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digital or analog bridge

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chosen_1

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Hi.
I am designing an inverter. My programing is below average and I need to decide whether to use a digital or analog microcontroller for switching my switches. I need to have a PWM output (Unipolar or Bipolar).
 
What frequency are you planning to use?
Fixed or variable PWM?
Voltage and/or current feedback?
Power level?
What type of load?
What is the voltage source?
etc
 
What is an analog microcontroller? Do you mean one with a built-in D/A and/or A/D.

For PWM inverter control you need a microcontroller that can output a PWM signal. A built-in A/D might be useful for converting the DC voltage you are trying to regulate, to a digital signal the µC can use to control the PWM period (assuming your desired output is a DC voltage).
 
getting my DC from rectified mains supply. Haven't decided on switching frequency yet. Need fixed 220VAC/50Hz output. Voltage source inverter.
 
voltage source is rectified+filtered mains (for testing).
Haven't decided on switchin frequency yet.
Need fixed voltage magnitude and frequency on AC output.
 
Please check Texas Instruments power management web page.
**broken link removed**

When they acquired Unitrode, they got a treasure trove of app notes, applications, and dedicated ICs. They have greatly expanded afterwards.

Start with the app notes. They have every conceivable configuration and topology you can imagine. Both analog and digital.
 
Blue, I need 9 A(rms) and 220 Vac(rms) on the output of my inverter. So, I need to decide how I'm going to generate my PWM signal. No DSP board. Is there a single chip I can use that's efficient in power processing? Analog circuits for generating PWM signals seem too big and likely to make whole system not function. Please suggest alternative method.
 
Am I understanding you corectly that you are going to use the 220 VAC mains as the power source and then rectify it to DC then reinvert it back to 220 VAC again?
But at a different frequency right?
 
Yes, tcm

Yes,tcm. But my mains is also at 50Hz. Someone may ask, why?...this is for academic purpose and not packagin or domestic use. I'm just using rectified mains as my available DC for testing. The objective is to have a constant 220VAC,50Hz and supply 2kW at full load. Hope that explains context. Blue, I'm not using a battery.
 
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Spellin leading to confusion

Hahaha :p:D For me confusion usually leads to my spelling!

What type of purpose and accuracy are you looking for on the inverter side of the system?
do you need a pure sine wave or a very constant voltage or some form of current limiting?

We need far more information relating to what you are trying to produce on the output side of the device.
And what academic purpose it serves. Often times there are alternative methods that can and will produce fare better results than what a home made device can do.
 
3% or less? I wish my local utility company could get een half way close to that!

Do you have some type of system in mind? There are dozens of ways you can get a clean very low distrtion sine wave at the voltage, frequency and power you need.

However the trade off in the circuitry is that the simpler systems are very inefficient power wise while an efficient system is going to be far more compilcated.

What are you demonstrating that needs a low distortion sine wave produced from an inverter?
 
You have quite a job in front of you. A 2kVA on-line, double conversion with 3% THD. UPS Companies devote entire design teams to such tasks. Why re-invent the wheel? Just go out and buy yourself a UPS.

**broken link removed**
 
Lol!...You r not helping me. I know 3% is insane but that's what my Prof wil accept as my spec. I don't think he strickly expects it. I just need to build an inverter and demonstrate it works by supplying a load of said rating. I have to design it from first principles.
 
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