Cycle Estimation-Based Deadbeat Interleaving Method for Critical Mode Totem-Pole Rectifiers

Abstract

In totem-pole boost rectifiers, critical mode (CRM) operation is associated with varying switching frequency and duty ratio. This makes it difficult to precisely manage the phase shift between interleaved phases. To address this challenge, we propose a novel interleaving method based on cycle estimation. The switching cycle is estimated by predicting the zero-crossing instants. By analyzing the input current ripple, the relationship among phase shift, duty ratio, and switching cycle can be derived. Therefore, after frequency transition, the phase shift and switching cycle can be updated to provide a precise deadbeat control. Different from conventional methods, the proposed interleaving methods can dynamically modulate the phase shift without the usage of high-speed current sensors. A 1.6 kW, 160–950 kHz GaN-based, two-phase interleaved totem-pole rectifier is designed as the proof of concept. 98.24% peak efficiency and 0.995 power factor are captured. Experimental results effectively validate the interleaving method.