Abstract
The main contributions of this thesis are on the energy-based modeling, analysis and control methods with applications in renewable energy systems that are written in two parts. In the first part of the thesis, we present the design and analysis of feedback control systems with countable set of actions. Nearest-action selection based control laws are presented for a class of linear systems and of nonlinear systems, and the analysis is presented based on the passivity-based control theories. The main results are applied to the control of energy storage systems and of multi-agent systems. In the second part of the thesis, we present the energy-based hydrodynamic modeling of the Ocean Grazer wave energy converters.