Small-signal characterization of the forward-flyback converters with active clamp

Modelling and Control of Active Clamp Forward Converter with Centre Tap Transformer

“…While the power-stage operation and dc characteristics of ACFCC have already been given in [15,16], the compensator design and closed-loop analysis of ACFCC are the subject of current research works, because the small-signal dynamics of ACFCC is markedly different from those of conventional forward converters due to the presence of the clamp circuit in the energy transfer process during the off period. Though the small-signal dynamics of ACFCC using switch model presented in previous publication [9] provides theoretical background for open-loop analysis, however, development of mathematical model for small-signal analysis, controller design, and closedloop performance evaluation are not yet fully explored. This paper presents the theoretical and practical details involved in the dynamic modelling, control design, open-loop, and closed-loop analyses of ACFCC.…”

“…In order to deliver a high current with a small ripple component, the active clamp forward converter consists of transformer with centre tap at secondary side leading to a quasi-integrated magnetic. The quasi-integrated magnetic facilitates the reduction in the size of output filter inductor, reduced core loss, and better utilization of core air gap [9].…”

High-performance front-end converter for avionics applications

“…In addition, a more accurate method of analysis that can also be applied to other active-clamped converters is presented. Earlier attempts of understanding the small-signal dynamics of active-clamped converters [11][12][13] do not lead to a solution for the proposed converter. Hence, an averaged-switch converter model has been derived and experimentally verified.…”

Analysis, Design and Implementation of an asymmetrical half-bridge converter

“…There are seven operating stages during one switching period in the adopted half-bridge ZVS flyback converter with synchronous rectifier. tI t2 t3 t4 (2) Based on the voltage-second balance across the primary inductance, one can obtain the clamp capacitor voltage is vc=Dvi, (3) where D is the duty cycle of switch S1. When switch S2 turns on, the transformer primary side voltage v'p equals -vyn where n is turn ratio between the second side winding turn and the primary side winding turn.…”

“…The passive RCD clamp circuit can be used to reduce the energy stored in the leakage inductance so that the voltage stress of switch can be reduced. The flyback converters with resonant techniques [1][2][3] were proposed to increase the system efficiency and reduce the switching losses of active switch. However, the voltage stress of active switch in the resonant flyback converter is too high especially for the high input voltage.…”