Efficiency and Conducted EMI evaluation of a single-phase power factor correction boost converter using state-of-the-art SiC MOSFET and SiC diode

Abstract

SiC-based diodes and MOSFETs switch extremely quickly with low conduction losses. Thus, from the perspective of efficiency, such devices are ideal for a continuous conduction mode (CCM) boost power factor correction (PFC) converter. However, the circuit parasitic becomes alive while switching with high dv/dt and di/dt values, which necessitates the need for EMC compliance measurements. Employing the best available low-loss SiC MOSFET and diode, in this study, a 1 kW PFC boost converter prototype was designed, developed, and evaluated with the objective of quantifying the efficiency and electromagnetic compatibility signature. The efficiency is evaluated through two approaches, namely, a circuit simulation and a laboratory measurement. The electromagnetic interference (EMI) is monitored using LISN and EMC analyzer. To maximize the efficiency, a fast, clean switching of the SiC is necessary. Utilizing a low-parasitic printed circuit board design approach and switching the selected low-loss SiC devices with a 0 Ω external gate drive resistance, this PFC boost yields a peak efficiency of 97.2% at full rated power when switched at 250 kHz. Furthermore, the EMI noise was measured at 66 and 250 kHz. It was found that the same EMI filter size satisfies the CISPR 11 Class B conducted EMI limit at both switching frequencies with a noise of approximately 10 dB higher at 250 kHz. As the main contribution of the present study, the best case efficiency and worst case EMI are evaluated in this study.