Various aspects of home brew inverters

Author Message

Joined: 09/08/2007
Location: Australia
Posts: 4406
Posted: 03:41am 08 Jul 2018      

It sounds to me as though your toroid is beginning to head towards saturation as you lower the frequency.
The flux swing in the core will be 20% higher at 40Hz than at 50Hz.

One way to test this theory, would be to lower your dc supply voltage by 20%.
Try running it at 21.9v instead of at 27.4v.
See if you can then go down to 40Hz without the current peaking above around 0.5A.

Really, forcing it down to 40Hz is rather like performing an unnatural act on it....
But its all in the interests of the learning process.

Well done Poida !Edited by Warpspeed 2018-07-09
Cheers,  Tony.