Electric Propulsion for Unmanned Underwater Vehicles: Motor Design, Energy and Thermal Management, Control, and Charging

Unmanned Underwater Vehicles (UUVs) are used for ocean research and underwater exploration along with military applications. The underwater environment that UUVs operate in poses unique design constraints that govern the design of the electric propulsion system of UUVs. Such designs must be oriented around high torque generation, extending mission duration, and maintaining optimal temperatures. This paper reviews developments to address these parameters around UUV design. Concepts for motor designs, energy management, thermal management, control systems and charging infrastructure centered around the environmental constraints are presented. This paper adopts a sustainability lens throughout to highlight impacts that could be overlooked. Research gaps are identified in each area, including the reliance on simulation-only validation, the absence of cooling studies for transverse flux motors, and the limited work on renewable recharging during deployment. There has yet to be a review paper which overviews UUV electric propulsion with a scope as broad as this paper while featuring the environmental impacts and sustainability of the content covered. From the information in this paper, UUV electric propulsion research advances high performance and energy efficient designs often only in one technical dimension while sustainability aspects are also concurrently pushed.