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This paper presents the design, modeling, and control of an isolated dc-dc three-port converter (TPC) based on an interleaved-boost full-bridge converter with pulsewidth modulation (PWM) and phase-shift control for hybrid renewable energy systems. In the proposed topology, the switches are driven by phase-shifted PWM signals, where both phase angle and duty cycle are the controlled variables. The power flow between the two inputs is controlled through the duty cycle, whereas the output voltage can be regulated effectively through the phase shift. The primary-side MOSFETs can achieve zero-voltage-switching (ZVS) operation without additional circuitry. Additionally, due to the ac output inductor, the secondary-side diodes can operate under zero-current-switching (ZCS) conditions. In this study, the operation principles of the converter are analyzed and the critical design considerations are discussed. The dynamic behavior of the proposed ac-inductor-based TPC is investigated by performing state-space modeling. Moreover, the derived mathematical models are validated by simulation and measurements. In order to verify the validity of the theoretical analysis, design, and power decoupling control scheme, a prototype is constructed and tested under the various modes, depending on the availability of the renewable energy source and the load consumption. The experimental results show that the two decoupled control variables achieve effective regulation of the power flow among the three ports. [ABSTRACT FROM PUBLISHER]

This paper presents a zero-voltage-switching (ZVS) full-bridge dc–dc converter combing resonant and pulse-width-modulation (PWM) power conversions for electric vehicle battery chargers. In the proposed converter, a half-bridge LLC resonant circuit shares the lagging leg with a phase-shift full-bridge (PSFB) dc–dc circuit to guarantee ZVS of the lagging-leg switches from zero to full load. A secondary-side hybrid-switching circuit, which is formed by the leakage inductance, output inductor of the PSFB dc–dc circuit, a small additional resonant capacitor, and two additional diodes, is integrated at the secondary side of the PSFB dc–dc circuit. With the clamp path of a hybrid-switching circuit, the voltage overshoots that arise during the turn off of the rectifier diodes are eliminated and the voltage of bridge rectifier is clamped to the minimal achievable value, which is equal to secondary-reflected input voltage of the transformer. The sum of the output voltage of LLC resonant circuit and the resonant capacitor voltage of the hybrid-switching circuit is applied between the bridge rectifier and the output inductor of the PSFB dc–dc circuit during the freewheeling phases. As a result, the primary-side circulating current of the PSFB dc–dc circuit is instantly reset to zero, achieving minimized circulating losses. The effectiveness of the proposed converter was experimentally verified using a 4-kW prototype circuit. The experimental results show 98.6% peak efficiency and high efficiency over wide load and output voltage ranges. [ABSTRACT FROM AUTHOR]

This paper proposes a new zero-voltage switching (ZVS) pulse width modulation (PWM) three-level (TL) full-bridge (FB) dc–dc converter, which is composed of a TL FB converter and a TL half-bridge (HB) converter. It is well suited for high input voltage and high-power applications. The proposed topology has the following attractive features: off-state voltage on all switches in the circuit is only half of the input voltage; full input voltage is utilized on the load for the whole operating range; TL output waveform is achieved, which significantly reduces the requirements for the input and output filters; simple switching scheme can be used to control the output voltage in wide range. The converter can achieve ZVS for all power switches in wide load range and even at light load condition; furthermore, less conduction loss is added to achieve soft switching. The operation and important analysis of the proposed converter are given. Experiments are carried out to validate the proposed converter, and efficiency curves are tested and given. [ABSTRACT FROM AUTHOR]

This paper presents a new soft-switching dc/dc converter for high-input-voltage applications. Two half-bridge converters connected in series with interleaved asymmetric pulsewidth modulation (PWM) are adopted to limit the voltage stress of each power switch at one-half of the input dc bus voltage. In each half-bridge converter, two asymmetrical dc/dc circuits with the same active switches are connected in parallel at the output side to share the load current and reduce the current stresses of the secondary windings and rectifier diodes. Since two half-bridge converters are operated with interleaved PWM, the output ripple currents partially cancel each other so that the resultant ripple current at the output side is reduced. Active switches in the proposed circuit can be turned on at zero-voltage switching during the transition interval due to the resonant behavior by the output capacitance of MOSFETs and the leakage inductance of transformers. Experiments based on a laboratory prototype with 960-W rated power are provided to demonstrate the performance of the proposed converter. [ABSTRACT FROM PUBLISHER]

In this paper, a novel three-phase soft-switching inverter is presented. The inverter-switch turn on and turn off are performed under zero-voltage switching condition. This inverter has only one auxiliary switch, which is also soft switched. Having one auxiliary switch simplifies the control circuit considerably. The proposed inverter is analyzed, and its operating modes are explained in details. The design considerations of the proposed inverter are presented. The experimental results of the prototype inverter confirm the theoretical analysis. [ABSTRACT FROM AUTHOR]