Reducing transformer size for 24VDC to 240VAC inverter

Thread Starter

1VA7

Joined Sep 9, 2013
1
Hi, I have an inverter with 24VDC input and 240VAC output. The transformer in the inverter is very bulky and I cannot use it because of the weight issues. Can it be replaced with a smaller transformer which will be light weight (<2kg will be ideal)? Please help. Thanks in advance.
 

ronsimpson

Joined Oct 7, 2019
451
With out knowing what type of inverter you have it is hard to say anything smart.
I don't need to know who made the inverter but how it works. There are many different ways to make a inverter.
 

LesJones

Joined Jan 8, 2017
2,522
If it is an old inverter the transformer primary will be driven by a 48 volt peak to peak square wave or stepped waveform into it's center tapped primary at 50 or 60 Hz. As a result the transformer will be quite large. Modern inverters stepup the input voltage via a smaller transformer running at a much higher frequency. (Hence a smaller transformer to handle the same power.) The output of the transformer is then rectified to provide a high voltage DC supply. This is then converted back to an AC waveform of 50 or 60 Hz using high voltage mosfets. In either of these types you will not be able to just fit a smaller transformer. (The manufacturer would not fit a larger transformer than needed.) I think your only hope is that if it it the older design you could replace it with the more modern type.

Les.
 

Metalloy

Joined Jun 30, 2018
1
Hi,

If this transformer is operating at 50-60Hz, then reducing the size will reduce the power.
However, if it is operating at PWM frequency, you can (in theory) reduce the size be increasing the frequency of PWM.
Transformer Core Size (power handing capacity) is inversely prop. to frequency.
 

jpanhalt

Joined Jan 18, 2008
8,776
A more complex approach would be to use a higher frequency to get from 24VDC to your higher voltage at an appropriate power, rectify it, then convert the rectified voltage to a convenient frequency, sine wave with switching mosfets. That's a lot more complex, but may weigh less.
 
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