control single phase AC-motor

Discussion in 'The Projects Forum' started by h.d, Oct 24, 2007.

  1. h.d

    Thread Starter Active Member

    Oct 22, 2007
    150
    0
    hi
    i want to design circuit to drive an speed control for single phase AC-motor
    P=1.5hp
    v=220 v
    f=50hz

    i want to control it using PWM . the signal of PWM come from PIC16F877A
    that signal will trigger the power element that used(IGBT,MOSFET)
    am need help in design that circuit also how to use the signal from PIC(5V,20mA) to trigger power element(high cureent)?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    I believe the PIC website has several applications articles that deal with PWM motor control.
     
  3. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    PWM control of a DC Motor is pretty easy. PWM control of an AC motor is challenging, as both frequency and voltage must change together. You should be able to write an algorithm to do such, but I do not envy you the task.

    For your voltage and frequency requirements, I would choose MOSFET rather than IGBT.

    For an AC motor, you'll want your MOSFETs in a push-pull arrangement, or possibly an H-bridge.

    To drive MOSFETs from your PIC, you'll need drivers. Here is an excellent document to begin learning about driving MOSFETs: http://www.powersystems.eetchina.com/PDF/2007JUL/PSCOL_2007JUL26_DROP_TA_101.PDF?SOURCES=DOWNLOAD
     
  4. h.d

    Thread Starter Active Member

    Oct 22, 2007
    150
    0

    thnks man,
    about PWM for ac-motor ,i agree with u
    and thanks for the link u put it.
    but if i use dc-motor 12V or 24 V 1.5 hp the current will arise to 20 A and thats an important problem?isnt it?
     
  5. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    There are several MOSFETs which can handle 20 Amps or more. You can also parallel MOSFETs if you have trouble acquiring high current MOSFETs.
     
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