.FreeFluids.Instruments.PI

Information

This blocks defines the transfer function between the input u and the output y as PI system:

               1
 y = k * (1 + ---) * u
              T*s
         T*s + 1
   = k * ------- * u
           T*s

If you would like to be able to change easily between different transfer functions (FirstOrder, SecondOrder, ... ) by changing parameters, use the general model class TransferFunction instead and model a PI SISO system with parameters
b = {k*T, k}, a = {T, 0}.

Example:

 parameter: k = 0.3,  T = 0.4

 results in:
             0.4 s + 1
    y = 0.3 ----------- * u
               0.4 s

It might be difficult to initialize the PI component in steady state due to the integrator part. This is discussed in the description of package Continuous.