16 batteries inveter system

[Adajo]

pls I need an explantion on inverters that run on 16 (12 volts series connected) batteries. I only know about inverter working on 12 volts not 192 volts (12volts x16)

 

[tpetar]

pls I need an explantion on inverters that run on 16 (12 volts series connected) batteries. I only know about inverter working on 12 volts not 192 volts (12volts x16)

You know for 192V of course, but you didnt see, its electric car.

Major thing in inverters is how to get high power but on lower current, just because that, batteries goes in serie to make higher voltage.

Theoretical example :

12V System 500W need 42A
24V System 500W need 21A

Can You imagine what will happen and how long will run on one 12V at that amperage (few minutes).
Also you need bigger wire diameter,.... ... ...

Lead acid batteries are for /10 or /20 discharging time, acording to that you need to plan battery bank.



I'm tired to writing about inverters and batteries, on edaboard you have lots threads about that theme.
Just search!


:wink:

 

[BradtheRad]

Do you want to produce something in the region of 120 VAC? Then you do not need to make a conventional inverter. Since you already have DC power close to that volt level, your converter will resemble a chopper type of circuit. You can do without a transformer.

You will need a pulse generator. What waveform it should produce will be based on which of 3 output waveforms you want (described below).

You use a simple H-bridge. Load is at the center.

1.

Simplest method is to create AC square waves. This will give you +192 and -192V across the load.

You can remove a battery or two, if you only want the equivalent of 120 VAC.

2.

There is the modified sine waveform. Sort of like square waves on a reduced duty cycle. Needs a more sophisticated pulse generator.

3.

There is true sine waveform. Since you already have the high V to begin with, you may get by with driving the mosfets from a sine wave drive circuit. (This is more efficient than step-up inverters which send massive current through the mosfets.)

The mosfets will carry only as much current as your load draws. (It is wise to make them 2x that to provide a generous margin.) They need to be rated for well over 200V.

 

[tpetar]

@Bradtherad

Low Harmonics Single Phase Multilevel Power Inverter

Low Harmonics Single Phase Multilevel Power Inverter

 

[BradtheRad]

Low Harmonics Single Phase Multilevel Power Inverter

Yes, that is enlightening.

I have a true sinewave inverter. 2000W.

It has a lot of mosfets inside. I knew they had to have high current going through them. Not all at once, or it would produce a square wave.

So I could only imagine what kind of turn-on sequence is used, in order to create a sine wave.

Now I get an idea from your link how it is done.

 

[tpetar]

Also see this ;-) :

 

[BradtheRad]

Also see this ;-) :

MQP_D_1_2.pdf (5.32 MB)

Good article. I was interested to see that it sometimes takes strokes of genius, sometimes hit-or-miss, to make a sinewave inverter.

Hi-power compact inverters have really come into demand. They are not easy to homebrew. To make one requires that we know a few secrets about overcoming the bugs.

So I had concluded that it takes a genius who really knows his stuff, somewhere at the company, to make a foolproof hi-power inverter that is successful on the market.

And it's in his, and the company's, interests not to reveal the trade secrets as to how to overcome the bugs.

So we must scrounge to discover those secrets, bit by bit.