Forums » Electrical Engineering

frequency distortion

    • 133 posts
    January 13, 2019 4:08 AM PST

    Selecting  Variable speed control for motor can cause frequency distortion? any solution for this??

    • 1 posts
    February 28, 2019 10:02 PM PST

    You can install a filter on the motor side.

  • March 1, 2019 2:21 PM PST

    Disclaimer:  VFD design is not my area of expertise.

    Hameedullah Ekhlas said:

    Selecting  Variable speed control for motor can cause frequency distortion? any solution for this??

    I'm guessing you are discussing line-side waveform distortion caused by harmonics passed back to the line from the non-linear front-end (rectifier).

    So, yes, there are solutions.  However, we don't know if the drives in question are voltage source, current source, or more importantly - active front-end, or passive (plain old diodes).

    First place I'd look would be the specific mfg application guide, or design guide.  They know exactly what they are dealing with and they are very interested in reducing the harmonics at the Point-of-Common-Coupling.

    Filters for line-side wave form distortion will be on the line side.  I have seen drives with both reactors and caps, and some with caps only, and one that had a line-side reactor.

    Any VFD load-side filters will be to control motor side cable dv/dt and increase motor power factor.

     

    carl

    • 133 posts
    March 2, 2019 11:14 AM PST

    Thanks carl.