step up

[shanky25]

Hey friends.

I am shashank from India. I actually wanted to build a circuit which can step up 12V or 24V to around 230V. The current rating of my batteries would be around 10-15Ah. Since my application is a battery operated vehicle, i cant opt for a transformer as such. The circuit should be able to step up the voltage, amplify the current and that too with a good efficiency. Would you please suggest me such a circuit using power electronics anything of such kind?

Regards
Shashank

 

[blueroomelectronics]

Why would a battery operated vehicle need 230V? Why not use 12 or 24V motors instead?

 

[shanky25]

Ahh it isnt a toy vehicle. The motor specifications itself are 230 V

 

[blueroomelectronics]

Then use more batteries, an inverter will be very inefficient and one that can deliver the power to run motors will be very expensive.

PS stepping up voltage means current goes down. You can't amplify both.

 

[Andy1845c]

Is this a full size electric car?

I'm not an expert, but the electric cars I have seen use many 12v batterys in series to get several hundred volts DC.

You can find inverter circuits that would make 12v DC into 120 or 240v AC, but the power output will be far below what you would need to power a car.

EDIT: Sorry, posted at the same time as you, Bill, lol

 

[shanky25]

what if i maintain the current same and steup up the voltage ! because the batteries of high amp rating are very expensive and heavy too.

 

[shanky25]

@ Andy

How many such batteries would u suggest me to connct in series? because that even adds a lot to the weight and hence in the reduction of the BHP of the motor!

 

[blueroomelectronics]

Nope current will go down as volts go up. Basic electricity.
Example 10A @ 1V will be 1A @ 10V easy peasy.

 

[shanky25]

@ Andy

Even if I connect a few batteries in series, how do i charge them?

 

[shanky25]

@ Bill

What If i use a bug boost inverter? the efficiency might not be as high though, what about the current rating?

 

[blueroomelectronics]

Even if I connect a few batteries in series, how do i charge them?

Well that's why you use low voltage DC motors in your car. 48V is reasonable and probably won't kill you.

As for a converter to boost they're around 90% efficient if well designed and very expensive.

 

[shanky25]

@ Bill
So what kind of converter would you suggest

 

[blueroomelectronics]

I wouldn't recommend a converter. I'd match the supply to the motor.

 

[shanky25]

@ Bill

Exactly Bill but for that I need an inverter atleast. How about getting into power electronics to search for a solution?

 

[shanky25]

@Bill

The specifications of the motor are 4Hp 230v

 

[blueroomelectronics]

If this is your school assignment I'd pick something else.

 

[shanky25]

No not at all Bill. This is for one of my publications. Hope you help me out with some idea !

 

[blueroomelectronics]

Are any of your publications online?

 

[Andy1845c]

Are they AC or DC motors? Where did you get them?

I would suggest you do alot of googling on the subject of electric cars. They are certinly not simple.

If you are trying to make an existing car into an electric car, che out some of the kits made. Google for "electric car conversion" or somthing like that. It will give you an idea of all the stuff that is involved.

 

[Roff]

@Bill

The specifications of the motor are 4Hp 230v

4HP is about 3kW. 3kW/230V=13A. This assumes perfect efficiency in the motor, which won't happen.
3kW/12V=250 Amps! Again assuming 100% efficiency.