Anyone here done LLC converters?

Of course, The harmonics won?t be odd any more, but should not matt er much since anything above 2 Fres will be attenuated, although the conten ts of the reactive current will be larger

Cheers

Klaus

It should work although the common method for LLC soft-start is to start at a high frequency (where the voltage gain of the whole converter is very low) and then let the frequency gradually drop down until the loop kicks in and begins regulating the frequency.

These guys are proposing both, frequency as well as duty-cycle control:

Thanks Joerg ?

Good article reference and exactly what was looking for

Cheers

Klaus

On Saturday, September 23, 2017 at 5:47:11 AM UTC+10, Klaus Kragelund wrote :

op

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n target the resonant point

Looks like the serial form of the Baxandall class-D converter.

On Saturday, September 23, 2017 at 4:09:01 AM UTC+2, snipped-for-privacy@ieee.org wrot e:

te:

loop

can target the resonant point

o work out how to inject the extra current to replace the quadrature curren t you would have got from the extra capacitance or inductance that would ha ve made the tank resonant at the frequency that you want - but it can be do ne.

It is possible to linearize the resonant converter with a trick, so feedbac k control gets a lot easier. Depends on what control IC is used

Can you elaborate on the replacement of quadrature current?

Cheers

Klaus

On Saturday, September 23, 2017 at 8:29:58 PM UTC+10, Klaus Kragelund wrote :

ote:

rote:

l loop

o 50%?

I can target the resonant point

to work out how to inject the extra current to replace the quadrature curr ent you would have got from the extra capacitance or inductance that would have made the tank resonant at the frequency that you want - but it can be done.

ack control gets a lot easier. Depends on what control IC is used

Not in any useful way, in this kind of forum. Send me an e-mail if you have a specific idea in mind.