Power and energy analysis of commercial small wind turbine systems

Small wind turbines harvest wind energy to provide carbon free energy for residential and small commercial applications. Current technology consists of a diode-bridge rectifier and an off-the-shelf generator. Such a simplified system does not utilize the full capacity of the turbine because the generator drive system is not designed specifically for wind turbine applications. This paper presents the technology that is commonly used in small wind turbines today. The relationship of the wind turbine´s mechanical characteristics and the generator power characteristics are explained and some basic design considerations for small wind systems are discussed. The tests utilize a permanent magnet (PM) generator which is connected to the grid via an industrial inverter, and run for different speeds to examine the output power characteristics. Standard operation as well as the control of such a system is covered in detail.