Design and verification of switching frequency dual chaos modulator for EMI reduction in super-high-speed electric air compressor controllers

SiC MOSFETs with high switching frequency characteristics have been applied to super-high-speed electric motors (SHSEAC) controllers to meet the control requirements of SHSEAC. However, the high-speed switching of SiC MOSFETs induces high-frequency oscillations, resulting in severe electromagnetic interference (EMI). Spread spectrum technique is widely used to suppress EMI, which uses mapping to generate chaotic sequences and modulate them. However, the existing mapping models whose generated sequences have poor stability and randomness, and traditional SVPWM have poor immunity to interference. To address the above problems, this paper first constructs a Logistic-Tent composite mapping model and then proposes a dual chaotic modulation algorithm based on amplitude and frequency. Finally, a switching frequency dual chaotic space vector pulse width modulation (DC-SVPWM) modulator is designed. And its EMI suppression effect is compared with different modulators. The results show that the amplitude of the EMI voltage power spectrum of the Logistic-Tent chaotic sequence is reduced by 20.8 dB compared to the Logistic chaotic sequence. The DC-SVPWM modulator reduces the EMI voltage power spectrum of the fixed-frequency SVPWM modulator by the maximum of 29.72 dB, so that the designed DC-SVPWM is able to reduce EMI effectively.