Example or tutorial for implementing 3-phase voltage

[Maverickmax]

3-phase voltage

Hi

Do you know where to find example or tutorial for implementing 3-phase voltage?

That goes to math calculationg as well

Thank you

Maverick max

 

[kordix]

3-phase voltage

Hi,
what do u mean exactly by 3-phase voltage and what type of implementation?
i think i can help

 

[jallem]

3-phase voltage

Implementing?...do you mean generating?
When you talk about 3 phase I assume you are
talking about AC 3 phase, right? That means mayor
word, big voltages and a lot of power. If that is the
case, then this is the wrong forum for you.

 

[Maverickmax]

Re: 3-phase voltage

Well

I am interested to develop code to generate 3-Phase sinewave using my microcontroller

Maverick Max

 

[kordix]

3-phase voltage

Actually, it can be the right forum if we talk about motor control!!
i used the PIC16F876 to generate the needed pulses to control a three phases motor... in which we construct (internally) the 2 missed phases given that the third one is an input:

 

[anksyete]

Re: 3-phase voltage

hi,

if you use math library of programming languages, you can easily generate 3 phase voltages, and 120 degrees phase angles must be added also, but this routine works very slowly and if you want generate a 50 or 60 Hz signal, you may generate a 1 phase signal approximately in 2 minutes !!

I suggest to sample the 3 phase voltages in anotler program and write it as an array in microcontroller programmer. you must add a delay and it will be much more faster

 

[coshkun]

Re: 3-phase voltage

Last week we had an experiment in microcontroller lab. class.We generated sinewave using it's transfer function.If you took digital controller class ,you already know how to
implement a transfer function by programming.That's the one way of doing it.
Second solution is using table.You can produce table using MATLAB.Take samples (at which rate you want) and create a table using that values.As another guy stated you can produce three phase sinwave just using 120 degree delay.
Best regards
Coskun

note:I forgot to say that if you want to generate sinwave using transfer function,then your microcontroller must have a DAC.

 

[Mr_Programmer]

Re: 3-phase voltage

Easy way...
Write a lookup table in memory and use a pointer, the lookup table contains the precalculated values for a sine wave, as example 256 values for a 8bit DAC (128 values are also working...).
For each phase you want to create use a seperate pointer on the lookup table.
Now write a timer routine which will increment the pointer position and put out the current value of the lookup table to the DAC.
If you want to create a sine wave with 50Hz and you have a lookup table with 256 entries then your timer routine need to get called every 78µs. If you have a slower µ-Controller then you can easily increase the stepsize for the pointer and then your timer routine can be called not so often...

Regards...

 

[nipun]

Re: 3-phase voltage

interesting discussion there.i had a practical in college to control the speed of 3Φ induction motor.it was based on 3Φ PWM inverter employing integrated gate bipolar transistor(IGBT) to generate 3Φ from 0- 100 HZ and a duty cycle from
0 - 100 %.it employed a 89c52 µc.i know the math part behind it but dont have the code of controlling the gate of igbt.u can find in any standard book for POWER ELECtronics.