In Simulink, I have the choice between various variable-step solvers. Which is best to use with PLECS?
In general, the default solver of Simulink 'ode45' is recommended.
However, your choice of circuit parameters may lead to stiff differential equations if the time constants in the circuit differ by many orders of magnitude. In that case you should choose one of Simulink’s stiff solvers to increase the simulation speed; we recommend using 'ode15s' or 'ode23tb'.