Single-switch dual output flyback DC/DC converter with time multiplexing control

Controlling two outputs with a single controlling switch in the power converter presents difficulties when two contrasting actions are required to raise one output and decrease the other. This paper studies the application of time multiplexing control (TMC) technique on power converters, with particular interest on single-switch multiple-output converters. Each output has its own feedback control circuit but these discrete feedback control loops are intermittently switched to regulate the duration of the 'on period' and 'off period' of the power switches. The inclusion of multiplexing logic to incorporate multiple controllers will improve the regulation of the auxiliary outputs and the main output within the tolerances required for electronic equipment. The output errors can be distributed between the outputs according to the time sharing factor of the time multiplexing logic controller. Simulation and experimental results on a single-switch dual-output flyback converter with and without TMC are reported to verify the error sharing capability of the proposed method. This control approach suggests a possible solution in improving the overall performance of the power supply in terms of output voltage regulation.

[1]  Bong-Hwan Kwon,et al.  Asymmetrical PWM half-bridge convertor with independently regulated multiple outputs , 2006 .

[2]  Wing-Hung Ki,et al.  Single-inductor multiple-output switching converters , 2001, 2001 IEEE 32nd Annual Power Electronics Specialists Conference (IEEE Cat. No.01CH37230).

[3]  Jai P. Agrawal.  Determination of cross regulation in multioutput resonant converters , 1990, Fifth Annual Proceedings on Applied Power Electronics Conference and Exposition.

[4]  Keng C. Wu.  Switch-mode power converters : design and analysis , 2006 .

[5]  Oscar Garcia,et al.  Optimizing the winding strategy of the transformer in a flyback converter , 1996, PESC Record. 27th Annual IEEE Power Electronics Specialists Conference.

[6]  Daniel W. Hart,et al.  Introduction to Power Electronics , 1996 .

[7]  Bong-Hwan Kwon,et al.  DC–DC Converter Using a Multiple-Coupled Inductor for Low Output Voltages , 2007, IEEE Transactions on Industrial Electronics.

[8]  Marian K. Kazimierczuk,et al.  Small-signal analysis of open-loop PWM flyback dc-dc converter for CCM , 1995, Proceedings of the IEEE 1995 National Aerospace and Electronics Conference. NAECON 1995.

[9]  Keyue Smedley,et al.  Cross regulation in flyback converters: analytic model and solution , 2001 .

[10]  Abraham Pressman,et al.  Switching Power Supply Design , 1997 .

[11]  Milan M. Jovanovic,et al.  Analysis and design of weighted voltage-mode control for a multiple-output forward converter , 1993, Proceedings Eighth Annual Applied Power Electronics Conference and Exposition,.

[12]  Dragan Maksimovic,et al.  Modeling of cross-regulation in multiple-output flyback converters , 1999, APEC '99. Fourteenth Annual Applied Power Electronics Conference and Exposition. 1999 Conference Proceedings (Cat. No.99CH36285).