Abstract: The reason of harmonic wave in the magnetic flux density was analyzed according to the magnetic circuit characteristic, distribution of magnetic flux density, magnetic properties of silicon steel sheet and connection mode of excitation winding. Using the spectrum analysis results of magnetic flux density in the frame of the core as the measurement condition, the service properties of GO silicon steel sheet applied to 3D wound core transformer were measured. The basis of the measurement method was proposed by analyzing the magnetic properties of different size GO silicon steel sheets and their application status in 3D wound core. The type selection suggestions was proposed by the test results of different size silicon steel sheets.

Key words: 3D wound core, harmonic wave, silicon steel sheet, loss