mredbautista
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« on: May 04, 2006, 05:03:42 05:03 » |
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Dear friends,
I want to generate a 3 phase voltage using PWM or HPWM in PIC16F877. The output of the PIC will be feed to the IGBT with a power supply of 48volts DC. Actually the load motor is 3 phase 48Vac, 1 hp. This is a special motor for old printing machiniries. Basically, it seems that i am building low voltage Variable Frequency Drive (VFD).
I already have the IGBT but the PIC control it seems that it is my bottleneck.
I need some help or suggestion or share on how to construct the PICBASIC code. This is my first time to build 3 phase using PWM/HPWM.
Attach file is the zip-excel file for the 3 phase, I want to build whose output is the same as the graph shown.
More power to all,
mred
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bajrang
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« Reply #1 on: May 04, 2006, 08:17:26 08:17 » |
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mredbautista
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« Reply #2 on: May 04, 2006, 09:25:04 09:25 » |
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Thanks a lot my friend, I have now the idea.
I have some clarification is it possible to use 16F877 to produce 3 phase sine wave?
If anybody have experience, please share...
Warm Regards,
mred
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bajrang
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« Reply #3 on: May 04, 2006, 10:08:50 10:08 » |
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Dear friend,
since 16f877 has got only two CCP modules(hardware) it is not possible to generate 3 phase sine wave output, unless you use software for pwm generation that too will be messy.
Best to use 16f777 that has got 3CCP modules.
I have practically realised this circuit. THe problems i faced are:
1)sometimes an erratic peak appears-> probably related to crystal stability ?
2)loss in sine-wave purity-> because of 20 degree resolution in lookup
we can have more discussion.
regards,
bajrang
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Yazi
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« Reply #4 on: May 04, 2006, 12:13:33 12:13 » |
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hello bajrang, it is very interesting as project can you share with as your work?.
best regards
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sombre
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« Reply #7 on: May 16, 2006, 12:49:46 12:49 » |
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hello bajrang, it is very interesting as project can you share with as your work?
10x by advance
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