Simscape Foundation Lib & Power Systems

Hi Guys,

Quick question regarding the conversions and interactions between the Simscape Power Systems Library and the Simscape Foundation Library? I'm trying to model a simulation mimicking a Transfer Switch, flicking between AC Voltage Sources depending on their value. Just for researching sake, I'm trying to use the Simscape Electronics Libraries SPDT Switch, which responds to a control voltage signal rising above or below a set Threshold. I was trying to configure it so the value of the incoming AC Voltage Source would determine the path of the signal flow, however the AC Voltage source from the Simscape Foundations Library can only connect to port 'c' and not the 'vT' input.

Furthermore, the AC Voltage Source from the Simscape Power Systems Library, can only connect to the vT input if a voltage measurement is obtained across a load and passed through a Simulink to Ps converter.

I can appreciate that there might not be a way around this, but I'm just wondering why this is the case? Why the AC Voltage Source from the Simscape Foundations Library can't connect to both port C and vT? Or why the AC Voltage source from the Simscape Power Systems Libraries need to go through this measurements and conversions in order to pass it into the vT input of the SPDT Switch? I've attached an example of what I mean in a model.

Any help would be much appreciated, and if anyone has any questions regarding my query please do not hesitate to ask, and I can try and provide more understanding on the situation!

Thanks in advance, Ali.