Hybrid power-system architecture for micro-grid

Abstract

Load-independent, fixed-speed operation of prime-movers, such as gas turbines and diesel engines, leads to degraded efficiency at part-loaded conditions. This thesis looks at a hybrid power-system architecture that can boost fuel economy through coordinated variable-speed operation of both prime-movers and drive loads. The propulsion plant of an electric ship serves as an example of a micro-grid with a focus on efficiency and dynamic performance. The proposed power distribution system employs doubly-fed machines for generation and for variable speed loads, and can be used where variable-speed operation improves prime-mover efficiency while minimizing required power electronics ratings. The hybrid power-system architecture achieves reduced fuel footprint, less weight and volume constraints by minimizing system power-electronics rating and allows for a selection of an optimum prime-mover.