functionsaturationAnalytic

Analytic iron saturation function

Information

Returns analytic saturation function. 

  Input: psi0     unsaturated flux pu
  Output: psi     saturating flux as function of psi0
The analytic expression for the saturating flux function is 
  psi = (c[1]/c[2])*tanh(c[2]*psi0) + c[3]*psi0
For xratio < < 1 the coefficients c are related to 
  xratio      ratio saturated/unsaturated coupling impedance
  psi_sat     saturation value of flux pu
in the following way 
  c[1] = 1-xratio
  c[2] = (1-xratio)/(psi_sat-xratio)
  c[3] = xratio

Inputs

TypeNameDefaultDescription
Realpsi0unsaturated flux pu
Realc

Outputs

TypeNameDefaultDescription
Realpsin=0: saturated flux, n=1: derivative d_psi/d_psi0