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Regulated Resonant LLC Converter

This example shows the operation of a regulated resonant LLC converter.


The LLC converter is a DC/DC converter based on a resonant circuit which allows soft-switching operation.

The converter output voltage is regulated using a PI regulator. The output of the regulator is the switching frequency (Fs) which will keep the converter output voltage at the desired voltage set point (Vref). You can change the regulator gains by double-clicking on the PI Regulator block.


Start the simulation and observe on Scope1, the behavior of the regulated converter under a input voltage step (340V to 390V). Also, observing waveforms on Scope2, you will see that the current lags the voltage applied to the resonant circuit which allows the MOSFETs to be turned on with zero voltage.