Optimized design of unified platform for light industrial applications using SiC MOSFETs and mixed DC-link capacitors

Inhalt:
A unified platform for single- and 3-phase AC input for light industrial applications is feasible by using SiC MOSFETs and diodes in power factor correction (PFC) stage in order to keep the DC-link voltage constantly at 540 V. System output power can be increased from 5.25 kW for commercial fridge inverter applications to 7 kW for commercial air-conditioning applications with single-phase input, by changing the PFC SiC MOSFET with RDS(on) from 30 mOmega to 14 mOmega. The combination of paralleled electrolytic capacitors and film capacitors in DC link significantly reduces capacitor quantity and PCB space. The risk of anti-resonance of paralleled capacitors is influenced by equivalent series resistance (ESR) and stray inductance, and can be prevented when the ESRof the electrolytic capacitor is higher than the anti-resonant characteristic impedance.