[PIC] SPWM inverter Using PIC16F876A

[Pulsetronics]

Hi Guys, I just completed my Push pull modified sine wave inverter, Now I want to design another one using H-bridge mosfet connection, Am a novice on how to write the code. I write Both in C and Asm. Waiting for reply. Thanks

 

[ashugtiwari]

what exactly you want to know? For using H bridge, at any time drive diagonally opposite MOSFET's and other two mosfets should be off. The switch should occur between mosfet pairs when half cycle completes.
As far as code writing goes, C is simpler, follow any of these scenarios.
1. SWPM with complementary PWM output using ECCP/COG/CWG/standalone PWM module and drive the complementary PWM output to diagonally opposite MOSFET's, while other two are switched OFF.
2. PIC16F876A does not ECCP, so instead switch one of either high side or low side mosfet is permanently on for half cycle and other fed with PWM and change mosfet for next half cycle.

I hope, i answered the question, if not plz let me know with the exact question.

 

[Pulsetronics]

Thanks ashugtiwari, but the problem am having is that i don't know how to start my code. Please you can suggest me a link or a sample code. Thanks

 

[FvM]

Did you search Edaboard for SPWM threads? There's e.g. this one https://www.edaboard.com/threads/96053/

 

[Pulsetronics]

yes FVM thanks to you but I couldn't get a direct and easy answer that is why I created my thread. I only need some ideas before I start my codings.

 

[ALERTLINKS]

Regarding sine wave generation and sinusoidal pulse width modulation, Tahmid has written quite a few articles and have posted them on his blog. You can find them here:


Generation and Implementation of Sine Wave Table
https://tahmidmc.blogspot.com/2011/01/generation-and-implementation-of-sine.html

Smart Sine - Software to generate sine table
https://tahmidmc.blogspot.com/2012/10/smart-sine-software-to-generate-sine.html

Generation of sine wave using SPWM in PIC16F684
https://tahmidmc.blogspot.com/2012/10/generation-of-sine-wave-using-spwm-in_10.html

600W 50Hz sine wave inverter test circuit
https://tahmidmc.blogspot.com/2012/10/600w-50hz-sine-wave-inverter-test.html

Feedback in sine wave inverter (PIC16F series based)
https://tahmidmc.blogspot.com/2012/11/feedback-in-sine-wave-inverter-pic16f.html

Demystifying The Use of Table Pointer in SPWM - Application in Sine Wave Inverter
https://tahmidmc.blogspot.com/2013/02/demystifying-use-of-table-pointer-in.html

Sine Wave Generation without ECCP - Using single CCP Module of PIC16F877A
https://tahmidmc.blogspot.com/2013/02/generation-of-sine-wave-without-eccp_16.html

Sine Wave Generation with "Fast PWM Mode" of AVR - using ATmega16
https://tahmidmc.blogspot.com/2013/02/sine-wave-generation-with-fast-pwm-mode_2525.html

I hope everyone finds these articles/tutorials helpful.

 

[--BawA--]

BY which SPWM scheme you want to drive your H-Bridge? Bipolar or Unipolar?

 

[Pulsetronics]

Thanks to BawA. I want to drive using Bipolar

 

[--BawA--]

Ohk if this is the case, you can refer to links in post#6

 

[ashugtiwari]

Little late for reply. This example code may help for SPWM generation. For complementary output for inverter, use the complementary mode in CCP module. The controller used is different but the code can be used without any modification.

Hope that helps.