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What happens if i apply different AC frequencies into a motor?

  1. Feb 24, 2013 #1
    so lets say i have a motor and two sinusodial AC power supplies. they both have different frequencies but the same voltage. i apply both of them into the induction motor. what will happen in terms of speed or anything else which can affect the motor's performance?
  2. jcsd
  3. Feb 24, 2013 #2
    AC motors are designed to work with 3 sinusoidal frequencies at 60 hrtz these three frequencies are 180 degrees offset from each other.
    If you apply 2 or 3 differing frequencies. Those frequencies may multiply into reflective waves. Complementary waves.
    or harmonic waves. In short applying imbalanced frequencies will damage the stator windings. Motors that are designed for PWM signals are wound with wires that are designed to survive high frequencies. Usually thicker shielding.
    Also the offset isimportant. Applying the wrong frequency offsets can also lead to rotor lock. (magnetically bound in one position) . Or single phasing by damaging the windings.
  4. Feb 25, 2013 #3
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