Design and Optimization of a Novel Dual-Port Linear Generator for Oceanic Wave Energy Conversion

All the existing linear generators used for oceanic wave energy conversions are basically single-port linear electrical generators (SPLEGs). The conventional SPLEG transfers electrical power to the load/grid discontinuously due to its working principle and the intermittent nature of oceanic waves. This paper proposes a new dual-port linear electrical generator (DPLEG) topology, which is capable to transfer electrical power with an adequate voltage even at zero vertical velocity of the oceanic wave. The analysis shows that the efficiency and the performance of the DPLEG depend greatly on the stator tooth design. For this reason, the proposed DPLEG is optimized using the genetic algorithm for successful operation. The shape optimization method is implemented to determine the stator tooth shape of the DPLEG. By optimizing the stator tooth shape, the force ripples of the proposed DPLEG is further reduced by 40.89%. The analysis is carried out using multiphysics simulation, and the electromagnetic performance is determined by the finite-element analysis. Simulation results show that the shape optimization of the stator tooth not only minimizes the force ripples of the translator but also increases the power generation of the DPLEG. A laboratory prototype of the proposed DPLEG is built to test the concept of the proposed DPLEG topology. The experimental results verify its unique advantage by showing that it can generate an adequate voltage even at zero vertical velocity of the oceanic wave which cannot be achieved using the existing SPLEGs.