Performance Evaluation of a Two-Phase Interleaved Transition Mode Boost Converter Power Factor Correction with Phase Shedding

This paper evaluated a design of a two-phase interleaved boost converter operating in transition mode for power factor correction (PFC) application. Phase shedding was employed to further improve the efficiency at light-load conditions. While the design was simulated to assess the stability of the converter, a 350W-prototype was built to verify the analyses. Results showed that the prototype had a worst line regulation of 0.388% and load regulation of 0.451% while the simulation of the converter stability had a gain margin of at least -6dB and phase margin of at least 45 degrees. While the power factor achieved was above 0.9 down to 20% load, the measured efficiencies peaked to 96.55% at nominal low-line and 97.92% at nominal high-line, making the PFC converter compliant to 80 Plus Gold and ErP Tier 1 Lot 3 requirements. As the phase shedding level was set to 20% of the nominal power, the measured efficiency remained above 91% down to 10% load at nominal lines. In terms of electromagnetic compatibility, the prototype passed the harmonic current emission standard EN61000-3-2 Class A requirement and EN55032 conducted EMI emission Class A requirement with sufficient margin. For these reasons, the design can be implemented for practical PFC applications.