For single-inductor dual-output (SIDO) DC-DC converter operating in continuous conduction mode (CCM), load variation of one output will affect the voltage of the other output, i.e. there exists cross regulation between its two outputs. To suppress the cross regulation of SIDO DC-DC converter operating in CCM, a novel ripple based control technique, called as capacitor current ripple (CCR) control technique, is proposed in this paper. The operation principle of SIDO CCM buck converter and the proposed CCR control technique are presented. The small signal model of CCR controlled SIDO CCM buck converter is established by state space averaging method. Bode plots based on small signal model show that the proposed CCR controlled SIDO CCM buck converter significantly reduces cross regulation and improves the transient performance compared with peak current mode (PCM) controlled SIDO CCM buck converter. In addition, the effect of the variation of loads on the stability of the proposed CCR controlled SIDO CCM buck converter is analyzed by eigenvalue analysis. Finally, experimental results are provided to verify the analysis results.

Peak current mode (PCM) control has been widely used for the control of switching dc-dc converters due to its excellent transient performance. With the development of single-inductor dual-output (SIDO) dc-dc converters, PCM control technique is introduced to the control of SIDO dc-dc converters. Conventional PCM buck converter has only one reference current, with two inductor current borderlines are used to divide the operation modes of inductor current. However, PCM SIDO buck converter has more inductor current borderlines as it has one more reference current than that of PCM buck converter. In this paper, inductor current borderlines of PCM SIDO buck converter are investigated, and unified discrete iterative model of PCM SIDO buck converter is established. The effect of the difference of reference currents, initial inductor current and input voltage on the stability of PCM SIDO buck converter has been discussed by using bifurcation diagrams. The study results show that the stability of PCM SIDO buck converter is sensitive to the difference of reference currents, initial inductor current and input voltage. The stability boundary of the difference of reference currents, stability region of initial inductor current, and stability boundary of input voltage are derived. Lyapunov exponent and experimental results are carried out to verify the theoretical analysis results.

It is well-known that the ripple control technique benefits from fast load transient response and small cross regulation for single-inductor dual-output (SIDO) dc–dc converter. However, existing capacitor current ripple (CCR) controlled SIDO buck converter suffers from incomplete operation state and single switching path. Thus, it has a limited stable load range. In order to extend the stable load range and suppress cross regulation of SIDO buck converter in continuous conduction mode (CCM), a novel ripple control technique, called as capacitor current and capacitor voltage ripple (CCVR) control, is proposed in this article. The operation principle of the proposed CCVR controlled SIDO CCM buck converter is presented, and its discrete iterative map model is established. Furthermore, the stability and stable load range have been discussed by using bifurcation diagrams. Based on the established small signal model, Bode plots are given to show the performance in suppressing cross regulation. Finally, simulation and experiment results are provided to verify the theoretical analysis. It shows that the proposed CCVR control technique can be applied to SIDO CCM buck converter to extend its stable load range and suppress its cross regulation.

To analyse the stable operation range with varied input and output voltages, bifurcation behaviours and operation region of current‐mode‐controlled single‐inductor dual‐output (SIDO) boost converter are investigated. The inductor current borders and one‐dimensional discrete‐mapping model are deduced firstly. On the basis of the model, the bifurcation diagram and corresponding Lyapunov exponent spectrum are analysed. Two transition conditions and boundary equations of the converter are derived, where its working state transits from stability to instability, and its operation mode shifts from continuous conduction mode (CCM) to discontinuous conduction mode (DCM). The operation region with different circuit parameters can be estimated and divided through the parameter space maps, which is significant for the design of circuit parameters and stability control. Time‐domain simulations and experimental results are presented to verify the theoretical analysis results. The research results show that the three kinds of bifurcation behaviours including period‐doubling bifurcation, border collision bifurcation, and tangential bifurcation exist in the current‐mode‐controlled SIDO boost converters. Different from the previous works, the SIDO boost converter has a particular bifurcation trend when border collisions occur. The trend includes that operation mode shifts from CCM to DCM and then backs to CCM, and system period increases or decreases doubly.

A dual-carrier modulation technique is proposed to improve the performance of the half-bridge resonant converter in this paper. By alternately using two different sawtooth waveforms as a carrier, the dual-carrier modulation combines the characteristics of both variable frequency modulation and fixed-frequency modulation. According to the structure of modulator, there are two kinds of dual-carrier modulation: type A and type B. Type A dual-carrier modulation is suitable for resonant converters operating in inductive region to achieve a wide zero voltage switching (ZVS) range, while type B dual-carrier modulation is preferred for resonant converters operating in capacitive region to obtain a wide zero current switching range. By utilizing both switching frequency modulation and duty ratio modulation, the proposed dual-carrier modulation not only extends soft-switching range of the resonant converter, but also reduces switching frequency variation range. In order to verify the benefits of the proposed modulation, a 500-W dual-carrier modulated LCC resonant converter operating in inductive region is designed and built. Simulation and experimental results show the prototype achieves ZVS soft-switching operation for 200–400 V input voltage and 100–500 W output power, with only about 10 kHz switching frequency variation.