Design and Analysis of a Novel Lightweight Translator Permanent Magnet Linear Generator for Oceanic Wave Energy Conversion

© 1965-2012 IEEE. At present, most of the linear generators contain a heavy translator for converting wave power from the ocean into electrical power. As the translator is connected to the buoy, the buoy dynamic performance is reduced by the large mass and, as a result, low velocity of the translator would degrade the electricity generation of the linear generator. This problem has been minimized by the new design in this paper, where the translator is clipped off at first and split into two separate portions to minimize its weight. The secondary stator is magnetically coupled with a special m-shaped main stator which is used to flow the necessary magnetic flux. The weight of the proposed translator is 21.82% lower than that of conventional one and 49.1% by using a recently available permanent magnet with higher specifications. The finite-element method is applied in ANSYS simulation environment for the analysis and comparison between the proposed and conventional designs. Different parameters of the conventional and the proposed linear generator have been discussed in this paper. The simulation results show that the proposed design can generate the same amount of electricity as the existing one with almost half of the translator size. According to the mathematical model, it is understood that the dynamics of the translator would be higher for its lower mass and vice versa. Therefore, minimizing the translator size would result in decrease of mass, which increases the dynamics of the buoy connected to the translator

Analysis and design of a novel linear generator for harvesting oceanic wave energy

© 2015 IEEE. In almost every permanent magnet linear generator (PMLG), demagnetization would greatly degrade the electricity generation capability over time. This paper proposes a novel PMLG which consists of a permanent magnet excitation generator (PMEG) to supply electrical excitation to the field winding of an electromagnetic linear generator (EMLG) which functions as the main power generator. The proposed generator can reduce the demagnetization problem of the conventional PMLG. The finite element analysis is performed by using the commercial software package ANSYS/ANSOFT for designing the proposed PMLG, and the genetic algorithm has been used to find the optimal pole size, pole pitch, air gap length and load variation to maximize the output power. Special m-shaped stator core is designed for the PMEG to minimize the leakage flux and cogging force. The voltage, current, power, magnetic flux density, force components and applied force are also analyzed and discussed

Oceanic Wave Energy Conversion by a Novel Permanent Magnet Linear Generator Capable of Preventing Demagnetization

© 1972-2012 IEEE. In the conventional permanent magnet linear generators (PMLGs) used for oceanic wave energy conversion system, demagnetization could cause everlasting degradation in electrical power generation. This paper presents a new design that can be applied to various PMLGs to avoid demagnetization. To check the effectiveness of the proposed technique, a PMLG is considered, which allows both the fixed and variable length of airgaps for analysis. The finite element analysis is used by using the software package ANSYS/Ansoft to simulate the testing PMLG for two conditions: with and without using the proposed technique. Different parameters and characteristics of the PMLG under both conditions are presented in detail. Both the simulation and test results show that the proposed design is able to avoid the demagnetization problem successfully

A Split Translator Secondary Stator Permanent Magnet Linear Generator for Oceanic Wave Energy Conversion

© 1982-2012 IEEE. Almost all flux switching permanent magnet linear generators (FSPMLGs) and Vernier hybrid machines contain a heavy solid translator due to their design limitations for electricity generation from the oceanic waves. This paper presents the new design of an FSPMLG in which the translator weight is reduced and an additional static steel core is inserted inside the translator cavity to improve the magnetic flux linkage of the main stator. The generated voltage, current, power, efficiency, core loss, force ripples, and cogging force minimization of the proposed FSPMLG are presented. From the dynamic model of the oceanic wave, it is shown that the translator with lower mass could generate electricity more effectively. The special stator and translator sets have been optimized by using the genetic algorithm before they are used in the proposed FSPMLG. To analyze the performance and verify the feasibility of the new design of FSPMLG, finite element analysis is performed by using the commercial software package ANSYS/Ansoft

A New Modulation Technique to Improve the Performance of Three Phase Inverters

© 2020 IEEE. In various applications, including power supplies for superconductor insertion systems, grid-tied photovoltaic (PV) system and motor drives, three phase voltage source inverters are now commonly used where power conversion efficiency relies heavily on modulation techniques. Different types of pulse width modulation (PWM) techniques are used to mitigate this issue. Total harmonic distortion (THD) and switching energy loss are considered as the main performance parameter of inverters. But, the traditional techniques of PWM cause significant losses and exhibit low power conversion efficiency. A new modulation technique is proposed in this paper that offers lower THD and losses in power conversion. The proposed modulation technique is verified in MATLAB/Simulink environment

Raman scattering characterization of Mn composition and strain in Ga1-xMnxSb/GaSb epitaxial layers

Raman scattering (RS) experiments have been performed for simultaneous determination of Mn composition and strain in Ga1-xMnxSb thin films grown on GaSb substrate by liquid phase epitaxy technique. The Raman spectra obtained from various Ga1-xMnxSb samples show only GaSb-like phonon modes whose frequency positions are found to have Mn compositional dependence. With the combination of epilayer strain model, RS and energy dispersive x-ray (EDX) experiments, the compositional dependence of GaSb-like LO phonon frequency is proposed both in strained and unstrained conditions. The proposed relationships are used to evaluate Mn composition and strain from the Ga1-xMnxSb samples. The results obtained from the RS data are found to be in good agreement with those determined independently by the EDX analysis. Furthermore, the frequency positions of MnSb-like phonon modes are suggested by reduced-mass model. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei