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  1. #1
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    How to choose right PWM frequency for 3 phase ac motor

    hello.
    i would like to know how to choose correct val;ue of pwm frequency for 3 phase ac motor.

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  2. #2
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    Re: How to choose right PWM frequency for 3 phase ac motor

    There's the fundamental frequency and the carrier frequency. The carrier frequency is several times the fundamental. There's no particular formula. It depends on what's feasible for you to work with. A benefit of a faster carrier frequency: smaller L and C values are sufficient to filter it out.



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  3. #3
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    Re: How to choose right PWM frequency for 3 phase ac motor

    look at the igbt's you will be using - read the data sheet carefully - compute the worst case conduction and switching losses at 20kHz - see how the switching losses go up at the freq goes up, 30, 40, 50 kHz this should be your guide ...

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    a lot of large motor drives are only 5kHz ...



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