variable frequency control for AC motor speed control

[C0J]

Hi,

i will like to implement a variable frequency control to control the speed of a single phase induction motor.

(230V,50hz supply converted to DC & convert back to AC with a smaller freq & voltage using H-bridge inverter & sinusoidal PWM to control the speed (lower speed) of single phase induction motor)

Need advises on the following:

1) Is is possible to implement the VF control stated above using CCS C?
Have heard that it is better to implement using assembly language but i will like to implement using CCS C if possible

2) Have seen sinusoidal PWM done by using a sine lookup table.
Is the sine lookup table implemented using array? & is the value in each array element the value to be loaded to CCPR1L register which specify the duty cycle of the PWM?

3) Does anyone know of any link that discuss about VF control with sinuisodal PWM using CCS C or other C compiler

Thanks alot for the help given

CJ

[PCM programmer]

Start at the Microchip motor control webpage:
http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=2125&param=en026178

[C0J]

Thanks PCM

[electrogen]

look at the microchip motor control application notes. They have several application notes for several kind of motors.

also there is a great deal of application reports on DSP solution for motor control with complete codes and hardware settings on the Texas Instruments web site focus.ti.com...> search for application reports.
although they all are based on their DSP TMS320F24X, you can port the code to the PIC(dsPIC is better for such appn).

you can use two methods, one- construct a look up table of sine values
or compute these values on the fly(this needs a faster processor) for the later the vector control is the best though it's more efficient for three-phase motors. anyway the above two sources were more than enough for me when I started.

good luck!
_________________
chips are forever

[C0J]

Thanks electrogen