Download electrical engineering technology emt 113/4

Document related concepts

Rectifier wikipedia , lookup

Electric power system wikipedia , lookup

Opto-isolator wikipedia , lookup

Utility frequency wikipedia , lookup

History of electric power transmission wikipedia , lookup

Transformer wikipedia , lookup

Stray voltage wikipedia , lookup

Coilgun wikipedia , lookup

Switched-mode power supply wikipedia , lookup

Buck converter wikipedia , lookup

Electrification wikipedia , lookup

Three-phase electric power wikipedia , lookup

Resonant inductive coupling wikipedia , lookup

Voltage optimisation wikipedia , lookup

Rectiverter wikipedia , lookup

Mains electricity wikipedia , lookup

Power engineering wikipedia , lookup

Brushless DC electric motor wikipedia , lookup

Alternating current wikipedia , lookup

Brushed DC electric motor wikipedia , lookup

Commutator (electric) wikipedia , lookup

Variable-frequency drive wikipedia , lookup

Electric motor wikipedia , lookup

Stepper motor wikipedia , lookup

AC motor wikipedia , lookup

Electric machine wikipedia , lookup

Induction motor wikipedia , lookup

Transcript
THE ELECTRICAL FREQUENCY ON THE ROTOR.
 The induction motor works by inducing voltages and current in the rotor of the
machine-called a rotating transformer.
 Like a transformer; primary (stator) induced a voltage in the secondary
(rotor)
 Unlike a transformer, the secondary frequency not necessarily the same as
primary.
 If the rotor of a motor is locked so that it cannot move, the rotor will have the
same frequency as the stator.
 If the rotor turns at synchronous speed, the frequency on the rotor will be zero.
 For nm=0 r/min & the rotor frequency fr=fe ïƒ slip, s = 1
nm=nsync & the rotor frequency fr=0 ïƒ slip, s = 0
- For any speed in between, the rotor frequency is directly proportional to
the difference between the speed of the magnetic field nsync and the speed of
the rotor nm.
n n
s
sync
nsync
m