Simulate Nonlinear Stator Core Behavior IPMSM motor

I am trying to simulate magnetic saturation in our motor, but I am uncertain about determining the nonlinear state of our engine. I have explored this method on the following link, https://www.mathworks.com/help/mcb/gs/estimate-initial-rotor-position-using-pulsating-high-frequency-dual-pulse-injection.html. However, I am struggling to comprehend their implementation. Could someone please explain it to me?

Thank you very much

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Could someone please explain it to me?