Abstract: This research presents a full-bridge DC-DC converter that utilizes zero-voltage zero-current switching (ZVZCS), structured around a dual-transformer configuration with two output filter capacitors. The converter is engineered for seamless integration with DC collection systems in medium-voltage renewable energy applications, where stability, adaptability, and efficiency are of utmost importance. The primary switches function under a pulse width modulation (PWM) strategy with a fixed duty cycle to control voltage and power output. Under full load conditions, the main full-bridge circuit provides the majority of the power and achieves zero-voltage switching (ZVS) due to the meticulous design of the main transformer’s turn ratio, which significantly reduces switching losses. To support this, an auxiliary circuit implements ZVZCS and manages a minor portion of the power. Efficiency can be further enhanced by fine-tuning the auxiliary transformer's turns ratio, which balances power contribution while minimizing conduction losses. In addition to traditional control techniques, a fuzzy logic controller is integrated to improve real-time adaptability. The fuzzy controller dynamically modifies control signals in response to fluctuating input voltage, load conditions, and switching timing, enabling the converter to sustain soft-switching conditions even amidst transient disturbances or parameter variations. It supersedes inflexible threshold-based decision-making. Utilizing linguistic principles, this approach facilitates a more intelligent management of system nonlinearity and uncertainty. The design features, the definition of the fuzzy rule base, and the optimization strategies for the suggested converter are thoroughly detailed. In order to confirm the efficacy of the proposed method and to validate the simulation outcomes, a prototype rated at 200 V / 2 kv / 3 kw has been constructed and evaluated. The findings indicate enhanced switching performance, improved thermal management, and increased overall efficiency as a result of the integrated application of ZVZCS and fuzzy logic control.

Downloads: | DOI: 10.17148/IJIREEICE.2025.131019