Five-frequency-band random PWM with overlap operator optimization for harmonic peak suppression

To address the limitations of conventional Random Switching Frequency PWM (RSFPWM)—specifically diminishing harmonic suppression returns and low-frequency spectral leakage, this work develops a Five-Frequency-Band Random PWM (FFB-RPWM) strategy. The approach discretizes the switching frequency spectrum into five configurable sub-bands with variable overlap, establishing a multi-cluster harmonic distribution architecture. A novel overlap operator ( δ ) regulates spectral spreading characteristics, with analytical verification confirming minimal harmonic magnitude at δ =0.4. Hardware-aligned simulations using a three-phase two-level inverter validate superior performance under identical average switching frequency: Critical harmonic peaks reduce by 4.5% at fundamental switching frequency (10 kHz) and 0.5% at second-order harmonics (20 kHz) versus RSFPWM, alongside enhanced spectral uniformity. The solution delivers improved electromagnetic compatibility for high-frequency power conversion systems.