Analysis and design of the DCM operation boost PFC converter with magnetic control

Abstract

In this study, a novel control scheme for the discontinuous conduction mode (DCM) operation boost power factor correction (PFC) converter is proposed. Instead of adopting constant duty cycle (CDC) control, variable duty cycle control or frequency control, the magnetic control or variable inductor control is adopted to regulate the output voltage, so CDC and switching frequency can be implemented for the switch. The operation principles of the proposed control scheme are discussed in details, and the analysis of the input current, power factor, boundary condition and design considerations are presented. In addition, the modelling of the variable inductor and the DCM operation boost PFC converter with variable inductor are derived in detail, by linearising the non-linear components, the model of the DCM operation boost PFC converter with the proposed control scheme can be obtained, and the design procedures of the PI controller are presented. Finally, a 70 W experimental prototype is built to verify the theoretical analysis and the effectiveness of the proposed control scheme.

Analysis and design of LLC resonant converter with variable magnetising inductance control

“…Based on the converter power level and switching frequency, the EE42 magnetic core with N87 ferrite material is selected to build the variable transformer, and the air gap is 0.5 mm. Based on the datasheet [26], the inductance factor A L = 603 nH can be obtained. Then, the required number of turns to reach the maximum magnetising inductance can be calculated based on the following equation [27]: From (18), N pri = 24.8 can be calculated. To leave some margin, in practice N pri = 26 and N sec = 6 are selected.…”

Split Parallel Semibridge Switching Cells for Full-Power-Range Efficiency Improvement

“…It should be noted that the TCM is not fully applicable on semi-bridge switching cell due to inductor current unipolarity. Another alternative is the discontinuous current mode (DCM) [16] [17] in which the inductor current is zero for a portion of the switching cycle This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication.…”

Wide voltage gain range application for full‐bridge LLC resonant converter with narrow switching frequency range

“…To solve the above‐mentioned problems, many different approaches have been proposed. Generally, the existing solutions can be categorised into the following three groups: (i) accurate design methodologies [10–13]; (ii) hybrid modulation strategies [14–20]; (iii) modifications on traditional LLC topology [21–25] or topology morphing control strategy [26–29].…”

“…In addition to the traditional pulse frequency modulation (PFM), as summarised in [14], LLC resonant converters also have other modulation strategies, like phase shift modulation (PSM), pulse width modulation (PWM), and resonant frequency modulation (RFM) [15–18]. By combining these different modulation strategies, hybrid modulation strategies can be proposed to narrow the operating switching frequency range in the wide voltage gain range applications.…”