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A new concept of high-voltage dc-dc power conversion is presented in this paper. Its distinctive feature lies in distributing the high input voltage asymmetrically between two primary-side series-connected switch pairs. This allows using switches of optimal ratings in their respective class: the low-voltage switch pair implemented with MOSFETs only, and the high-voltage switch pair implemented with insulated gate bipolar transistors (IGBTs) only. As the switches in a switch pair are of the same type and voltage rating, they are maximally utilized. With an active snubber on the secondary side of the isolation transformer, a hybrid zero-voltage-switching-zero-current-switching (ZCS) scheme, which is different from the zero-voltage and zero-current-switching technique, is realized and makes all IGBTs be zero-current-switched and all MOSFETs be zero-voltage-switched from very light load to full load condition with minimal circulating energy. The ZCS snubber energy is completely released to the load, leading also to a duty-cycle gain. The operating principles, dc analysis, and design guidelines will be given. A 2-kW, 1500/48-V experimental prototype has been built and evaluated. The measured efficiency of the converter is found to be 92.4% at the rated condition. [ABSTRACT FROM AUTHOR]

The switched-capacitor (SC) converters are ideal switching-mode power supplies for consumer portable electronic devices due to their nature of being light weight, small size, and high-power density. However, they suffer from a discontinuous input-current waveform with large di/dt, which leads to significant electromagnetic interference emission. This paper proposes a configuration of SC converters connected in parallel, with their inputs and outputs interleaved and adaptively controlled. The interleaving operation is performed by using an original type of control in which both the capacitors’ charging time TON and switching frequency are adjusted to get the line and load regulation. It is shown that, for a given range of variation of the supply voltage and load, there always exists a solution [TON, TS] that assures both output-voltage regulation and perfect interleaving. Experimental results are provided to validate the feasibility of the proposed scheme. Precise interleaving, and good line and load regulation are maintained for all the designated range, including the transient periods. [ABSTRACT FROM PUBLISHER]

Proposes a direct current (dc)-dc boost converter operating under zero-voltage-transition (ZVT) conditions. Information on ZVT-pulse-width modulation boost converter; DC analysis and time-domain simulation; Discussion on alternating current small signal analysis; What the proposed converter achieves.

Focuses on the development of zero-voltage-transition pulsewidth modulation (PWM) dc-dc converter by adding two active switches and three diodes to the structure of a quasi-resonant converter. Description of zero-voltage-transition technique; Analysis of a steady-state cycle and derivation of the dc voltage conversion ratio; Design considerations and practical challenges; Experimental results.

An exact algorithm for computing the transient response and the steady-state of DC-to-DC converters containing three reactive elements is proposed. The procedure is 'top-down' and automatable; it starts from a general, symbolic formulation and works down to the actual circuit. The method is applied to the analysis of the boost-buck converter operating in both continuous and discontinuous conduction modes. The basic circuit considered for the boost-buck converter contains mutual coupling between the input and output inductors, DC resistances of the inductors and on-resistance of the switching elements, but no load capacitor. The influence of the mutual inductance on the currents ripple is studied. The results are compared with the response, computed using a numerical method, of the boostbuck converter containing a load capacitor. [ABSTRACT FROM AUTHOR]