Dynamic Behavior of Stand-alone Wind Turbine Generator System with Wind Turbine Performance Deterioration

It is necessary to establish an autonomous condition monitoring for small-scale stand-alone wind turbine generator systems, which are mainly utilized in regions with no electricity. As a first phase of its development, dynamic behavior of a system with the performance deterioration of a wind turbine is investigated using a dynamic simulation model. In the target system, a straight-wing vertical axis wind turbine is mainly operated at a constant tip speed ratio, i.e., a maximum power coefficient point, without an anemometer from the viewpoints of the simplicity of system configuration and the low system cost. Numerical analyses show that the performance deterioration of the wind turbine causes a significant decrease in the power generating capability during operation due to a deviation in the operating point of the system from a maximum power coefficient point. Furthermore, a system characteristic that is closely linked to the performance deterioration of the wind turbine and can be estimated during operation without an anemometer is identified.