This paper presents an isolated high-frequency (HF) multi-port dc/dc converter for PV interfacing systems. In the proposed multi-port converter, an HF transformer with multiple input windings and single output winding is utilized. Each input port is based on a proposed two-quadrant inverter topology which connects a PV module to the HF transformer. The output port is tied to a dc-bus using a rectifier. The proposed two-quadrant inverter topology prevents current flow from the ac-side to the dc-side. This action prevents circulating currents between different ports. Each two-quadrant inverter is controlled to harvest maximum power from its associated PV module. The analysis and operation scenarios of the proposed multi-port converter are discussed. PSCAD/EMTDC software package is used to simulate the proposed PV interfacing system to investigate the operation of the proposed multi-port converter topology and to examine the dynamic system behavior. In addition, an experimental prototype is developed to validate the operation scenarios of the proposed multi-port dc/dc converter and to examine the performance of the presented PV interfacing system.

This paper proposes a soft switching isolated phase-shifted full-bridge DC-DC converter using active clamping circuit for fuel cell power generation applications. An active clamping circuit is added to the primary side of the high frequency transformer to clamp voltage spikes and recycle the energy trapped in the leakage inductor. The presented converter has the advantages of a small number of components, simple circuit configuration, reduced voltage stress and a wide input voltage range. The soft switching operation of the presented converter allows for high switching frequency with high power conversion efficiency. Analysis, simulation, operation principles and a design example of the proposed converter are conducted using PSIM simulation software. Various operation modes and their equivalent circuits during each operating cycle are investigated in detail. A down scale 1.2 kW of simulation and 350 W of experimental prototypes are developed to validate the wide output voltage gain of the proposed converter employing a wide range low input voltage to maintain a regular output voltage with a maximum power conversion efficiency of 98% and 96.5% at full load are achieved due to the ability of the proposed converter to minimize switching losses rated power conditions. The results from simulation and experimentation are used to validate the operation and modeling and to strengthen the viability and efficiency of the suggested converter topology.

This paper introduces an off-board charger designed for electric vehicles (EVs), capable of charging a wide range, from low-voltage to high-voltage EVs. The charger utilizes an interleaved AC-DC converter, where each supply phase connects to an interleaved buck-boost converter via an isolating transformer, followed by a bridge rectifier. To maintain balanced current operation, the control strategy incorporates three distinct control loops. The outer loop is responsible for regulating the output voltage of the charger, while the middle cascaded loop manages the battery charging current. The final control loop ensures that the grid current remains sinusoidal with a unity power factor. Additionally, a phase shift scheme for the interleaved switches has been proposed to minimize output current ripple. Moreover, an inductive current equalizer has been implemented to address varying current stress on the interleave inductances caused by mismatched inductance values. Furthermore, the charger features a modular design that allows it to function effectively even in the event of a failure in one of the boost submodules. The performance of the charger, along with its ability to operate as a level ‘3’ charger, has been evaluated using PSCAD/EMTDC simulation software and a scaled-down experimental prototype.