AC Sweep Analysis LLC Resonant Converter


I have been trying to perform an AC sweep (open loop) for an LLC resonant converter and I haven’t been able to succeed.
I have seen the videos of implementing the m-sine AC sweep, however I couldn’t implement them in the case of frequency controlled LLC converters.

Please, could you provide me some help on how to implement it. Also, it would be very useful if you can make a video with this problem.



I will put together a video. It should be straightforward. Until then have a play with the attached sim.

There is an important “trick” to consider, since an “increase” in frequency will correspond with a reduction in gain, in order to get plots that make sense you need to put a “-1” gain block in front of the AC probe. This will then correspond with a negative gain value in the PI controller.

Hello Albert,

Thanks for your help!
I will take a look to that file.

Dear Albert,

Thank you for the sim. files. I have a query regarding closed-loop AC Sweep. In order to get a closed-loop gain and phase plots, should I just have to change the value of MUX to 1? Because doing so, the results seem to be incorrect.

Hello, can you please share the LLC AC sweep simulation again?