Determination of iron core losses under influence of third-harmonic flux component

The core loss for a magnetic material under excitation can be estimated from the flux density versus the field-strength loops or B-H loops. A method is presented for predicting the position, size, and number of minor loops formed in the B-H loop, while harmonics of known magnitude and phase angle occur along with the fundamental under distorted excitation. The data required for this method are a set of B-H loops at the fundamental excitation frequency and loops formed under third-harmonic excitation frequencies over a range of flux densities.