ATMEGA16/32 based single microcontroller inverter with battery charger

[pnjbtr]

what's the ideal trans ratio of CT for stabilizers ?

Ratio for CT(Current Transformer) depends upon,voltage.
voltage that we required on secondery side for operational amplifier(LM358,LM324 etc),or comparator.(393 and 339).
E And I type core used in C/T.For mid range and small voltage stablizers.
Babon size 1/4*1/4 inch(6.35mm*6.35mm) is suitable.
3 turns of swg,17 and 1000 turns of swg 40.
See attach files.

 

[sahu]

Ratio for CT(Current Transformer) depends upon,voltage.
voltage that we required on secondery side for operational amplifier(LM358,LM324 etc),or comparator.(393 and 339).
E And I type core used in C/T.For mid range and small voltage stablizers.
Babon size 1/4*1/4 inch(6.35mm*6.35mm) is suitable.
3 turns of swg,17 and 1000 turns of swg 40.
See attach files.

thank u for reply. my req is o\p side 1v @5kva load.hear we use

 

[pnjbtr]

SWG,12 is required for 5kva load.
What is current of 1 volt?

 

[rajudp]

as per the pic 1 volt goes to the adc input need only m amps

 

[pnjbtr]

as per the pic 1 volt goes to the adc input need only m amps

But SAHU asked for 1v@5kva load.
I do not know exact formula for current transformer,
I think it can done with practical.
5kva load mean approxi=17AMPS.SWG12 can tolerate.
Wind only single turn of SWG12 in suitable babon(former) and insert core.
During max 17amp load measure voltage drop of swg12.
These volt may very small in mv.
For example if we measure 10mv across swg12.
So 10mv is our primary.
now we need turns for 1 volt on secondary side.
Then we add 100 turns for 1 volt.

 

[anoop kr]

its very nice Tahmid.Wish you all success....go on...

 

[sahu]

But SAHU asked for 1v@5kva load.
I do not know exact formula for current transformer,
I think it can done with practical.
5kva load mean approxi=17AMPS.SWG12 can tolerate.
Wind only single turn of SWG12 in suitable babon(former) and insert core.
During max 17amp load measure voltage drop of swg12.
These volt may very small in mv.
For example if we measure 10mv across swg12.
So 10mv is our primary.
now we need turns for 1 volt on secondary side.
Then we add 100 turns for 1 volt.

right now i am using 1 CT. there winding as below

300 - 300 turn secondary
1 turn primary

i use only 0- 300 tape........ & open next 300 turn tape
complete the stb. connect load ....

A> 2 pc 750 watt room heater + 1 pc 1500watt Emerson rod. & my home load etc.
o\p current =8amp ac.......pin 7 0.485v dc.
agen we disconnect 2 pc 750 watt room heater + 1 pc 1500watt Emerson rod.
connect my

B> 24v\1000w inv.ok
when inv charging start o\p current =4 amp .pin 7_ 2.5v dc.

SO I MANGE IT VOLT THROUGH WATT \680 OM RESISTANCE PEARLER OF PIN 7.
found here 1.02v dc.
i am confuse .....why
A> o\p current =8amp ac.......pin 7 0.485v dc.
B> o\p current =4 amp .pin 7_ 2.5v dc.
pl clear me & SUGGEST ME ALSO........
i think here problem ...inductive , capacitive & liner load.......LEADING & LAGGING

thank all of u

 

[babalola]

Hi Tahmid,
Find attached my schematic
regards,
babalola

 

[pnjbtr]

i think your inverter,s charging system is consist of triac or SCR(thyrestor).These devices(triac etc) provide volts in form of pulses to transformer.And transformer,s initial current always much higher than normal condition,It is also called surge load.

right now i am using 1 CT. there winding as below

300 - 300 turn secondary
1 turn primary

i use only 0- 300 tape........ & open next 300 turn tape
complete the stb. connect load ....

A> 2 pc 750 watt room heater + 1 pc 1500watt Emerson rod. & my home load etc.
o\p current =8amp ac.......pin 7 0.485v dc.
agen we disconnect 2 pc 750 watt room heater + 1 pc 1500watt Emerson rod.
connect my

B> 24v\1000w inv.ok
when inv charging start o\p current =4 amp .pin 7_ 2.5v dc.

SO I MANGE IT VOLT THROUGH WATT \680 OM RESISTANCE PEARLER OF PIN 7.
found here 1.02v dc.
i am confuse .....why
A> o\p current =8amp ac.......pin 7 0.485v dc.
B> o\p current =4 amp .pin 7_ 2.5v dc.
pl clear me & SUGGEST ME ALSO........
i think here problem ...inductive , capacitive & liner load.......LEADING & LAGGING

thank all of u

 

[sahu]

i think your inverter,s charging system is consist of triac or SCR(thyrestor).These devices(triac etc) provide volts in form of pulses to transformer.And transformer,s initial current always much higher than normal condition,It is also called surge load.

i think u r right sir .pl sausage me how can menage it for load sensing .......

 

[pnjbtr]

i think u r right sir .pl sausage me how can menage it for load sensing .......

Sahu ji see this schematic.
And describe where you are reading,0.485v dc with 8amp load.
And 2.5v dc with load of 4amp.
This is a simple schematic diagram of a comparator.
At 2 number pin of ic ,we apply almost 2.4 volts by divider resistances.
2.4 volts are reference voltage.
When pin number 3 of ic will receive volts more than ref(2.4).
Output pin 1 will become high,(led will on).
This schematic does not have initial current(surge load),delay capability.For delay we can use NAND GATE schimmit trigger ic(4093,etc).
I also see these types of over load protection circuits without CT(current transformer).
Some people use WIRE WOUND resistance(in mil ohm,10watts),in series of wire,that goes to output socket.
And dropped voltage of resistance can apply to an opto-coupler(pc817,or 4n35),which operates a transistor and op-amplifier.

 

[Tahmid]

Hi everyone,

Here I give the PCB for my design:

Top and bottom:

Bottom Copper:

Top Silk:

The PCBs were then modified by a professional. I hope to upload those soon as well. These are the ones I designed myself. As I am not a professional at PCB designing, the boards became slightly large.

Tahmid.

 

[babalola]

Hi Tahmid,

This is a very good effort keep it up.Is it possible to converter this design to sine-wave inverter by modification to only the software?

 

[Tahmid]

Hi,
I'm not sure. I don't think so, as this uses push-pull converter. For sine wave I would need a full-bridge converter.

Tahmid.

 

[sahu]

Sahu ji see this schematic.
And describe where you are reading,0.485v dc with 8amp load.
And 2.5v dc with load of 4amp.
This is a simple schematic diagram of a comparator.
At 2 number pin of ic ,we apply almost 2.4 volts by divider resistances.
2.4 volts are reference voltage.
When pin number 3 of ic will receive volts more than ref(2.4).
Output pin 1 will become high,(led will on).
This schematic does not have initial current(surge load),delay capability.For delay we can use NAND GATE schimmit trigger ic(4093,etc).
I also see these types of over load protection circuits without CT(current transformer).
Some people use WIRE WOUND resistance(in mil ohm,10watts),in series of wire,that goes to output socket.
And dropped voltage of resistance can apply to an opto-coupler(pc817,or 4n35),which operates a transistor and op-amplifier.

thank u Mr. pnjbtr for repply.
i think we can use 741 ,358 or 324 ?

 

[pnjbtr]

hi,Tahmid.Did you ever measure specific gravity of acid(with hydro meter)?
At that time when your inverter indicates,that battery is full now.

Hi,
I'm not sure. I don't think so, as this uses push-pull converter. For sine wave I would need a full-bridge converter.

Tahmid.

 

[Tahmid]

No, I haven't. I only measured the battery voltage.

 

[babalola]

Hi Tahmid,
Below is the schematic of my inverter project with the open-loop code written in Mikroe version 8.2.0.0.
Target specifications :
1. Output=230vac+/-1%, 50Hz
2. Overload/short-circuit protection
3. Output power 1000VA

The help needed on this project are:
1 basics of how to generate sine-wave look-up table for this project
2 what is the amplitude modulation ratio of this signal
ma = vm_ref/vm_carrier
3 addition and implementation of VERRY EFFECTIVE overload/short-cirrcuit protection
4 implementation of output voltage regulation to 230V+/-1% for both linear and non linear load at 0-full load


The transformer characteristics are as follows:
Primary resistance=0.2ohms
Secondary resistance.=1.5ohms
Leakage inductance secondary=2.76mH
Leakage inductance Primary=0.012mH
turn ratio =1:18

LOOKING FORWARD TO YOUR HELP
Regards,
Babalola.

 

[sahu]

today i change my C.T.,turn ratio are 1 turn primary & 100 turn secondary. check o\p of ct ac voltage ,o\p volt change in liner load according to liner load. o\p frq 50hz .but when connected my inv (anti pearler SCR use) during charging mode o\p frq of CT 150hz.
why ? pl clear any body......
in this case , how check o\l load with 16f676 micro controller @ 1 volt(100%)?

 

[Tahmid]

Hi babalola,
I'll help you with the project whenever I get some free time.

Thanks.
Tahmid.