Sensitivity Analysis and Optimal Design of a Linear Magnetic Gear for Direct-Drive Wave Energy Conversion

Abstract

An optimized method for the linear magnetic gear (LMG) is proposed in the present study and the designed LMG is employed in the direct-drive wave power generation system. Conventional methods, such as analytical methods, may be inapplicable. Unlike the conventional motor structures, the proposed LMG has the double air-gap structure, which makes it more difficult for the design optimization. Therefore, a practical and effective method that combines the finite element analysis (FEA) and particle swarm optimization (PSO) is proposed to optimize the LMG. In order to decrease the computational expense of the optimization, main factors are categorized, based the influence on the motor performance. They are categorized into sensitive and non-sensitive parameters in this regard. Then, the FEA-PSO method is used to optimize sensitive parameters. The lower-speed and higher-speed parts of the optimized LMG are connected to the buoy and the secondary parts of the permanent magnet linear generator (PMLG), respectively, so that the wave energy converter is employed in the direct-drive wave power generator system. The present study shows that the proposed LMG method can be applied to adjust the frequency of the secondary motor, equal to or close to the natural frequency of the seawater. Therefore, the proposed method can be employed to obtain the maximum wave power. In order to validate the performance of the optimal design, a prototype is produced and tests are carried out. INDEX TERMS Linear magnetic gear (LMG), finite-element method (FEM), field flux modulation, optimal design.

Multi-Physical Coupling Field of a Permanent Magnet Linear Synchronous Generator for Wave Energy Conversion

“…The GA method is adopted to optimize the parameters which is described in section III, and the goal of optimization is achieved the minimum cost and the efficiency which are expressed by (5) and (6). The sensitivity analysis [24] is used to reduce the computational time. Therefore, some parameters of the PMLSG have been assumed constant values such as the number slots, the number of pole pairs, and the phases.…”

A Novel Back-Stepping Sliding Mode Control Strategy of Direct-Drive Wave Energy Converters

“…The ocean is rich in fossil energy, biological resources, and renewable energy. As a representative of marine renewable energy, wave energy can persistently preserve large power density [1]. Wave energy generation has become a hot topic in both academia and industry.…”

Optimal Design and Analysis of a Novel Reluctance Axial Flux Magnetic Gear

“…Among the different structures of radial flux (coaxial) [24], linear [25], transverse flux [26], arcuate [27], and axial flux, the axial flux (AFMG) structure has been more widely considered [28][29][30]. This is due to the isolation of the input and output shafts, providing the possibility of oscillation of the axes relative to each other, and lower occupation of the axial space.…”