Design Optimization and Analysis of Consequent-Pole MLS for WEC

Linear actuators for wave energy conversion (WEC) require maintenance-free operation, high efficiency, and reliability. To address these needs, magnetic lead screw (MLS), which convert the linear motion of waves into rotational motion through non-contact magnetic coupling, have emerged as a promising solution. However, in traditional permanent magnet (PM) MLS, the PMs at the translator ends only work for a limited duration, resulting in low PM utilization. To address this issue, this paper proposes a consequent-pole MLS, where half of the PMs in the translator are replaced with ferromagnetic materials. First, the topology and operating principle of the consequent-pole MLS is introduced. Subsequently, the structural parameters of the consequent-pole MLS are optimized to achieve high thrust force density and low thrust force cost. Finally, the performance comparison analysis is performed between the proposed consequent-pole MLS and the traditional MLS. This paper provides theoretical guidance for the design of MLSs in WEC.