+ Post New Thread
Results 1 to 18 of 18
  1. #1
    Newbie level 2
    Points: 20, Level: 1

    Join Date
    Apr 2013
    Posts
    2
    Helped
    0 / 0
    Points
    20
    Level
    1

    speed control of an motor by V/f method using pic16f877

    My project is speed control of an ac motor by v/f method. We have to get variable voltage and variable frequency output which will be given to an ac motor. We are using IGBT H- bridge. Using pic16f877 we have to generate the pwm signals which drive the inverter. Can anyone plz help, how to generate pwm signals which will give the variable frequency and voltage? Thank you.

  2. #2
    Advanced Member level 1
    Points: 3,016, Level: 12
    Jestin_cubetech's Avatar
    Join Date
    Jun 2012
    Posts
    499
    Helped
    74 / 74
    Points
    3,016
    Level
    12
    Blog Entries
    6

    Re: speed control of an motor by V/f method using pic16f877

    if you are a beginner then PIC CCS/mikroC is a good option
    there are many in built functions for PWM,timer ... etc

    in hardware section use a opto-isolator between PIC and IGBT driving circuit.
    ----------------------------------------------
    One man's fault is other man's lesson...
    ----------------------------------------------



  3. #3
    Newbie level 2
    Points: 20, Level: 1

    Join Date
    Apr 2013
    Posts
    2
    Helped
    0 / 0
    Points
    20
    Level
    1

    Re: speed control of an motor by V/f method using pic16f877

    Thanks for the reply. Yeah am using the isolation part. But i wanted to know how to get the variable freq. and voltage and the how to generate the pwm pulses for the same.

    - - - Updated - - -

    Thanks for the reply. Yeah am using the isolation part. But i wanted to know how to get the variable freq. and voltage and the how to generate the pwm pulses for the same.



  4. #4
    Advanced Member level 1
    Points: 3,016, Level: 12
    Jestin_cubetech's Avatar
    Join Date
    Jun 2012
    Posts
    499
    Helped
    74 / 74
    Points
    3,016
    Level
    12
    Blog Entries
    6

    Re: speed control of an motor by V/f method using pic16f877

    PIC -CCS
    SETUP_CCP1();
    setup_power_pwm(PWM_CLOCK_DIV_4 | PWM_FREE_RUN | PWM_DEAD_CLOCK_DIV_4,1,10000,1000,0,1,0);
    set_pwm1_duty(duty);
    ----------------------------------------------
    One man's fault is other man's lesson...
    ----------------------------------------------



    •   AltAdvertisment

        
       

  5. #5
    Junior Member level 3
    Points: 1,437, Level: 8
    Achievements:
    7 years registered

    Join Date
    Dec 2009
    Location
    india
    Posts
    30
    Helped
    1 / 1
    Points
    1,437
    Level
    8

    Re: speed control of an motor by V/f method using pic16f877

    Quote Originally Posted by Jestin_cubetech View Post
    PIC -CCS
    SETUP_CCP1();
    setup_power_pwm(PWM_CLOCK_DIV_4 | PWM_FREE_RUN | PWM_DEAD_CLOCK_DIV_4,1,10000,1000,0,1,0);
    set_pwm1_duty(duty);

    hello dears ...

    can you elaborate ..further ... because i am also trying to do variable frequency and variable voltage for Single phase 220V motor Speed control, Using PIC16f877.

    i am struggling to do this ..
    Please help me ...

    i need of Only pwm parts .. remaining i will take care ..

    thanks
    madhu.



  6. #6
    Junior Member level 3
    Points: 1,437, Level: 8
    Achievements:
    7 years registered

    Join Date
    Dec 2009
    Location
    india
    Posts
    30
    Helped
    1 / 1
    Points
    1,437
    Level
    8

    Re: speed control of an motor by V/f method using pic16f877

    Hello nitin..

    are got reply for the same ? share with me ..boss ..

    hello jestin..can you share the code for V/F control



  7. #7
    Advanced Member level 1
    Points: 3,016, Level: 12
    Jestin_cubetech's Avatar
    Join Date
    Jun 2012
    Posts
    499
    Helped
    74 / 74
    Points
    3,016
    Level
    12
    Blog Entries
    6

    Re: speed control of an motor by V/f method using pic16f877

    Quote Originally Posted by madhu hegde View Post
    hello dears ...

    can you elaborate ..further ... because i am also trying to do variable frequency and variable voltage for Single phase 220V motor Speed control, Using PIC16f877.

    i am struggling to do this ..
    Please help me ...


    i need of Only pwm parts .. remaining i will take care ..

    thanks
    madhu.
    hi madhu hegde

    what do you mean by variable frequency ?
    PWM generation basics
    1, PWM duty cycle
    2, PWM time period

    in most case PWM time period is fixed.
    ----------------------------------------------
    One man's fault is other man's lesson...
    ----------------------------------------------



  8. #8
    Advanced Member level 3
    Points: 3,983, Level: 14
    embpic's Avatar
    Join Date
    May 2013
    Location
    india
    Posts
    742
    Helped
    80 / 80
    Points
    3,983
    Level
    14

    Re: speed control of an motor by V/f method using pic16f877

    follow this link which exact answer of ur question

    ww1.microchip.com/downloads/en/AppNotes/00889b.pdf



    •   AltAdvertisment

        
       

  9. #9
    Member level 4
    Points: 1,432, Level: 8
    peeyushsigma's Avatar
    Join Date
    Apr 2012
    Location
    New Delhi, India
    Posts
    71
    Helped
    19 / 19
    Points
    1,432
    Level
    8

    Re: speed control of an motor by V/f method using pic16f877

    jestin is right PWM (Pulse With Modulation ) of CCP module generates fixed frequency with variable duty cycle square wave.

    so first decide fixed frequency with variable duty cycle or only variable frequency..



  10. #10
    Advanced Member level 4
    Points: 7,332, Level: 20
    Venkadesh_M's Avatar
    Join Date
    Jun 2013
    Location
    Coimbatore, India
    Posts
    1,375
    Helped
    258 / 258
    Points
    7,332
    Level
    20

    Re: speed control of an motor by V/f method using pic16f877

    Here is the files for generating sine wave with pwm in pic micro controller.. Change the program to generate different v/f...
    https://www.edaboard.com/thread297108.html



  11. #11
    Junior Member level 3
    Points: 1,437, Level: 8
    Achievements:
    7 years registered

    Join Date
    Dec 2009
    Location
    india
    Posts
    30
    Helped
    1 / 1
    Points
    1,437
    Level
    8

    Re: speed control of an motor by V/f method using pic16f877

    Quote Originally Posted by Venkadesh_M View Post
    Here is the files for generating sine wave with pwm in pic micro controller.. Change the program to generate different v/f...
    https://www.edaboard.com/thread297108.html
    Hell Dears..All.

    i want control the speed of Single phase motor , means i have to generate 3phase pwm output with 2-pahse should be with 120Deg phase shift another one is 90deg phase shift .

    with this i need Variable voltage with Variable frequency output , and also called V/F .

    this is i needed , if any one done this with PIC16f877 ?

    please share me only code ... power section will take care .



  12. #12
    Advanced Member level 1
    Points: 3,016, Level: 12
    Jestin_cubetech's Avatar
    Join Date
    Jun 2012
    Posts
    499
    Helped
    74 / 74
    Points
    3,016
    Level
    12
    Blog Entries
    6

    Re: speed control of an motor by V/f method using pic16f877

    hi-tech c code for variable PWM time period

    Code:
    #include 
    #define _XTAL_FREQ 20000000
    
    
    int time_prd=255,tmp;
    unsigned char PRESCL=4;
    unsigned long freq;
    
    
    pwm_periode(char pwm_prd,char prescl)    //prescl 1/16/4   default 1  
    {
    PR2=pwm_prd;
    time_prd=pwm_prd;
    if(prescl>4)
    {
    T2CKPS1=1;       //PRESCLAR VALUE 1:16 
    T2CKPS0=1;
    PRESCL=16;
    }
    else if(prescl>1)
    {
    T2CKPS1=0;       //PRESCLAR VALUE 1:4 
    T2CKPS0=1;
    PRESCL=4;
    }
    else 
    {
    T2CKPS1=0;       //PRESCLAR VALUE 1:1
    T2CKPS0=0;
    PRESCL=1;
    }
    TMR2ON=1;
    }
    
    
    void freq_disp()
    {
    float tmp1;
    //  PR2 = ( ( 1/pulse frequency in Hz ) / ( 1/clock speed x 4 x prescaler value ) ) - 1
    //F= _XTAL_FREQ/(4*PRESCL*(1+PR2))
    tmp1=4*PRESCL*(1+time_prd);	
    freq=_XTAL_FREQ/tmp1;                 //frequency 
    }
    ----------------------------------------------
    One man's fault is other man's lesson...
    ----------------------------------------------



  13. #13
    Junior Member level 3
    Points: 1,437, Level: 8
    Achievements:
    7 years registered

    Join Date
    Dec 2009
    Location
    india
    Posts
    30
    Helped
    1 / 1
    Points
    1,437
    Level
    8

    Re: speed control of an motor by V/f method using pic16f877

    hello jastin .

    is it for 3 phase sine pwm with v/f .?

    i need of 3 phase , in that one should be 90Deg phase shift . Because i am doing controlling of Single phase motor , you can see this Application note - noarail.com/members2/d/3907-2/AN967A.pdf , Author: Padmaraja Yedamale.

    please help ...



  14. #14
    Advanced Member level 1
    Points: 3,016, Level: 12
    Jestin_cubetech's Avatar
    Join Date
    Jun 2012
    Posts
    499
    Helped
    74 / 74
    Points
    3,016
    Level
    12
    Blog Entries
    6

    Re: speed control of an motor by V/f method using pic16f877

    ----------------------------------------------
    One man's fault is other man's lesson...
    ----------------------------------------------



  15. #15
    Junior Member level 3
    Points: 1,437, Level: 8
    Achievements:
    7 years registered

    Join Date
    Dec 2009
    Location
    india
    Posts
    30
    Helped
    1 / 1
    Points
    1,437
    Level
    8

    Re: speed control of an motor by V/f method using pic16f877

    Hello JAstin .

    yes i have seen this , but this is for 3-phase induction motor, not for Single phase induction motor .

    i am giving little troubling you , so sorry . please check this ..Application note - noarail.com/members2/d/3907-2/AN967A.pdf

    in that Figure no -5 , That is i wanted ,
    can you help me .



    •   AltAdvertisment

        
       

  16. #16
    Advanced Member level 1
    Points: 3,016, Level: 12
    Jestin_cubetech's Avatar
    Join Date
    Jun 2012
    Posts
    499
    Helped
    74 / 74
    Points
    3,016
    Level
    12
    Blog Entries
    6

    Re: speed control of an motor by V/f method using pic16f877

    ----------------------------------------------
    One man's fault is other man's lesson...
    ----------------------------------------------



  17. #17
    Junior Member level 3
    Points: 1,437, Level: 8
    Achievements:
    7 years registered

    Join Date
    Dec 2009
    Location
    india
    Posts
    30
    Helped
    1 / 1
    Points
    1,437
    Level
    8

    Re: speed control of an motor by V/f method using pic16f877

    Quote Originally Posted by Jestin_cubetech View Post
    hi , thanks ..

    i will start doing this and come back to you .

    thanks ..lot.



  18. #18
    Junior Member level 3
    Points: 1,437, Level: 8
    Achievements:
    7 years registered

    Join Date
    Dec 2009
    Location
    india
    Posts
    30
    Helped
    1 / 1
    Points
    1,437
    Level
    8

    Re: speed control of an motor by V/f method using pic16f877

    Hello Jastin .

    i try to program the asm code with PIC16f72 ... but lot of error is comming . can you help me



--[[ ]]--