混合级联变换器改进型移相PWM技术的设计与评估

This study explores the spectral characteristics of grid-connected hybrid cascaded converters (HCC) on the basis of phase-shifted pulse-width modulation (PSPWM). Mathematical derivation indicates that the conventional PSPWM (CPSPWM) fails to suppress the low-order harmonics within HCC, resulting in noticeable output waveforms distortion. To address this issue, a modified PSPWM (MPSPWM) approach is developed to improve the output performance without increasing the total loss. Laboratory test results are provided, and they validate the effectiveness of the proposed MPSPWM technique. Moreover, two different HCC topologies are discussed, and they are compared from the output quality point of view, revealing that one topology outperforms the other throughout most of the operating range.