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Matching between low-voltage high-current capacity battery/fuel cell with high-voltage low-current motors in electric vehicles (EVs) requires paralleling-connection multi-stage power electronic converter with accurate modeling and control system. For high-voltage low-current drives of EVs with high-boosting/bucking gain, single-stage single-arm DC/DC converters suffer from unstable output voltage and the impractical choice of charging/discharging elements. Therefore, a multi-stage multi-arm DC/DC converter is researched to solve the problems of high boosting/bucking gain and minimized the voltage and current ripples. This paper presents parametric sizing, dynamic modeling, and analysis of all logical operational modes for a new high-gain DC/DC converter suitable for deployment in EV applications. The proposed topology composes of three-stage interleaved-input composed of cascaded two stages and double float-output as a third stage with bidirectional current capability. In this study, parametric design, and sizing for the three stages are performed according to the prerequisite ratings. Then, an analysis is conducted on rules of operating the DC/DC converter along with a discussion on considerations taken into account for such a critical design. An investigation of the dynamic behavior of the suggested DC/DC converter is carried out through a state-space model with switches’ states. Furthermore, a simulation and measurement-based validation of the derived mathematical models are conducted. The theoretical based analysis, design, and boosting gains are confirmed through a constructed and tested prototype given data on power supply and load utilization. A discussion on the choice of semiconductor equipment and reactive elements is provided for the proposed DC/DC converter. The experimental results show that the three stages can be used in a separate mode or in a cascaded booster.

Efficient heat dissipation in lithium-ion battery packs is crucial for safety, necessitating a thorough assessment of thermal performance during the design phase. This study utilizes Newman’s Pseudo two-dimensional (P2D) model and three-dimensional computational fluid dynamics to depict heat generation and dissipation. The main objectives include evaluating heat dynamics, establishing optimal temperature limits, and assessing State of Charge (SOC) and State of Health (SOH) estimations. The battery pack, configured in 6s2p, features plastic-wrapped cylindrical modules with air-filled domains, connected in parallel pairs with aluminum wires. Active materials comprise positive electrodes like Lithium Cobalt Oxide (LCO), Lithium Nickel Manganese Cobalt Oxide (NMC), Lithium Iron Phosphate (LFP), and Lithium Manganese Oxide (LMO), with graphite as the negative electrode and a separator (Lithium Hexa Fluoro Phosphate). Results indicate that air-cooled NMC electrode chemistry achieves a peak heat dissipation of 102.48W, maintaining an optimal temperature range of 21.3deg C to 32.8deg C. After 1000 cycles, the optimal temperature limit of 32.8deg C with an 80% capacity loss minimizes negative impacts during charge/discharge cycles. SOC and SOH remain at 100% and 80%, utilizing an 8Ah battery with a nominal voltage of 4.2V, and a 3.9-year life expectancy, addressing charge/discharge cycle issues.