srm(switched reluctant motor) pi control

[elbinaz]

Hi everyone. Can somebody help me? I have a problem to control srm using PIC16F877. It is 3~.Thanks.

[temtronic]

Showing us your code, PIC type and CCS C version.....
as well as the hardware schematic
...would help us help you !

[elbinaz]

temtronic thanks for your help. My version is 4,068 and my pic is 16f877. It must give me six pwm. I don't have my code. I want to find available code or similar. I am not a master to write code.

[Ttelmah]

It won't.
The 877, has _two_ PWM channels only.

You can potentially generate 'software' PWM channels, but only at relatively low speed.

Are you really sure you need 6 PWM channels?. Most motor control systems use three, but then need complementary outputs on the three channels to involve three channels but six signals. Chips with power control PWM modules offer this.

Microchip has some very good application notes of motor control using these chips.

For six completely separate PWM channels at high speed, you need a lot more up-market chips, like some of the DsPIC's.

So you need to tell us more, and do some research yourself:

What do the phases need to generate - are there genuinely six phases, or just three with the other three signals being derivable from the first three?. You talk about 3 phases, but then say you require six pwm's...

What frequencies and range of control are needed?.

What do you actually need to 'do' with the signals - just sinusoidal synthesis, or more complex control - are you going to be ramping speeds etc.?.

Don't commit yourself to a chip that won't do the job - a vast amount more work, and may well be impossible....

There are 'example' systems for this in the Microchip application notes, but _all_, _will_ need modification to suit other hardware and. A 3 phase pWM motor control system with hardware, would cost several thousand dollars to write the software and the same again to design the driver hardware. You are not going to find an 'off the shelf freebie', which will have all of this. Cheaper and easier if this is a 'one off', to just buy a built motor controller.

To put this in perspective, I have designed polyphase motor control systems for servo applications at work. However when I wanted a similar but rather smaller system supporting higher speeds for a one off 'home' application, I bought an off the shelf unit. I reckoned it was about 50* cheaper than developing a 'one off', and I didn't have a couple of months of free time available....

Best Wsihes

[elbinaz]

Ttelmah thanks. You are right. I want to use 18f46. It has 4 pwm. I will use 3~ motor. Also I want to use 1~ because that dcdc converter. Do you have advice or available code? Best Wishes.