Hybrid wind-photovoltaic power systems. Structure complexity and energy efficiency, control and energy management

Abstract

The objective of this paper is the design of isolated micro-grids for remote applications based on renewable energy (wind and photovoltaic). Several structures with different associated complexity degrees are studied and compared: in particular for the wind system, the AC―DC converter structure can be either a PWM voltage-source rectifier or a simple diode bridge. Each system structure is dedicated to LV (Low Voltage) or VLV (Very Low Voltage) applications. A comparative study of corresponding energy management strategies and architectures is proposed regarding the tradeoff between structure complexity and energy efficiency. An experimental study of the selected architecture is developed, with its system of management and control. The proposed system is capable of operating in off-grid and grid-connected mode, with a seamless transition from one state to the other.