The invention discloses a low-frequency
harmonic suppression modulation method of a high-switching-frequency
silicon carbide inverter. A main circuit is connected with a dual-
carrier modulation modulefor suppressing low-frequency
harmonic waves and a current polarity extraction module; a three-phase output current in the main circuit is inputted to the current polarity extraction module, and a three-phase fundamental wave current is obtained; the three-phase fundamental wave current and a three-
phase modulation wave are input into a double-
carrier modulation module for suppressing low-frequency
harmonic waves, and the module outputs driving signals of six
silicon carbide power switching devices to a main circuit, so a control loop of the whole double-
carrier modulation method for suppressing the low-frequency harmonic
waves of the high-switching-frequency
silicon carbide inverter is formed. A driving
signal is obtained by comparing double carriers with a modulation wave; a driving vacant region is added between upper and lower tube driving signals, a dead zone is obtained without additionally adding a switch-on
delay link, a control loop does not have a
delay link caused by switch-on
delay, the current polarity extraction module is added, the amplitude of double carriers is changed according to the current polarity, and the purpose of suppressing low-frequency harmonic waves of the high-switching-frequency
silicon carbide inverter is achieved.