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[SOLVED] Pic 16f876a Pure Sinewave inverter

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This design has no charging system but if you want to add you can simply change the MCU to a higher version and modified the code...
 

kabeer02 said:
This design has no charging system but if you want to add you can simply change the MCU to a higher version and modified the code...
Click to expand...

I need a some edge with start... any reference will be appreciated
 

Dear Sir,
I am new at this forum,
I want to build a 1000VA sin wave inverter built in charger.
Please Help Me,

Thank you,
Tanvir
 
Last edited by a moderator:

Hi, please am new in this forum. I tried the pure sine wave inverter on breadboard but not working with 20Mhz crystal. when i use 3.5Mhz crystal, it worked without connecting to the transformer. i have bought several 20Mhz crystal but still gave the same result. i programmed the pic using the required parameters. i use pic16f876a-I/sp. can someone please help me out. Thanks in advance
 

At 20MHz, voltage should be within 4.5V-5V. capacitors with crystal has smaller value. Above 4MHz, configuration setting is different. Did you used bypass capacitor very close to power pins on the IC?
 
The voltage i applied was within 4.8v to 5v for both crystals. i dint bypass capacitor. I fixed it the same was it was in the circuit diagram. But what i observed was that with the 20mhz crystals, pin 9 and 10 was reading 0.95v while with 3.5mhz crystal it was reading 0.65v and 0.95V
 

Hi All,

I am new on the website, and I saw all the open topics for inverter and so on. I only need a source code for driving two transistors that form a half bridge. I want to built an inverter 12V DC -> 24V AC. Can someone provide me the source code for this, or just a part of it. I would like to do a PWM inverter in which I can change the frequency and duty cicle from 2 ADC. The ADC conversion I think I can manage but the PWM part it is a bit difficult for me. From the hardware point of view I don't have a problem, just the program gives me a hard time.

Thanks in advance.
 

Re: pwm inverter circuits

Taner said:
My design is a sine-wave stand-alone PWM voltage-source inverter (Not UPS)
with PIC16F876A MCU, with parameters: Uin=12V DC, Uo=230V AC, 50Hz, P=500W.
Inverter have an integrated input under/over voltage protection, output voltage regulation, output current protection and overtemperature protection.
Output voltage is a pure sine-wave, generated with built-in PWM module of PIC MCU,
with frequency 20Khz.
:D
Click to expand...

Hi,

Can you please upload an archive with this setup and source code. Or if you done that please let me now where I can find it.

Thanks!
 

Feedback Loop

Hello

I saw this interesting thread and was really thankful to members who posted their valuable project here.

Although i have built a sine wave inverter (not with a PIC MCU) and totally different design approach.
The inverter works fine but i have a problem in adjusting the closed loop feedback loop.
I will explain it here. (please see the attached PDF document)

I generate a sinewave and get a rectified feedback.
At exact peak i measure the voltage- INV_VOLT
I have a variable voltage SET_V through a pot (0-5v)

I have 100 rows of 32 sine weighted variables each (1-100% duty)

At every ZCD event , i compare the SET_V and INV_VOLT and increase or decrease the row index.

This has a good effect a better stable sine wave, but not very stable , some oscillations are present within 1v.
another effect is on loading, the voltage drops by 4-5 volts (NO LOAD = 230VAC)

Can some learned member share an algorithm , how this can be achieved in my scheme?

Please remember , i correct o/p every 10ms.

Earlier i tried at a higher frequency with comparing 32 samples on similar lines on Taners code...
Which did not work....

Expecting help
 

Attachments

  • feedback topology.pdf
    20 KB · Views: 552

Re: Feedback Loop

abicash said:
Hello

I saw this interesting thread and was really thankful to members who posted their valuable project here.

Although i have built a sine wave inverter (not with a PIC MCU) and totally different design approach.
The inverter works fine but i have a problem in adjusting the closed loop feedback loop.
I will explain it here. (please see the attached PDF document)

I generate a sinewave and get a rectified feedback.
At exact peak i measure the voltage- INV_VOLT
I have a variable voltage SET_V through a pot (0-5v)

I have 100 rows of 32 sine weighted variables each (1-100% duty)

At every ZCD event , i compare the SET_V and INV_VOLT and increase or decrease the row index.

This has a good effect a better stable sine wave, but not very stable , some oscillations are present within 1v.
another effect is on loading, the voltage drops by 4-5 volts (NO LOAD = 230VAC)

Can some learned member share an algorithm , how this can be achieved in my scheme?

Please remember , i correct o/p every 10ms.

Earlier i tried at a higher frequency with comparing 32 samples on similar lines on Taners code...
Which did not work....

Expecting help
Click to expand...
I am so sorry for my late reply. It is my careless. Now, I reply it. I think it should be check for your hardware device used in your prefer design. According to my experience, I have adjusted the switching devices (MOSFET) to be sure obtain their threadhold level and Filter design also adjusted until to be smooth sine wave output. I also used source code from Taner's design too.* It is completed.
************* With regrads
************* thuhtayag
 

Re: Feedback Loop

thuhtay said:
I think it should be check for your hardware device used in your prefer design. According to my experience, I have adjusted the switching devices (MOSFET) to be sure obtain their threadhold level and Filter design also adjusted until to be smooth sine wave output. I also used source code from Taner's design too.*
Click to expand...

Hello thuhtay
Thanks for replying
Actually i am not at all using Taner's code or design.
It is my own design.
Without feedback, the sinewave is very good.No problem with o/p filters or devices.
I am only stuck at feedback correction.I have explained in my earlier post how i tried to achieve it.
Somehow i tried using a PI library but am unable to set parameters for PI , i never achieve stable and correct o/p voltage with that.
So now i only do an on/off control type algorithm, with an offset.
 

Hello,

In my experience, It is confirm about nearly 300 Watts.
 

Hello thuhtay

What are you saying ??:cry::???:
I am saying that this problem is NOT RELATED TO EXISTING CODE.

I am using my own code with a problem which i explained ---->>>> here
 

Can someone explain how the feedback works from the code,how is the lookup table being adjust when the their is voltage changes from the ADC
 

I saw a spwm inverter design with pic16f876a, it has LCD, PFC charging method , could anyone please recommend any thread where I can get hex file here, I know that the designer will take take the design files at edaboard.
 

Someone requested inverter monitor circuit, sharing it with proteus files including hex code.

- - - Updated - - -

uploading Proteus files of complete board (Working) in case anybody wants to play with the project, LCD monitor is not working as the model is missing in proteus lib. If anybody can try this project with an Arduino board will be appreciated.
 

Attachments

  • Inverter Monitor.zip
    269.4 KB · Views: 484
  • SINEINV Proteus.zip
    226.8 KB · Views: 492
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