A high-gain isolated DC–DC converter for renewable energy and electric vehicle applications: Long-term field validation and machine-learning-assisted performance assessment

High-gain isolated DC–DC converters are essential for interfacing low-voltage renewable sources such as photovoltaic (PV) modules and fuel cells with the high-voltage DC links required in electric vehicle (EV) traction and charging systems; however, existing high step-up designs typically rely on multi-switch or magnetically complex topologies and are validated only under short-term laboratory conditions, leaving critical gaps in long-term stability, spectral behaviour, and real-field performance. This work presents a low-cost isolated high-gain DC–DC converter capable of boosting 8.5–12 V inputs to as high as 700 V using a single high-frequency transformer and a simple SG3525–LM393 analogue voltage-mode control architecture, thereby reducing component count and implementation complexity while maintaining high step-up capability. Comprehensive laboratory characterization – including steady-state gain measurement, transformer flux balance verification, transient line/load disturbance evaluation, switching waveform inspection, and Fast Fourier Transform-based electromagnetic analysis – confirms continuous-conduction-mode operation with stable high voltage gain, minimal ripple, strong closed-loop regulation, and effective switching-noise suppression with harmonic amplitudes below 20 dB up to 5 MHz. Outdoor experiments conducted using a commercial solar PV panel further demonstrate the converter's robustness under naturally varying irradiance, reliably producing up to 700 V without auxiliary conditioning. To evaluate long-term behaviour, 990 operating samples collected over 90 days are analysed using a CatBoost regression model, achieving R 2 = 0.9705, MAE = 8.08 V, and RMSE = 11.22 V, thereby validating the suitability of machine-learning techniques for performance prediction and digital twin development in high-gain converters. The combined results establish that the proposed topology offers a unique combination of high voltage gain, excellent electromagnetic compatibility, low implementation cost, simplified analogue control, and experimentally verified long-term field reliability, making it a strong candidate for renewable-energy-powered EV systems, high-voltage DC-link applications, and distributed DC microgrid environments.