Speed Fluctuation Suppression Control of Super-High-Speed Electric Air Compressors Considering High-Frequency Electromagnetic Excitation

With silicon carbide metal-oxide-semiconductor field-effect transistors (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 speeds while optimizing electromagnetic parameters can reach the same effect at high speeds. But neither of them can work at super high speed. So, this article focuses on the suppression of high-frequency electromagnetic excitation brought by SiC mosfet through its electronic control parameters. First, we conduct dynamic modeling and analysis of SHSEAC and calculate its stability domain. Then, by designing a deep deterministic policy gradient (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 meets the CISPR 25 standard in suppressing EMI but also controls speed fluctuations below 20 r/min and reaches the production level.