An Update on the Electronic Connection Issues of Low Power SWTs in AC-Coupled Systems: A Review and Case Study

Abstract

Small wind turbines (SWTs) have been a common option for rural electrification during recent decades. Recently, an application for connecting these devices to the grid was proposed. This requires an AC-coupled configuration, which brings the need for a power converter necessary for connection to the AC bus. This publication analyzes the requirements and commercial availability of such power converters, coming first to a conclusion on the lack of existing electronic power converters for SWTs, mainly in the lowest power range (<1 kW). As a result of this need, PV power converters were proposed, as they are both economically competitive and commercially available. The use of PV power converters for SWT AC-coupled applications is therefore analyzed as well, bringing a second conclusion: their use is possible but not straightforward, as some adaptations have to be taken into account. Finally, a suggested adaptation is proposed, in terms of hardware and software; the first field results of a prototype are presented, and they look very promising.

Keywords

• small wind turbine
• AC-coupled
• electronic power converter
• solar PV inverter
• overvoltage protection
• prototype field test