A Novel Discrete Hybrid Dual Random SVPWM Scheme for Reducing PMSM Harmonic Intensity

Aiming at suppressing the switching frequen- cy harmonics, a novel discrete hybrid dual random control (DHDRC) technique is proposed in this article. Based on the space vector pulsewidth modulation (SVPWM) strategy, the DHDRC-SVPWM technique is applied to randomize the switching period and pulse position by selecting dual discrete random factors from predefined discrete sequences. Accordingly, the original switching narrowband harmonic energy of SVPWM is extended to a wide range of frequencies. To analyze the harmonic dispersion degree quantitatively, the power spectrum is deduced to assess the performance of the discrete random SVPWM. Then, the connection between the discrete sequence and the harmonic energy distribution is obtained under random variables following a discrete uniform distribution. The obtained results demonstrate that the proposed technique significantly expands harmonic clusters in the frequency domain, thereby reducing the harmonic intensity. The present study provides a reference to investigate random SVPWM and improve electromagnetic interference and noise in power converters.