Speed fluctuation suppression control of super-high-speed electric air compressors considering high-frequency electromagnetic excitation

With Silicon carbide metal-oxide-semiconductor field-effect transistor (SiC MOSFET) being used as inverters in super high speed electric air compressors (SHSEAC) controllers, the high switching frequency of SiC MOSFETs would cause serious electromagnetic interference (EMI) and ulteriorly lead to speed fluctuation. Suppressing load excitation can only reduce speed fluctuations at low speed, while optimizing electromagnetic parameters can reach the same effect at high speed. But neither of they can work at super high speed. So this paper suppressed high-frequency electromagnetic excitation brought by SiC MOSFET through its electronic control parameters. Firstly, we conduct dynamic modeling and analysis of SHSEAC and calculate its stability domain. Then, by designing a DDPG speed fluctuation suppression controller, the SiC MOSFET switching frequency is controlled within the stable domain. Finally, the EMI tests were conducted on SHSEAC at rated and peak speeds. The results showed that the DDPG speed fluctuation suppression controller not only meet the CISPR 25 standard in suppressing EMI, but also control speed fluctuations below 20rpm and reach the production-level.