Analysis of current harmonics in inverter-driven interior permanent magnet synchronous machines

This paper presents the analysis of current harmonics in an inverter-driven interior permanent magnet machine for different modulation methods. In contrast to other approaches, the influence of the saliency (L_d ≠ L_q) on the harmonics is being considered. By use of the rms-value of the currents, analytically closed equations can be deduced and tedious Fourier analyses of single harmonics can be avoided. The derivation of the analytic equations is described and the results are verified by numerical simulation as well as by experimental results.