Power converter for vertical axis micro-wind generators

Abstract

This paper presents a bidirectional DC-DC converter for small Vertical Axis Wind Turbines (VAWT) for naval application. VAWT are better suited to naval applications, compared to common Horizontal Axis Wind Turbines (HAWT). VAWT can capture the wind from any direction without needing to be directly pointed to the wind. Moreover, the direct drive generator can be placed at the base of the wind turbine, so there is no need for a nacelle. VAWT operate efficiently at lower tip-speed ratio (TSR), therefore being quieter than HAWT. Among VAWT, Darrieus turbine has better efficiency but it is not self-starting. To allow the start-up of the wind turbine, a bidirectional DC-DC converter, linked with an active bridge, is required. As high efficiency is required for energy conversion, therefore a synchronous buck/boost converter topology is chosen. A prototype was built and tested on a dedicated test bed to simulate the wind turbine behavior.