Building a 30 Amp Buck Convertor - 18v to 40v Input_19v to 30v Output at 30 Amps

Thread Starter

Dragonoid

Joined Nov 27, 2017
16
Hello,
I want to design an Buck Convertor for my application which require 18v to 40v Input_19v to 30v Output at 30 Amps,The Basic Need of this supply is to Charge Battery and provide power to a load System simultaneously.

1) I am using an 20 Amp 0-24v Transformer.
2) Buck Convertor O/P is controlled via MCU With User Data Input.
3)Short Circuit Protection.
4)Current Limiting.
 

crutschow

Joined Mar 14, 2008
27,013
18v to 40v Input_19v to 30v Output at 30 Amps
You can't get more voltage out of a buck converter than the input voltage.
If you want more volgage you will need to use a buck-boost converter.
1) I am using an 20 Amp 0-24v Transformer.
A transformer RMS current rating needs to be derated about 60% for the DC output of a rectifier-capacitor filter, thus the maximum current into the converter will be about 12Adc.

The maximum output DC voltage of that transformer using a full-wave bridge will be about 30V, so that will also be the maximum output from a buck converter.
 

dendad

Joined Feb 20, 2016
3,811
Why do you need a 19 to 30V out if you are charging a battery?
What is your battery type? What sort of battery protection will it need? There are a lot of details missing from your request.
Is this a UPS? and what is the final load requirements?
 

Thread Starter

Dragonoid

Joined Nov 27, 2017
16
There are some problem in the specs,I need 22v to 28v Supply with a total Current limit of 20 A Continuous.
And the Battery is Feeding Power into load continuously during charging of battery in parallel.
 

dendad

Joined Feb 20, 2016
3,811
Basically, is this a 24V lead/acid battery charger?
The battery chemistry is important to know as the wrong supply can kill the battery.
There are lots of high current 24V battery chargers available on places like Aliexpress and Ebay. Have you looked there?
 

Thread Starter

Dragonoid

Joined Nov 27, 2017
16
The Problem with SCR Based Chargers is the Continues Current Spikes generated at the Output End of the Charger Which some times create a problem with the Electronics connected as load on the other side of the battery.
 

Papabravo

Joined Feb 24, 2006
15,795
The critical component required for this design will be the inductor. As the current requirements in the inductor go up, the design becomes more and more challenging. There is a tug of war between the wire guage and the number of turns on the core. There there is the matter of core saturation. AFAIK your design will require a greater than average design effort by someone who really knows what they are doing when it comes to component selection and PCB layout. You can't skimp on this stuff.
 
Top