I would like to implement the topology described in this reference board using a 3-phase interleaving approach. I am able to calculate the Boost mode ripple current through the output capacitor using equations found in research papers. I would like to calculate the Buck-boost mode output ripple current too. I am aware of the ripple current cancellation effects of interleaving, and I imagine the ripple current through each phase would be calculated as a traditional Buck-boost converter. How could I calculate the combined ripple current of the three phases?