Given:
Core I permeability μ1 - nonlinear*
Core E permeability μ2 - nonlinear*
Core material density ρ = 7650 kg/m^{3},
Frequency f = 400 Hz.
Winding1 no-load current 16.5 mA,
Winding1 number of turns 324.
Winding1 conductor cross-section 0.19 mm^{2}
Winding1 average turn length 111 mm.

Task: Calculate the core losses in the no-load mode of transformer.

Solution: In no load mode the secondary winding is in open circuit state. There is current only in the primary winding.
The primary winding is modelled as multi-turn winding - the average current density is specified.

Core is laminated, zero conductivity is specified. Core losses are calculated using Bertotti equation:
p_{v} = k_{h}·f·B_{m}^{2} + k_{c}·f^{2}·B_{m}^{2} + k_{e}·(f·B_{m})^{3/2}
Coefficients k_{h}, k_{c}, k_{e} are calculated as a result of the curve fitting using free utility Core loss coefficients calculator.

Results:
Core E magnetic loss is 0.87 W.
Core I magnetic loss is 0.12 W.
Flux density distribution in the core:

* Reference: Core loss and magnetization curves are provided by Arnold Magnetics.