A Comprehensive Study and Optimization of Solar and TEG based Power Systems for Outer Space Applications

Abstract

The ongoing increase in the usage of non-renewable energy sources to meet the world demands has caused a massive increase in world pollution, leading to various issues such as global warming and climate change. This has motivated researchers and engineers to undertake intensive research into renewable energy sources which are clean, noise free and can be used in the long term. This thesis introduces design concepts that are aimed to aid designers in optimizing the design of renewable energy power source systems. The PV and TEG have been selected as the key examples to be studied. First, the thermodynamic modelling of the PV/TEG system and its application to outer space systems is examined where the output energy of the PV/TEG can be determined. Moreover, the model is also used as a basis for a genetic algorithm based optimization of the PV/TEG system in terms of maximizing power generation and minimizing mass. The next aspect that is covered in this thesis is the design of the associated DC/DC converter which is important for controlling or maximizing the energy that is acquired from the renewable energy source. Specifically, this thesis introduces an improved method of deriving the transfer functions that relate the inputs to the states of the DC-DC converter. Finally, two novel maximum power point tracking algorithms (MPPT) are introduced and applied to maximize the power extracted from the solar panel and the thermoelectric generator (TEG). These algorithms are known as the “Lock-On Mechanism” and a modified fuzzy logic control based MPPT algorithm. The novel MPPT algorithms are shown to track the MPP quicker and more accurately than that of conventional and previously proposed counterparts.