A dynamic controller, based on the Stability Transformation Method (STM), has been used to stabilize unknown and unstable periodic orbits (UPOs) in dynamical systems. An advantage of the control method is that it can stabilize unknown UPOs. In this study, we introduce a novel control method, based on STM, to stabilize UPOs in DC-DC switching power converters. The idea of the proposed method is to apply temporal perturbations to the switching time. These perturbations are calculated without information of the locations of the target orbits. The effectiveness of the proposed method is verified by numerical simulations and laboratory measurements.

A multiple-input switched-capacitor DC-DC converter which can realize long battery runtime is proposed in this letter. Unlike conventional converters for a back-lighting application, the proposed converter drives some LEDs by converting energy from solar cells. Furthermore, the proposed converter can charge a lithium battery when an output load is light. The validity of circuit design is confirmed by theoretical analyses, simulations, and experiments.

This paper studies two kinds of simple switched dynamical systems with piecewise constant characteristics. The first one is based on the single buck converter whose periodic/chaotic dynamics are analyzed precisely using the piecewise linear phase map. The second one is based on a paralleled system of the buck converters for lower voltages with higher current capabilities. Referring to the results of the single system, it is clarified that stable multi-phase synchronization is always possible by the proper use of the switching strategies and adjustment of the clock period. Presenting a simple test circuit, typical operations are confirmed experimentally.

This paper studies nonlinear dynamics of a simplified model of multiple-input parallel buck converters. The dynamic winner-take-all switching is used to achieve N-phase synchronization automatically, however, as parameters vary, the synchronization bifurcates to a variety of periodic/chaotic phenomena. In order to analyze system dynamics we adopt a simple piecewise constant modeling, extract essential parameters in a dimensionless circuit equation and derive a hybrid return map. We then investigate typical bifurcation phenomena relating to N-phase synchronization, hyperchaos, complicated superstable behavior and so on. Ripple characteristics are also investigated.

This paper describes the effect of power line inductance and smoothing capacitance on a single-phase AC power supply system. Voltage fluctuations were calculated when the three main types of smoothing circuit (capacitor input, choke input, and power factor correction types) were used and the magnitude of power line inductance and smoothing capacitance were changed. First, we show the difference in voltage fluctuation in the case of constant resistance and negative resistance in a DC-DC converter. Second, we show the waveforms for which the power line inductance affects the voltage fluctuation of the AC power supply system. Finally, we propose the boundary condition for the power line inductance affecting the voltage fluctuation of the AC power supply system and estimate AC power supply system stability.

All power electronic circuits with state feedback controlled switching can be described as nonlinear time-varying dynamical systems. The occurrence of chaos--where the ripple waveforms become aperiodic--is common in such systems. It is shown here that this natural phenomenon may be effectively used in minimizing electromagnetic interference problems in power electronic circuits. This is because converters operating chaotically tend to spread the spectrum, thereby reducing the interference power at any target frequency. We also present the ways of calculating the average values of state variables and the power spectrum under chaotic operation.

In this letter, introducing a highly accurate model for a real current mode DC-DC converter, an innovative design strategy is proposed in order to optimize circuit behavior in cases in which chaotic effects are present.