Space Harmonics of Synchronous Machines Calculated by Finite-Element Method

Space harmonics of synchronous machines are investigated in this paper through a specially designed synchronous machine. A 2-D finite-element method is used to calculate the magnetic field of the machine. The space harmonic magnitude and phase angle can be computed based on the magnetic flux density. The machine is specially designed and can be excited from the direct axis, quadrature axis, and various intermediate axes. The overall finite-element calculation accuracy is validated by the measured open-circuit characteristic curves. The space harmonic investigation in this paper provides valuable insight of the space harmonic contents of synchronous machines, which can help to develop a more advanced harmonic prediction method for the synchronous machine's design and operation.