Optimal Dual Constant Switching Frequency Control for CRM Buck-Buck/Boost PFC Converter

Ma, Chao; Yao, Kai; Wu, Chengjian; Chen, Jienan; Li, Lingge; Guan, Chanbo; Zhang, Zhen

doi:10.1109/ecce.2019.8913197

Cited by 3 publications

(1 citation statement)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To reduce switching loss in light-load and low-input-voltage conditions, the switching frequency is typically limited. The fixed ON-time method and switching frequency limit (SFL) method were suggested [7][8][9] to reduce switching loss under light-loads and low-input-voltages. The light-load efficiency can be improved to a certain level by limiting switching frequency.…”

Section: Introductionmentioning

confidence: 99%

CRM PFC Converter with New Valley Detection Method for Improving Power System Quality

2019

View full text Add to dashboard Cite

High efficiency and the power factor of power converters, are very important factors which can improve power system quality. In particular, research on improving low efficiency and the power factor at light-load conditions is essential. A boost power factor correction (PFC) is most commonly used in home appliances, with several operations being at light-loads; the critical conduction mode (CRM) control, fixed ON-time control, and valley detection technique are mainly applied to PFC control. However, these control schemes have the following problems: (1) low efficiency, due to sudden increase in switching frequency at light-loads; and (2) low power factor, due to switching ON-time limitation. This paper presents a new valley detection method that can actively extend the fixed ON-time to overcome these problems. Furthermore, a new valley point detection circuit and an ON-time extension signal generation circuit are proposed and described in detail. The superiority of the proposed method is demonstrated via comparison with two existing CRM PFC control methods, namely fixed ON-time (conventional#1) and existing valley detection (conventional#2) methods. Experimental results at 20% load demonstrate that the proposed method shows an efficiency improvement of 2.1%, compared with the fixed ON-time strategy; and a power factor improvement of 34.9%, compared with the existing valley detection strategy.

show abstract

Section: Introductionmentioning

confidence: 99%