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This paper contributes to the analysis and development of a new power electronics system for bidirectional wireless power transfer (WPT). The major focus is the analysis and implementation of a new current-fed resonant topology with current-sharing and voltage-doubling features. A new bidirectional WPT system with current-fed half-bridge voltage-doubler circuit is proposed and analyzed with series–parallel and series resonant networks. Traditionally used parallel L–C resonant tank in transmitter circuit with current-fed WPT topology causes higher voltage stress across the inverter devices to compensate the reactive power consumed by the loosely coupled coil. In the proposed topology, this is mitigated by adding a suitably designed capacitor in series with the transmitter coil; thus, developing a series–parallel CLC tank. Detailed analysis and design is reported for both grid-to-vehicle and vehicle-to-grid operations. The power flow is controlled through variable frequency modulation. Soft switching of the devices is obtained irrespective of the load current. A proof-of-concept experimental hardware prototype rated at 1.2 kW is developed and tested. Experimental results are presented to verify the analysis and demonstrate the performance of the system with bidirectional power flow. [ABSTRACT FROM AUTHOR]

Impulse commutation obtains zero current commutation of devices in a circuit with a short resonance impulse using a simple resonant tank. This concept has been studied, extended, and implemented for a three-phase push–pull current-fed single-inductor topology to achieve soft commutation and device voltage clamping solving the traditional issue of device turn-off voltage overshoot. The push–pull topology is attractive owing to single inductor, all common source devices connected to common supply ground, and reduced gate driving requirements. Detailed operation, analysis, and design of this topology have been reported with impulse commutation. With a small resonant tank and partial resonance, impulse commutation procures merits of voltage clamping, low circulating current, and load adaptive zero-current switching of the devices. Variable-frequency modulation regulates load voltage and maintains the impulse commutation with source voltage variation. Experimental results on a 1-kW proof-of-concept hardware prototype are demonstrated to observe the operation, performance, and verify the proposed concept and claims. [ABSTRACT FROM PUBLISHER]

This paper proposes a current-fed non-isolated soft-switching bidirectional dc/dc converter for interfacing energy storage to dc microgrid. The proposed converter employs a current-fed half-bridge boost converter at front-end followed by an LCL resonant circuit to aid in soft-switching of semiconductor devices. A voltage doubler at output is selected to enhance the gain by $2 \times $. The LCL resonant circuit also adds a suitable voltage gain. Therefore, the topology offers overall high voltage gain without transformer or large number of multiplier circuits. For buck operation, high side voltage is first divided by half with capacitor divider to gain higher stepdown ratio. Converter operates at high switching frequency to realize merits of reduced magnetics and filters. Zero voltage turn-on is achieved for all switches and zero current turn-on and turn-off is achieved for all diodes for both buck/boost operation. Voltage across switches and diode is clamped naturally without any external snubber circuit. Detailed analysis and design have been proposed. A proof-of-concept experimental prototype rated at 350 W has been designed, developed, and tested in the laboratory to demonstrate the performance and validate the claims of the converter for wide load variation. [ABSTRACT FROM AUTHOR]

A current-fed three-phase push–pull bidirectional dc–dc converter is proposed with unique features of natural zero current commutation and natural device voltage clamping. The proposed topology is suitable for uninterruptible power supply, storage, renewable energy sources, and interfacing two dc buses of 48- and 380-V dc buses in a dc microgrid. The proposed converter implements a novel and innovative modulation that results in natural commutation with zero current switching (ZCS) and device voltage clamping of low voltage side (LVS) current-fed devices, and zero voltage switching (ZVS) turn-on of high voltage side (HVS) voltage-fed devices. It eliminates the use of passive/active clamp circuits to mitigate the turnoff voltage spike across the devices, a traditional problem associated with current-fed topologies. Additionally, the higher ripple frequency reduces the volume of the transformer and the input inductor, making it suitable for high-power applications. The detailed modulation scheme, steady-state operation, and analysis, design, and soft-switching conditions have been explained. Simulation results obtained using PSIM 9.3 have been illustrated to verify the modulation, analysis, and proposed design. Experimental results have been demonstrated for full load (1 kW), half-load (500 W), and 20% load conditions on a proof-of-concept hardware prototype to validate the claims and performance. The efficiency is plotted against various load conditions for a wide range of battery voltage variation (40–59 V). Peak efficiencies of 95.8% and 93.8% are obtained at half-load condition for an input voltage of 59 V and nominal voltage (48 V), respectively. The experimental results for battery charging (reverse direction) using dual phase-shift plus pulsewidth modulation are given. The ZVS of HVS switches and the synchronous rectification of LVS active switches are shown through experimental results. [ABSTRACT FROM AUTHOR]

An impulse-commutated current-fed three-phase dc/dc converter is proposed. It is a three-inductor current divider topology that reduces the current stress of the components. The proposed converter attains zero current switching (ZCS) of the semiconductor devices via impulse commutation utilizing the circuit paracitics. The devices' voltage is clamped at Vo/n. Voltage clamping and zero-current commutation of devices are load independent. Load voltage is regulated by employing variable-frequency modulation. The current-fed topology with inherent boost ability simplifies the transformer design by reducing the required turns ratio. Rectifier diodes also commutate with ZCS without ringing and eliminate the need for a secondary snubber. A comprehensive study of the proposed converter together with the experimental results obtained from a laboratory prototype of 1 kW have been presented to validate the claims and to evaluate the converter's performance. The proposed converter is suitable for low-voltage high-current applications requiring high voltage gain. It inherently offers short-circuit protection. [ABSTRACT FROM AUTHOR]