Design and optimization of a novel hybrid transverse / longitudinal flux, wound-field linear machine for ocean wave energy conversion

This paper develops an analytical model for a novel double-sided hybrid transverse/longitudinal flux linear machine for use in ocean wave energy converter (WEC) applications. While several machine topologies exist for direct-drive power take-off in buoy-type WECs, the intent of this paper is to introduce a new type of linear machine for possible use as a direct-drive in future WECs. The topology considered consists of a short primary (stator) and a long secondary (translator). The translator is sandwiched between two stators that carry flux in the longitudinal direction, while the translator carries flux in the transverse direction. Operating conditions for WECs require low speeds, yielding machine characteristics such as a large number of coil turns, high inductance, and high force density. Finite element analysis (FEA) is used to optimize and validate analytical results as well as calculate leakage and magnetizing inductance.