High-Frequency Spread-Spectrum Modulations for Wide-Bandgap Voltage Source Converters

The high efficiency and the electromagnetic compatibility of wide-bandgap (WBG) power converters can be further improved using spread-spectrum (SS) modulations. This paper evaluates and compares the impact of SS techniques on voltage source converters (VSC) that use gallium nitride (GaN) semiconductors. These modulations work with a variable switching frequency, so they generate fewer switching losses. Moreover, SS modulations generate smaller low-order harmonics than the classical space vector pulse width modulation (SVPWM) does. The power losses are analysed using Matlab/Simulink and PLECS, and then compared with SVPWM. Moreover, this paper evaluates the frequency spectrum and the THD of the different SS modulations. Simulation results under various operating points are reported and compared.