Numerical Investigation of Transient Heat Dissipation Using Solid-Fin-Enhanced Phase-Change Material in High-Voltage Connectors

High-voltage (HV) cables and connector terminals in electric vehicles (EVs) are susceptible to high current loads. Due to high current, there is excessive temperature rise near the terminals and crimping region inside the connectors. Excessive temperature beyond critical limits may pose risks to connected components and compromise passenger safety. Conventional cooling approaches are often energy-intensive and rely on active thermal management systems, which may not always be suitable for high power applications. Therefore, there is a need for a localized, rapid, and reliable passive thermal management strategy that can be retrofitted into existing connector designs with some structural modifications that would provide significant safety enhancements. This study proposes a novel approach by incorporating phase-change material along with solid fins inside the connector. The PCM has been placed co-axially surrounding the terminals of the connectors and enclosed inside a casing to ensure no direct contact with the connector components. The fins are also enclosed inside the same casing with projections going into the PCM. The PCM acts as heat storage unit, delaying the time for the peak temperature to rise and the fins distribute the heat rapidly inside the PCM. The objective is to maintain the terminal temperature below 100°C with 125 A current rating. A 3-D transient thermal analysis was performed on a CAD model encompassing PCM with solid fins inside the female connector. A comparative analysis between a traditional connector to a fin enhanced PCM connector showcased a drastic delay in temperature rise (acting time) by 115 seconds. Furthermore, the slope of rise in temperature decreased significantly beyond 100°C, slowing the rapid heating of the terminals. Thus, a passive sustainable system is designed for localized thermal management of HV Connectors.