Hello Peter,
The “Fault (Three-Phase)” block is a Simscape electrical block whose inputs are physical signals, which are different to regular Simulink Signals. Input control signals, such as step modules, PWM modules, or signal generators must be converted to physical signals before being fed to the Externally triggered fault control input (“F”) port of the Fault block. For more information about physical signals, refer to this link - https://www.mathworks.com/help/simscape/ug/basic-principles-of-modeling-physical-networks.html.
To connect Simulink Sources to Simscape diagrams, follow the workflow described in this link - https://www.mathworks.com/help/simscape/ug/connecting-simscape-diagrams-to-simulink-sources-and-scopes.html.
To address the second query about the composite three-phase port, the “Modelling Option” block parameter can be changed to “Expanded three-phase ports”. Open the block parameters of the “Fault (Three-Phase)” by double clicking on the block. In the “Modelling Option” drop-down field, choose “Expanded three-phase ports”. This will enable the three different phases (“a”, “b”, and “c”) separately, and they will be visible as individual ports on the block which can then be connected to the three-phase circuit. For more information about three-phase ports, refer to this link - https://www.mathworks.com/help/sps/ug/three-phase-ports.html.
