Iron Loss of Different Oriented Silicon Steels under Complex Electromagnetic Condition

The iron losses of different oriented silicon steels were tested under conditions of different harmonic numbers (3rd, 5th, 7th), harmonic content (10%, 30%, 50%, 70%) and different DC bias magnetic field (5-120 A·m-1) and the effects of harmonic and DC bias magnetic field on the iron loss were analyzed. The results show that the iron losses of the tested silicon steels all increased with the increase of the harmonic number and content and showed a linear relationship with the harmonic number. The thinner the silicon steel thickness, the smaller the iron loss increasing amplitude with the harmonic content increasing was. The influence of the DC bias magnetic field on the iron loss was less than that of the harmonic. The iron loss increased with the increase of the DC bias magnetic field strength and finally tended to be constant. The measured iron loss of silicon steel 27K090 reached 0.982 53 W·kg-1 under the condition of the 3rd harmonic of 30% content and overlapping the 30 A·m-1 DC bias magnetic field, which was larger than the sum of iron losses under the single harmonic condition and under the single DC bias magnetic field condition (0.927 18 W·kg-1)