Generation of Electrical Power by using High Graded Permanent Magnet Linear Generator in Wave Energy Conversion

Abstract

The conventional permanent magnet linear generator (PMLG) used for oceanic wave energy extraction are made of ordinary graded neodymium iron boron (NdFeB) permanent magnets (PMs). As a result, while the temperature of the generator gradually increases because of continuous operation, the generation of electrical power would be low because of demagnetization. In this paper, it is analyzed that, the conventional PMLG can not produce much electricity at high temperature because of using the ordinary graded NdFeB PMs. On the other hand, NdFeB that can maintain its remanence magnetism at high temperature saturates at low magnetic field. Therefore, high graded N48H NdFeB is proposed to be used in the PMLG to overcome this dilemma. Simulation results show that, because of using N48H PMs in the PMLG, the generated voltage, current, flux linkage and output power reaches to higher value than that of using the conventional N35 NdFeB PMs. The proposed PMLG with N48H is able to produce 28% more electrical power output than that of using the conventional N35. Finite element method is used for the simulation platform. During the simulation, same operating temperature and parameters of the PMLG is considered for both the high graded and ordinary one for fare comparisons.