.PowerSystems.AC3ph.Transformers.TrafoSatEff

Information

Stray-impedance and resistance, with non-ideal magnetic coupling, i.e. non-zero magnetisation current, eddy current losses and effective saturation.
Delta topology: impedance is defined as winding-impedance (see info package Transformers).

Note: the saturation is treated as a 'time-average-effect' with the intention to omit variable transforms.
It has to be decided, under which conditions the approximation is acceptable. If this is not the case, use Transformers.TrafoSat (more computation intensive).
The factor 0.66 in the expression of the effective pu flux is an estimation, between sqrt(1/3) (eff value of unsaturated flux) and sqrt(2/3) (amplitude of unsaturated flux).

SI-input: values for stray and coupling impedances are winding dependent.

  r[k]   = R[k]
  x[k]   = omega_nom*L[k]
  x0[k]  = omega_nom*L0[k]
  redc   = Redc
  xm     = omega_nom*Lm
  xm_sat = omega_nom*Lm_sat, saturation value of inductance
  psi_sat, pu saturation value of flux (no SI-value!)

pu-input: values for stray and coupling impedances are winding-reduced to primary side.

  r[k]   = R[k]/R_nom[k]
  x[k]   = omega_nom*L[k]/R_nom[k]
  x0[k]  = omega_nom*L0[k]/R_nom[k]
  redc   = Redc/sqrt(R_nom[1]*R_nom[2])
  xm     = omega_nom*Lm/sqrt(R_nom[1]*R_nom[2])
  xm_sat = omega_nom*Lm_sat/sqrt(R_nom[1]*R_nom[2]), saturation value of inductance
  psi_sat, pu saturation value of flux

with

  R_nom[k] = V_nom[k]^2/S_nom,  k = 1(primary), 2(secondary)

Saturation needs high-precision integration!