Innovative IGBT-based charging systems for improved submarine battery management

Abstract

This innovative charger-discharger utilizing the technology of IGBT, designed for lead-acid submarine batteries, is discussed in the present manuscript. Within the system, a bidirectional DC-DC converter links the Battery-Ultra Capacitor system, ensuring Depth of Charge and State of Charge are controlled very precisely to avoid sulfation. Over 12 months of field tests, IGBT chargers succeeded in obtaining 93 % charge efficiency; at its turn, the one with linear charging, provided by traditional rectifiers, for instance, was already 85 %, meaning it literally snatched huge energy savings and was cost-wise beneficial. The system showed a better thermal stability at just 2.3 °C standard deviation fluctuation. As per the regression, if the efficiency is improved by 1 %, the life of the battery is extended to nearly 0.53 months. The result was further confirmed by ANOVA, and the fall of batteries was predicted with 92 % accuracy with the help of a Random Forest model. As such, on balance of performance, cost, and reliability, the most appropriate technology for the submarine application is that of the IGBT rather than the SiC MOSFETs or GaN transistors. It conserves power and gas generation for improved operational efficiency and higher battery life, and improves overall sustainability.