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A novel high-conversion-ratio bidirectional dc–dc converter with coupled inductor is proposed in this paper. Compared with the bidirectional converters based on coupled inductor, this new topology can realize a higher step-up voltage gain and lower step-down voltage gain with a lower turn ratio in an appropriate duty cycle. In proposed converter, the windings of the coupled inductor are reversely connected to transfer energy from high voltage source or low voltage source. Then, a clamp capacitor is applied to reduce voltage stress on main switch; therefore, the conduction loss of the main switches can be reduced by using a low resistance switch, and the clamp capacitor can also recycle the energy of the leakage inductor in coupled inductor. Besides, the soft-switching technique is used to achieve zero voltage switching, so the efficiency can be further improved. The main circuit and its steady-state operating principle are analyzed in detail. Finally, a 25–200 V 200 W bidirectional dc–dc converter is implemented to verify its performance. [ABSTRACT FROM AUTHOR]

A new three-level dc/dc converter is proposed in this paper. The outstanding features of this converter are that it operates with zero-voltage-switching (ZVS) from full-load to near no-load conditions with hardly any circulating freewheeling primary current due to its novel structure. Since the converter has little primary circulating current and its switches are exposed to only half of the input voltage, it has high efficiency even under light loads. In this paper, the new converter is introduced, its basic operating principles are explained, its modes of operation and its steady-state characteristics are discussed in detail as is its design, and experimental results obtained from a prototype converter that confirm its feasibility are presented. [ABSTRACT FROM AUTHOR]

This paper presents a new isolated auxiliary current pump module (ACPM), to improve the dynamic response of dc–dc converters under load transients. The developed isolated ACPM can be used as a generic auxiliary module for both isolated and nonisolated step-up/step-down dc–dc converters. The isolated ACPM is a low-power bidirectional converter, designed with higher bandwidth and operates only during the load transients. The performance of the developed auxiliary power converter has been evaluated in conjunction with an interleaved boost converter as main converter, which suffers from poor dynamic performance due to inherent right half plane zero effect. A suitable control scheme is designed and implemented for interleaved boost converter operating in conjunction with proposed isolated ACPM. Load current injection circuit employed in the proposed control scheme eliminates the requirement of complex nonlinear control algorithms. The proposed control scheme in particular suits for current-mode controlled converters operating along with isolated ACPM. Experimental results for a 250-W 100-kHz interleaved boost converter prototype with ACPM are presented. The peak overshoot/undershoot and the transient recovery time are reduced significantly with the incorporation of developed isolated ACPM. [ABSTRACT FROM AUTHOR]

This paper compares different cascaded and multilevel topologies to interface supercapacitors to a dc bus in regenerative braking applications. It is shown that the modular multilevel dc/dc converter (MMC) can benefit from both reduced voltage and increased frequency across the inductor to reduce its weight and volume when using phase shifting modulation. The proposed control method is able to balance supercapacitor voltage while providing precise output current control. The converter topology and control method are validated with simulations and experimental results. [ABSTRACT FROM AUTHOR]