Analysis of an electromechanical battery for rural electrification in sub-Saharan Africa

Abstract

This paper presents the thermal and structural analysis of an electromechanical battery energy storage system designed to enhance rural electrification in sub-Saharan Africa. The system consists of a flywheel rotor, an electrical machine, bearings and a containment structure. The flywheel rotor was constructed from E-glass fiber, the machine from imported NdFeB magnets and commercial energy efficient bearings. With the exception of the power electronics and magnets, local materials were used for the manufacture of the flywheel system. The system was designed to operate between 8,000 rpm to 25,000 rpm with a rated storage capacity of 300Wh. Numerical stress analysis was performed during the design stage to ensure that the maximum tensile strength is not exceeded. A lumped parameter thermal model was used to estimate the temperature distribution to ensure safe operating conditions of the flywheel system and environment. The results of both analyses are presented.