The "To File" block prints the simulation output to a file. Using the "To File" block generally isn't appropriate for parameter sweeps unless you want to store the results of each simulation (which also requires changing the name of the output file for each parameter set).
What's more appropriate here is to use the approach taken in the "Buck Converter with Parameter Sweep" demo model. Specifically, the use of a Signal Outport at the top level schematic so that the plecs('simulate') command returns simulation data (see the help excerpt below). Then one would manage the results and any file IO in the simulation script. That demo also illustrates how to run the simulation in parallel (if you have PLECS 4.6).
Attached is a modified version of your model. I assume you'll want to restructure the output, add headers, etc. but all of that is basic Octave file IO for which there are plenty of resources available.
