25 to 1.3 p.u.
Xq = 0.75 to 0.8 p.u.
RE: typical Locked rotor/Nominal current ratio for synchronous motor
Charles Concordia "Synchronous Machines Theory and Performance," General Electric, 1951,
often uses:
Xd=1.25 pu
Xq=0.75 pu
If there is a symmetric rotor, then Xd=Xq=1.25pu, for example
RE: typical Locked rotor/Nominal current ratio for synchronous motor
inversely proportional to sub-transient reactance X", e.g
for X"=0.2 the ratio is 5.