The model is realized as asynchronous state-machine, the
machine states are defined using the enumeration type State,
defined in the
TapChangerPhaseShifterLogicCommon class.
The transitions are defined using a when - elsewen structure,
which allows the asynchronous behavior of the machine, and the
relevant conditions are evaluated at the previous integration
step.
The input variables are two booleans, which indicate if the
monitored variable is under the Min limit or above the Max
one.
The output variable tap represents the position of the
tap-changer/phase shifter to be used in the next integration step,
and it is updated by the transitions of the status-machine.