Modelling of thermal and charge/discharge cycle behaviors of nickel metal hydride (NI-MH) battery system

Mohammad Firdaus, Abu Hashim (2013) Modelling of thermal and charge/discharge cycle behaviors of nickel metal hydride (NI-MH) battery system. Masters thesis, Universiti Sains Malaysia.

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Abstract

Berdasarkan kesan pencemaran persekitaran yang rendah, bateri Nikel Logam Hidrida dianggap sebagai salah satu bateri yang paling sesuai untuk kenderaan elektrik pada masa kini. Tenaga yang dihantar oleh bateri Nikel Logam Hidrida bergantung kepada profil discas. Secara amnya, tenaga keupayaan yang disimpan di dalam bateri tidak dapat dikeluarkan secara keseluruhannya. Dua model yang berbeza dan tidak bersandar, iaitu cas/discas dan terma telah dibina. Model persamaan pembezaan separa matematik yang diperolehi telah diselesaikan dengan menggunakan kaedah Explicit, penghampiran beza terhingga. Model penyelesaian dan simulasi ini telah dilakukan dengan menggunakan bantuan perisian MATLAB R2011a. Model cas/discas ini mampu untuk meramalkan jumlah masa untuk discas bateri di bawah pelbagai kadar discas. Model ini juga menunjukkan bahawa sel dengan elektrod tebal akan mempunyai potensi sel yang lebih rendah kerana rintangan dalaman yang tinggi. Jumlah ketebalan bagi sel 1 adalah 0.101 cm, sel 2 adalah 1.90 cm dan sel 3 adalah 0.12 cm, di mana sel 1 mempunyai potensi sekitar 1.35V, sel 2 1.29V, dan sel 3 1.34V. Selain itu, model terma yang telah dibina dalam 1-dimensi dan 2-dimensi mampu meramal taburan suhu di dalam sel. Kesahihan keputusan simulasi ini telah ditentu sahkan dengan data eksperimen daripada sumber-sumber rujukan dan juga dengan bantuan perisian MINITAB. Berdasarkan keputusan yang diperolehi daripada simulasi, ia boleh disimpulkan bahawa model 1-dimensi dibentangkan di dalam kerja-kerja ini boleh meramal kelakuan terma di bawah olakan tabii manakala model 2-dimensi digunakan apabila pengecasan di bawah olakan paksa. Proses pengecasan ini adalah eksotermik dan akan mencapai suhu yang sangat tinggi kira-kira 44ºC sehingga 57ºC di bawah kadar pengecasan yang tinggi dan pengecasan terlampau. Due to low environmental impact, the Nickel Metal Hydride battery has been considered to be one of the most promising candidate battery for electrical vehicle nowadays. The energy delivered by the Nickel Metal Hydride battery depends heavily on its discharge profile and generally it is not possible to extract the whole energy that is stored in the battery. Two independent models for charge/discharge cycle and themal behavior have been developed. The governing equations are solved by the explicit method, using finite difference approximation. Then, the partial differential numerical simulation was performed using MATLAB R2011a software. The charge/discharge model is capable to predict the total discharge time of a battery under various discharge rates. It also shows that cell with thicker electrode have lower potential due to higher internal resistance. Total thickness for cell 1 is 0.101 cm, cell 2 is 1.90 cm, and cell 3 is 0.12 cm which is cell 1 have a potential approximately 1.35V, cell 2 1.29V, and cell 3 1.34V. On the other hand, the thermal models are developed in 1-dimensional and 2-dimensional and capable of predicting the temperature distributions inside a cell. The simulation results are validated and verified with referred sources of experimental data and using MINITAB software. Based on the results obtained from simulations, it can be concluded that the 1-dimensional model presented in this work can predict thermal behavior well under natural convention while 2-dimensional model was used when charging under forced convention. The charging process is exothermic and will reach very high temperature approximately 44ºC to 57ºC under high charging rate and overcharge.

Item Type: Thesis (Masters)
Additional Information: Full text is available at irplus.eng.usm.my
Subjects: T Technology > TK Electrical Engineering. Electronics. Nuclear Engineering > TK7800-8360 Electronics
T Technology > TN Mining Engineering. Metallurgy
Divisions: Kampus Kejuruteraan (Engineering Campus) > Pusat Pengajian Kejuruteraan Bahan & Sumber Mineral (School of Material & Mineral Resource Engineering) > Thesis
Depositing User: Badli Syahar Bakhtier_PKejut
Date Deposited: 01 Mar 2018 07:11
Last Modified: 12 Apr 2019 05:26
URI: http://eprints.usm.my/id/eprint/39196

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