The authors discuss the harmonic-balance finite-element method (HBFEM) for a time-periodic magnetic field with saturation and hysteresis characteristics and its applications. The HBFEM makes it possible to calculate the distribution of harmonic magnetic flux at an AC magnetization, and it does not require the intricate calculation associated with the time variation. Comparisons between numerical analysis and experimental results are presented. It is shown that the HBFEM can be efficiently used to design a triplex and a special hybrid high-speed motor connected to a power source and external circuit in which the third harmonic components play an important role. >