How can I accociate a parameter to each file?

I am calculating coil current distribution in a cross-section and I successfully visualized the output at every time step with Paraview.

But I couldn’t associate a parameter that varies with time with every vtk file.

Is there any way to do that by just modifying vtk file? Maybe use global value? but I couldn’t find out how to use it.

For more clear discussion, I attached three vtk files. And I would like to store voltage like 10, 15, and -10 in the vtk files. Ultimately, I would like to annotate the value

all_data1.vtk (638 Bytes)
all_data2.vtk (639 Bytes)
all_data3.vtk (637 Bytes)

PythonCalculator provide a t_value variable that you can use.